In Situ Observations of Interstellar Pickup Ions from 1 au to the Outer Heliosphere

Interstellar pickup ions are an ubiquitous and thermodynamically important component of the solar wind plasma in the heliosphere. These PUIs are born from the ionization of the interstellar neutral gas, consisting of hydrogen, helium, and trace amounts of heavier elements, in the solar wind as the heliosphere moves through the local interstellar medium. As cold interstellar neutral atoms become ionized, they form an energetic ring beam distribution comoving with the solar wind. Subsequent scattering in pitch angle by intrinsic and self-generated turbulence and their advection with the radially expanding solar wind leads to the formation of a filled-shell PUI distribution, whose density and pressure relative to the thermal solar wind ions grows with distance from the Sun. This paper reviews the history of in situ measurements of interstellar PUIs in the heliosphere. Starting with the first detection in the 1980s, interstellar PUIs were identified by their highly nonthermal distribution with a cutoff at twice the solar wind speed. Measurements of the PUI distribution shell cutoff and the He focusing cone, a downwind region of increased density formed by the solar gravity, have helped characterize the properties of the interstellar gas from near-Earth vantage points. The preferential heating of interstellar PUIs compared to the core solar wind has become evident in the existence of suprathermal PUI tails, the nonadiabatic cooling index of the PUI distribution, and PUIs' mediation of interplanetary shocks. Unlike the Voyager and Pioneer spacecraft, New Horizon's Solar Wind Around Pluto (SWAP) instrument is taking the only direct measurements of interstellar PUIs in the outer heliosphere, currently out to ∼ 47 au from the Sun or halfway to the heliospheric termination shock.

0939 Anxiety Symptoms Moderate the Effects of Sleep Loss on Children’s Emotions

Introduction

An abundance of cross-sectional research links inadequate sleep with poor emotional health, but experimental studies in children are rare. Further, the impact of sleep loss is not uniform across individuals, and pre-existing anxiety might potentiate the effects of poor sleep on children’s emotional functioning.

Methods

N=53 children (mean age 9.0 years; 56% female) completed multi-modal, emotional assessments in the lab when rested and after two nights of sleep restriction (7h and 6h in bed, respectively). Sleep was monitored with polysomnography and actigraphy. Subjective reports of affect and arousal, psychophysiological reactivity, and objective emotional expression were examined during two emotional processing tasks, including one where children were asked to suppress their emotional responses.

Results

After sleep restriction, deleterious alterations were observed in children’s affect and their emotional reactivity, expression, and regulation. These effects were primarily limited to positive emotional stimuli. The presence of anxiety symptoms moderated most of the alterations in emotional processing observed after sleep restriction.

Conclusion

Results suggest inadequate sleep preferentially impacts positive compared to negative emotion in pre-pubertal children and that pre-existing anxiety symptoms amplify these effects. Implications for children’s everyday socio-emotional lives and long-term affective risk are highlighted.

Support

NIMH grant #R21MH099351

VIII. On the movements of the flame in the explosion of gases

(1.) On the Rate of Movement of the Flam, and the produced in theExplosion of Gases. Humphry Davy was the first to observe the rate at which an explosion of gases was propagated in a tube, and he also made the first rough experiment on the tem­perature reached in an explosion. When gas from the distillation of coal (which he found more inflammable than fire-damp) was mixed with eight times its volume ofair, and was fired in a glass tube 1 foot long and 1/4 inch in diameter, the flame took more than a second to traverse the tube. When cyanogen mixed with twice its volume of oxygen was fired in a bent tube over water, the quantity of water displaced showed that the gases had expanded fifteen times their original bulk. Bunsen, in 1867, made the first careful measurement of the rate at which an explosion is propagated in gases, and he also made the first systematic researches on the pressure and temperature produced by the explosion of gases in closed vessels. His results led him to the remarkable conclusion that there was a discontinuous combustion in explosions. When electrolytic gas, or when carbonic oxide with haltits volume of oxygen, is fired, only one-third of the mixture is burnt, according to Bunsen, raising the temperature of the whole to about 3000° C. No further chemical action then occurs until the gaseous mixture falls, by cooling, below 2500° C. Then a further combustion begins, and so on<italic>per Saltum</italic>. These deductions were criticised by Berthelot, who pointed out that they assumed the constancy of the specific heats of steam and of carbonic acid at high temperatures.

