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1.
J Evol Biol ; 27(5): 929-38, 2014 May.
Article in English | MEDLINE | ID: mdl-24725009

ABSTRACT

Mate choice for compatible genes is often based on genes of the major histocompatibility complex (MHC). Although MHC-based mate choice is commonly observed in female choice, male mate choice remains elusive. In particular, if males have intense paternal care and are thus the choosing sex, male choice for females with dissimilar MHC can be expected. Here, we investigated whether male mate choice relies on MHC class I genes in the sex-role reversed pipefish Syngnathus typhle. In a mate choice experiment, we determined the relative importance of visual and olfactory cues by manipulating visibility and olfaction. We found that pipefish males chose females that maximize sequence-based amino acid distance between MHC class I genotypes in the offspring when olfactory cues were present. Under visual cues, large females were chosen, but in the absence of visual cues, the choice pattern was reversed. The use of sex-role reversed species thus revealed that sexual selection can lead to the evolution of male mate choice for MHC class I genes.


Subject(s)
Major Histocompatibility Complex/genetics , Mating Preference, Animal/physiology , Smegmamorpha/physiology , Analysis of Variance , Animals , Female , Genotype , Major Histocompatibility Complex/immunology , Male , Smegmamorpha/genetics , Smegmamorpha/immunology
2.
J Evol Biol ; 27(2): 404-16, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24417444

ABSTRACT

Sexual selection is often prevented during captive breeding in order to maximize effective population size and retain genetic diversity. However, enforcing monogamy and thereby preventing sexual selection may affect population fitness either negatively by preventing the purging of deleterious mutations or positively by reducing sexual conflicts. To better understand the effect of sexual selection on the fitness of small populations, we compared components of female fitness and the expression of male secondary sexual characters in 19 experimental populations of guppies (Poecilia reticulata) maintained under polygamous or monogamous mating regimes over nine generations. In order to generate treatments that solely differed by their level of sexual selection, the middle-class neighbourhood breeding design was enforced in the monogamous populations, while in the polygamous populations, all females contributed similarly to the next generation with one male and one female offspring. This experimental design allowed potential sexual conflicts to increase in the polygamous populations because selection could not operate on adult-female traits. Clutch size and offspring survival showed a weak decline from generation to generation but did not differ among treatments. Offspring size, however, declined across generations, but more in monogamous than polygamous populations. By generation eight, orange- and black-spot areas were larger in males from the polygamous treatment, but these differences were not statistically significant. Overall, these results suggest that neither sexual conflict nor the purging of deleterious mutation had important effects on the fitness of our experimental populations. However, only few generations of enforced monogamy in a benign environment were sufficient to negatively affect offspring size, a trait potentially crucial for survival in the wild. Sexual selection may therefore, under certain circumstances, be beneficial over enforced monogamy during captive breeding.


Subject(s)
Mating Preference, Animal , Poecilia/physiology , Animals , Body Size , Breeding , Clutch Size , Female , Male , Poecilia/anatomy & histology , Population Dynamics
3.
J Evol Biol ; 25(5): 938-48, 2012 May.
Article in English | MEDLINE | ID: mdl-22404434

ABSTRACT

To what extent within-species (static) allometries constitute a constraint on evolution is the subject of a long-standing debate in evolutionary biology. A prerequisite for the constraint hypothesis is that static allometries are hard to change. Several studies have attempted to test this hypothesis with artificial-selection experiments, but their results remain inconclusive due to various methodological issues. Here, we present results from an experiment in which we selected independently on the slope and the elevation of the allometric relationship between caudal-fin size and body size in male guppies (Poecilia reticulata). After three episodes of selection, the allometric elevation (i.e. intercept at constant slope) had diverged markedly between the lines selected to increase or decrease it, and showed a realized heritability of 50%. In contrast, the allometric slope remained unaffected by selection. These results suggest that the allometric elevation is more evolvable than the allometric slope, this latter representing a potential constraint on adaptive trait evolution. To our knowledge, this study is the first artificial-selection experiment that directly tests the evolvability of static allometric slopes.


