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1.
Genome Biol ; 17: 89, 2016 May 05.
Article in English | MEDLINE | ID: mdl-27150269

ABSTRACT

Dobrynin et al. (Genome Biol 16:277, 2015) recently published the complete genome of the cheetah (Acinonyx jubatus) and provided an exhaustive set of analyses supporting the famously low genetic variation in the species, known for several decades. Their genetic analyses represent state-of-the-art and we do not criticize them. However, their interpretation of the results is inconsistent with current knowledge of cheetah evolution. Dobrynin et al. suggest that the causes of the two inferred bottlenecks at ∼ 100,000 and 10,000 years ago were immigration by cheetahs from North America and end-Pleistocene megafauna extinction, respectively, but the first explanation is impossible and the second implausible.


Subject(s)
Acinonyx/genetics , Genome , Animals , Male
2.
Acta Neurol Scand ; 129(5): 307-18, 2014 May.
Article in English | MEDLINE | ID: mdl-24117192

ABSTRACT

OBJECTIVES: In Parkinson's disease (PD), Parkinson's disease dementia (PDD) and Parkinson's disease-mild cognitive impairment (PD-MCI) are common. PD-MCI is a risk factor for developing PDD. Knowledge of cognition in early-stages PD is essential in understanding and predicting the dementia process. MATERIALS AND METHODS: We describe the cognitive profile in early-stage PD patients with no prior clinical suspicion of cognitive impairment, depression or psychiatric disturbances, and investigate possible features distinguishing patients with cognitive deficits, defining a PD-MCI risk-profile. Single Photon Emission Computerized Tomography (SPECT) DaT-scan and neurological examination confirmed the diagnosis. Mini-mental state examination-, Addenbrooke's Cognitive Examination, Unified Parkinson's Disease Rating Scale scoring, Hoehn &Yahr/Activity of Daily Living staging and a neuropsychological test battery were applied. Mild cognitive impairment patients were identified according to modified criteria by Troster necessarily omitting subjective cognitive complaints. 80 patients, mean age 61.0 years (SD 6.6), mean duration of disease 3.4 years (SD 1.2) were included. 76 patients were neuropsychologically tested. RESULTS: 26 (34%) patients fulfilled modified PD-MCI criteria, 18 (69%) of these showed episodic memory deficits, 14 (54%) executive dysfunction, 13 (50%) language/praxis deficits, 12 (46%) visuospatial/constructional deficits and 9 (35%) attention/working memory deficits. Cognitive impairment was associated with higher Unified Parkinson's Disease Rating scale (UPDRS)-, bradykinesia- and rigidity scores and more symmetric distribution of symptoms, but not tremor scores. Patients with cognitive impairment were less educated. Other demographic and clinical variables were comparable. CONCLUSIONS: 34% of early-stage PD patients without prior clinical suspicion of cognitive impairment exhibit cognitive impairment, which is associated to disease severity, especially bradykinesia, rigidity, axial symptoms and less asymmetry of motor symptoms, even at early disease stages and when cognitive symptoms are mild.


Subject(s)
Cognition Disorders/etiology , Parkinson Disease/psychology , Cognition Disorders/epidemiology , Cognitive Dysfunction/epidemiology , Cognitive Dysfunction/etiology , Female , Humans , Hypokinesia/epidemiology , Hypokinesia/etiology , Male , Middle Aged , Muscle Rigidity/epidemiology , Muscle Rigidity/etiology , Neuropsychological Tests , Parkinson Disease/epidemiology , Severity of Illness Index
4.
Proc Biol Sci ; 280(1750): 20122244, 2013 Jan 07.
Article in English | MEDLINE | ID: mdl-23173207

