Evidence of iteroparity in the widely distributed diadromous fish inanga Galaxias maculatus and potential implications for reproductive output.

Gaps in understanding variability among populations of inanga Galaxias maculatus in the timing of reproduction were addressed in southern New Zealand (NZ), where G. maculatus constitutes a declining fishery. Reproductive activity was delayed by 1 month on the west coast compared with the east coast and the west coast spawning season was prolonged into winter. The evidence for post-spawning survival of some fish was unequivocal from histological studies. These older and larger fish contributed disproportionately to egg production. Estimates of fecundity were considerably lower than those previously calculated for NZ populations. The importance of quality habitats being available during critical life history periods are highlighted. It was apparent that some streams supported fish that were larger and in better condition and that this translated into greatly increased fecundity. Future research should focus on whether this is a legacy of these fish experiencing better pre-settlement marine habitat as larvae, or higher quality instream habitat enhancing the growth and development of adults.

Parental environment changes the dormancy state and karrikinolide response of Brassica tournefortii seeds.

BACKGROUND AND AIMS: The smoke-derived chemical karrikinolide (KAR(1)) shows potential as a tool to synchronize the germination of seeds for weed management and restoration. To assess its feasibility we need to understand why seeds from different populations of a species exhibit distinct responses to KAR(1). Environmental conditions during seed development, known as the parental environment, influence seed dormancy so we predicted that parental environment would also drive the KAR(1)-responses of seeds. Specifically, we hypothesized that (a) a common environment will unify the KAR(1)-responses of different populations, (b) a single population grown under different environmental conditions will exhibit different KAR(1)-responses, and (c) drought stress, as a particular feature of the parental environment, will make seeds less dormant and more responsive to KAR(1). METHODS: Seeds of the weed Brassica tournefortii were collected from four locations in Western Australia and were sown in common gardens at two field sites, to test whether their KAR(1)-responses could be unified by a common environment. To test the effects of drought on KAR(1)-response, plants were grown in a glasshouse and subjected to water stress. For each trial, the germination responses of the next generation of seeds were assessed. KEY RESULTS: The KAR(1)-responses of seeds differed among populations, but this variation was reduced when seeds developed in a common environment. The KAR(1)-responses of each population changed when seeds developed in different environments. Different parental environments affected germination responses of the populations differently, showing that parental environment interacts with genetics to determine KAR(1)-responses. Seeds from droughted plants were 5 % more responsive to KAR(1) and 5 % less dormant than seeds from well-watered plants, but KAR(1)-responses and dormancy state were not intrinsically linked in all experiments. CONCLUSIONS: The parental environment in which seeds develop is one of the key drivers of the KAR(1)-responses of seeds.

Familial Alzheimer's disease and inherited prion disease in the UK are poorly ascertained.

AIMS: To ascertain the frequency and geographical distribution of patients diagnosed with known genetic causes of Alzheimer's disease (AD) and inherited prion disease (IPD) in the UK 2001-2005. By comparison with frequencies predicted from published population studies, to estimate the proportion of patients with these conditions who are being accurately diagnosed. METHODS: All the positive diagnostic test results (from both genetic testing centres) were identified for mutations in presenilin-1 (PSEN1), presenilin-2 (PSEN2), amyloid precursor protein (APP) and prion protein genes (PRNP) for patients resident in the UK in a 5 year period. The variation in the incidence of mutation detection between UK regions was assessed with census population data. Published studies of the genetic epidemiology of familial early onset AD (EOAD) were reviewed to produce estimates of the number of patients in the UK that should be detected. RESULTS: The rate of detection of EOAD and IPD varied very significantly and consistently between regions of the UK with low rates of detection in Northern and Western Britain (72% less detection in these regions compared with Central and Southeast Britain). The estimates from population studies further suggest a greater number of patients with EOAD than are diagnosed by genetic testing throughout the UK. CONCLUSIONS: It is likely that patients with EOAD and IPD are not being recognised and referred for testing. With the prospect of meaningful disease modifying therapeutics for these diseases, this study highlights an issue of relevance to neurologists and those planning for provision of National Health Services.

Optimising seed processing techniques to improve germination and sowability of native grasses for ecological restoration.

