Associations of stream geomorphic conditions and prevalence of alternative reproductive tactics among sockeye salmon populations.

In many species, males may exhibit alternative life histories to circumvent the costs of intrasexual competition and female courtship. While the evolution and underlying genetic and physiological mechanisms behind alternative reproductive tactics are well studied, there has been less consideration of the ecological factors that regulate their prevalence. Here, we examine six decades of age composition records from thirty-six populations of sockeye salmon (Oncorhynchus nerka) to quantify associations between spawning habitat characteristics and the prevalence of precocious sneakers known as 'jacks'. Jack prevalence was independent of neutral genetic structure among stream populations, but varied among habitat types and as a function of continuous geomorphic characteristics. Jacks were more common in streams relative to beaches and rivers, and their prevalence was negatively associated with stream width, depth, elevation, slope and area, but positively related to bank cover. Behavioural observations showed that jacks made greater use of banks, wood and shallows than guard males, indicating that their reproductive success depends on the availability of such refuges. Our results emphasize the role of the physical habitat in shaping reproductive tactic frequencies among populations, likely through local adaptation in response to variable fitness expectations under different geomorphic conditions.

VLS (Vapor-Liquid-Solid): Newly Discovered Growth Mechanism on the Lunar Surface?

A probable vapor-liquid-solid (VLS) type of growth has been discovered for the first time in nature on the surface of lunar rock 15015. Scanning electron microprobe and energy dispersive x-ray data indicate that the growth occurs as metallic iron stalks from about 0.015 to 0.15 micrometer in diameter, with bulbous tips consisting of a mixture of iron and sulfur and measuring from about 0.03 to 0.2 micrometer in diameter. The stalk length is two to ten times the bulb diameter.

Mineralogy, petrology, and surface features of lunar samples 10062,35, 10067,9, 10069,30, and 10085,16.

The primary rocks are a sequence of titanium-rich basic volcanics, composed of clinopyroxene, plagioclase, and ilmenite with minor olivine, troilite, and native iron. The soil and microbreccias are respectively loose and compacted mixtures of fragments and aggregates of similar rocks, minerals, and glassy fragments and spheres. Impact events are reflected by the presence of shock metamorphosed rock fragments, breccias, and glasses and their resulting compaction to form complex breccias, glass-spattered surfaces, and numerous glass-lined craters. Chemistry of the glasses formed by the impact events is highly variable, and the high iron and nickel content of a few moundlike features suggests that at least some of the projectiles are iron and nickel-rich meteorites.

Lunar metallic particle ("mini-moon"): an interpretation.

A troilite-rich nickel-iron particle ("mini-moon") recovered from the moon may be a mound detached from a sphere of silicate glass. Erosion and pitting of the particle may have been caused by passage through a cloud of hot gas and particulate matter formed by meteorite impact on the lunar surface. This explanation is in contrast to the theory that the particle was meteoritically derived molten material that was furrowed during solidification after lunar impact, subsequently pitted by high-velocity particles, and then abraded and polished by drifting dust while on the lunar surface.

Autonomic symptom burden is associated with MS-related fatigue and quality of life.

BACKGROUND: Nonspecific symptoms such as fatigue and dizziness are common in multiple sclerosis (MS), even in patients with normal exams. Little is known about the relationship of autonomic dysfunction with these symptoms and quality of life. OBJECTIVE: Assess the association of autonomic symptom burden with fatigue, clinical status and quality of life. METHODS: Subjects completed an autonomic symptom (COMPASS-31), quality of life (MSQOL-54) and fatigue (FSS) questionnaire at their routine MS clinic follow-up. Demographic and clinical data were collected from the medical record. Pearson correlations were assessed between autonomic symptoms and fatigue, quality of life, disability and disease duration. RESULTS: One-hundred subjects completed the study (mean age 48 years; 78% female; 84% relapsing-remitting), mean disease duration was 14.7 years and mean EDSS 2.5. MSQOL-54 composite scores were 58 physical and 65 mental. COMPASS-31 correlated with MSQOL-54 (Physical R= -0.60; Mental -0.54; p<0.001) and FSS (R=0.51; p<0.001). There was no relationship between COMPASS-31 and EDSS (R=0, p=0.97) or disease duration (R= -0.02, p=0.84). CONCLUSIONS: Autonomic symptom burden is correlated with decreased quality of life and increased fatigue. Autonomic symptoms are present early in the disease and at low disability and may reflect aspects of disease burden that are not well-captured by current disability measures.

