Ammonium dithionate- a new material for highly sensitive EPR dosimetry

Polycrystalline ammonium dithionate has been examined for its radiation response in the low dose range (<5Gy) using EPR technique. The SO(3)(-) radical ion was detected as a single EPR line with a peak-to-peak derivative width of ca. 0.44mT in irradiated samples and its intensity was found to vary linearly with dose. At equal and moderate settings of microwave power and modulation amplitude ammonium dithionate was at least seven times more sensitive than l-alanine which is the most common EPR dosimeter standard. Pulse experiments were performed on the powder samples to obtain the longitudinal relaxation time. These and microwave saturation experiments served to indicate the optimal microwave power to be applied during measurements as an EPR dosimeter for best sensitivity of this material. It is thus claimed that ammonium dithionate has excellent potential to become an EPR dosimeter with a low limit of the measurable dose for cases where tissue equivalence is not required or can be corrected for.

Evaluation of three serological tests for brucellosis in naturally infected cattle using latent class analysis

Serological methods are traditionally used in diagnosis of brucellosis. However, the comparative performance of these tests and their accuracy under the local environment in Zambia has not been assessed. Thus, the objective of our study was to evaluate the diagnostic performance of three serological tests for brucellosis; Rose Bengal Test (RBT), competitive ELISA (c-ELISA) and Fluorescence Polarisation Assay (FPA) in naturally infected cattle in Zambia without an appropriate reference test to classify animals into truly infected and non-infected. Serological test results from a study to determine sero-prevalence were used to compare the performance of RBT, c-ELISA and FPA in diagnosing brucellosis in traditional cattle. Since none of the tests can be seen as a perfect reference test or gold standard, their performance in a population of naturally infected cattle was evaluated using latent class analysis which allows the sensitivity (Se) and specificity (Sp) to be estimated in the absence of a gold standard. The highest Se was achieved by the c-ELISA (97%; Credible Posterior Interval (CPI)=93-100%) and the highest Sp by the FPA (93%; CPI=85-99%), conversely these tests also had the lowest Sp and Se, respectively, with the RBT performing well in both the Se (93%; CPI=84-98%) and Sp (81%; CPI=61-97).

Characterisation of mycobacteria isolated from slaughter cattle in pastoral regions of Uganda

Background

Bovine tuberculosis is a zoonotic problem in pastoral cattle and communities in Uganda. Tuberculin tests in pastoral cattle had shown a high herd but low animal prevalence, with a high proportion of avian reactors. No work had been done to identify the mycobacterial species involved. The objective of the study was to isolate and characterise Mycobacterial species causing tuberculous lesions in slaughtered animals. Lesioned organs compatible with bovine tuberculosis in slaughtered cattle from pastoral areas in Uganda were collected and cultured to isolate mycobacteria. AccuProbe culture identification kits for the Mycobacterium tuberculosis complex, M. avium complex and M. avium were used to identify the isolates. Spoligotyping and Insertion Sequence (IS) 1311 and IS1245 Restriction Fragment Length Polymorphism analysis (RFLP) were used to further characterise the isolates.

Results

Of the 61 lesioned organs and tissues cultured, 19 isolates were identified as M. bovis, 3 as M. avium subsp.hominissuis, 1 as M. intracellulare, 1 as a mixed culture of M. bovis and M. avium sp. and 1 as M. avium sp. and unidentified mycobacteria. Eleven other mycobacteria outside the tuberculosis and avium complex groups were also isolated. Ten new spoligopatterns grouped into three clusters were identified from M. bovis isolates. Two of the three M. avium subsp.hominissuis isolates showed similar patterns on the IS1311 RFLP but all were different on the IS1245 RFLP.

Conclusion

The isolation of M. bovis confirms the ongoing infection with spoligotypes unique to Uganda. Isolation of environmental mycobacteria could explain the high avian or non specific tuberculin reactor patterns commonly observed in pastoral cattle and suggests their pathogenic or opportunistic role in the infection of cattle with disseminated bovine tuberculous lesions.

An ESR and ENDOR study of irradiated 6Li-formate

Lithium formate ((6)LiOOCH.H(2)O), 95% (6)Li enrichment, combined with an exchange of crystallization water with D(2)O was investigated. The ESR spectrum of the radiation induced free radicals stable at room temperature consists of a singlet with a narrow line width, 0.92mT. (6)Li has smaller magnetic moment and nuclear spin, which resulted in the narrower line width accompanied with an increase in peak amplitude. In comparison with lithium formate with natural isotopic composition, (6)Li (7.5%, I=1) and (7)Li (92.5%, I=3/2), the sensitivity was increased by a factor of two. With optimised spectrometer settings (6)Li formate had seven times higher sensitivity compared to alanine. Therefore this material is proposed as a dosimeter material in a dose range down to 0.1Gy. The g and the (13)C-hyperfine (hf) tensors of the CO(2)(-) radical anion, major paramagnetic products, were evaluated to be g=(2.0037, 1.9975, 2.0017), and A((13)C)=(465.5, 447.5, 581.3) MHz for polycrystalline samples at room temperature. Furthermore, the (1)H-hf and (6)Li-hf tensors observed for the surroundings of CO(2)(-) by ENDOR technique were in fairly good agreement with DFT calculations. The CO(2)(-) radicals are found to be so stable that the formate is applicable to the ESR dosimetry, because of fully relaxing in a fully relaxed geometrical structure of the CO(2)(-) component and remaining tight binding with the surroundings after the H atom detachment from HCO(2)(-).

