Notified occupational mental disorders: associations with health and income.

BACKGROUND: Studies indicate that workers' compensation claim processes may affect patients' health negatively. However, few studies focus on patients with mental health claims, and the claim process varies between countries. AIMS: The aims of this study were to examine whether being notified to the Danish Labour Market Insurance with an occupational mental health condition was associated with changes in visits to the general practitioner (GP), use of medicine and annual income. METHODS: Study participants were 965 patients with a mental disorder examined at a department of occupational medicine. Of these, 669 patients were notified with an occupational mental disorder, 296 were not. Health-related outcomes, including GP visits and prescriptions of psychotropic drugs, were estimated at baseline during the year of medical examination, while annual income was estimated a year before the examination. The follow-up was the year after the year of examination for all outcomes. Outcomes were collected from the Danish National Bureau of Statistics. Analyses were conducted using Poisson regression and conditional logistic regression. RESULTS: All measured outcomes decreased from baseline to follow-up in both groups. These changes were not significantly different depending on notification status at baseline. CONCLUSIONS: This study suggests that being notified with an occupational mental disorder does not significantly affect health-related outcomes. A significant decrease in annual income over time was seen in both groups, the notified and the unnotified group, highlighting the importance of providing support to all employees with a mental disorder.

Risk of depressive disorder following disasters and military deployment: systematic review with meta-analysis.

BACKGROUND: Numerous studies describe the occurrence of post-traumatic stress disorder following disasters, but less is known about the risk of major depression. AIMS: To review the risk of depressive disorder in people surviving disasters and in soldiers returning from military deployment. METHOD: A systematic literature search combined with reference screening identified 23 controlled epidemiological studies. We used random effects models to compute pooled odds ratios (ORs). RESULTS: The average OR was significantly elevated following all types of exposures: natural disaster OR = 2.28 (95% CI 1.30-3.98), technological disaster OR = 1.44 (95% CI 1.21-1.70), terrorist acts OR = 1.80 (95% CI 1.38-2.34) and military combat OR = 1.60 (95% CI 1.09-2.35). In a subset of ten high-quality studies OR was 1.41 (95% CI 1.06-1.87). CONCLUSIONS: Disasters and combat experience substantially increase the risk of depression. Whether psychological trauma per se or bereavement is on the causal path is unresolved.

Intravenous immunoglobulin products contain neutralizing antibodies to vaccinia.

BACKGROUND AND OBJECTIVES: Individuals with primary or secondary immune-deficiency diseases may be at risk for vaccinia infection if widespread smallpox-immunization programmes are implemented in the United States of America (USA) for bioterrorism preparedness. The objective of this study was to determine whether commercial immune globulin (intravenous, human) products contain biologically active antibodies to vaccinia that have the potential to protect people, with immune deficiencies, from complications of vaccinia. MATERIALS AND METHODS: Eight currently United States (US)-licensed and two European intravenous immunoglobulin (IVIG) products were tested in a vaccinia plaque-reduction neutralization assay. The in vivo activity of five of these lots was assessed in severely immune-deficient mice. RESULTS: All tested products contained neutralizing anti-vaccinia activity, in vitro and in vivo. CONCLUSIONS: The use of IVIG by individuals with inherited or acquired humoral immune deficiencies may provide some protection if they are inadvertently exposed to vaccinia.

Evaluation of a radioimmunoassay and establishment of a reference interval for salivary cortisol in healthy subjects in Denmark.