ABSTRACT

A classic question in evolutionary biology concerns the tempo and mode of lineage evolution. Considered variously in relation to resource utilization, intrinsic constraints or hierarchic level, the question of how evolutionary change occurs in general has continued to draw the attention of the field for over a century and a half. Here we use the largest species-level phylogeny of Coenozoic fossil mammals (1031 species) ever assembled and their body size estimates, to show that body size and taxonomic diversification rates declined from the origin of placentals towards the present, and very probably correlate to each other. These findings suggest that morphological and taxic diversifications of mammals occurred hierarchically, with major shifts in body size coinciding with the birth of large clades, followed by taxonomic diversification within these newly formed clades. As the clades expanded, rates of taxonomic diversification proceeded independently of phenotypic evolution. Such a dynamic is consistent with the idea, central to the Modern Synthesis, that mammals radiated adaptively, with the filling of adaptive zones following the radiation.


Subject(s)
Biological Evolution , Body Size , Fossils , Mammals/anatomy & histology , Paleontology/methods , Animals , Mammals/genetics , Phenotype , Phylogeny , Regression Analysis
5.
Clin Neurophysiol ; 122(11): 2305-9, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21636319

ABSTRACT

OBJECTIVE: The significance of electromyography (EMG) guidance in botulinum toxin (BT) treatment has been much debated. The aim of this study was to evaluate if EMG guidance in the treatment of torticollis in BT-naive patients had a better outcome than treatment after clinical evaluation alone. METHODS: Twenty-six patients with torticollis were included and treated for 1 year in this prospective, blinded study. Quantitative EMG was performed simultaneously in the four most frequently affected muscles: the sternocleidomastoid muscles and the posterior neck muscles on both sides. EMGs were analysed for turns per second. Clinical ratings were performed by an experienced neurologist (A). Injections were given by another neurologist (B), who was blinded to the ratings. In group 1, the results of the EMG were available to the treating neurologist B, whereas in group 2, neurologist B was blinded. In group 1, treatment with BT was given when turns per second were higher than 100. RESULTS: In patients treated guided by EMG, clinical outcome, evaluated by objective ratings, was better than in patients treated based on clinical judgement alone (p = 0.05). In group 2, 105 muscles were treated with BT. Of these, 37 did not show dystonic EMG activity. CONCLUSIONS: Treatment with BT guided by EMG results in better clinical outcome than treatment without EMG and reduces the amount of BT used. SIGNIFICANCE: EMG guidance by interference pattern analysis may optimise BT treatment in torticollis by a more precise injection and may reduce side effects and the risk of development of antibodies to BT.


Subject(s)
Botulinum Toxins, Type A/therapeutic use , Electromyography/methods , Neuromuscular Agents/therapeutic use , Torticollis/drug therapy , Torticollis/physiopathology , Adult , Aged , Botulinum Toxins, Type A/administration & dosage , Evoked Potentials, Motor/drug effects , Evoked Potentials, Motor/physiology , Female , Humans , Injections, Intramuscular , Male , Middle Aged , Neck Muscles/drug effects , Neck Muscles/innervation , Neck Muscles/physiopathology , Neuromuscular Agents/administration & dosage , Prospective Studies , Single-Blind Method , Torticollis/diagnosis , Treatment Outcome
6.
Acta Neurol Scand ; 121(3): 198-203, 2010 Mar.
Article in English | MEDLINE | ID: mdl-19785640

ABSTRACT

BACKGROUND: The role of electromyography (EMG) recorded from the external anal sphincter (EAS) in the diagnosis of atypical parkinsonian syndromes is a matter for continuous debate. Most studies addressing this issue are retrospective. METHODS: In this study, we prospectively investigated six patients with Parkinson's Disease (IPD), 14 patients with multiple system atrophy (MSA) and eight with progressive supranuclear palsy (PSP) using EMG of the EAS, motor-evoked potential (MEP) to the EAS and EMG of m. gastrocnemius and nerve conduction velocity measured at the sural nerve. Patients were followed up for 2 years to secure correct diagnosis. RESULTS: The mean duration of motor unit potentials (MUPs) recorded from the EAS was significantly longer in patients with MSA and PSP compared with MUPs recorded from patients with PD (P < 0.005 for both). There were no signs of diffuse loss of motor neurons or peripheral neuropathy. MEP revealed signs of supranuclear affection in patients with MSA, whereas in patients with PSP the mechanism is a focal loss of motor neurons in Onuf's nucleus. CONCLUSION: Abnormal EMG of the EAS is strongly suggestive of atypical parkinsonism and the pathophysiology may be different in patients with MSA and PSP.