Dynamical effects and ergodicity in the dipolar glass phase: evidence from time-domain EPR and phase memory time studies of AsO(4)(4-) in Rb(1-x)(NH(4))(x)H(2)PO(4) (x = 0,0.5,1)

Three-pulse electron spin echo envelope modulation (ESEEM), hyperfine sublevel correlation spectroscopy (HYSCORE) investigations and two-pulse electron spin echo (ESE) measurements of phase memory time T(M), were carried out, in the 20-200 K temperature range, on an AsO(4)(4-) paramagnetic probe stabilized in RbH(2)PO(4) (RDP), NH(4)H(2)PO(4) (ADP), and dipolar glass Rb(0.5)(NH(4))(0.5)H(2)PO(4) (RADP). The results obtained on ADP revealed hyperfine interaction of the probe ion with the (14)N of the ammonium ion, the coupling constant satisfying the condition of 'cancellation' at a field of 480 mT. The ammonium ion was found to be in two different sites in ADP, which became indistinguishable on the formation of dipolar glass RADP. These results were confirmed by HYSCORE spectral measurements. The fast Fourier transform (FFT) spectra of three-pulse ESEEM decays have clearly revealed the interaction with protons in the [Formula: see text] bond both in ADP and RDP; and in RADP with an averaged coupling constant. The phase memory times in RADP exhibited strong temperature dependence and were found to be dependent on the nuclear spin quantum number m(I) of (75)As. The temperature dependence of T(M) exhibited a well-defined maximum around 90 K, coinciding with the temperature of onset of 'freezing' in Rb(0.5)(NH(4))(0.5)H(2)PO(4). This is symptomatic of dynamic fluctuations in the dipolar glass phase, with onset around 150 K, going through a maximum around 90 K and slowing down on further cooling. These results suggest that in RADP, a dynamical mechanism with progressive slowing down below 90 K is operative in the glass formation. This implies that the RADP system, with x = 0.5, exists in an ergodic relaxor (R)-state in the 20-200 K temperature range wherein every fluctuating monodomain can be viewed as statistically representative of the whole sample.

Positive symptoms and duration of illness predict functional laterality and attention modulation in schizophrenia

OBJECTIVE

Dichotic listening (DL) performance in schizophrenia, reflecting hemispheric asymmetry and the functional integrity of the left temporal lobe, can vary with clinical characteristics. Previous studies have not taken the co-linearity of clinical variables into account. The aim of the present study was to evaluate the roles of positive symptoms and duration of illness in DL through Structural Equation Modeling (SEM), thus allowing for complex relationships between the variables.

METHOD

We pooled patients from four previous DL studies to create a heterogeneous group of 129 schizophrenic patients, all tested with a consonant-vowel syllables DL procedure that included attentional instructions.

RESULTS

A model where positive symptoms predicted a laterality component and duration of illness predicted an attention component in DL was confirmed.

CONCLUSION

Positive symptoms predicted reduced functional laterality, suggesting involvement of left temporal lobe language processing. Duration of illness predicted impaired attention modulation, possibly reflecting the involvement of frontotemporal networks.

Neuropsychological test profiles in schizophrenia and non-psychotic depression

OBJECTIVE

The study examined to what degree schizophrenia is characterized by a neuropsychological (NP) test profile specific in shape and level compared with depression and normal functioning.

METHOD

Fifty-three patients with schizophrenia, 45 with non-psychotic depression, and 50 normals were assessed with a comprehensive NP test battery and clinical instruments. NP test scores were factor analyzed into seven composite scores.

RESULTS

Schizophrenia patients performed significantly below normals across all seven composite scores, whereas depression patients were impaired in two. Verbal memory was most impaired. Sixty-two percent of schizophrenia patients were moderately or severely impaired, the corresponding figure for depression was 28%. Impairment was moderately associated with IQ level and clinical symptom load in schizophrenia, but not in depression.

CONCLUSION

Schizophrenia is characterized by deficits across a wide range of NP functions. Thirty-eight percent of the patients are within normal limits. A mild and limited NP disturbance is apparent in depression.

Conduction electron spin resonance of small silver particles

Electron spin resonance (ESR) spectroscopy has been used to study the conduction electron spin resonance (CESR) of small silver particles stabilized in dehydrated Ag-rho zeolite. Silver particles were produced by hydrogen reduction at elevated temperatures and diameter of the stabilized particles was calculated based on the linewidth of CESR signal using Kawabata theory.

Cortisol level predicts executive and memory function in depression, symptom level predicts psychomotor speed

OBJECTIVE

On a group level depression is related to hypercortisolism and to psychomotor retardation, executive dysfunction and memory impairment. However, intra-group heterogeneity is substantial. Why some are impaired while others remain in the normal range, is not clear. The present study aims at discerning the relative contribution of present symptom severity and hypercortisolism to impairment in the three domains of cognition.