Paediatric intensive care and neonatal intensive care airway management in the United Kingdom: the PIC-NIC survey

In 2011, the Fourth National Audit Project (NAP4) reported high rates of airway complications in adult intensive care units (ICUs), including death or brain injury, and recommended preparation for airway difficulty, immediately available difficult airway equipment and routine use of waveform capnography monitoring. More than 80% of UK adult intensive care units have subsequently changed practice. Undetected oesophageal intubation has recently been listed as a 'Never Event' in UK practice, with capnography mandated. We investigated whether the NAP4 recommendations have been embedded into paediatric and neonatal intensive care practice by conducting a telephone survey of senior medical or nursing staff in UK paediatric intensive care units (PICUs) and neonatal intensive care units (NICUs). Response rates were 100% for paediatric intensive care units and 90% for neonatal intensive care units. A difficult airway policy existed in 67% of paediatric intensive care units and in 40% of neonatal intensive care units; a pre-intubation checklist was used in 70% of paediatric intensive care units and in 42% of neonatal intensive care units; a difficult intubation trolley was present in 96% of paediatric intensive care units and in 50% of neonatal intensive care units; a videolaryngoscope was available in 55% of paediatric intensive care units and in 29% of neonatal intensive care units; capnography was 'available' in 100% of paediatric intensive care units and in 46% of neonatal intensive care units, and 'always available' in 100% of paediatric intensive care units and in 18% of neonatal intensive care units. Death or serious harm occurring secondary to complications of airway management in the last 5 years was reported in 19% of paediatric intensive care units and in 26% of neonatal intensive care units. We conclude that major gaps in optimal airway management provision exist in UK paediatric intensive care units and especially in UK neonatal intensive care units. Wider implementation of waveform capnography is necessary to ensure compliance with the new 'Never Event' and has the potential to improve airway management.

Small-Signal Performance and Modeling of sub-50nm nMOSFETs with f above 460-GHz

We have fabricated and tested the performance of sub-50nm gate nMOSFETs to assess their suitability for mixed signal applications in the super high frequency (SHF) band, i.e. 3-30GHz. For a 30nm×40 μm×2 device, we found f(T) =465GHz at V(ds)=2V, V(g)=0.67V, which is the highest cut-off frequency reported for a MOSFET produced on bulk silicon substrate so far. However, our measurements of f(max) and noise figure indicate that parasitics impose limitations on SHF operation. We also present a high-frequency ac model appropriate to sub-50nm gate length nanotransistors, which incorporates the effects of the parasitics. The model accurately accounts for measurements of the S and Y parameters in the frequency range from 1 to 50GHz.

Measuring quality of life in PSP: the PSP-QoL

OBJECTIVE

To develop a new patient-reported outcome measure for progressive supranuclear palsy (PSP) and to test its psychometric properties.

METHODS

First, the authors generated a pool of potential scale items from in-depth patient interviews. Second, the authors administered these items, in the form of a questionnaire, to a sample of people with PSP and traditional psychometric methods were used to develop a rating scale satisfying standard criteria for reliability and validity. Third, the authors examined the psychometric properties of the rating scale in a second sample.

RESULTS

In stage 1, a pool of 87 items was generated from 27 patient interviews. In stage 2, a scale with two subscales (physical, 22 items; mental, 23 items), satisfying standard criteria for reliability and validity, was developed from the response data of 225 patients with PSP. In stage 3, the scale was examined in 188 people with PSP. Missing data were low, scores in both subscales were evenly distributed, floor and ceiling effects were small. Reliability was high (Cronbach's alpha 0.93, 0.95; test-retest 0.95, 0.92). Validity was supported by the interscale intercorrelation (0.60), factor analysis, and the magnitude and pattern of correlations with four other rating scales, disease severity, and disease duration. The psychometric properties of the new scale were similar in the United Kingdom and North America, and in clinic- and community-based samples studied.

CONCLUSIONS

The Progressive Supranuclear Palsy Quality of Life scale (PSP-QoL) may be a helpful patient-reported scale for clinical trials and studies in PSP.