Subject(s)
Anal Canal/physiopathology , Electromyography/methods , Parkinsonian Disorders/diagnosis , Parkinsonian Disorders/physiopathology , Aged , Evoked Potentials/physiology , Female , Humans , Male , Middle Aged , Multiple System Atrophy/diagnosis , Multiple System Atrophy/physiopathology , Prospective Studies , Supranuclear Palsy, Progressive/diagnosis , Supranuclear Palsy, Progressive/physiopathology
7.
Eur J Neurol ; 14(6): 663-6, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17539946

ABSTRACT

Patients with hereditary spastic paraplegia (HSP) are often treated with antispastic drugs to relieve symptoms but documentation is lacking. In this study, gabapentin was tested in a double-blind crossover trial on a group of patients with HSP and linkage to the SPG4 locus. There was no difference between periods with gabapentin and placebo treatment in clinical assessment, self-reported parameters or paired transcranial magnetic stimulation evaluation of motor cortical excitability.


Subject(s)
Adenosine Triphosphatases/genetics , Amines/therapeutic use , Anticonvulsants/therapeutic use , Cyclohexanecarboxylic Acids/therapeutic use , Spastic Paraplegia, Hereditary/drug therapy , Spastic Paraplegia, Hereditary/genetics , gamma-Aminobutyric Acid/therapeutic use , Adult , Aged , Cross-Over Studies , Double-Blind Method , Female , Gabapentin , Humans , Male , Middle Aged , Spastin , Statistics, Nonparametric
8.
Eur J Nucl Med Mol Imaging ; 34(4): 508-16, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17096096

ABSTRACT

PURPOSE: Single-photon emission computed tomography (SPECT) with [123I]FP-CIT is a marker for loss of presynaptic dopamine transporters in the striatum in Parkinson's disease (PD). We used [123I]FP-CIT SPECT in order to evaluate binding to the dopamine transporter before and after neurosurgical treatment with bilateral stimulation in the subthalamic nucleus (STN). METHODS: Thirty-five patients with levodopa-responsive PD were examined with [123I]FP-CIT SPECT pre-operatively (baseline scan: mean 3 months before surgery), and 3 and 12 months after surgery. RESULTS: Pre-operatively, all patients already had substantial signs of severe nigrostriatal neuronal loss as determined from the [123I]FP-CIT SPECT scans. One year after surgery the specific [123I]FP-CIT binding to the striatum was significantly reduced by 10.3% compared with the pre-operative baseline scan. The mean time span from the baseline scan before surgery to the follow-up scan 1 year after surgery was 16.2 months. Hence, the rate of reduction equals a mean annual reduction of 7.7%. A comparable control group of patients with PD who did not undergo surgery was also examined longitudinally. In this group the specific binding of [123I]FP-CIT was reduced by 6.7% per year. CONCLUSION: The specific binding of [123I]FP-CIT was reduced equally in the STN-stimulated patients and a group of non-operated PD patients with advanced disease. Our study does not support the notion that electrode implantation and STN stimulation exert a neuroprotective effect by themselves.