A commercial radioimmunoassay (RA) for salivary cortisol was evaluated using certified reference material in water and spiked to pooled saliva in the range 2.1-89.1 nmol/L. A variance component model for describing the effects of age, body mass index (BMI), diurnal variation, gender, days of sick leave during the past year, and smoking habits was established. Reference intervals for salivary cortisol in 120 healthy individuals performing their routine work were established according to the International Union of Pure and Applied Chemistry (IUPAC) and the International Federation of Clinical Chemistry (IFCC). The method evaluation of the certified reference material in water did not show any bias of the method, i.e. recovery was 97% [CI: 94%; 100.9%]. LOD (detection limit) was 1.59 nmol/L. The ratio between analytical and within-subject variation (CVa/CVi) was 0.14, indicating that the method was adequate for measurement in healthy subjects. Reference intervals were estimated to be from 3.6 to 35.1 nmol/L for samples at the time of awakening (05.27-07.27), 7.6-39.4 nmol/L for peak level in saliva samples collected 20 min after awakening (05.47-07.47), and LOD 10.3 nmol/L for late afternoon samples (17.00-19.00). Reactivity (increase from awakening to 20 min after awakening) was estimated to be 82% [CI: -179; 345%] and recovery (decrease from 20 min after awakening to 18.00) to be 80% [CI: 51; 109%]. Eighteen percent of the subjects showed a decrease in cortisol in saliva from awakening to 20 min after awakening. Salivary cortisol was not affected by age, body mass index, gender, smoking habits or days of sick leave during the past year.

Cortisol in urine and saliva: relations to the intima media thickness, IMT.

OBJECTIVE: The objective of the study was to analyse the relations between excretion of cortisol in urine and saliva and the intima media thickness (IMT) of the artery carotis communis. DESIGN AND METHODS: In a cross-sectional study, 121 healthy participants completed a comprehensive questionnaire. Additionally, three samples of urine and four samples of saliva were collected in the 24 h before the examination, which included an ultrasound examination of the artery carotis communis, measuring height, weight, hip and waist width, blood pressure after 10 min of rest, and analysis of blood samples for cholesterol, high density lipoprotein (HDL)-cholesterol, and HbA(1c). The highest average of three measurements of IMT immediately before cartosis bulbous from either left or right side was used in the analyses as the dependent variable IMT. RESULTS: Values of cortisol in urine adjusted for creatinine were not related to IMT, but the level of salivary cortisol 1 h after awakening and the reactivity in salivary cortisol the first hour after awakening were significantly associated with IMT in women i.e. high cortisol was associated with low IMT. This result remained significant in multiple regression analysis including age, body mass index (BMI), cholesterol, HbA(1c), and alcohol. CONCLUSION: The reactivity in salivary cortisol the first hour in the morning might be used in research relating to stress, hormonal changes and early atherosclerosis.

Reference intervals and variation for urinary epinephrine, norepinephrine and cortisol in healthy men and women in Denmark.

Reference intervals for urinary epinephrine, norepinephrine and cortisol in 120 healthy individuals performing their routine work were established according to the International Union of Pure and Applied Chemistry (IUPAC) and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) for use in the risk assessment of exposure to occupational stress. Reference intervals were established for three different times of the day: in morning samples (05.45-07.15) the limit of detection (LOD) was 2.10 micromol epinephrine/mol creatinine (82 women) and 2.86 micromol epinephrine/mol creatinine (37 men), and the reference interval was 3.6-29.1 micromol norepinephrine/mol creatinine and 2.3-52.8 micromol cortisol/mol creatinine (119 women and men); in afternoon samples (15.30-18.30) the reference interval was 0.64-10.8 micromol epinephrine/mol creatinine (82 women), 1.20-11.2 micromol/epinephrine/mol creatinine (36 men), 11.0-54.1 micromol/ norepinephrine/mol creatinine and LOD was 42.4 micromol cortisol/mol creatinine (117 women and men); in evening samples (21.45-23.45) LOD was 8.66 micromol epinephrine/mol creatinine (81 women) and 7.99 micromol/epinephrine/mol creatinine (36 men), the reference interval was 11.0-54.1 micromol norepinephrine/mol creatinine, and LOD was 42.4 micromol cortisol/mol creatinine (117 women and men). A variance component model for describing the effects of age, body mass index (BMI), diurnal variation, gender, days of sick leave during past year and smoking habits was established. Women showed a higher morning value but excreted lower amounts of epinephrine during the day as compared to men. No gender differences could be demonstrated for the excretion of norepinephrine and cortisol. Excretion of epinephrine and norepinephrine increased with smoking and decreased with increased BMI. No effects were observed in the excretion of cortisol.