Permeance to oxygen of detached Capsicum annuum fruit

The internal oxygen concentration and rate of oxygen consumption of detached capsicum fruits (Capsicum annuum L.) were monitored over several days. From this their overall permeance to oxygen was calculated. When wax was applied to the pedicel and its scar, permeance was reduced by 80–90%, indicating that most gas exchange occurred through this area. Readings from O2 sensors attached to the skins of the fruits were compared to those from O2 sensors inserted into the fruit cavity. These indicated that the cuticle was the major barrier to gas diffusion and that there was a concentration gradient through the capsicum flesh. Permeance of the cuticle was found to be about 0.64 x 10–4 mol O2/Pa.m2.s, while permeance to CO2 was 2–3 times higher. This suggests that the cuticle is composed of a coherent film. The low rate of gas diffusion through capsicum cuticle may allow recycling of respired CO2 by photosynthesis in the flesh before harvest.

Clinical and endocrine effects of a microdose GnRH agonist flare regimen administered to poor responders who are undergoing in vitro fertilization

OBJECTIVE

To assess the endocrine and clinical responses to microdose GnRH agonist (GnRH-a) that was administered in the early follicular phase before controlled ovarian hyperstimulation to poor responders who were candidates for IVF-ET.

DESIGN

Prospective nonrandomized trial with historical controls.

SETTING

Tertiary care university-affiliated infertility practice.

PATIENT(S)

Thirty-four IVF-ET candidates with a prior poor response to a standard long-protocol GnRH-a controlled ovarian hyperstimulation regimen (cycle A). Patients were divided into two groups based on their age at the initiation of cycle A (Group 1: < or = 39 years, n = 15; Group 2: > or = 40 years, n = 19).

INTERVENTION(S)

Low-dose oral contraceptive (x 21 d) followed by GnRH-a (leuprolide acetate; 40 micrograms s.c. b.i.d.) flare and urofollitropin initiated on day 3 of GnRH-a administration (cycle B).

MAIN OUTCOME MEASURE(S)

Comparative analysis of clinical responses (total urofollitropin dose used and number of oocytes retrieved as well as fertilization and clinical and ongoing pregnancy rates) and endocrine responses (serum E2, FSH, LH, T, and P levels) between cycles A and B in the two groups. Early follicular phase serum E2 and FSH changes in groups 1 and 2 were compared with changes in nine normal responder controls who were receiving a standard long-protocol GnRH-a/urofollitropin regimen (group 3).

RESULT(S)

Maximal E2 levels as well as clinical and ongoing pregnancy rates were higher in cycle B patients receiving microdose GnRH-a. Cancellation rates in cycle B were lower than in cycle A. Statistically significant increases in treatment day 6 serum FSH levels were noted during cycle B in both groups 1 and 2 but not in group 3 controls. No abnormal rises in LH, P, or T were noted in any of the groups.

CONCLUSION(S)

Microdose GnRH-a enhances urofollitropin response and clinical outcome in poor responders undergoing IVF-ET. This may be due to enhanced release of early follicular phase endogenous FSH without concomitant deleterious rises in androgen levels or corpus luteum rescue.

The relation between chemically measured total iron-binding capacity concentrations and immunologically measured transferrin concentrations in human serum

We sought to determine if serum total iron-binding capacity (TIBC) is equivalent to serum transferrin (TRF) so that a low-cost colorimetric chemical assay for unsaturated iron-binding capacity (UIBC) could be substituted for a high-cost immunologic assay for TRF. Our study design included independent and blinded measurements of UIBC, serum iron, and TRF concentrations in human serum samples. Data from five independent correlation studies carried out at three different Quest Diagnostics laboratories were combined into one data set containing 570 paired results for TIBC and TRF. r2 was 0.941 when three outliers were eliminated from the 570-sample data set. Scatter about the regression line was fully accounted for by the CVs for the TIBC and TRF assays. When each test is measured precisely and without bias, the ratio of TIBC (mumol/L) to TRF (g/L) in SI units is close to the theoretically expected value of 25.0.

Acidosis and coma after hemodialysis

Ethylene glycol poisoning is a rare yet potentially fatal illness seen most commonly in association with ingestion by alcoholics or in suicide attempts. It is characterized by an elevated anion gap metabolic acidosis, osmolal gap, calcium oxalate crystals in the urine, and a well-defined clinical picture. Prompt treatment is crucial because effective intervention can prevent the neurologic, cardiac, pulmonary, and renal sequelae associated with ethylene glycol poisoning. Hemodialysis offers rapid clearance of ethylene glycol and its toxic metabolites. In this article, the case of a hemodialysis patient who suffered contamination of the dialysate solution with ethylene glycol, leading to altered mental status, coma, and severe anion gap metabolic acidosis, is reported. Despite prolonged dialysis and correction of the acidosis, the patient remained comatose and subsequently died.