Grasslands across the globe are undergoing expansive degradation due to human impacts and climate change. If restoration of degraded native grassland is to be achieved at the scale now required, cost-effective means for seed-based establishment of grass species is crucial. However, grass seeds present numerous challenges associated with handling and germination performance that must be overcome to improve the efficiency of seeding. Previous research has demonstrated that complete removal of the palea and lemma (husk) maximises germination performance, hence we investigated the effects of complete husk removal on seed handling and germination of four temperate Australian grass species. Three techniques were tested to remove the husk - manual cleaning, flaming or acid digestion (the latter two followed by a manual cleaning step); these techniques were refined and adapted to the selected species, and germination responses were compared. The complete removal of the husk improved seed handling and sowability for all species. Germination was improved in Microlaena stipoides by 19% and in Rytidosperma geniculatum by 11%. Of the husk removal methods tested, flaming was detrimental to seed germination and fatal for one species (R. geniculatum). Compared to manual cleaning, sulphuric acid improved the overall efficacy of the cleaning procedure and increased germination speed (T50) in Austrostipa scabra, Chloris truncata and M. stipoides, and improved final germination in R. geniculatum by 13%. The seed processing methods developed and tested in the present study can be applied to grass species that present similar handling and germination performance impediments. These and other technological developments (seed coating and precision sowing) will facilitate more efficient grassland restoration at large scale.

Reduction of odor and nasal pungency associated with aging.

Aging can seriously blunt suprathreshold sensations mediated by the olfactory receptor system and by common chemical receptors. Despite large individual differences, on the average any given stimulus seemed only about half as intense to the elderly (20 subjects, 65-83 yrs) as to the young (20 subjects, 18-25 yrs). The nature of the loss was a constant percentage reduction of perceived magnitude at stimulus levels from weak to strong. The stimuli were iso-amyl butyrate (a nonirritating fruity odor) and CO2 (which is practically odorless but triggers common chemical sensations effectively). The method used was magnitude matching, by which subjects made numerical estimates of the perceived magnitude of various levels of the two chemical stimuli and of the loudness of low-pitched noises. The loudness estimates served to adjust each subject's chemical estimates to help compensate for individual idiosyncrasies in the use of numbers and potential biases associated with age. Common chemical and olfactory losses seem to be unrelated; aging can dull one sense and leave the other acute.

Glossopharyngeal (vagoglossopharyngeal) neuralgia: a study of 217 cases.

In 217 cases of glossopharyngeal neuralgia seen at the Mayo Clinic between 1922 and 1977, the disease was more common in patients older than 50 years (57%), but also occurred in 43% who were between 18 and 50. Spontaneous remissions were noted by 161 patients, but 37 had no periods of pain relief. Syncope was rarely a problem. Involvement was bilateral in 12%. The combination of glossopharyngeal and trigeminal neuralgia was found in 25 patients. Positive results on the cocaine test in 112 of 125 patients aided in diagnosis. Carbamazepine is the favored medication. Early surgical experience consisted of extracranial avulsion of the glossopharyngeal nerve or intracranial section at the jugular foramen; since 1948, surgical treatment has included section of the glossopharyngeal nerve and usually the upper rootlets of the vagus nerve and additional section of the fifth cranial nerve when trigeminal neuralgia was associated. Good relief of pain was obtained surgically in 110 patients.

Familial spastic paraplegia, mental retardation, and precocious puberty.

Two brothers had progressive spastic paraplegia and precocious puberty develop due to Leydig's cell hyperplasia when they were 2 years old. Both later had moderate mental retardation. Family members displayed brisk lower-extremity reflexes and dysarthria in a pedigree that suggested autosomal dominant inheritance with variable expression. Precocious puberty has been associated with other neurologic syndromes. Its occurrence in two brothers with spastic paraplegia has not, to our knowledge, been previously reported.

Brain-stem auditory evoked potential abnormalities with unilateral brain-stem lesions demonstrated by magnetic resonance imaging.

We correlated the brain-stem auditory evoked potential (BAEP) abnormalities in 24 patients with discrete unilateral brain-stem lesions demonstrated by magnetic resonance imaging. In 18 patients who had BAEP abnormalities either confined to or more severe on stimulation of one ear, the lesion on magnetic resonance imaging was in the brain stem ipsilateral to the corresponding ear. Mesencephalic lesions produced amplitude abnormalities of the IV/V complex while pontine lesions resulted in abnormalities of earlier components (wave II and/or III). Prolongation of the I-III interpeak latency tended to occur with pontine lesions and of the III-V interpeak latency with mesencephalic lesions. Unilateral brain-stem lesions, particularly at the mesencephalic level, often produced BAEP abnormalities on both ipsilateral and contralateral monaural stimulation.

Magnetic resonance imaging. Clinical correlation in 64 patients with multiple sclerosis.