Subject(s)
Animal Fins/physiology , Body Size , Poecilia/physiology , Adaptation, Physiological , Animals , Biological Evolution , Breeding , Data Interpretation, Statistical , Female , Inheritance Patterns , Male , Regression Analysis , Selection, Genetic , Sex Characteristics , Trinidad and Tobago
4.
J Evol Biol ; 24(12): 2631-8, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21955207

ABSTRACT

Variation in static allometry, the power relationship between character size and body size among individuals at similar developmental stages, remains poorly understood. We tested whether predation or other ecological factors could affect static allometry by comparing the allometry between the caudal fin length and the body length in adult male guppies (Poecilia reticulata) among populations from different geographical areas, exposed to different predation pressures. Neither the allometric slopes nor the allometric elevations (intercept at constant slope) changed with predation pressure. However, populations from the Northern Range in Trinidad showed allometry with similar slopes but lower intercepts than populations from the Caroni and the Oropouche drainages. Because most of these populations are exposed to predation by the prawn Macrobrachium crenulatum, we speculated that the specific selection pressures exerted by this predator generated this change in relative caudal fin size, although effects of other environmental factors could not be ruled out. This study further suggests that the allometric elevation is more variable than the allometric slope.


Subject(s)
Animal Fins/growth & development , Poecilia/growth & development , Predatory Behavior , Animal Fins/anatomy & histology , Animals , Body Size , Geography , Male , Palaemonidae/physiology , Poecilia/anatomy & histology , Trinidad and Tobago
5.
J Fish Biol ; 78(6): 1647-61, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21651521

ABSTRACT

Male pregnancy in the family Syngnathidae (pipefishes, seahorses and seadragons) predisposes males to limit female reproductive success; sexual selection may then operate more strongly on females and female sexual signals may evolve (sex-role reversal). A bewildering array of female signals has evolved in Syngnathids, e.g. skin folds, large body size, colouration, markings on the body and elaborate courtship. These female sexual signals do not seem quantitatively or qualitatively different from those that evolve in males in species with conventional sex roles where males provide females or offspring with direct benefits. In several syngnathid species, males also evolve ornaments, females are choosy in addition to being competitive and males compete as well as choosing partners. Thus, sex roles form a continuum, spanning from conventional to reversed within this group of fishes. Cases are presented here suggesting that stronger sexual selection on females may be most extreme in species showing classical polyandry (one male mates with several females, such as many species where males brood their eggs on the trunk), intermediate in polygynandrous species (males and females both mate with more than one partner, as in many species where males brood their eggs on the tail) and least extreme, even exhibiting conventional sex roles, in monogamous species (one male mates solely with one female, as in many seahorses and tropical pipefishes). At the same time caution is needed before unanimously establishing this pattern: first, the connection between mating patterns, strength of sexual selection, sex roles and ornament expression is far from simple and straightforward, and second, knowledge of the actual morphology, ecology and behaviour of most syngnathid species is scanty. Basically only a few Nerophis, Syngnathus and Hippocampus species have been studied in any detail. It is known, however, that this group of fishes exhibits a remarkable variation in sex roles and ornamentation, making them an ideal group for the study of mating patterns, sexual selection and sexually selected signals.


Subject(s)
Mating Preference, Animal , Sex Characteristics , Smegmamorpha/physiology , Animals , Environment , Female , Male , Pair Bond
6.
J Fish Biol ; 78(6): 1855-60, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21651533

ABSTRACT

In a habitat choice experiment straight-nosed pipefish Nerophis ophidion and broad-nosed pipefish Syngnathus typhle avoided eelgrass Zostera marina covered with filamentous algae. Both juveniles as well as brooding adult males of the two species clearly preferred to position themselves in Z. marina without growth of filamentous algae.


Subject(s)
Choice Behavior , Ecosystem , Smegmamorpha , Zosteraceae/microbiology , Animals , Male , Sweden , Ulva
7.
J Fish Biol ; 78(6): 1861-7, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21651534

ABSTRACT

Broad-nosed pipefish Syngnathus typhle were used to investigate whether males used scent in their search for mates. When the males in an experiment had access to olfactory cues only, they did not locate females better than they located males. Thus, S. typhle, was less successful in mate search when visual cues were absent.