Tizanidine treatment of spasticity caused by multiple sclerosis: results of a double-blind, placebo-controlled trial. US Tizanidine Study Group.

This multicenter, stratified, randomized, placebo-controlled, double-blind trial evaluated tizanidine for use in the United States for spasticity secondary to MS. The 15-week trial was divided into baseline (weeks 0 and 1), titration (2 mg to a maximum of 36 mg/d; weeks 2 to 4), and plateau (weeks 5 to 13) phases, followed by dose tapering (week 14) and a final visit (week 15). Primary efficacy parameters were scores on muscle tone (Ashworth Scale) and type and frequency of muscle spasms (patient diaries). All efficacy parameters were evaluated by the physician/assessor, and the physician/prescriber was responsible for all dosage adjustments. The patient, physician/assessor, and physician/prescriber made global evaluations of antispastic efficacy. Tizanidine produced a significantly greater reduction than placebo in spasms and clonus (patient diaries) but no significant differences in Ashworth scores. Patients and physician/prescribers, but not physician/assessors, gave significantly better scores in the overall assessment of efficacy and tolerability. No significant differences in other secondary efficacy parameters were noted. Adverse events were reported for 66 (61%) of the 109 placebo-treated patients and 101 (91%) of the 111 tizanidine-treated patients; 6 (6%) and 14 (13%) discontinued treatment, respectively. Patient and physician perception of improvement demonstrated more consistent differences between groups than did the Ashworth Scale, perhaps because of inexperience with this measure or failure to consider time between drug administration and assessment.

Immunosuppression with high-dose i.v. cyclophosphamide and ACTH in progressive multiple sclerosis: cumulative 6-year experience in 164 patients.

One hundred sixty-four patients with chronic progressive multiple sclerosis (MS) have been treated with a regimen of high-dose IV cyclophosphamide and ACTH over the past 6 years. Their status was reviewed to determine complications associated with treatment, dosage of medication used to induce a remission, factors which may predict a response to therapy, and subsequent course following treatment. One year following initial treatment, 81% of patients were improved or stabilized. Reprogression occurred in 69% of patients at a mean time of 17.6 months. Fifty-eight patients who initially stabilized after treatment and then reprogressed were treated a second time. One year after retreatment, 70% of these patients were improved or stabilized. Alopecia, nausea and vomiting, and minor infections were the most frequent complications. There were no deaths associated with treatment, the complication rate did not change with multiple treatments, and no late complications have yet been observed. Improvement tended to occur in younger patients with shorter disease duration. Although this treatment regimen is generally well tolerated and can favorably affect the course of chronic progressive MS in a majority of patients, a single treatment does not induce a permanent remission, and some form of maintenance treatment or retreatment is required. Current treatment programs involve testing a modified induction regimen and periodic outpatient booster injections to maintain remission.

Therapy of relapsing multiple sclerosis. Treatment approaches for nonresponders.

There is increasing impetus to begin disease-modifying therapy for relapsing multiple (R-MS) early, before the development of irreversible tissue damage and resultant permanent disability. However, all of the currently-approved therapies for relapsing multiple sclerosis are only partially effective for patients as a group. Treatment failure can be due to noncompliance with therapy, intolerable adverse effects, the development of neutralizing antibodies, or non-responsive disease. Neurologists managing patients on disease-modifying therapy for R-MS must remain vigilant for these issues and take appropriate action when necessary.

Immunosuppressive treatment of multiple sclerosis.

Multiple sclerosis is thought, by many investigators, to be an immunologic disease. Therefore, a rationale exists for treating this disease by immunosuppressive therapy. In exacerbating-remitting multiple sclerosis, corticosteroids and adrenocorticotropic hormone are the most widely used drugs; high doses of intravenously administered methylprednisolone have recently gained favor. Chronic progressive multiple sclerosis has been treated with a number of immunosuppressive regimens, several of which have shown promise to date. Cyclophosphamide and azathioprine have been used most often and are reviewed in this report, as are other agents currently under investigation. No firm guidelines for the treatment of chronic progressive multiple sclerosis can be offered, but an approach to immunosuppressive therapy is suggested in this review.