Hypertension in the hemodialysis population: any relation to one-year survival?

Few studies have quantified the effect of hypertension on survival in the hemodialysis population. We report the effect of hypertension on 1-year survival in 649 hemodialysis patients (89% black). In univariate analysis, hypertension was associated with improved 1-year survival (relative risk [RR], 0.48; P = 0.002 compared with normotensive patients). This effect of hypertension was mostly caused by the associated antihypertensive treatment because untreated hypertensive patients had survival rates equal to normotensive patients (RR, 0.87; P = 0.70). On the other hand, treated hypertensive patients fared better than normotensive patients (RR, 0.41; P = 0.0006). This was also true in multivariate analysis, in which antihypertensive treatment was associated with reduced RR (RR, 0.55; P = 0.02) whereas the level of blood pressure per se was insignificant (RR, 0.99; P = 0.63 per 1 mm Hg increase in predialysis mean arterial pressure). Other factors of significance in multivariate analysis included age (RR, 1.03/y; P = 0.0004), serum albumin (RR, 0.38/g; P = 0.002), and diabetes mellitus (RR, 1.58; P = 0.06). Our study suggests that antihypertensive treatment has a favorable effect on survival in the hemodialysis population irrespective of the level of blood pressure control.

Leukaemia inhibitory factor treatment stimulates muscle regeneration in the mdx mouse

A number of growth factors are involved in coordinating muscle cell proliferation and differentiation, particularly after injury and in disease. Leukaemia inhibitory factor (LIF) strongly stimulates the proliferation of myoblasts in vitro and in vivo and its expression in muscle after injury suggests that LIF may have a role as a trauma factor. The mdx mouse was used to study the effects of LIF on in vivo muscle regeneration during disease. The rationale for using trophic factors such as LIF to treat neuromuscular disease includes the understanding that these molecules show some degree of selectivity for the population of cells in which they are effective. LIF was administered to muscle of the mdx mouse using osmotic pumps implanted subcutaneously in unrestrained mice. The growth factor was continuously delivered into the vastus lateralis muscle at 7 U/mu 1 for 7 days via a catheter. The results show that LIF increased the rate of muscle regeneration in mdx mice by stimulating the formation of larger myotubes. LIF treatment also increased the number of regenerating myotubes in the perfused area. This myotrophic action indicates that LIF contributes to muscle regeneration. Together with its known neurotrophic action, LIF is a potential therapeutic agent for the treatment of neuromuscular disease.

Effects of air pollution on daily hospital admissions for respiratory disease in London between 1987-88 and 1991-92

STUDY OBJECTIVE

To investigate whether air pollution levels in London have short term effects on hospital admissions for respiratory disease.

DESIGN

Poisson regression analysis of daily counts of hospital admissions, adjusting for effects of trend, seasonal and other cyclical factors, day of the week, holidays, influenza epidemic, temperature, humidity, and autocorrelation. Pollution variables were particulates (black smoke: BS), sulphur dioxide (SO2), ozone (O3), and nitrogen dioxide (NO2), lagged 0-3 days.

SETTING AND PATIENTS

All immediate admissions for respiratory disease (ICD 460-519) to hospitals in London health districts in the five years April 1987 to February 1992 for all ages and the 0-14, 15-64, and 65+ age groups.

MAIN RESULTS

O3 (lagged one day) was significantly associated with an increase in daily admissions among all age groups, except the 0-14 group, and this effect was stronger in the "warm" season (April-September). In this season, the relative risks of admission associated with an increase in 8 hour O3 levels of 29 ppb (10th to 90th centile) were 1.0483 (95% CI 1.0246, 1.0726), 1.0294 (0.9930,1.0672), 1.0751 (1.0354,1.1163), and 1.0616 (1.0243,1.1003) for all ages and age groups 0-14, 15-64, and 65+ respectively. Very few significant associations were observed with the other pollutants, though these tended to be positive. Controlling for other pollutants made little difference to the O3 coefficients. There was evidence of a threshold at about 40-60 ppb O3 (maximum hourly or maximum 8 hour).