METHOD

Morning saliva cortisol was measured in 26 subjects with recurrent major depression prior to a neuropsychological examination with tests known to be sensitive to cognitive impairment in depression.

RESULTS

Cortisol level correlated with executive dysfunction and post-encoding memory deficits, but not with processing speed. Depression level correlated with processing speed. These patterns remained significant after controlling for confounders through partial correlations.

CONCLUSION

The association between cortisol and cognition is not an artifact of psychiatric symptom load. High level of saliva cortisol is associated with aspects of cognition that can be dissociated from psychomotor retardation, which is dependent on symptom load.

Enhanced sensitivity of lithium dithionates doped with rhodium and nickel for EPR dosimetry

Electron paramagnetic resonance (EPR) studies of X-irradiated lithium dithionate, Li(2)S(2)O(6) x 2H(2)O, doped with Ni and Rh have shown that these impurities enhance the yield of radicals formed by X-irradiation at room temperature. The signal in the doped samples, measured peak-to-peak of the single EPR derivative line attributed to the SO(3)(-) anion was about 3-4 times that of the pure lithium dithionate and more than 10 times stronger than the alanine signal. These impurities also shortened the spin-lattice relaxation time, T(1), which gives the possibility to measure the doped samples at a higher microwave power. This implies that sensitivity could be further enhanced in the already sensitive EPR dosimeter material lithium dithionate.

Formates and dithionates: sensitive EPR-dosimeter materials for radiation therapy

Polycrystalline formates and dithionates are promising materials for EPR dosimetry, as large yields of radiation induced stable radicals are formed with a linear dose response. Rapid spin relaxation rates were detected in many of the substances, indicating that a high microwave power can be applied during EPR acquisition in order to improve sensitivity. Different techniques used to further improve the sensitivity, such as the replacement of 7Li with 6Li or exchange of protons with deuterons in the corresponding crystalline matrices and metal ion doping are discussed. It is concluded that formates and dithionates may be up to 10 times as sensitive as L-alpha-alanine.

General psychopathology is more important for executive functioning than diagnosis

OBJECTIVE

Impaired executive functioning (EF) has often been reported in patients with major depression or schizophrenia. We hypothesize that the variance in EF is more affected by level of general psychopathology than by diagnosis.

METHOD

Forty-three patients with major depression and 47 with schizophrenia were included. EF was measured with Wisconsin Card Sorting Test, Stroop Colour Word Test, Paced Auditory Serial Addition Test, Digits Backwards and Controlled Oral Word Association Test. The level of general psychopathology was measured with Brief Psychiatric Rating Scale - Expanded and Positive and Negative Syndrome Scale, the General psychopathology subscale.

RESULTS

The level of general psychopathology predicted more of the variance in EF than diagnosis. In multivariate analyses, the effect of general psychopathology on EF was more robust for adjustment for diagnosis than vice versa.

CONCLUSION

Future research on cognitive functioning in psychiatric patients should include level of general psychopathology to avoid overemphasising effects of diagnoses.

Release of TNF-alpha from in vitro-stimulated monocytes is negatively associated with serum levels of apolipoprotein B in patients with type 2 diabetes

Impaired course of inflammation is a likely mechanism behind a number of diabetic complications. The present study was undertaken to investigate lipopolysaccharide-induced production of tumour necrosis factor (TNF)-alpha in monocytes from patients with type 2 diabetes and to assess its relationship with diabetes-associated metabolic abnormalities. Monocytic TNF-alpha mRNA production was lower in the diabetic participants compared to their corresponding controls. Diabetic subjects who had been receiving simvastatin treatment had TNF-alpha mRNA production similar to that of the healthy participants. The release of TNF-alpha from diabetic cells correlated negatively with serum levels of apolipoprotein B (apoB) (R = -0.755, P = 0.001), total plasma cholesterol (R = - 0.702, P = 0.002) and the presence of retinopathy (R = -0.572, P = 0.021). No such associations were found in the control subjects. In a multiple linear regression model, only the level of apoB and diabetes duration demonstrated significant effects on the release of TNF-alpha, with apoB alone accounting for 57% of the variation. We conclude that production of TNF-alpha mRNA in response to the bacterial stimulant is compromised in poorly controlled type 2 diabetes. Lipid abnormalities are associated with the observed defect. Impaired cytokine production represents a significant defect in the functioning of the immune system and may contribute to aberrations in the course of inflammation in the diabetic state.

51V(n, beta)52Cr reaction for neutron dosimetry: development and assessment of a spectrophotometric method for determination of Cr in vanadium at sub ppm level

With a view to monitoring the changes in coloration caused by the nuclear reaction 51V(n, beta)52Cr in solution of vanadyl sulphate and using it for neutron dosimetry, electronic absorption spectra of vanadyl sulphate solutions were investigated at different concentrations of chromate impurity in micromolar range. It was observed that the presence of chromate enhances the absorptivity over a wide wavelength range serving essentially as a colouring agent for vanadium matrix, presumably due to charge transfer process. The absorbance at 380 nm varied linearly over a wide concentration range. The limit of detection of chromate obtained is shown to be adequate for detecting neutron-induced chemical transmutation of vanadium to chromium under standard reactor conditions, when used with long path length cells. It was observed that the absorbance does not change on electron irradiation, suggesting that radiolytic effects due to beta decay, if any, do not interfere in the measurement of neutron-induced changes. In addition to its potential for neutron dosimetry, this is the first report of a simple and direct method of estimation of Cr in vanadium matrix at sub ppm level.