Subject(s)
Corpus Striatum/metabolism , Deep Brain Stimulation , Dopamine Plasma Membrane Transport Proteins/metabolism , Parkinson Disease/metabolism , Parkinson Disease/therapy , Tropanes/pharmacokinetics , Adult , Aged , Corpus Striatum/diagnostic imaging , Female , Humans , Male , Middle Aged , Parkinson Disease/diagnostic imaging , Radionuclide Imaging , Radiopharmaceuticals/pharmacokinetics , Treatment Outcome
9.
Eur J Neurol ; 12(11): 842-50, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16241972

ABSTRACT

Patients with Parkinson's disease (PD) often have lower urinary tract symptoms (LUTS). Studies have indicated a correlation between dopaminergic degeneration and LUTS and presence of overactive bladder. We evaluated 18 patients with Parkinson's disease using single-photon emission computerized tomography (SPECT) imaging of the dopamine transporter with [(123)I]-FP-CIT, and bladder symptoms were assessed using questionnaires and full urodynamic evaluation both in medicated state and after cessation. Bladder symptoms correlated with age, stage and severity of disease but not with uptake of the ligand in the striatum. Patients with bladder symptoms had a significant lower uptake in the striatum compared with patients without LUTS. In patients with severe bladder dysfunction, LUTS correlated with putamen/caudate ratio. The specific binding of the ligand did not correlate with urodynamics parameters or any change in these after wash-out. Our findings suggest that the presence of LUTS is associated with the degeneration of the total number of nigrostriatal dopaminergic neurones, whilst the severity of bladder dysfunction is correlated with the relative degeneration of the caudate nucleus. The effects of medication on bladder control, as evaluated by urodynamics are believed to involve structures outside the basal ganglia.


Subject(s)
Corpus Striatum/metabolism , Parkinson Disease/metabolism , Urinary Bladder, Neurogenic/metabolism , Adult , Dopamine , Female , Humans , Male , Middle Aged , Parkinson Disease/complications , Parkinson Disease/physiopathology , Surveys and Questionnaires , Tomography, Emission-Computed, Single-Photon , Tropanes/metabolism , Urinary Bladder, Neurogenic/etiology , Urodynamics
10.
Eur J Nucl Med Mol Imaging ; 31(12): 1631-8, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15583914

ABSTRACT

PURPOSE: The aim of this study was to ascertain whether combined presynaptic and postsynaptic dopaminergic single-photon emission computed tomography (SPECT) scanning is useful for differentiation between patients with idiopathic Parkinson's disease (IPD), patients with multiple system atrophy of the striatonigral type (MSA) and healthy subjects. METHODS: SPECT measurements of the dopamine transporter (DAT) were done with 123I-beta-CIT, while for determination of the dopamine D2-like receptors (D2), 123I-epidepride was used. Clinical evaluation and SPECT scans were carried out in 14 patients with IPD, eight patients with MSA and 11 healthy age-matched control subjects. RESULTS: Putaminal DAT binding was reduced to 32% of control values in IPD and to 19% of control values in MSA . Significantly higher striatal asymmetry in DAT binding was found in MSA than in controls, but IPD patients had significantly higher asymmetry than MSA patients. Striatal D2 binding did not differ significantly between patients and healthy controls but the ratio between caudate DAT and D2 binding was significantly higher in patients with IPD than in those with MSA, even when disease severity was taken into account. CONCLUSION: Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference greater than 15% are likely to suffer from IPD. Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference of between 5% and 15% are more likely to have MSA. 123I-epidepride SPECT measurements may add further diagnostic information, since the ratio between DAT and D2 receptor binding is significantly higher in IPD than in MSA.


Subject(s)
Cocaine/analogs & derivatives , Membrane Glycoproteins/metabolism , Membrane Transport Proteins/metabolism , Multiple System Atrophy/diagnostic imaging , Multiple System Atrophy/metabolism , Nerve Tissue Proteins/metabolism , Parkinson Disease/diagnostic imaging , Parkinson Disease/metabolism , Receptors, Dopamine D2/metabolism , Tomography, Emission-Computed, Single-Photon/methods , Adult , Aged , Benzamides/pharmacokinetics , Brain/diagnostic imaging , Brain/metabolism , Cocaine/pharmacokinetics , Diagnosis, Differential , Dopamine Plasma Membrane Transport Proteins , Female , Humans , Iodine Radioisotopes/pharmacokinetics , Male , Middle Aged , Pyrrolidines/pharmacokinetics , Radiopharmaceuticals/pharmacokinetics , Reproducibility of Results , Sensitivity and Specificity
11.
Eur J Neurol ; 10(6): 695-9, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14641515