Subject(s)
Sexual Behavior, Animal , Smegmamorpha/physiology , Smell , Animals , Choice Behavior , Cues , Female , Male
8.
J Evol Biol ; 24(4): 823-34, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21276111

ABSTRACT

Inbreeding depression, which generally affects the fitness of small populations, may be diminished by purging recessive deleterious alleles when inbreeding persists over several generations. Evidence of purging remains rare, especially because of the difficulties of separating the effects of various factors affecting fitness in small populations. We compared the expression of life-history traits in inbred populations of guppy (Poecilia reticulata) with contemporary control populations over 10 generations in captivity. We estimated inbreeding depression as the difference between the two types of populations at each generation. After 10 generations, the inbreeding coefficient reached a maximum value of 0.56 and 0.16 in the inbred and control populations, respectively. Analysing changes in the life-history traits across generations showed that inbreeding depression in clutch size and offspring survival increased during the first four to six generations in the populations from the inbred treatment and subsequently decreased as expected if purging occurred. Inbreeding depression in two other traits was weaker but showed similar changes across generations. The loss of six populations in the inbred treatment indicates that removal of deleterious alleles also occurred by extinction of populations that presumably harboured high genetic load.


Subject(s)
Inbreeding , Poecilia/genetics , Animals , Clutch Size , Survival Analysis , Time Factors
9.
Proc Biol Sci ; 267(1444): 677-80, 2000 Apr 07.
Article in English | MEDLINE | ID: mdl-10821612

ABSTRACT

As a conspicuous evolutionary mechanism, sexual selection has received much attention from theorists and empiricists. Although the importance of the mating system to sexual selection has long been appreciated, the precise relationship remains obscure. In a classic experimental study based on parentage assessment using visible genetic markers, more than 50 years ago A. J. Bateman proposed that the cause of sexual selection in Drosophila is 'the stronger correlation, in males (relative to females), between number of mates and fertility (number of progeny)'. Half a century later, molecular genetic techniques for assigning parentage now permit mirror-image experimental tests of the 'Bateman gradient' using sex-role-reversed species. Here we show that, in the male-pregnant pipefish Syngnathus typhle, females exhibit a stronger positive association between number of mates and fertility than do males and that this relationship responds in the predicted fashion to changes in the adult sex ratio. These findings give empirical support to the idea that the relationship between mating success and number of progeny, as characterized by the Bateman gradient, is a central feature of the genetic mating system affecting the strength and direction of sexual selection.


Subject(s)
Fishes/genetics , Fishes/physiology , Sex Determination Processes , Sexual Behavior, Animal , Animals , Female , Fertility , Male , Pregnancy , Sex Ratio
10.
Proc Biol Sci ; 267(1458): 2151-5, 2000 Nov 07.
Article in English | MEDLINE | ID: mdl-11413626

ABSTRACT

Where both sexes invest substantially in offspring, both females and males should discriminate between potential partners when choosing mates. The degree of choosiness should relate to the costs of choice and to the potential benefits to be gained. We measured offspring quality from experimentally staged matings with preferred and non-preferred partners in a sex-role-reversed pipefish, Syngnathus typhle L. Here, a substantial male investment in offspring results in a lower potential reproductive rate in males than in females, and access to males limits female reproductive success rather than vice versa. Thus, males are choosier than females and females compete more intensely over mates than do males. Broods from preferred matings were superior at escaping predation, when either males or females were allowed to choose a partner. However, only 'choosing' females benefited in terms of faster-growing offspring. Our results have important implications for mate-choice research: here we show that even the more competitive and less choosy sex may contribute significantly to sexual selection through mate choice.


Subject(s)
Fishes/physiology , Animals , Animals, Newborn , Female , Fishes/growth & development , Gender Identity , Male , Pair Bond , Sexual Behavior, Animal
11.
Genetics ; 152(3): 1057-63, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10388824

ABSTRACT

Clustered mutations are copies of a mutant allele that enter a population's gene pool together due to replication from a premeiotic germline mutation and distribution to multiple successful gametes of an individual. Although the phenomenon has been studied in Drosophila and noted in a few other species, the topic has received scant attention despite claims of being of major importance to population genetics theory. Here we capitalize upon the reproductive biology of male-pregnant pipefishes to document the occurrence of clustered microsatellite mutations and to estimate their rates and patterns from family data. Among a total of 3195 embryos genetically screened from 110 families, 40% of the 35 detected de novo mutant alleles resided in documented mutational clusters. Most of the microsatellite mutations appeared to involve small-integer changes in repeat copy number, and they arose in approximately equal frequency in paternal and maternal germlines. These findings extend observations on clustered mutations to another organismal group and motivate a broader critique of the mutation cluster phenomenon. They also carry implications for the evolution of microsatellites with respect to mutational models and homoplasy among alleles.


