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1.
J Evol Biol ; 30(2): 235-243, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27905665

ABSTRACT

Female multiple mating has been extensively studied to understand how nonobvious benefits, generally thought to be of genetic nature, could overcome heavy costs such as an increased risk of infection during mating. However, the impact of infection itself on multiple mating has rarely been addressed. The interaction between the bacterium Wolbachia and its terrestrial crustacean host, Armadillidium vulgare, is a relevant model to investigate this question. In this association, Wolbachia is able to turn genetic males into functional females (i.e. feminization), thereby distorting the sex ratio and decreasing the number of available males at the population scale. Moreover, in A. vulgare, females have been shown to mate multiply under laboratory conditions and males prefer uninfected females over infected ones. Additionally, different Wolbachia strains are known to infect A. vulgare and these strains differ in their transmission rate and virulence. All these elements suggest a potential impact of different Wolbachia strains on multiple mating. To investigate this assumption, we collected gravid females in a wild A. vulgare population harbouring both uninfected females and females infected with one of two different Wolbachia strains (wVulM and wVulC) and performed paternity analyses on the obtained broods using microsatellite markers. We demonstrate that (i) multiple paternity is common in this wild population of A. vulgare, with a mean number of fathers of 4.48 ± 1.24 per brood and (ii) females infected with wVulC produced broods with a lower multiple paternity level compared with females infected with wVulM and uninfected ones. This work improves our knowledge of the impact of infections on reproductive strategies.


Subject(s)
Isopoda/parasitology , Paternity , Sex Ratio , Wolbachia/pathogenicity , Animals , Female , Male , Microsatellite Repeats
2.
Mol Ecol ; 23(10): 2619-35, 2014 May.
Article in English | MEDLINE | ID: mdl-24750488

ABSTRACT

Animal-bacterial symbioses are highly dynamic in terms of multipartite interactions, both between the host and its symbionts as well as between the different bacteria constituting the symbiotic community. These interactions will be reflected by the titres of the individual bacterial taxa, for example via host regulation of bacterial loads or competition for resources between symbionts. Moreover, different host tissues represent heterogeneous microhabitats for bacteria, meaning that host-associated bacteria might establish tissue-specific bacterial communities. Wolbachia are widespread endosymbiotic bacteria, infecting a large number of arthropods and filarial nematodes. However, relatively little is known regarding direct interactions between Wolbachia and other bacteria. This study represents the first quantitative investigation of tissue-specific Wolbachia-microbiota interactions in the terrestrial isopod Armadillidium vulgare. To this end, we obtained a more complete picture of the Wolbachia distribution patterns across all major host tissues, integrating all three feminizing Wolbachia strains (wVulM, wVulC, wVulP) identified to date in this host. Interestingly, the different Wolbachia strains exhibited strain-specific tissue distribution patterns, with wVulM reaching lower titres in most tissues. These patterns were consistent across different host genetic backgrounds and might reflect different co-evolutionary histories between the Wolbachia strains and A. vulgare. Moreover, Wolbachia-infected females carried higher total bacterial loads in several, but not all, tissues, irrespective of the Wolbachia strain. Taken together, this quantitative approach indicates that Wolbachia is part of a potentially more diverse bacterial community, as exemplified by the presence of highly abundant bacterial taxa in the midgut caeca of several A. vulgare populations.


Subject(s)
Biological Evolution , Isopoda/microbiology , Symbiosis/genetics , Wolbachia/physiology , Animals , Bacterial Load , Female , Genetics, Population , Male , Microbiota , Microsatellite Repeats , Sequence Analysis, DNA , Wolbachia/genetics
3.
J Evol Biol ; 27(8): 1623-30, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24836164

ABSTRACT

For conspecific parasites sharing the same host, kin recognition can be advantageous when the fitness of one individual depends on what another does; yet, evidence of kin recognition among parasites remains limited. Some trematodes, like Coitocaecum parvum, have plastic life cycles including two alternative life-history strategies. The parasite can wait for its intermediate host to be eaten by a fish definitive host, thus completing the classical three-host life cycle, or mature precociously and produce eggs while still inside its intermediate host as a facultative shortcut. Two different amphipod species are used as intermediate hosts by C. parvum, one small and highly mobile and the other larger, sedentary, and burrow dwelling. Amphipods often harbour two or more C. parvum individuals, all capable of using one or the other developmental strategy, thus creating potential conflicts or cooperation opportunities over transmission routes. This model was used to test the kin recognition hypothesis according to which cooperation between two conspecific individuals relies on the individuals' ability to evaluate their degree of genetic similarity. First, data showed that levels of intrahost genetic similarity between co-infecting C. parvum individuals differed between host species. Second, genetic similarity between parasites sharing the same host was strongly linked to their likelihood of adopting identical developmental strategies. Two nonexclusive hypotheses that could explain this pattern are discussed: kin recognition and cooperation between genetically similar parasites and/or matching genotypes involving parasite genotype-host compatibility filters.