Rational clinical immunotherapy for multiple sclerosis.

In this article, we assess the roles and the efficacy of immunopharmacologic agents in the treatment of multiple sclerosis (MS) and other demyelinating disease syndromes. The initial clinical manifestations of demyelinating disease, immunotherapeutic goals, efficacy of individual agents, and specific immunopharmacologic recommendations are discussed. MS and other idiopathic demyelinating disease syndromes can be effectively managed with immunotherapy. Exacerbations are treatable, and the frequency and severity of exacerbations can be reduced. Although some agents have a minor effect on progression of disability, current approaches have not proved to have a major influence on treatment of progressive MS. Immunotherapy for inflammatory demyelinating disease necessitates a high degree of clinical certainty about the diagnosis. Because all available therapeutic agents have limitations and significant toxic effects, careful consideration is necessary before use. Treatment should be individualized on the basis of the clinical course of the disease and the degree of patient disability.

Management of impairment, disability, and handicap due to multiple sclerosis.

In this article, we update management measures for patients with multiple sclerosis (MS) that can improve or prevent impairment, disability, and handicap and include those factors that a primary-care physician can implement or facilitate. The medical literature since 1989 was reviewed. Although new drug trials hold promise to decrease impairment from MS, well-coordinated interdisciplinary care to minimize disability and handicap most profoundly affect the quality of life for patients with MS. MS is usually not severely disabling, and appropriately timed intervention can prevent secondary impairment and reduce disability and handicap. Pharmacologic, physical, and psychosocial issues--ranging from spasticity, pain, weakness, and tremor to neurogenic bowel management and sexuality--are addressed. General wellness measures remain important. The influence of the Americans With Disabilities Act is discussed, and specific adaptive equipment and social resources are outlined. The ultimate goals of management of patients with MS are functional independence and efficient use of medical and community resources: a focus on "ability" rather than "disability." Although impairment can limit function, wellness and adjustment have no boundaries.

VMN hypothalamic dopamine and serotonin in anorectic septic rats.

During sepsis, catabolism of proteins and associated changes in plasma amino acids occur. Tryptophan and tyrosine, and their derivatives serotonin (5-HT) and dopamine (DA), influence hypothalamic feeding-related areas and are associated with the onset of anorexia. We hypothesized that anorexia of sepsis is associated with changes in serotonin and dopamine in the ventromedial nucleus (VMN) of the hypothalamus. The aim of this study was to test our hypothesis by measuring intra-VMN changes of these two neurotransmitters at the onset of anorexia during sepsis. Fischer 344 male rats had an intracerebral guide cannula stereotaxically implanted into the VMN. Ten days later, in awake, overnight-food-deprived rats, a microdialysis probe was inserted through the in situ VMN cannula. Two hours thereafter, serial baseline serotonin and dopamine concentrations were measured. Then cecal ligation and puncture to induce sepsis or a control laparotomy was performed under isoflurane anesthesia. VMN microdialysis samples were serially collected every 30 min for 8 h after the surgical procedure to determine 5-HT and DA changes in response to sepsis. During the hypermetabolic response to sepsis, a strong association occurred between anorexia and a significant reduction of VMN dopamine concentration (P < 0.05; constant rate of dopamine decrease in the Study group of 0.99 pg per 2 h); no changes occurred in 5-HT in association with anorexia of sepsis. Six hours after operation, a single meal was offered for 20 min to assess the response of neurotransmitters to food ingestion. Food intake was minimal in anorectic septic rats (mean size of the after food-deprived meal in the Septic group was 0.03+/-0.01 g, that of the Control group was 1.27+/-0.14 g; P = 0.0001), while Control rats demonstrated anticipated changes in neurotransmitters in response to eating. We conclude that the onset of anorexia in septic rats is associated with a reduction in VMN dopamine.

Blunted ACTH response to hypoglycemic stress in depressed patients but not in patients with schizophrenia.