Compounds of 6Li and natural Li for EPR dosimetry in photon/neutron mixed radiation fields

Formates and dithionates of 6Li, enriched and 7Li in natural composition of Li offer a possibility to measure the absorbed dose from photons and thermal neutrons in a mixed radiation field for instance at a boron neutron capture therapy (BNCT) facility. Tests with formates and dithionates of enriched 6Li and lithium compounds with natural composition have been performed at the BNCT facility at Studsvik, Sweden. Irradiations have been performed at 3 cm depth in a Perspex phantom in a fluence rate of thermal neutrons 1.8 x 10(9) n cm(-2) s(-1). The compounds were also irradiated in a pure X-ray field from a 4MV linear accelerator at 5 cm depth in a phantom with accurately determined absorbed doses. The signal intensity and shape was investigated within 3 h after the irradiation. A single line spectrum attributed to the CO2- radical was observed after irradiation of lithium formate. An increase in line width occurring after neutron irradiation in comparison with photon irradiation of the 6Li sample was attributed to dipolar broadening between CO2- radicals trapped in the tracks of the alpha particles. A spectrum due to the SO3- radical anion was observed after irradiation of lithium dithionate. The signal amplitude increased using the 6Li in place of the Li with natural composition of isotopes, in studies with low energy X-ray irradiation. Due to the decreased line width, caused by the difference in g(N) and I between the isotopes, the sensitivity with 6Li dithionate may be enhanced by an order of magnitude compared to alanine dosimetry. After comprehensive examination of the different combinations of compounds with different amounts of 6Li and 7Li regarding dosimetry, radiation chemistry and EPR properties these dosimeter material might be used for dose determinations at BNCT treatments and for biomedical experiments. Interesting properties of the radical formation might be visible due to the large difference in ionization density of neutrons compared to photons.

Ammonium Formate, a Compound for Sensitive EPR Dosimetry

Alanine EPR dosimetry has been applied successfully when measuring intermediate and high radiation doses. Although the performance of alanine dosimetry is being improved, the sensitivity of the material is too low for a fast and simple low- dose determination. Here we present the results using ammonium formate as an EPR dosimeter material. Ammonium formate is seven times more sensitive than alanine, using spectrometer settings optimized for the latter. Deuterated ammonium formate is found to be more than eight times more sensitive than alanine. Analysis of signal stability with time shows that the ammonium formate signal is stable by 5 min after irradiation and that no change in signal intensity is found during 8 days. The atomic composition of ammonium formate is closer to that of tissue than alanine, and thus the energy dependence is smaller than that of alanine at photon energies below 200 keV. Power saturation studies indicate that the energy transfer between the spins and the lattice is fast in ammonium formate, which gives the possibility of using high microwave power without saturation to further increase the sensitivity. These results suggest that ammonium formate has some important properties required of an EPR dosimeter for applications in dosimetry in the dose range typical for radiation therapy.

Attention profile in schizophrenia compared with depression: differential effects of processing speed, selective attention and vigilance

OBJECTIVE

The aim of the study is to investigate whether subjects with schizophrenia and major depression display attention deficits for different reasons.

METHOD

Subjects with schizophrenia (n = 53), recurrent major depression (n = 50) and normal controls (n = 50) were administered with 11 measures of processing speed, selective attention and vigilance. Indices of basal speed, speeded attention, non-speeded attention and vigilance were computed.

RESULTS

Both clinical groups were impaired on all chronometric tests. The schizophrenic subjects were also more impaired on speeded attention compared with basal processing speed. Only the schizophrenics were impaired on the non-speeded measures of selective attention. Compared with the schizophrenics, the depressives showed a decrement in vigilance.

CONCLUSION

Reduced performance on attention tests in major depression is because of a non-specific speed reduction and loss of vigilance consistent with lack of effort. In addition to generally impaired processing speed, the schizophrenic subjects exposed a deficit in selective attention, indicating executive dysfunction.

Antibody responses in sheep vaccinated against Staphylococcus aureus mastitis: a comparison of two experimental vaccines containing different adjuvants

A double-blind, placebo-controlled study was conducted to compare two vaccines using different adjuvants with regard to their ability to stimulate antibody production against the alpha- and beta-toxins and the exopolysaccharide of Staphylococcus aureus. The vaccines contained identical antigens, consisting of inactivated whole bacteria of two strains of S. aureus in addition to alpha- and beta-toxoid. One vaccine contained mineral oil, while the other used a water-soluble acrylic acid polymer resin (Carbopol) as adjuvant. Saline served as the placebo. One hundred and forty ewes were vaccinated twice before lambing, by subcutaneous injection with vaccine or placebo in the region of the supramammary lymph node, and were observed and sampled over a period of 6 months. The vaccine containing mineral oil as adjuvant induced significantly greater immune responses to the alpha- and beta-toxins than did the vaccine containing Carbopol. The latter vaccine induced higher levels of antibodies to exopolysaccharide. The degree of local adverse reactions did not differ between the two groups. The results indicate differences between the oil-adjuvanted and Carbopol-adjuvanted vaccines with regard to their ability to stimulate antibody production against S. aureus protein antigens in sheep.