The intima media thickness and coronary risk factors.

AIM: to estimate the degree of atherosclerosis in the carotids with different measurements of the intima media thickness (IMT), obtained by ultrasound and to analyze the correlations of these measures to coronary risk factors. DESIGN AND PARTICIPANTS: 130 employed men and women volunteered after public announcement. MEASURES: Health and life-style were charted using a comprehensive questionnaire. Anthropometric measurements, and blood pressure after 10 min of rest were obtained at clinical examination. Blood tests included analyses for fibrinogen, cholesterol, and HDL-cholesterol. The IMT was measured bilaterally three times at the transition of a. carotis to bulbus as well as on a. carotis 0.5 cm proximal thereto. Analyses were conducted with four methodologically different ways of expressing IMT as the dependent variable: IMT(left), IMT(communis), IMT(mean) and IMT(max). RESULTS: Among the measurements of IMT, IMT(max) showed the strongest correlations to coronary risk factors, significantly associated with sex and age. In univariate analyses only the degree of physical activity in the leisure time correlated significantly to IMT(max) among men. When adjusted for age, HDL-cholesterol, BMI, systolic blood pressure and physical activity in leisure time in a multiple linear regression analysis IMT(max) showed significant correlations to physical activity in leisure time and systolic blood pressure among men older than 45 years. Among women IMT(max) was significantly correlated to HDL-cholesterol (inversely), which remained significant in the multiple regression analysis including the same factors as for men. CONCLUSIONS: IMT(max) among four measures of IMT showed the strongest associations to coronary risk factors in otherwise healthy individuals.

Ontogeny of Th1 memory responses against a Brucella abortus conjugate.

Protective immune responses to intracellular pathogens such as Brucella abortus are characteristically Th1-like. Recently we demonstrated that heat-killed B. abortus (HKBa), a strong Th1 stimulus, conjugated to ovalbumin (HKBA-OVA), but not B. abortus alone, can alter the antigen-specific cytokine profile from Th2- to Th1-like. In this report we study the ability of a single injection of B. abortus to switch a Th2 to a Th1 response in immature mice. One-day- and 1-week-old mice were given a single injection of B. abortus in the absence or presence of OVA, and at maturity mice were challenged with an allergenic preparation, OVA with alum (OVA-A). B. abortus given without OVA did not diminish the subsequent Th2 response in either age group. In contrast, mice receiving a single injection of B. abortus-OVA at the age of 1 week, but not those injected at the age of 1 day, had reversal of the ratio of OVA-specific Th1 to Th2 cells and decreased immunoglobulin E levels after allergen challenge as adults. Within 6 h both 1-day- and 1-week-old mice expressed interleukin-12 p40 mRNA following either B. abortus or B. abortus-OVA administration. However, only the 1-week-old mice exhibited increased expression of gamma interferon (IFN-gamma) mRNA. The absence of the early IFN-gamma response in 1-day-old mice may explain their inability to generate a Th1 memory response. These results suggest that at early stages of immune development, responses to intracellular bacteria may be Th2- rather than Th1-like. Furthermore, they suggest that the first encounter with antigen evokes either a Th1- or a Th2-like response which becomes imprinted, so that subsequent memory responses conform to the original Th bias. This has implications for protection against infectious agents and development of allergic responses.

Immunoglobulin G3 from polyclonal human immunodeficiency virus (HIV) immune globulin is more potent than other subclasses in neutralizing HIV type 1.