In this study, 7 hospitalized patients with major depression (MD), 5 hospitalized patients with schizophrenia (S), and 13 control subjects (C) were administered 0.15 units/kg of regular insulin at 1600 h by intravenous bolus infusion. ACTH, cortisol, and glucose levels were measured intermittently for 2h following infusion. Baseline ACTH, cortisol and glucose levels were similar in Cs, MDs, and Ss. The mean glucose nadir was equivalent for Cs, patients with MD, and patients with S. Patients with MD had a blunted ACTH response (F = 3.28; df = 12,126; p = .0004) and cortisol response (F = 4.20; df = 12,132; p = .0001) to hypoglycemia when compared to Cs and patients with S. Carroll Depression Rating Scale scores in patients with S (23 +/- 10) were similar to patients with MD (30 +/- 8) and significantly higher than in controls (1 +/- 2) (F = 55.2; df = 2.22; p = .0001). These findings suggest that patients with MD show different ACTH and cortisol responses to hypoglycemic stress which are not explained by negative feedback of baseline ACTH or cortisol, glucose nadir, or the number of depressive symptoms per se.

Visual, somatosensory, olfactory, and gustatory hallucinations.

Hallucinations that involve any of the sensory modalities may accompany a number of functional and organic conditions. Although characteristics of the hallucinations are not specific, they are characteristic and suggestive of specific disorders. Appropriate evaluation and treatment require consideration of the past psychiatric, neurologic, and medical history; assessment of accompanying psychiatric and neurologic signs and symptoms; and degree of response to conventional therapy. Any patient with hallucinations of recent onset or presenting a significant change in the nature of prior hallucinations, particularly when the patient does not respond to conventional therapy, deserves an evaluation to rule out treatable organic factors.

Ventilatory dysfunction in multiple sclerosis.

Multiple sclerosis (MS) can produce a variety of different respiratory abnormalities because of the multi-focal nature of central nervous system involvement in the disease. This article reviews the different patterns of respiratory involvement in MS and correlates them with the known neuroanatomy of respiratory control. Methods of monitoring pulmonary function in MS are explored, and the treatment of acute ventilatory failure in MS is discussed.

Pituitary-adrenal axis response to arginine vasopressin in patients with major depression.

Arginine vasopressin (AVP) was administered to 21 patients with major depression and 20 normal control subjects. Thirty-two subjects also underwent an overnight dexamethasone suppression test. The patient group did not differ significantly from the control group in adrenocorticotropic hormone (ACTH) or cortisol response. Dexamethasone suppression status did not affect ACTH or cortisol response. This study supports the hypothesis that unlike the response to corticotropin releasing hormone, the ACTH response to AVP is not attenuated in depression.

Tubular carcinoma of the breast: an institutional review.

Tubular carcinoma of the breast is a rare, but distinct, well-differentiated histologic subtype of invasive carcinoma, known for its favorable prognosis. Review of the literature reveals controversy relative to the frequency of tubular carcinoma, the mammographic appearance, the incidence of lymph node metastases, and the need for axillary node dissection. In consideration of these variables and because of the concern that this type of breast cancer was being surgically over-treated, this review was undertaken. Through the use of our tumor registry, a retrospective review of patients with invasive breast cancer was carried out from January 1984 to September 1995. Of 1483 total cases of invasive breast carcinoma, 22 (1.5%) had a diagnosis of pure tubular carcinoma (> 90% tubular component). The mean age was 58 years (range, 37-80). In 14 patients, the lesion was detected solely by mammography with a mean size of 1.0 cm (range, 0.5-1.5 cm). The mean pathologic tumor size was 1.2 cm (range, 0.5-2.9 cm). The mean number of nodes, in 22 axillary specimens, was 19 (range, 8-30). In one patient, there was lymph node metastasis to a single node (4.5% incidence), which demonstrated tubular characteristics. Presently, 18 of the patients are alive and disease free, with a mean follow-up of 3.5 years (range, 4 months to 9 years). Our study confirms the low incidence of pure tubular carcinoma, 1.5 per cent, with the lesions being small, 1.2 cm in mean size. The mammographic lesions had no unique features that would distinguish tubular from other invasive carcinomas. With the small tumor size and the overall excellent prognosis, these patients are ideal candidates for breast preservation. Most importantly, the review did demonstrate that even in pure tubular breast carcinoma, lymph node metastases, though rare, can occur.

Subchronic toxicity study of Caramel Colour II in F344 rats.