Spleen size: how well do linear ultrasound measurements correlate with three-dimensional CT volume assessments?

Ultrasound measurement of splenic length is standard practice, but it is not known how well this represents the true size of the spleen. Previous studies, using a combination of measurements from in vivo and resected spleens, were subject to error because of changes in splenic size. The aim of this study was to correlate the dimensions of the spleen measured by ultrasound with the splenic volume measured by helical CT. Ultrasound examination was performed on 50 adult patients at the time of their attendance for abdominal CT. Linear dimensions of the spleen were measured with the patient first in the supine and then in the right lateral decubitus (RLD) position. The splenic volume was calculated from a three-dimensional reconstruction of the CT images. There was good correlation, using Spearman's rank correlation, between ultrasound measurements and CT volumes with correlation coefficients exceeding 0.7 for all parameters except one. The linear measurement that correlated most closely with CT volume was the spleen width measured on a longitudinal section with the patient in the RLD position (correlation coefficient (r)=0.89, p<0.001). There was also good correlation between splenic length measured in the RLD position and CT volume (r=0.86, p<0.001). We conclude that a good correlation exists between in vivo ultrasound assessment of splenic size and true splenic volume. The most accurate single measurement is spleen width measured on a longitudinal section with the patient in the RLD position. However, measurement of splenic length, which is the most commonly used in clinical practice, also correlates well with splenic volume, particularly when performed with the patient in the RLD position.

New materials for ESR dosimetry

New materials for electron spin resonance (ESR) dosimetry have been investigated with the aim to find systems more sensitive than L-alanine accepted as a standard for high dose determinations. Among the investigated systems ammonium tartrate, 2-methylalanine, salts of formic acids and dithionates have been found to be more sensitive than alanine by a factor 2-10. The lower limit applies to tissue equivalent materials, while much higher sensitivities were obtained with formates and dithionates containing heavier atoms. The increased sensitivity was mainly attributed to suitable ESR properties of the room temperature stable radicals as regards spectral shape (narrow lines, little or no hyperfine structure) and microwave saturation properties (short relaxation times). The radical structures have when necessary been clarified by ENDOR spectroscopy, while the saturation properties have been screened by pulsed ESR measurements.

Conformational preference and remote (1,10) stereocontrol in biphenyl-2,2'-dicarboxamides

The double ortholithiation and electrophilic quench of N,N,N'N'-tetraisopropylbiphenyl-2,2'-dicarboxamide 1 is diastereoselective, giving the chiral, C(2)-symmetric atropisomers of the 3,3'-disubstituted products 3. These chiral atropisomers can be converted with moderate to good stereoselectivity to their achiral, centrosymmetric epimers by heating. The stereoselectivity of the double lithiation-quench reaction is determined by the stereochemistry of the intermediate doubly lithiated species 2, either diastereoisomer of which may be formed stereospecfically from the corresponding atropisomeric dibromo compounds.[reaction: see text]

Honig's model of working memory and brain activation: an fMRI study

The present study investigated changes in neuronal activation with fMRI related to Honig's model of working memory, which is much less studied compared with other working memory models. In contrast to other studies which have applied recognition procedures, the primary aim with the present study was to examine brain activation when subjects had to continuously recall and forget items held in working memory. The results showed that the mid-ventrolateral frontal cortex was particularly activated in the left hemisphere, whereas the mid-dorsolateral frontal cortex was particularly activated in the right hemisphere during execution of the working memory task. The findings are discussed in relation to process- and domain-specific accounts of working memory.

Prognostic factors in major depression: a long-term follow-up study of 323 patients

BACKGROUND

Optimal long-term treatment of major depression should assess the background factors affecting remission and recurrent episodes. The duration and number of previous depressive episodes has been shown to be important for recurrence. This long-term prospective study of patients with major depression assessed the prognostic effect of variables related to childhood, social life and occupation.

METHODS

The study examined 323 patients in two follow-up examinations 12-25 years from the initial examination to the second follow-up. Stepwise logistic regression was used to evaluate the prognostic effect for depression at the second follow-up.

RESULTS

The risk of depression at the second follow-up was associated with several psychosocial factors in childhood, female gender, social isolation and a negative attitude towards one's own occupation.

LIMITATIONS

The patient group was selected from the practice of only one psychiatrist.

CONCLUSIONS

Several psychosocial factors in childhood, female gender, social isolation and a negative attitude towards one's own occupation have previously been shown to be associated with the risk of depression. The results in this study suggest that these factors are also important in predicting the outcome of a major depressive episode and the risk of recurrent episodes.