Passive antibody prophylaxis against human immunodeficiency virus type 1 (HIV-1) has been accomplished in primates, suggesting that this strategy may prove useful in humans. While antibody specificity is crucial for neutralization, other antibody characteristics, such as subclass, have not been explored. Our objective was to compare the efficiencies of immunoglobulin G (IgG) subclasses from polyclonal human HIV immune globulin (HIVIG) in the neutralization of HIV-1 strains differing in coreceptor tropism. IgG1, IgG2, and IgG3 were enriched from HIVIG by using protein A-Sepharose. All three subclasses bound major HIV-1 proteins, as shown by Western blot assay and enzyme-linked immunosorbent assay. In HIV-1 fusion assays using X4, R5, or X4R5 envelope-expressing effector cells, IgG3 more efficiently blocked fusion. In neutralization assays with cell-free viruses using X4 (LAI, IIIB), R5 (BaL), and X4R5 (DH123), a similar hierarchy of neutralization was found: IgG3 > IgG1 > IgG2. IgG3 has a longer, more flexible hinge region than the other subclasses. To test whether this is important, IgG1 and IgG3 were digested with pepsin to generate F(ab')(2) fragments or with papain to generate Fab fragments. IgG3 F(ab')(2) fragments were still more efficient in neutralization than F(ab')(2) of IgG1. However, Fab fragments of IgG3 and IgG1 demonstrated equivalent neutralization capacities and the IgG3 advantage was lost. These results suggest that the IgG3 hinge region confers enhanced HIV-neutralizing ability. Enrichment and stabilization of IgG3 may therefore lead to improved HIVIG preparations. The results of this study have implications for the improvement of passive immunization with polyclonal or monoclonal antibodies and suggest that HIV-1 vaccines which induce high-titer IgG3 responses could be advantageous.

Immunity and protection against Brucella abortus.

Brucella abortus is an intracellular pathogen that causes disease in cattle and in humans. The response against B. abortus involves the whole gamut of the immune system, from innate to adaptive immunity resulting from stimulation of antigen-presenting cells, NK cells, CD4(+) and CD8(+) T cells, and B cells.

Reference interval and subject variation in excretion of urinary metabolites of nicotine from non-smoking healthy subjects in Denmark.

BACKGROUND: Passive smoking has been found to be a respiratory health hazard in humans. The present study describes the calculation of a reference interval for urinary nicotine metabolites calculated as cotinine equivalents on the basis of 72 non-smokers exposed to tobacco smoke less than 25% of the day. METHODS: Twenty subjects (passive smokers) exposed to tobacco smoke more than 25% of the day (subjectively assessed) and 32 smokers were used to validate the estimated reference interval. Urine samples were collected three times during the day approximately at 06.30, 17.00 and 22.45 h. RESULTS: Within-subject variation was found to be 89.4, 72.6, and 79.2% and between-subject variation was found to be 64.5, 64.2, and 36.1%. No gender difference could be demonstrated. In general all subjects showed increased concentrations in the afternoon and evening samples compared to the morning samples. Parametric reference interval for excretion of nicotine metabolites in urine from non-smokers was established according to International Union of Pure and Applied Chemistry (IUPAC) and International Federation for Clinical Chemistry (IFCC) for use of risk assessment of exposure to tobacco smoke. The reference interval for urinary cotinine was estimated to be 1.1-90.0 micromol/mol creatinine in morning samples from non-smokers. An intercomparison between the radioimmunoassay (RIA) method used for determination of nicotine metabolites and a gas chromatography-mass spectrometry (GC-MS) method for determination of cotinine was carried out on 27 samples from non-smokers and smokers. Results obtained from the RIA method showed 2.84 [confidence interval (CI): 2.50; 3.18] times higher results compared to the GC-MS method. A linear correlation between the two methods was demonstrated (rho=0.96). CONCLUSION: The RIA method is rapid and adequate for clinical use in the assessment of exposure to tobacco smoke, i.e. ratio between CV(a)/CV(ti) was<0.50.