ABSTRACT

The aim of the study was the effect of injections with botulinum toxin A (BTX-A) on reduced jaw opening, caused by paradoxical, antagonistic activity of jaw elevator muscles after brain stem lesions. The study included a male (51 years) and a female (69 years) patient. Subjective assessment, clinical recordings, muscle blocks and electromyography (EMG) were used to diagnose paradoxical activity, and to plan, guide and evaluate the treatment. The paradoxical innervation pattern was unilateral in the male and bilateral in the female. The paradoxical activity during jaw opening amounted to 24-109% of the level during maximum biting, and bursts of paradoxical activity were also present during chewing. EMG-guided blocks and later BTX-A injections of the affected muscles increased the opening by 9-23 mm from pre-treatment values of 15-18 mm, and normalized chewing. The study proved BTX-A to be an effective treatment for reduced jaw opening caused by paradoxical activity. Treatment was optimized by EMG evaluation of the current activity of the jaw elevator muscles, permitting individual treatment plans with longer intervals between BTX-A injections and lower doses than with conventional treatment for oromandibular dystonia. Thus the treatment only had to be repeated one to two times per year to maintain acceptable jaw mobility.


Subject(s)
Botulinum Toxins, Type A/therapeutic use , Jaw Diseases/drug therapy , Masticatory Muscles , Neuromuscular Agents/therapeutic use , Aged , Electromyography , Female , Humans , Jaw Diseases/diagnosis , Jaw Diseases/physiopathology , Male , Masticatory Muscles/physiopathology , Middle Aged , Movement/physiology
12.
Neurology ; 60(9): 1536-9, 2003 May 13.
Article in English | MEDLINE | ID: mdl-12743249

ABSTRACT

Two families were referred with different clinical diagnoses of dystonia. Twenty-four family members were examined clinically, and mutation analyses were performed. Most of the affected individuals had laryngeal myoclonus and more severe dystonia of the legs than usually reported in myoclonus-dystonia syndrome. Sequence analyses revealed a previously unreported deletion (974delC or R325X) in exon 7 in the epsilon-sarcoglycan gene in members of both families. The two families were found to be related.


Subject(s)
Chromosomes, Human, Pair 14/genetics , Cytoskeletal Proteins/genetics , Dystonic Disorders/genetics , Membrane Glycoproteins/genetics , Myoclonus/genetics , Age of Onset , Child, Preschool , DNA Mutational Analysis , Exons/genetics , Female , Genes, Dominant , Humans , Infant , Male , Pedigree , Sarcoglycans , Sequence Deletion , Syndrome
14.
Ugeskr Laeger ; 163(38): 5161-7, 2001 Sep 17.
Article in Danish | MEDLINE | ID: mdl-11577518

ABSTRACT

Knowledge of the neurophysiology of bladder control is growing, as better diagnostic methods are developed and because clinical interest in the field is greater and treatments are better. It is problematic that the symptoms are very few and do not provide much information about the lesions in the nervous system. We describe the bladder symptoms in most neurological diseases, and the neurophysiology of normal voiding is described. A strategy for handling neurological bladder symptoms is outlined.