Subject(s)
Fishes/genetics , Microsatellite Repeats/genetics , Mutation , Animals , Cell Lineage , Cluster Analysis , Female , Genotype , Male , Pregnancy
12.
Eur Spine J ; 7(5): 381-6, 1998.
Article in English | MEDLINE | ID: mdl-9840471

ABSTRACT

The purpose of this study was to examine the influence of estrogen-progestin replacement therapy and exercise on the lumbar spine mobility and back symptoms of early postmenopausal women. The population sample consisted of 78 healthy, 49- to 55-year-old women, 0.5-5 years after menopause, who were randomized into three groups, two receiving different protocols of estradiol valerate combined with medroxyprogesterone acetate replacement therapy, and the third group a placebo. These groups were then randomized into exercise and control cases and monitored for 2 years. The mobility of the lumbar spine was measured and symptoms investigated using the Million and Oswestry pain and disability questionnaires and pain drawings at the baseline and after 1 and 2 years. During the follow-up, the mobility of the lumbar spine decreased in all six groups. The decrease was most evident in those who had been the most flexible at baseline (P < 0.0001). The decrease was less notable in the hormone replacement therapy groups than in the control group. When the replacement therapy groups were pooled together, the difference was significant at a P < 0.05 level. No difference was seen between the hormone combinations. The exercise intervention was insufficient to influence lumbar spine mobility. Only sporadic cases of back symptoms appeared and disappeared among the subjects during the follow-up, and no preventive or aggravating effects of hormone replacement therapy or the exercise program on symptoms were detected.


Subject(s)
Estrogens/therapeutic use , Exercise Therapy , Hormone Replacement Therapy , Low Back Pain/drug therapy , Progestins/therapeutic use , Spine/physiopathology , Disability Evaluation , Female , Humans , Lumbosacral Region , Middle Aged , Pain Measurement , Postmenopause/physiology , Reproducibility of Results
13.
Br J Obstet Gynaecol ; 104 Suppl 16: 19-25, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9389779

ABSTRACT

OBJECTIVE: To compare two doses of a transdermal oestradiol gel (Divigel/Sandrena) plus oral sequential medroxyprogesterone acetate (MPA) with oral oestradiol valerate plus oral sequential MPA (Divina/Dilena). DESIGN: Two year, randomised, open-label, comparative study. SETTING: Menopausal outpatient clinic in Helsinki. SUBJECTS: Postmenopausal women with climacteric complaints or already using HRT. INTERVENTIONS: (1) One gram gel containing 1 mg oestradiol for 3 months plus 20 mg oral MPA during the last 14 days; (2) 2 g gel containing 2 mg oestradiol for 21 days plus 10 mg oral MPA during the last 14 days; (3) 2 mg oestradiol valerate tablets for 3 weeks plus 10 mg oral MPA during the last 10 days. In all groups, each treatment period was followed by a 7-day medication-free interval. MAIN OUTCOME MEASURES: Climacteric complaints, bleeding control, bone mineral density, biomarkers of bone metabolism, lipid profile, tolerability and safety. RESULTS: With each preparation, climacteric complaints were significantly reduced and good bleeding control was obtained. In addition, maintenance of bone mineral density as well as a reduction of bone turnover was achieved in all groups. Lipid parameters showed no unfavourable changes. Continuation rates were similar in all groups with overall 74% of patients completing the first year, whereas 94% of patients who elected to continue completed the second year. Tolerability of the gel was good: only 1.7% of patients discontinued treatment due to skin irritation. CONCLUSIONS: Transdermal oestradiol gel and oral oestradiol valerate tablets, used in combination with oral sequential MPA, are effective regimens of HRT in postmenopausal women. Transdermal oestradiol gel is an efficient, well-tolerated form of HRT.