[The connection between the intima-media-complex and atherosclerosis]. / Sammenhaeng mellem intima-media-komplekset og aterosklerose.

In atherosclerosis several years will pass from development of the first fatty streaks to the first clinical event. In epidemiological investigations of atherosclerosis it is therefore desirable to have a valid method for detecting atherosclerosis in the earliest stages, which is harmless and can be performed repeatedly without risks in the healthy volunteer. Measuring the intima-media-complex (IMT) using ultrasound constitutes such a method. Results from international research are reviewed and it is concluded that the method should be applied in Denmark in atherosclerosis research.

Induction and regulation of Th1-inducing cytokines by bacterial DNA, lipopolysaccharide, and heat-inactivated bacteria.

Th1 immune responses, characterized by production of gamma interferon (IFN-gamma), are associated with protective immunity to viruses and intracellular bacteria. Heat-killed Brucella abortus promotes secretion of Th1-inducing cytokines such as interleukin-12 (IL-12) and IFN-gamma and has been used as a carrier to induce Th1 responses to vaccines. To explore which bacterial constituents could mediate this response and how it is regulated, murine spleen cells were cultured with B. abortus derived DNA, lipopolysaccharide (LPS), or whole killed organisms. Each constituent induced similar, substantial amounts of IL-10. However, only B. abortus and B. abortus DNA induced high levels of IFN-gamma and IL-12. B. abortus and B. abortus DNA-stimulated IL-12 production was maximal by 6 to 18 h, while IL-10 production steadily accumulated over this time period. These kinetics suggested that IL-10 may eventually downmodulate the Th1-like cytokine response to B. abortus and B. abortus DNA, which was confirmed by using neutralizing antibody. In the absence of IL-10, B. abortus LPS induced strong IFN-gamma responses, but IL-12 p70 levels were still undetectable from BALB/c spleen cells. LPS induced IL-12 if the spleen cells were primed with IFN-gamma and IL-10 was neutralized, indicating that LPS can stimulate IL-12 production under the most favorable conditions. Responses to Escherichia coli LPS and DNA mirrored the responses to B. abortus components, suggesting that immune effects observed with these constituents may be generalizable to many microbial species. In vivo experiments demonstrated the same hierarchy of responses for IL-12 production. These findings support the likelihood that microbial components, if used as carriers or adjuvants, can differ substantially in their ability to effect a Th1 response.

Age dependence of clinical and pathological manifestations of autoimmune demyelination. Implications for multiple sclerosis.

A prominent feature of the clinical spectrum of multiple sclerosis (MS) is its high incidence of onset in the third decade of life and the relative rarity of clinical manifestations during childhood and adolescence, features suggestive of age-related restriction of clinical expression. Experimental allergic encephalomyelitis (EAE), a model of central nervous system (CNS) autoimmune demyelination with many similarities to MS, has a uniform rapid onset and a high incidence of clinical and pathological disease in adult (mature) animals. Like MS, EAE is most commonly seen and studied in female adults. In this study, age-related resistance to clinical EAE has been examined with the adoptive transfer model of EAE in SJL mice that received myelin basic protein-sensitized cells from animals 10 days (sucklings) to 12 weeks (young adults) of age. A variable delay before expression of clinical EAE was observed between the different age groups. The preclinical period was longest in the younger (<14 days of age) animals, and shortest in animals 6 to 8 weeks old at time of transfer. Young animals initially resistant to EAE eventually expressed well-developed clinical signs by 6 to 7 weeks of age. This was followed by a remitting, relapsing clinical course. For each age at time of sensitization, increased susceptibility of females compared to males was observed. Examination of the CNS of younger animal groups during the preclinical period showed lesions of acute EAE. Older age groups developed onset of signs coincident with acute CNS lesions. This age-related resistance to clinical EAE in developing mice is reminiscent of an age-related characteristic of MS previously difficult to study in vivo. The associated subclinical CNS pathology and age-related immune functions found in young animals may be relevant to the increasing clinical expression of MS with maturation, and may allow study of factors associated with the known occasional poor correlation of CNS inflammation and demyelination and clinical changes in this disease.