Sixty-four patients with possible, probable, or definite multiple sclerosis (McAlpine criteria) were clinically evaluated using the expanded disability status scale (EDSS) and Scripps neurologic rating scale (NRS). All were examined with a 0.15T magnetic resonance scanner using T2- and T1-weighted images. Correlations between EDSS and NRS scores and severity of disease detected on magnetic resonance imaging were determined. Significant correlations existed between EDSS and NRS with magnetic resonance ratings. Moderate correlations were observed in the motor, cerebellar, and brainstem subgroups of the clinical scales. Significant low correlations existed in the mood/mentation, vision (optic nerves), and bowel/bladder subgroups. Clinical and neuroimaging limitations may account for the lack of higher correlations. Significant correlations suggest the utility of magnetic resonance imaging in monitoring disease progression, and it may prove to be the technique of choice in following up patients with multiple sclerosis.

Clinical vs quantitative evaluation of cutaneous sensation.

A comparison of the evaluation of cutaneous sensation by neurologic examination and by quantitative assessment in 107 patients with various neuromuscular disease has shown that there is a reasonably good correlation between the recognition of abnormalities of cutaneous sensation by clinical and by quantitative methods. Clinical neurologists tend to underestimate abnormalities of touch-pressure sensation. The quantitative evaluation of cutaneous sensation is useful in quality control of the clinical examination, in correlating the nature of sensation loss with the compound action potential and morphometry of biopsied nerve, in providing a score of sensation to follow the course and the effect of treatment protocols, and in monitoring for an adverse effect on sensation by an environmental or industrial poison. There is a good correlation between abnormality of touch-pressure sensation and loss of large myelinated fibers of sural nerve in neuropathy.

Lumbosacral plexus neuropathy.

We describe 10 cases of lumbosacral plexus neuropathy in which no underlying condition was discovered on initial evaluation or on follow-up examination after an average of 6 years. The patients presented with pain and weakness. Recovery was delayed and often incomplete. When the lower plexus is involved, it may be confused with disk disease manifesting as "sciatica." This syndrome may be a counterpart to the well-described idiopathic brachial plexus neuropathy.

Trigeminal sensory neuropathy associated with connective tissue diseases.

We reviewed the clinical and laboratory features of 81 patients who had trigeminal sensory neuropathy (TSN) and a connective tissue disease (CTD). The neuropathy developed before the symptoms of CTD in 6/81 patients (7%), and in 38/81 patients (47%) TSN and CTD were diagnosed concurrently. The most frequently associated CTDs were undifferentiated connective tissue disease (38/81, 47%), mixed connective tissue disease (21/81, 26%), and scleroderma (15/81, 19%). Of 66 patients followed for more than 1 year (median, 5 years; range, 1 to 26 years), 8/66 patients (12%) had mild improvement and 2/66 (3%) had marked improvement of numbness; no patient had complete return of sensation. The facial numbness was frequently associated with moderate to severe facial pain that was usually resistant to pharmacologic therapy. None of the patients developed clinical or laboratory evidence of systemic vasculitis. The etiology of this cranial sensory neuropathy remains obscure.

Seronegativity for type 1 antineuronal nuclear antibodies ('anti-Hu') in subacute sensory neuronopathy patients without cancer.

We followed 21 patients with sensory neuronopathy without evidence of cancer for up to 23 years. All were seronegative for type 1 antineuronal nuclear antibodies (ANNA-1, also called "anti-Hu"). We additionally studied 67 seropositive patients with sensory neuropathy or a related neurologic syndrome. Ninety-one percent of the seropositive patients had a small-cell lung carcinoma. One, with a normal chest x-ray, had been followed for 7 years for sensory neuronopathy of indeterminate cause before serologic testing for ANNA-1 led to the discovery of the tumor by CT. We conclude that ANNA-1 seropositivity in a patient with sensory neuronopathy is strong evidence for an underlying small-cell lung cancer.

The frequency of carpal tunnel syndrome in computer users at a medical facility.

A survey was done of employees who were identified as frequent computer users. Although 29.6% of the employees reported hand paresthesias, only 27 employees (10.5%) met clinical criteria for carpal tunnel syndrome, and in 9 (3.5%) the syndrome was confirmed by nerve conduction studies. Affected and unaffected employees had similar occupations, years using a computer, and time using the computer during the day. The frequency of carpal tunnel syndrome in computer users is similar to that in the general population.

Carpal tunnel syndrome in Rochester, Minnesota, 1961 to 1980.