Subject(s)
Amphipoda/parasitology , Genetic Variation , Life Cycle Stages/physiology , Models, Biological , Trematoda/genetics , Animals , Coinfection , DNA Primers/genetics , Genotype , Host-Parasite Interactions , Microsatellite Repeats/genetics , New Zealand , Polymerase Chain Reaction , Species Specificity , Statistics, Nonparametric , Trematoda/physiology
4.
Clin Genet ; 82(3): 256-63, 2012 Sep.
Article in English | MEDLINE | ID: mdl-21696388

ABSTRACT

Kufor-Rakeb syndrome (KRS) is a rare autosomal recessive inherited juvenile parkinsonian syndrome caused by mutations in ATP13A2. We describe six patients from a consanguineous Greenlandic Inuit family, homozygous for a novel frame-shift mutation in exon 22 of ATP13A2 (c.2473C>AA, p.Leu825AsnfsX32). Disease onset varied from 10 to 29 years of age, the latest reported, and the clinical features were highly variable within a wide spectrum of an extrapyramidal-pyramidal syndrome with cognitive/psychiatric features. Ataxia was seen in two patients and axonal neuropathy in one, features not previously related to KRS. Dopamine transporter scans showed symmetrical, severely reduced uptake in striatum in two patients. Magnetic resonance imaging was without atrophy in one patient despite disease duration of 17 years, and cerebral and cerebellar atrophy was seen in another patient after 4 years of disease duration. The molecular pathogenic mechanisms of ATP13A2 mutations are discussed. The observation that the mutant transcript is not degraded by nonsense-mediated RNA decay and the fact that none of the eight heterozygous carriers from the family have KRS symptoms suggest that the mutant protein does not interfere and destroy the function of the wild-type ATP13A2 protein.


Subject(s)
Mutation , Parkinsonian Disorders/genetics , Proton-Translocating ATPases/genetics , Adult , Brain/pathology , Genotype , Greenland , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Nonsense Mediated mRNA Decay , Parkinsonian Disorders/enzymology , Phenotype , Proton-Translocating ATPases/metabolism
5.
Acta Neurol Scand ; 118(2): 126-31, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18294341

ABSTRACT

OBJECTIVE: A study in The Faroe Islands in 1995 suggested a high prevalence of idiopathic Parkinson's disease (IPD) and total parkinsonism of 187.6 and 233.4 per 100,000 inhabitants respectively. METHODS: Detailed case-finding methods 10 years later were used and a neurologist has verified the diagnosis. RESULTS: The crude prevalence of IPD and total parkinsonism was 206.7 per 100,000 and 227.4 per 100,000 respectively. The age-adjusted prevalence is twice as high as data from Norway and Denmark. Age at initiation of treatment and the fatality rate did not explain the increased prevalence. During 1995-2005, the average annual incidence was 21.1 per 100,000 persons for Parkinson's disease, and 22.9 per 100,000 persons, if including atypical parkinsonism. CONCLUSION: The high prevalence was verified and linked to a high incidence. The cause of the high prevalence is unknown, but neurotoxic contaminants in traditional food may play a role in the pathogenesis in this population, perhaps jointly with genetic predisposition.


Subject(s)
Parkinson Disease/epidemiology , Adult , Aged , Aged, 80 and over , Denmark/epidemiology , Environment , Family Health , Female , Geography , Humans , Incidence , Male , Middle Aged , Parkinson Disease/genetics , Prevalence
6.
J Affect Disord ; 57(1-3): 73-81, 2000.
Article in English | MEDLINE | ID: mdl-10708818

ABSTRACT

BACKGROUND: In a single-blind placebo-controlled study design we investigated the efficacy of acupuncture additionally applied to drug treatment in major depression. METHODS: We randomly included 70 inpatients with a major depressive episode in three different treatment groups: verum acupuncture, placebo acupuncture and a control group. All three groups were pharmacologically treated with the antidepressant mianserin. The verum group received acupuncture at specific points considered effective in the treatment of depression. The placebo group was treated with acupuncture at non-specific locations and the control group received pharmacological treatment plus clinical management. Acupuncture was applied three times a week over a period of 4 weeks. Psychopathology was rated by judges blind to verum/placebo conditions twice a week over 8 weeks. RESULTS: Patients who experienced acupuncture improved slightly more than patients treated with mianserin alone. CONCLUSIONS: Additionally applied acupuncture improved the course of depression more than pharmacological treatment with mianserin alone. However, we could not detect any differences between placebo and verum acupuncture.