Staphylococcus aureus capsular polysaccharide type 5 conjugate and whole cell vaccines stimulate antibody responses in cattle

Dairy heifers were immunized subcutaneously with one of four different vaccines which contained preparations of Staphylococcus aureus capsular polysaccharide type 5 (CP5) and a mineral oil adjuvant, or received a placebo containing saline and adjuvant. The vaccine containing a CP5-human serum albumin conjugate (CP5-HSA) and the vaccine with formaldehyde inactivated whole cells expressing CP5, both elicited strong anti-CP5 antibody responses. After two injections three weeks apart and a third injection 10 months later, the mean level and duration of the anti-CP5 antibody response was significantly higher in the whole cell group. No differences were found between the two groups with regard to the relative proportion of IgG subclasses, and the antibody responses to the polysaccharide were composed of both the IgG1 and IgG2. Vaccines containing only free CP5 or CP5 mixed with HSA produced weak and transient humoral immune responses. Only animals vaccinated with the whole cell vaccine or the conjugate vaccine showed responses to CP5 in a lymphocyte proliferation assay conducted one year after the third vaccination. This study indicates that CP5 expressed on the surface of formaldehyde inactivated whole cells, emulsified in an oil adjuvant, gives a strong and long lasting immune response in cattle. The use of conjugation technology, although effective, might not be necessary in order to achieve an immune response against S. aureus CP5 in cattle.

Imaging the surface of Staphylococcus aureus by atomic force microscopy

The surfaces of four strains of Staphylococcus aureus, which differed in their expression of capsular polysaccharides, were examined using atomic force microscopy. The images show that it is possible to get information about surface characteristics of S. aureus using atomic force microscopy (AFM) following simple preparation. Strains Smith Diffuse (serotype 2), Reynolds (serotype 5), Wood-46 (capsule negative) and JL243 (capsule negative) were grown on medium known to promote the expression of capsular polysaccharides. The bacteria were air-dried prior to being imaged using tapping-mode AFM. Differences in the appearance of the bacterial surfaces were evident between the strains. The two capsule-negative strains exhibited a smooth regular surface, as opposed to the mucoid appearance of the two strains having polysaccharide capsules. Moreover, comparison of images of the heavily encapsulated serotype 2 strain and the serotype 5 strain indicates that a type 2 capsule can be distinguished from a type 5 microcapsule.

General practitioners' reactions to non-compliant patients

OBJECTIVE

To examine how general practitioners (GPs) respond to patients who are non-compliant with medical advice and who doctors believe act irresponsibly towards their health.

DESIGN

Quantitative analysis of responses to questionnaire with case histories.

SETTING AND SUBJECTS

93 questionnaires completed by a random stratified sample of Norwegian GPs.

MAIN OUTCOME MEASURES

Scores relating to GPs' feelings and choice of main and sub-strategies for further treatment of patients.

RESULTS

The respondents typically felt discouraged or unaffected by non-compliant patients, younger doctors more often felt helpless while older ones were more content, and female doctors more often than male doctors felt irritated or angry. The main strategy preferred was to give the patient a new appointment. The young, the inexperienced, and females tended more often to ask a colleague for advice or refer to a specialist. Patient-centred sub-strategies were generally preferred, especially by younger doctors.

CONCLUSION

GPs' feelings towards and strategies for dealing with non-compliant patients vary, and the doctor's age, sex and clinical experience are central variables.

Multiple founder effects in spinal and bulbar muscular atrophy (SBMA, Kennedy disease) around the world

SBMA (spinal and bulbar muscular atrophy), also called Kennedy disease, is an X-chromosomal recessive adult-onset neurodegenerative disorder caused by death of the spinal and bulbar motor neurones and dorsal root ganglia. Patients may also show signs of partial androgen insensitivity. SBMA is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene on the X-chromosome. Our previous study suggested that all the Nordic patients with SBMA originated from an ancient Nordic founder mutation, but the new intragenic SNP marker ARd12 revealed that the Danish patients derive their disease chromosome from another ancestor. In search of relationships between patients from different countries, we haplotyped altogether 123 SBMA families from different parts of the world for two intragenic markers and 16 microsatellites spanning 25 cM around the AR gene. The fact that different SBMA founder haplotypes were found in patients from around the world implies that the CAG repeat expansion mutation has not been a unique event. No expansion-prone haplotype could be detected. Trinucleotide diseases often show correlation between the repeat length and the severity and earlier onset of the disease. The longer the repeat, the more severe the symptoms are and the onset of the disease is earlier. A negative correlation between the CAG repeat length and the age of onset was found in the 95 SBMA patients with defined ages at onset.

In vitro release of interferon-gamma by trichophytin-stimulated whole blood cell cultures from ringworm-vaccinated and control calves experimentally inoculated with Trichophyton verrucosum

Of a group of seven calves, four were vaccinated against bovine ringworm with the vaccine Ringvac bovis LTF-130 (Alpharma, Oslo, Norway), while three calves were left unvaccinated. All calves were inoculated epicutaneously with a virulent strain of Trichophyton verrucosum. Clinical signs were recorded. In response to stimulation with trichophytin, in vitro interferon-gamma (IFN-gamma) production in whole blood cell cultures was assessed in samples obtained pre- and post-vaccination and pre- and post-inoculation. A commercial enzyme immunoas say kit was used to measure IFN-gamma levels (Bovigam, CSL, Victoria, Australia). Control calves developed typical ringworm lesions, whereas vaccinated calves did not. Following vaccination, release of IFN-gamma in whole blood cell cultures indicated the presence of circulating trichophytin-specific lymphocytes. After inoculation with T. verrucosum, IFN-gamma production was demonstrated in samples from both vaccinated and control calves. This study showed that vaccination with Ringvac bovis LTF-130 elicits a protective immune response suggesting involvement of the cellular branch of the immune system. Experimental infection of naïve nonvaccinated calves with T. verrucosum, also indicated stimulation of a cell-mediated immune response essential for resolution of lesions.