The incidence of carpal tunnel syndrome in the population of Rochester, Minnesota, from 1961 through 1980 was determined by use of the medical records-linkage system of the Rochester Epidemiology Program Project at the Mayo Clinic; 1,016 patients (1,600 affected hands) were identified. Incidence (cases per 100,000 person-years) was 99 (crude) overall, whereas the age-adjusted rates were 52 for the men, 149 for the women, and 105 for both sexes combined. Age-adjusted incidence rates increased from 88 during the 1961 to 1965 quinquennium to 125 during the 1976 to 1980 quinquennium; these rates probably reflect better recognition rather than a true increase in incidence rates. Age-specific rates generally increased with age in men, whereas in women a peak was reached in the 45 to 54 age group.

Frequency of nerve fiber degeneration of peripheral motor and sensory neurons in amyotrophic lateral sclerosis. Morphometry of deep and superficial peroneal nerves.

Among 10 patients with amyotrophic lateral sclerosis who had combined biopsy of muscle and cutaneous nerves, two had a history of paresthesia that suggested involvement of peripheral afferent neurons. Of four patients without paresthesia, two had unequivocal abnormalities of touch-pressure sensation of the toe. On morphometric evaluations of lateral fascicles of deep peroneal nerve, one nerve had an abnormally low myelinated fiber density and seven of 10 had abnormally high frequencies of teased-fiber abnormalities. Teased fibers in which myelin was degenerating into linear rows of myelin ovoids and balls occurred in 10.5 percent of fibers in amyotrophic lateral sclerosis nerves as compared with 1.7 percent in control nerves (0.01 less than p less than 0.025). Estimates of density of myelinated fibers were less sensitive than estimates of the frequency of various changes in teased fibers for detecting abnormality.

Magnetic resonance imaging in multiple sclerosis: analysis of correlations to peripheral blood and spinal fluid abnormalities.

MRI of the brain, peripheral blood (PB) T cell subsets and B cells, CSF T cell subsets, CSF IgG concentration and incidence of CSF oligoclonal bands (OB), and plasma cells were studied in 32 clinically suspected MS patients. The CSF in MS patients with MRI lesions showed increased IgG concentration and higher incidence of plasma cells and OB compared with those without MRI lesions. In PB, the percentage of kappa light-chain positive B cells was significantly increased in patients with abnormal MRI as compared with controls. The correlation of MRI of the head and immunologic studies in MS will be helpful in better understanding the pathogenesis and dynamics of the disease.

Peripheral neuropathy in primary Sjögren's syndrome.

Sjögren's syndrome (dryness of eyes, mouth, and other mucous membranes) may be associated with disease of joints, blood, internal organs, skin, and central and peripheral nervous systems. We reviewed 33 cases of primary Sjögren's syndrome and peripheral neuropathy evaluated by neurologic examinations and EMG at the Mayo Clinic from 1976 to 1988, and studied sural nerve biopsy specimens in 11 of them. Symmetric sensorimotor polyneuropathy occurred most frequently, followed by symmetric sensory neuropathy. Autonomic neuropathy, mononeuropathy, or cranial neuropathy (especially trigeminal neuropathy) was superimposed on generalized neuropathy in approximately one-fourth of patients. The course generally was slowly progressive, except for a few patients who may have improved with prednisone therapy. Although spinal ganglion involvement might have accounted for some of the clinical and neurophysiologic findings, we found evidence that necrotizing vasculitis was involved in fiber degeneration. All nerve biopsies revealed perivascular inflammatory infiltrates and other vessel abnormalities, which were diagnostic in two cases and strongly suggestive of necrotizing vasculitis in six cases. Axonal degeneration predominated over demyelination and sometimes was focal or multifocal. In neuropathy of unknown cause, particularly if it is sensory, autonomic, or involves trigeminal nerve, consider Sjögren's syndrome.

Post-lumbar puncture headaches: experience in 501 consecutive procedures.

To ascertain the frequency and risk factors for post-lumbar puncture headache, we studied all adults who had an ambulatory lumbar puncture (LP) in a 1-year period. Patients filled out a questionnaire detailing their headache experience on the day of, and the 6 days following, LP. Those who did not return the questionnaire were telephoned. We systematically collected and analyzed many items, including the lumbar puncturist's experience, the degree of difficulty of the LP, CSF findings, final diagnosis, and the patient's demographic characteristics. Patients reporting headache before LP were more likely to report post-LP headaches. In addition to this, younger female patients with a lower body mass index have the highest risk of developing post-LP headaches. CSF opening pressure, cells, and protein, patient's position during LP, the duration of recumbency following LP, and the amount of CSF removed at the time of LP did not influence the occurrence of headache.