Risk of chronic effects on the central nervous system at low toluene exposure.

This study evaluates the chronic effects on the central nervous system of exposure to low concentrations of toluene (TWA < 20 ppm) on workers in a rotogravure plant. Ninety-eight male workers from a selection pool of 107 (92%) were examined neuropsychologically using a Cognitive Function Scanner, and neurologically by computerized methods measuring co-ordination ability, tremor and position stability. In addition measures of symptoms and former exposure were obtained by questionnaire. The workers were divided into three groups: Group 0 with no exposure to organic solvents (n = 19); Group 1 with exposure to TWA < 20 ppm of toluene for less than 13 years (n = 30) and Group 2 with exposure for more than 12 years (n = 49). Within Group 2, 37 (75%) had been exposed at levels exceeding 100 ppm for 10+ years before 1983. No significant differences were found between Group 0 and Group 1 regarding symptoms and results of the applied tests. Group 2 differed significantly from the two other groups in scoring higher on a symptom index (p = 0.04), particularly regarding concentration ability, reduced memory and fatigue. Group 2 scored significantly poorer on tests for visuospatial function, number learning and word recognition, while no differences regarding neurological functions were observed. The study showed no differences regarding neuropsychological and neurological functions between a non-exposed group of male workers and workers exposed to toluene less than 13 years at TWA < 20 ppm. However, long-term exposure to TWA (time weighted average) of toluene exceeding 100 ppm was associated with impaired neuropsychological function.

The duration of antidiuretic response of two desmopressin nasal sprays.

The duration of antidiuretic response and pharmacokinetics of desmopressin were investigated in 16 healthy, male overhydrated volunteers after intranasal administration of 20 microg desmopressin (dDAVP). The antidiuretic activity was determined by measuring urine osmolality and diuresis over a period of 24 hours. Both study preparations were equally effective regarding a rapid onset of activity and a highly reproducible extent of effect. Urine osmolalities, analyzed as areas under the time curve (AUCosm) were similar for both nasal sprays. Urine volumes were comparable. Bioequivalence was assessed for the primary criterion AUCosm by a calculated mean ratio (test/reference) of 100.9% (90% confidence interval ranging from 88.0% to 115.6%). Plasma levels of desmopressin, measured by a specific and sensitive radioimmunoassay method, were already detectable 20 minutes after administration. The mean time courses showed a similar shape with increased concentration levels for the test preparation. Consequently maximum desmopressin plasma concentrations were different, showing high interindividual variability. However, the times of reaching maximum plasma concentrations were similar. AUC(0-24h) was significantly raised after treatment with the test preparation (mean ratio of 127.9%; 90% confidence interval ranging from 106.6% to 153.5%). A subanalysis of the 2 reference batches with the two-sided t-test procedure for parallel groups resulted in a mean ratio of 83.1% with a 90% confidence interval ranging from 67.2% to 102.7%. The estimated ratios of the 2 batches of the reference preparation were borderline to the equivalence range. In conclusion, both study preparations had the same pronounced biological effect with different desmopressin bioavailabilities.

Pharmacokinetics of dexibuprofen administered as 200 mg and 400 mg film-coated tablets in healthy volunteers.