Subject(s)
Acupuncture Therapy/methods , Depressive Disorder, Major/therapy , Adult , Aged , Anti-Anxiety Agents/therapeutic use , Antidepressive Agents, Second-Generation/therapeutic use , Cross-Sectional Studies , Depressive Disorder, Major/diagnosis , Diazepam/therapeutic use , Female , Humans , Male , Mianserin/therapeutic use , Middle Aged , Psychiatric Status Rating Scales , Severity of Illness Index , Single-Blind Method , Time Factors , Treatment Outcome
7.
Braz J Med Biol Res ; 34(4): 493-500, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11285461

ABSTRACT

In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity.


Subject(s)
Exercise/physiology , Heart Rate/physiology , Life Style , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Rest , Time Factors
8.
J Acoust Soc Am ; 97(3): 1717-26, 1995 Mar.
Article in English | MEDLINE | ID: mdl-7699157

ABSTRACT

This paper reports some of the influences of individual reflections on the timbre of reproduced sound. A single loudspeaker with frequency-independent directivity characteristics, positioned in a listening room of normal size with frequency-independent absorption coefficients of the room surfaces, has been simulated using an electroacoustic setup. The model included the direct sound, 17 individual reflections, and the reverberant field. The threshold of detection and just-noticeable differences for an increase in level were measured for individual reflections using eight subjects for noise and speech. The results have shown that the first-order floor and ceiling reflections are likely to individually contribute to the timbre of reproduced speech. For a noise signal, additional reflections from the left sidewall will contribute individually. The level of the reverberant field has been found to have an effect on the contribution of the individual reflections. An increase in the level of individual reflections are most likely to be audible for the first-order floor and ceiling reflections, and certain reflections from the sidewalls.


Subject(s)
Loudness Perception , Acoustics , Auditory Threshold , Female , Humans , Male , Noise
9.
J Acoust Soc Am ; 103(1): 434-45, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9440331

ABSTRACT

This paper reports on the influence of individual reflections on the auditory spatial aspects of reproduced sound. The sound field produced by a single loudspeaker positioned in a normal listening room has been simulated using an electroacoustical synthesis of the direct sound, 17 individual reflections and the reverberant field. The threshold of detection was measured using the method of adjustment for five reflections using three subjects for noise and speech. The thresholds have been measured for two simulated situations (1) a loudspeaker with a frequency independent directivity characteristics and frequency independent absorption coefficients of the room surfaces and (2) a loudspeaker with directivity similar to a standard two-way system and absorption coefficients according to measurements of real materials. The results have shown that subjects can reliably distinguish between timbre and spatial aspect of the sound field, that the spectral energy above 2 kHz of the individual reflection determines the importance of the reflection for the spatial aspects, and that only the first order floor reflection will contribute to the spatial aspects.


Subject(s)
Auditory Perception , Sound , Space Perception , Amplifiers, Electronic , Auditory Threshold , Humans
10.
Nervenarzt ; 69(11): 961-7, 1998 Nov.
Article in German | MEDLINE | ID: mdl-9859117

ABSTRACT

In order to examine the efficacy of whole body acupuncture additionally applied to drug treatment in depression, a single-blind placebo-controlled study with 70 inpatients administered to three different treatment groups has been carried out. All patients were pharmacologically treated with the tetracyclic antidepressant mianserin. The verum group (n = 22) received acupuncture at specific points considered to be effective in the treatment of depression. The placebo group (n = 24) was treated with acupuncture at non-specific locations and the control group (n = 24) received only pharmacological treatment. Acupuncture was applied three times a week over a period of four weeks. Psychopathology was rated by judges blind to verum/placebo conditions twice a week over eight weeks with the CGI, GAS, BRMS and BfS rating scales. Additionally applied acupuncture improved the course of depression more than pharmacological treatment with mianserin did by itself. However, we could not detect any differences between placebo and verum acupuncture.


Subject(s)
Acupuncture Therapy , Antidepressive Agents, Second-Generation/therapeutic use , Depressive Disorder, Major/therapy , Mianserin/therapeutic use , Adult , Antidepressive Agents, Second-Generation/adverse effects , Combined Modality Therapy , Depressive Disorder, Major/diagnosis , Depressive Disorder, Major/psychology , Female , Humans , Male , Mianserin/adverse effects , Middle Aged , Outcome and Process Assessment, Health Care , Personality Inventory , Single-Blind Method , Treatment Outcome
11.
Braz. j. med. biol. res ; 34(4): 493-500, Apr. 2001. tab, graf
Article in English | LILACS | ID: lil-282606

ABSTRACT

In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity


Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Aging/physiology , Exercise/physiology , Heart Rate/physiology , Life Style , Age Factors , Aged, 80 and over , Rest , Time Factors
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