Subject(s)
Climacteric , Estradiol/administration & dosage , Estrogen Replacement Therapy/methods , Medroxyprogesterone Acetate/administration & dosage , Progesterone Congeners/administration & dosage , Administration, Cutaneous , Administration, Oral , Adult , Aged , Bone Density/drug effects , Cholesterol/blood , Estradiol/adverse effects , Estrogen Replacement Therapy/adverse effects , Female , Gels , Hot Flashes , Humans , Medroxyprogesterone Acetate/adverse effects , Middle Aged , Progesterone Congeners/adverse effects , Sweating , Treatment Refusal , Uterine Hemorrhage/prevention & control
14.
Br J Obstet Gynaecol ; 104 Suppl 16: 26-31, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9389780

ABSTRACT

OBJECTIVE: To compare the efficacy, safety and tolerability of an oestradiol gel (1.0 mg of oestradiol daily, Divigel/Sandrena) with those of an oestradiol delivering patch (delivering 50 micrograms oestradiol/24 h, Estraderm TTS) in hormone replacement therapy of postmenopausal women. Dydrogesterone tablets (Terolut), 10 mg daily for the first 12 days of every month, were used as the progestogen component of the therapy. MAIN OUTCOME MEASURES: The effect of treatment on clinical symptoms and on endometrium, total body bone mineral density and lipid metabolism as well as the tolerability of the treatments with special emphasis on skin irritation and compliance were evaluated. DESIGN: An open, randomised, controlled, parallel-group trial of 12 months' duration. SETTING: The Medical Clinic of Kalevankatu, Helsinki, Finland. PARTICIPANTS: One hundred twenty postmenopausal women were treated with transdermal oestradiol combined with dydrogesterone. In addition, 25 women without HRT served as a reference group for the bone mineral density measurements. RESULTS: Both treatment regimens were equally effective in alleviating climacteric symptoms, preserving bone mineral density and were equally safe. A trend towards heavier bleeding was detected in patients treated with the oestradiol delivering patch. A statistically nonsignificant decrease of total cholesterol and triglyceride concentrations but no change in high-density lipoprotein cholesterol concentration was observed in both groups. The acceptability of the treatment was higher in the gel group (96.4%) than in the patch group (90.7%). Only two (3.3%) women using the oestradiol gel complained of skin irritation whereas 28 patients (46.7%, P < 0.001) using the oestradiol delivering patch reported this adverse effect. CONCLUSIONS: Both the oestradiol gel and the oestradiol delivering patch are equally effective in hormone replacement therapy but the gel preparation is less irritative to the skin.


Subject(s)
Estradiol/administration & dosage , Estrogen Replacement Therapy/methods , Progesterone Congeners/administration & dosage , Administration, Cutaneous , Aged , Bone Density , Drug Therapy, Combination , Dydrogesterone/administration & dosage , Endometrium/anatomy & histology , Estradiol/blood , Estrone/blood , Female , Gels , Hot Flashes , Humans , Middle Aged , Patient Satisfaction , Uterine Hemorrhage
15.
Maturitas ; 26(2): 139-49, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9089564

ABSTRACT

OBJECTIVES: To evaluate the effect of 1- or 3-monthly sequential combinations of estradiol valerate (E2V) and medroxyprogesterone acetate (MPA) on menopausal symptoms, bone density, muscle strength and lipid metabolism in postmenopausal women. METHODS: Changes in bone mineral density (BMD), isometric muscle strength, serum lipids and climacteric symptoms were evaluated in 78 women, 49-55 years of age, with a spontaneous menopause 0.5-3 years earlier. Treatment group I received 2 mg E2V tablets for 11 days, followed by 2 mg E2V + 10 mg MPA for 10 days and placebo for an additional 7 days; treatment group II received 2 mg E2V for 70 days, 2 mg E2V + 20 mg MPA for 14 days, and placebo for 7 days. The placebo group received placebo continuously for 24 months. Each group was further randomised to exercise and non-exercise subgroups. RESULTS: Both hormone regimens significantly reduced menopausal symptoms, and prevented equally well the decrease of BMD both in the lumbar spine and proximal femur. A positive effect of exercise on BMD was observed in the placebo group. No synergistic effect of exercise and estrogen on BMD could be shown. Both hormone regimens increased the isometric strength of back extensor muscles. Serum total and LDL cholesterol decreased during the first year with both estrogen regimens. CONCLUSIONS: Estrogen-progestin regimens were equally effective in the control of menopausal symptoms and preventing bone loss, increasing muscle strength and lowering serum cholesterol.