Planum temporale, planum parietale and dichotic listening in dyslexia

A reduction or reversal of the normal leftward asymmetry of the planum temporale (PT) has been claimed to be typical of dyslexia, although some recent studies have challenged this view. In a population-based study of 20 right-handed dyslexic boys and 20 matched controls, we have measured the PT and the adjacent planum parietale (PP) region in sagittal magnetic resonance images. For the PT, mean left and right areas and asymmetry coefficients were compared. Since a PP area often could not be identified in one or both hemispheres, a qualitative comparison was used for this region. The total planar area (sum of PT and PP) was also compared between the two groups. A dichotic listening (DL) test with consonant-vowel syllables was administered to assess functional asymmetry of language. The results showed a mean leftward PT asymmetry in both the dyslexic and the control group, with no significant difference for the degree of PT asymmetry. Planned comparisons revealed however, a trend towards smaller left PT in the dyslexic group. In control children, but not in the dyslexic children, a significant correlation between PT asymmetry and reading was observed. A mean leftward asymmetry was also found for the total planar area, with no difference between the groups for the degree of asymmetry. Significantly fewer dyslexic children than control children showed a rightward asymmetry for the PP region. Both groups showed a normal right ear advantage on the DL task, with no significant difference for DL asymmetry. No significant correlation was observed between PT asymmetry and DL asymmetry. The present population-based study adds to recent reports of normal PT asymmetry in dyslexia, but indicates that subtle morphological abnormalities in the left planar area may be present in this condition.

Case-control study of risk factors for clinical mastitis in postpartum dairy heifers

A case-control study was carried out to evaluate risk factors for clinical mastitis occurring in dairy heifers between 1 and 14 d postpartum. Case and control heifers were matched on herd; the control was the heifer that calved closest in time, before or after, the particular case. Data were analyzed by conditional logistic regression. The final multivariate model included 339 case-control pairs. Blood in the milk, udder edema, teat edema, and milk leakage, all recorded at the time of parturition, were significant risk factors. Purchased heifers and heifers with skin lesions between udder and thigh were not at increased risk of clinical mastitis. Separate analysis of a subgroup of case-control pairs identified teat edema, blood in the milk, and milk leakage at calving as risk factors for clinical mastitis caused by Staphylococcus aureus.

The effects of UV-irradiation on the ESR-dosimetry of tooth enamel

Tooth enamel has been shown to be an excellent dosimeter material for retrospective dosimetry. A complication is that it is sensitive to ultraviolet light (UV), creating a signal that interferes with the dosimetric signal. Irradiation of tooth enamel by UV-light induces a mixture of stable and unstable free radicals. The unstable radicals disappear in about three weeks. Stable radicals are created both at the dosimetric peak and at the same g-value as the native peak. The stable peak coinciding with the native peak shows saturation behavior both for UVA/B- and UVC-light. The signal intensity from the sun is roughly estimated to induce a signal comparable to 15 mGy/h from 60 kV X-rays. The blue lamps used by dentists when hardening plastic repairs contain a narrow tail in the UVA/B-region, and it is shown here that these lamps also contribute to the stable peak coincident with the native peak. The contribution to the dosimetry peak, though negligible, at least for the irradiation times is used in this work. Most of the problems with UVA/B-induced signal contributions can probably be avoided by not using front teeth and teeth close to plastic repairs.

Behaviour problems in children with dyslexia

The association between behaviour problems and dyslexia was assessed in a population sample of 10- to 12-year-old children. Twenty-five dyslexic children and a matched control group were recruited through a screening in primary schools in the city of Bergen, Norway. For the assessment of behaviour problems the Child Behavior Checklist (CBCL), Teacher Self Report (TRF), and Youth Self Report (YSR) were filled out by parents, teachers, and children, respectively. Information on health and developmental factors were obtained from parents on a separate questionnaire designed for the study. The dyslexic group had significantly more behaviour problems than the control group according to both the CBCL and the TRF. On the YSR there was no significant difference between the groups. Dyslexic children had higher CBCL and TRF scores on the Total Behaviour Problem scale, the Internalizing and Externalizing subdomains, and the Attention problem subscale. The groups differed in social background, prenatal risk factors, birth weight, preschool language problems, and IQ, but these variables showed no relationship to the level of behaviour problems in the present sample. We conclude that pre-adolescent dyslexic children show a wide range of behaviour problems that cannot be attributed to social or developmental background variables.

Fibromyalgia is associated with panic disorder and functional dyspepsia with mood disorders. A study of women with random sample population controls

BACKGROUND

We compared ICD-10 psychiatric disorders in female patients with fibromyalgia (n=45) or functional dyspepsia (n=18) with age-matched random sample controls (n=49).

METHOD

Version 2 of The Schedules for Clinical Assessment in Neuropsychiatry (SCAN) was used for present state examination and lifetime diagnoses.