The pharmacokinetic properties of 2 film-coated preparations containing 200 mg and 400 mg dexibuprofen were compared in a single-dose, crossover study in 16 healthy, male volunteers. Dexibuprofen was absorbed rapidly (tmax 2.1 - 2.2 hours) reaching maximum concentrations of 12.4 microg/ml (200 mg), respectively 12.0 microg/ml (400 mg dose adjusted). For the characteristics AUC(0-12h) and AUC(0-infinity) arithmetic means of 49.2 (microg) x (h/ml)(200 mg) and 48.2 (microg) x (h/ml)(400 mg dose-adjusted), respectively 50.5 (microg) x (h/ml)(200 mg), and 49.2 (microg) x (h/ml)(400 mg) were calculated. No relevant differences for the pharmacokinetic characteristics terminal half-life, clearance, volume of distribution, and mean residence time were observed. A linear dose-relationship was shown over the investigated dose range. Mean ratios after dosage adjustment of the test preparation using the "2 one-sided t-tests" procedure were calculated. Bioequivalence was assessed for AUC(0-12h) with a mean ratio of 97.7% (90% CI: 92.4 - 103.3%), for AUC(0-infinity) with 97.1% (90% CI: 91.4 - 103.1%), and for Cmax with 97.5% (90% CI: 91.7 - 103.8%). Both dexibuprofen preparations were well tolerated. No changes in hematological and biochemical parameters were detected.

A comparative study of pharmacodynamics and bioavailability of 2 different desmopressin nasal sprays.

The antidiuretic effect and pharmacokinetics were investigated in 16 healthy, male overhydrated volunteers after intranasal administration of 20 microg desmopressin. The antidiuretic activity was measured by determination of urine osmolality and diuresis every 15 minutes over a period of 8 hours. Both study preparations were equally effective regarding a rapid onset of activity and a highly reproducible magnitude of effect. Urine osmolalities, analyzed as area under the time curve (AUCosm) and maximum urine osmolalities were similar for both nasal sprays. Urine volume, analyzed as area under the time curve, was raised after treatment with the test preparation. Bioequivalence was assessed for the primary criterion AUCosm by a calculated mean ratio (test/reference) of 102.8% and a 90% confidence interval ranging from 95.4% to 110.8%. Plasma levels of desmopressin, measured by a specific and sensitive radio-immunoassay method, were already detectable 20 minutes after administration. The mean time curves were parallel at different concentration levels. The maximum desmopressin plasma concentrations of both preparations were comparable, showing high interindividual variability. The times of reaching maximum plasma concentrations were similar. Desmopressin bioavailability was increased after treatment with the test preparation (mean ratio of 130.8% and a 90% confidence interval ranging from 109.9% to 155.7%). Both preparations showed a pronounced biological effect with similarly raised urine osmolalities. The detected differences in bioavailability seem to have no direct correlation to the biological response.

Isolation and expression during pollen development of a tobacco cDNA clone encoding a protein kinase homologous to shaggy/glycogen synthase kinase-3.

We have isolated a tobacco (Nicotiana tabacum L.) cDNA clone encoding a putative serine/threonine protein kinase, which shows highest homology to previously described families of alfalfa and Arabidopsis protein kinases and to their homologues rat glycogen synthase kinase-3 and Drosophila shaggy kinases. Northern experiments showed that NtK-4 is expressed in all sporophytic tobacco tissues tested, as well as in gametophytic and embryogenic pollen.

Molecular cloning and characterization of profilin from tobacco (Nicotiana tabacum): increased profilin expression during pollen maturation.

Profilin has recently been identified as an actin-binding protein in higher plants. A cDNA coding for tobacco profilin, which shared an average sequence identity of 75% with other plant profilins, was isolated from a tobacco pollen cDNA library by antibody screening. Tobacco profilin was expressed in Escherichia coli and purified by affinity to poly-(L-proline) Sepharose. A rabbit antiserum was raised against recombinant tobacco profilin and used to estimate the amount of profilin expressed in different tobacco tissues. Profilin can be detected in different somatic tissues, but the expression is 50-100 fold higher in mature pollen. Immunofluorescence and confocal laser scanning microscopy showed a homogeneous distribution of profilin in the cytoplasm of in vitro cultured pollen grains and pollen tubes of tobacco whereas some growing pollen tubes were stained more intensively a their tip. A possible role of pollen profilin as a developmentally upregulated microfilament precursor in mature pollen is discussed.