Subject(s)
Urinary Bladder, Neurogenic , Adult , Aged , Female , Humans , Male , Middle Aged , Quality of Life , Urinary Bladder, Neurogenic/diagnosis , Urinary Bladder, Neurogenic/etiology , Urinary Bladder, Neurogenic/physiopathology , Urinary Bladder, Neurogenic/therapy , Urination/physiology
16.
Ugeskr Laeger ; 162(38): 5066-70, 2000 Sep 18.
Article in Danish | MEDLINE | ID: mdl-11014135

ABSTRACT

Dystonia is a heterogeneous, neurological disease characterized by involuntary, sustained muscle contractions, frequently causing twisting and repetitive movements or abnormal postures. The patients are often difficult to diagnose, and the treatment is almost always only symptomatic. It is believed that about 75% of all patients with dystonia have primary dystonia, and 25-85% of these are hereditary. Seven gene loci for autosomal, dominant inherited dystonia and two for X-linked, recessive inherited dystonia are known at present, but the underlying genes are known only for DYT1 and DYT5. Testing is possible for these two in Denmark. Growing molecular genetic knowledge will lead to earlier and correct diagnosing, including prognosis, and may elucidate the pathogenesis, making better treatment possible.


Subject(s)
Dystonia/genetics , Dystonic Disorders/genetics , Adult , Child , Chromosome Mapping , Diagnosis, Differential , Dystonia/classification , Dystonia/diagnosis , Dystonia/therapy , Dystonic Disorders/classification , Dystonic Disorders/diagnosis , Dystonic Disorders/therapy , Female , Humans , Male , Prognosis
17.
Ugeskr Laeger ; 162(48): 6567-71, 2000 Nov 27.
Article in Danish | MEDLINE | ID: mdl-11187229

ABSTRACT

INTRODUCTION: Oromandibular dystonia (OMD) is a frequently disabling focal dystonia, which may be treated with injections of botulinum toxin in the affected muscles. The aim of the present study was to evaluate the population, effect and side-effects of patients treated in Denmark during a nine year period. METHODS: We evaluated all 45 consecutive patients treated with quantitative EMG guided injections of botulinum toxin for OMD. RESULTS: The OMD symptoms varied but were most often mixed symptoms (n = 13), jaw closing (n = 11) and jaw opening (n = 7). Thirty-two patients (71%) had other focal or generalised dystonia, and in 24 the additional dystonia were also treated with botulinum toxin. The 45 patients had a total of 277 treatments (mean 6.2 treatments pr. patient), each including one to six muscles. Marked effect was observed or experienced after 193 (70%) treatments, and 33 patients (73%) experienced at least one effective treatment. Side-effects occurred after 35 treatments (13%) experienced by a total of 16 patients (35.6%), most frequently as transient mild dysphagia. DISCUSSION: The study shows that botulinum toxin treatment of OMD, guided by quantitative EMG, is safe and effective.


Subject(s)
Botulinum Toxins/administration & dosage , Dystonic Disorders/drug therapy , Mandible , Adolescent , Adult , Aged , Botulinum Toxins/adverse effects , Dystonic Disorders/history , Female , History, 16th Century , Humans , Male , Medicine in the Arts , Middle Aged , Paintings/history , Retrospective Studies
18.
Clin Neurophysiol ; 110(9): 1650-4, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10479034

ABSTRACT

OBJECTIVE: To evaluate changes in quantitative EMG of injected and noninjected sternocleidomastoid muscles following long-term unilateral botulinum toxin treatment of cervical dystonia. METHODS: We investigated 27 patients with cervical dystonia, who received repeated unilateral botulinum toxin injections of the sternocleidomastoid muscle, with quantitative EMG at rest and at maximal voluntary contraction. The patients had on the average 7.1 botulinum toxin treatments and the follow-up period was on the average 31 months (SD 16). RESULTS: After the first treatment, the injected sternocleidomastoid muscles showed a significant decrease in turns/s (mean 45%) and amplitude (mean 52%) at rest, and in amplitude at maximal flexion (mean 24%) and rotation (mean 39%). Except for a reduction in turns/s at rotation (mean 19%) no further reductions in EMG parameters were seen after long-term treatment. The contralateral noninjected sternocleidomastoid muscles showed no significant change in EMG activity after the first BT treatment, but after long-term treatment a significant reduction in turns/s and amplitude at both maximal flexion (turns: mean 28%; amplitude: mean 25%) and rotation (turns/s: mean 32%; amplitude: mean 25%) were seen as compared to pretreatment values. CONCLUSION: The results indicate that there seems to be no cumulative chemodenervation by repeated botulinum toxin injections of sternocleidomastoid muscles measured by quantitative EMG. Contralateral noninjected sternocleidomastoid muscles however, seem to be affected following long-term treatment. The mechanism behind this finding is unknown.