RESULTS

Current psychiatric disorders (somatoform pain disorder and specific phobia omitted) were diagnosed in 80% of fibromyalgia patients (OR=8.3), 83% of functional dyspepsia patients (OR=10.3) and 33% controls. Among fibromyalgia patients 27% had lifetime panic disorder. Lifetime mood disorders were found in 83% of functional dyspepsia patients. First-degree relatives with psychiatric disorder were found in 16% of the fibromyalgia patients, 50% of functional dyspepsia patients and 20% of controls.

CONCLUSIONS

Fibromyalgia is associated with panic disorder and functional dyspepsia with mood disorders in substantial subgroups. Psychiatric symptoms and somatic complaints are closely related in these disorders.

Characterisation of isolates of Staphylococcus aureus from acute, chronic and subclinical mastitis in cows in Norway

Eighty-six Staphylococcus aureus isolates from cases of bovine mastitis were characterised biochemically and with respect to serotype, multilocus enzyme electrophoresis genotypes, antibiotic sensitivity, and production of enterotoxins A through D (SEA-D) and toxic shock syndrome toxin-1 (TSST-1). The samples were obtained from 81 different cows from 79 Norwegian dairy herds in 10 different counties in southern Norway. There was an equal representation of isolates from cases of acute, chronic and subclinical mastitis. Multilocus enzyme electrophoresis using 13 genetic loci showed that 69 of 86 isolates had the same electrophoretic type. This common electrophoretic type comprised isolates that differed in the expression of other phenotypical characteristics studied. Fifty-eight percent of the isolates produced one or more enterotoxins, predominantly a combination of SEC and TSST-1. Capsular serotyping revealed that 95% of the isolates belonged to serotype 8. No correlation was found between the factors studied and the clinical classification of mastitis. It appears that the majority of S. aureus isolates recovered from cases of bovine mastitis in Norway are genetically closely related and express common phenotypical characteristics.

The human elongation factor 1 A-2 gene (EEF1A2): complete sequence and characterization of gene structure and promoter activity

The eukaryotic elongation factor 1 A (eEF1A, formerly EF1alpha) is a key factor in protein synthesis, where it promotes the transfer of aminoacylated tRNAs to the A site of the ribosome. Two differentially expressed isoforms of eEF1A, designated eEF1A-1 and eEF1A-2, are found in mammals. Here we report the isolation and sequencing of the gene (HGMW-approved symbol EEF1A2) coding for the human eEF1A-2 isoform. Furthermore, we characterize the gene structure and the activity of the promoter. Isolation of overlapping clones from human libraries revealed that the human eEF1A-2 gene spans approximately 10 kb and consists of eight exons. The intron-exon boundaries of human EEF1A2 and EEF1A1 are conserved, yet the gene of the eEF1A-2 isoform is larger than the eEF1A-1 gene because of enlarged introns. Primer extension analysis identified the predominant transcription start site 166 bp upstream of the AUG codon. The start site maps to an adenine located within a consensus initiator element. Sequencing of a 2-kb 5'-flanking promoter region revealed no TATA element. However, several putative cis-regulatory elements were discovered. The 5'-promoter activity was characterized by transient transfection experiments. Progressive deletions of the upstream promoter region defined a minimal promoter region, ranging from -16 to +92, that is sufficient to drive transcription.

Founder effect in spinal and bulbar muscular atrophy (SBMA) in Scandinavia

We haplotyped 13 Finnish, 10 Swedish, 12 Danish and 2 Norwegian SBMA (spinal and bulbar muscular atrophy, Kennedy disease) families with a total of 45 patients and 7 carriers for 17 microsatellite markers spanning a 25.2 cM region around the androgen receptor gene on chromosome Xq11-q12 in search of a genetic founder effect. In addition, the haplotypes of 50 Finnish, 20 Danish and 22 Swedish control males were examined. All the Scandinavian SBMA families shared the same 18 repeat allele for the intragenic GGC repeat, which was present in only 24% of the controls. Linkage disequilibrium was also seen for the closest microsatellite markers. In addition, extended haplotypes of the Finnish, Swedish and Danish SBMA families revealed country-specific common founder haplotypes, which over time became gradually shortened by recombinations. No common haplotype was found among the controls. The data suggest that the SBMA mutation was introduced into western Finland 20 generations ago. Haplotype analysis implies a common ancestor for the majority of Scandinavian SBMA patients.

Development of ammonium tartrate as an ESR dosimeter material for clinical purposes

The crystalline substance ammonium tartrate is investigated with respect to its suitability as a clinical dosimetry material. The properties investigated are: the radical stability for absorbed doses relevant for clinical use, the improvement in sensitivity when the crystals are deuterated and the linear electron transfer (LET)-dependence. After photon irradiation to an absorbed dose of 20 Gy, the signal increases rapidly during the first 6 h. After this period, the changes are more moderate and can be corrected for. The signal-to-noise ratio of irradiated ammonium tartrate is twice the corresponding value of alanine. By deuterating the crystals, the sensitivity can be further improved by a factor of 1.4. As expected, the signal decreases with increasing LET of the radiation, but no changes in the spectrum shape was observed.