Subject(s)
Bone Density , Estradiol/analogs & derivatives , Estrogen Replacement Therapy , Estrogens, Conjugated (USP)/therapeutic use , Exercise Therapy , Lipid Metabolism , Medroxyprogesterone Acetate/therapeutic use , Muscle Contraction , Muscle, Skeletal/physiology , Postmenopause , Progesterone Congeners/therapeutic use , Cholesterol/blood , Cholesterol, LDL/blood , Climacteric/drug effects , Estradiol/administration & dosage , Estradiol/therapeutic use , Estrogens, Conjugated (USP)/administration & dosage , Female , Femur/drug effects , Humans , Isometric Contraction/drug effects , Lipids/blood , Lumbar Vertebrae/drug effects , Medroxyprogesterone Acetate/administration & dosage , Menopause/drug effects , Middle Aged , Muscle Contraction/drug effects , Muscle, Skeletal/drug effects , Osteoporosis, Postmenopausal/prevention & control , Placebos , Postmenopause/drug effects , Progesterone Congeners/administration & dosage , Prospective Studies
16.
Health Econ ; 5(5): 421-34, 1996.
Article in English | MEDLINE | ID: mdl-8922970

ABSTRACT

At the start of the 1990s, the economic situation in Finland deteriorated radically. During the depression (1991-93), health care expenditure decreased by about 10%, and was associated with considerable changes in Finnish health care. This paper reports studies of the determinants of use of physician services in Finland in the 1990s. The particular aim was to evaluate how utilization altered during the economic depression and during the changes in the health care system. Using econometric methods, an attempt was made to describe the changes in structure and level of utilization. The study was based on annual computer-assisted telephone interviews made during 1991-94. Visits to a doctor were analysed using a two-part model (logit and truncated negative binomial regression). Structural changes were tested by Chow-type tests and changes in the level of utilization by chronologically defined dummy variables for each year. The most significant changes (both in structure and level) occurred in the model explaining the number of visits (negative binomial regression) of chronically ill persons. Variables describing the continuity of care seem to be more important determinants of visits to a doctor than certain other availability and socioeconomic variables.


Subject(s)
Health Expenditures/trends , Health Services Needs and Demand/economics , Models, Econometric , Physicians/statistics & numerical data , Adult , Aged , Binomial Distribution , Continuity of Patient Care , Female , Finland , Health Services Needs and Demand/statistics & numerical data , Health Services Research , Humans , Logistic Models , Male , Middle Aged , Regression Analysis , Socioeconomic Factors , Surveys and Questionnaires
17.
J Cereb Blood Flow Metab ; 14(4): 628-38, 1994 Jul.
Article in English | MEDLINE | ID: mdl-8014210

ABSTRACT

In this methodological study, a procedure for measuring regional CBF (rCBF) with positron emission tomography and 15O-labelled tracers is optimized. Four healthy volunteers were subjected to eight studies with use of [15O]butanol as a tracer: four times while reading aloud and four times while reading silently from a phonologically balanced list of single words. The gain from these repeated intra-individual studies of the same activation state (fractionation) was demonstrated in terms of noise-equivalent counts in a phantom study. A computerized brain atlas was used to reformat the images to a common anatomical representation, thereby minimizing the effects of inter- and intra-individual anatomical and positional variations. This allowed the formation of inter- and intra-individual average subtraction images with error estimates. Differences between the two activation states were detected with use of an exploratory significance map based on a paired Student's t test. The results compared well with Friston's method of determining levels of statistical significance. No difference was obtained when comparing results from rCBF images and images generated from measurement of uptake of the tracer. The paradigm chosen for activation was shown to yield a constant activation level during the repeated measurements (i.e., no habituation).