Caramel Colour II is a distinct type of colourant with a pronounced reddish hue. It is made with sulphite reactants but without ammonia. The red colour and a high alcohol solubility provide functional characteristics that are important in foods or beverages containing natural flavour extractives. Caramel Colour II is widely used in ice creams and liqueurs; however, it represents less than 1% of total caramel colour manufacture. The toxicity of Caramel Colour II was evaluated in a 13-wk study in Fischer-344 (F344) rats. The test material was mixed with demineralized water and the solutions were given to the animals ad lib. in the drinking fluid. The concentrations of caramel colour in the drinking fluid were adjusted periodically to achieve the desired caramel colour intake/kg body weight/day. Groups of 20 rats/sex were given Caramel Colour II at levels of 0, 4, 8, 12 or 16 g/kg for at least 13 wk. There were no deaths in any of the groups fed Caramel Colour II. All rats fed caramel colour had soft faeces. All treated groups also had lower fluid consumption that was attributed to poor palatability of the high concentrations of caramel colour that were fed. A number of changes observed (reduced food consumption in all treatment groups except males given 4 g/kg; significantly lower body weights for males given 12 g/kg or more and for females given 8 g/kg or more; lower urine volume and higher specific gravity) were attributed to the reduced water intake and not considered to be toxicologically significant. There were no consistent treatment-related alterations in haematology or blood chemistry variables, and random changes noted were not associated with macroscopic or microscopic pathological alterations. There were no toxicologically important pathological findings. Based on this study, Caramel Colour II was not toxic in F344 rats treated for 13 wk. The highest dose level tested in this study (16 g/kg) was considered to be the no-observed-adverse-effect level.

The effect of diet fed to lambs on subsequent development of Trichostrongylus colubriformis larvae in vitro and on pasture.

Contrasting herbage diets were fed to lambs to evaluate their effect on subsequent development of Trichostrongylus colubriformis larvae in faeces and on pasture. The diets had either no condensed tannin (CT), lucerne (Medicago sativa cv. Otaio), white clover (Trifolium repens cv. Tahora), or had moderate to high concentrations of CT, sulla (Hedysarum coronarium cv. Grassland Aokau), Lotus corniculatus (cv. Grasslands Goldie), L. pedunculatus (cv. Grassland Maku), Dorycnium pentophyllum, and Dorycnium rectum. Trials were carried out in summer (warm) and in autumn (cool and moist). In summer, egg viability was evaluated in vitro with egg hatch and larval development assays. In both seasons faeces were placed on pasture to compare recovery of eggs and larvae from faeces and larvae from herbage on the high and low fertility farmlets on the AgResearch Ballantrae Hill Country Research Station. D. rectum and D. pentophyllum diets decreased (P<0.01) egg hatching and larval development in laboratory assays relative to other diets. In summer, the number of larvae recovered from faeces placed on pasture was far greater (P<0.001) if the lambs had been fed lucerne than any other diet, whereas recovery was always lowest from faeces of sheep fed D. rectum and D. pentophyllum. Although dietary differences were lower in autumn than in summer, larval recoveries were lower (P<0.05) from faeces of lambs fed D. rectum and L. corniculatus than from white clover, lucerne and sulla diets. This study indicates that the diet of the host can have a significant impact on egg hatching and the subsequent development of T. colubriformis larvae in the laboratory and in the field. In particular, D. rectum consistently reduced T. colubriformis development. Effects measured in vitro generally under-estimated effects measured under field conditions.

Ultrasound features of osteosarcoma of the mandible--a first report.

Ultrasound imaging is becoming widely used in the head and neck region as a first-line investigation to assess soft tissue swellings. Clinicians should be aware of the potential of diagnostic ultrasound to identify important signs of malignant disease involving bone. Involvement of the mandible by osteosarcoma is uncommon. A young adult patient presented with facial swelling and an apparently infected lower third molar extraction socket. Subtle signs were missed on dental radiographs. Diagnostic ultrasound investigation was pivotal in identifying sinister signs: namely, soft tissue mass associated with bone thinning, erosion, expansion, and the "sunray" appearance of the buccal cortex, which were suggestive of osteosarcoma. These findings enabled priority to be given to subsequent investigations using other modalities. We present a first report of the ultrasound features of osteosarcoma of the mandible and consider this to be a useful modality in an initial investigation.