Subject(s)
Botulinum Toxins, Type A/therapeutic use , Dystonia/drug therapy , Dystonia/physiopathology , Neck Muscles/drug effects , Neck Muscles/physiopathology , Adolescent , Adult , Aged , Child , Electromyography , Humans , Middle Aged , Retrospective Studies
19.
J Theor Biol ; 196(1): 61-72, 1999 Jan 07.
Article in English | MEDLINE | ID: mdl-9892556

ABSTRACT

The adaptive significance of the scrotum and the evolution of the descent of the testicles and epididymis have been a focus of interest among biologists for a long time. In this paper we use three anatomical character states of the scrotum and descensus: (1) testicles descended and scrotal; (2) testicles descended but ascrotal; (3) testicles not descended (testicondy). These states are then mapped on an up to date phylogeny of the Mammalia. Three main points arise out of this mapping procedure: (1) the presence of a scrotum is either primitive in extant Mammalia or primitive within eutherian mammals except Insectivora; (2) evolution has generally proceeded from a scrotal condition to progressively more ascrotal; (3) loss of testicular descensus is less common in mammalian evolution than is loss of the scrotum. In the light of these findings we discuss some current hypotheses regarding the origin and evolution of the scrotum. We find that these are all incomplete in so far as it is not the presence of the scrotum in various mammal groups that requires explaining. Instead, it is the reverse process, why the scrotum has been lost in so many groups, that should be explained. We suggest that the scrotum may have evolved before the origin of mammals, in concert with the evolution of endothermy in the mammalian lineage, and that the scrotum has been lost in many groups because descensus in many respects is a costly process that will be lost in mammal lineages as soon as an alternative solution to the problem of the temperature sensitivity of spermatogenesis is available.


Subject(s)
Biological Evolution , Body Temperature Regulation/physiology , Mammals/physiology , Scrotum/physiology , Testis/embryology , Animals , Epididymis/embryology , Male , Phylogeny
20.
Ugeskr Laeger ; 160(43): 6211-5, 1998 Oct 19.
Article in Danish | MEDLINE | ID: mdl-9803871

ABSTRACT

The acute symptoms after whiplash trauma can be explained by the neck sprain, but the pathogenesis of the "late whiplash syndrome" and the reasons why only some people have persistent symptoms more than six months are still unknown. Thirty-four consecutive cases of piskesmaeld injury were examined clinically three times; respectively within 14 days, after one month and finally seven months post-injury. In addition, MRI of the brain and the cervical spine, neuropsychological tests and motor evoked potentials (MEP) were done one month post-injury and repeated after six months, if abnormalities were found. We found the total recovery rate (asymptomatic patients) was 29% after seven months. All MEP examinations were normal. The correlation between MRI and the clinical findings was poor. Cognitive dysfunction as a symptom of brain injury was not found. Stress at the same time as the accident predicted more symptoms at follow-up. We conclude that long-lasting distress and poor outcome were more related to the occurrence of stressful life events than to clinical and paraclinical findings.


Subject(s)
Whiplash Injuries , Adolescent , Adult , Aged , Evoked Potentials, Motor , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neurologic Examination , Neuropsychological Tests , Prospective Studies , Stress, Psychological , Syndrome , Whiplash Injuries/diagnosis , Whiplash Injuries/physiopathology , Whiplash Injuries/psychology
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