Subject(s)
Brain/diagnostic imaging , Brain/physiology , Butanols , Cerebrovascular Circulation , Tomography, Emission-Computed/methods , Brain Mapping/methods , Humans , Models, Neurological , Oxygen Radioisotopes , Reading , Speech/physiology
18.
Arzneimittelforschung ; 43(9): 1014-7, 1993 Sep.
Article in English | MEDLINE | ID: mdl-8240450

ABSTRACT

Erythromycin acistrate (Erasis, CAS 96128-89-1) is a 2'-acetyl ester prodrug of erythromycin. Due to prolonged half-life it is more suitable for twice daily dosing than the conventional erythromycin preparations. In the present double-blind trial, totally 297 ambulatory patients with respiratory tract infections were treated either with erythromycin acistrate 800 mg daily or doxycycline 100 mg daily. 243 of the included patients had bronchitis, 15 patients bronchitis and other respiratory tract symptoms, 25 patients pneumonia and 14 other respiratory tract infections. The duration of treatment varied from 7 to 14 days depending on the severity of infection. The efficacy of both treatments was very good. 96.6% of the patients treated with erythromycin acistrate and 97.2% of the patients treated with doxycycline improved. The efficacy of erythromycin acistrate in the treatment of bronchitis and pneumonia was 96.7 and 100%, respectively. Only 5 of the totally 148 patients failed. Side effects (mainly gastrointestinal symptoms) were seen in 12.1% of the patients (20 patients in the erythromycin acistrate group and 16 patients in the doxycycline group). The results show that erythromycin acistrate dosed twice daily is as effective as doxycycline and well tolerated in the treatment of lower respiratory tract infections.


Subject(s)
Bronchitis/drug therapy , Erythromycin/analogs & derivatives , Pneumonia, Pneumococcal/drug therapy , Prodrugs , Acute Disease , Adult , Aged , Double-Blind Method , Doxycycline/administration & dosage , Doxycycline/therapeutic use , Erythromycin/administration & dosage , Erythromycin/adverse effects , Erythromycin/therapeutic use , Female , Humans , Male , Middle Aged , Respiratory Tract Infections/drug therapy
19.
J Nucl Med ; 33(6): 1191-9, 1992 Jun.
Article in English | MEDLINE | ID: mdl-1597738

ABSTRACT

Methods for whole-body PET imaging have been developed to provide a clinical tool for the detection and evaluation of primary and metastatic cancers. The axial FOV of the PET system is extended by imaging at multiple bed positions to cover the whole body. In typical rectilinear PET scans, only a small fraction of the data is collected to form two-dimensional projection images. In this work, 100% of the projection data was collected to form the two-dimensional projection images. These projection images were generated for continuous angles over 180 degrees by resorting sinogram data. In addition, tomographic images were formed by using filtered backprojection reconstruction without attenuation correction. Coronal and sagittal cuts were then extracted from the three-dimensional data set. The tomographic images were reconstructed to a resolution of 10.8 mm in all dimensions because of statistical limitations of the data. Both methods of image formation resulted in images of high quality with the tomographic reconstruction providing the highest contrast and resolution. An acquisition time of 1-2 min/bed position after a 10-mCi injection of [18F]fluoride ion or [18F]FDG was found to give a sufficient number of counts for producing images of good resolution and contrast, from a total scanning time of 32-64 min.


Subject(s)
Deoxyglucose/analogs & derivatives , Fluorine Radioisotopes , Image Processing, Computer-Assisted , Neoplasms/diagnostic imaging , Tomography, Emission-Computed/methods , Fluorodeoxyglucose F18 , Humans , Time Factors , Tomography, Emission-Computed/instrumentation
20.
Trends Ecol Evol ; 7(7): 237-41, 1992 Jul.
Article in English | MEDLINE | ID: mdl-21236017

ABSTRACT

The male pregnancy of pipefishes and seahorses has led to the inference that females compete most intensely for access to mates, because males limit female reproduction. However, recent work has shown that in different species either sex may be the predominant competitor for mates. In this family, there is an apparent association between the mating pattern and the sex roles: polygamous species show reversed sex roles whereas monogamous species exhibit 'conventional' sex roles. These studies emphasize that sex role reversal is not synonymous with male parental care.

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