CONCLUSIONS

O3 levels in London have a small but significant effect on hospital admissions for respiratory disease at all ages. The possible role of aerollergen as a confounding factor needs to be examined. Unlike other cities where similar effects have been reported, little or no effect of particulates was observed in London.

In vitro myoblast to myotube transformations in the presence of leukemia inhibitory factor

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine which exerts a variety of effects on many cell types including neuronal cells, and is a potent mitogen for myoblasts. At concentrations of 0.1-0.3 ng/ml, the peptide stimulates a maximal increase in cell number. LIF initiates a prolonged proliferative response lasting up to 13 days, when myoblasts are exposed to it in culture. LIF expression can be detected in vivo during development of limb muscle and in adult regenerating skeletal muscle tissue. Here, we studied the levels of expression of alpha-bungarotoxin-binding sites as a measure of acetylcholine receptors (AChRs), myosin light chain pattern and rate of myotube formation in fused, control and LIF-treated muscle cultures derived from mouse hind-limb muscles. We found that both the level of expression of AChRs and myosin light chain pattern, are normal, following exposure of the cells to LIF. There was no difference in the rate of myotube formation between LIF-stimulated and control myoblasts over a 10-fold concentration range (0.3-3.0 ng/ml) as determined by nuclei counts. Taken together, these results suggest that LIF, in combination with other cytokines, may act in vivo to stimulate rapid growth, without significant differentiation, during the early phases of myogenesis.

Specific binding of leukemia inhibitory factor to murine myoblasts in culture

Leukemia inhibitory factor (LIF) is a member of the cytokine family of growth factors. It has been shown to exert a variety of actions on a diverse range of cell types, including neuronal, bone, and hemopoietic cells (Hilton, 1992, Trends Biochem. Sci., 17:72-76). In many of these cell types, studies have indicated the presence of specific receptors for LIF (Godard et al., 1982, J. Biol. Chem., 267: 3214-3222; Hilton et al., Proc. Natl. Acad. Sci. USA, 85:5971-5975; Hilton and Nicola, 1992, J. Biol. Chem., 267:10238-10247.). The mechanism by which these receptors act is believed to involve tyrosine phosphorylation and the signal transducing receptor component gp130. We have previously shown that LIF is capable of inducing both human and murine myoblasts to proliferate in culture (Austin et al., 1992, J. Neurol. Sci., 112:185-191). We now report that LIF binds specifically to receptors on the surface of myoblasts, with an equilibrium dissociation constant of 400 pM and the number of receptors per cell varies with cell density. Binding competition studies showed that LIF binding to these receptor sites was not competed for by a number of other growth factors which stimulate myoblast proliferation including basic fibroblast growth factor (bFGF), transforming growth factor-alpha (TGF alpha), insulin-like growth factor 1 (IGF-1), and interleukin-6 (IL-6). There was a time and concentration-dependent down-regulation of receptor numbers following preincubation of myoblasts with LIF. The processing of these receptors subsequent to binding, involves as a first step, internalization and degradation by the myoblast. LIF appeared to stimulate myoblast proliferation rather than cell survival.

Triazolam in patients with obstructive sleep apnea

The purpose of this study was to assess the effect of triazolam (0.25 mg) on apnea duration and the arousal response to airway occlusion during sleep in patients with severe obstructive sleep apnea (OSA). Twelve male subjects with a mean (+/- SD) age of 46.6 +/- 14.1 yr and body weight of 260.8 +/- 55.9 lb were studied on two nights separated by a nonstudy night. They ingested triazolam (0.25 mg) or placebo 0.5 h before bedtime in a randomized double-blind crossover manner. In non-rapid-eye-movement (NREM) sleep, the mean (+/- SEM) duration of apnea/hypopnea was slightly increased (26.8 +/- 1.7 versus 23.8 +/- 1.2 s, p < 0.02) and the mean nadir in arterial oxygen saturation lower (80.1 +/- 1.9 versus 84.2 +/- 1.4%, p < 0.001) on triazolam nights. In NREM sleep, the deflections in esophageal pressure prior to apnea termination were higher on triazolam nights (53.3 +/- 5.4 versus 44.5 +/- 4.8 cm H2O, p < 0.001). However, the rate of increase in inspiratory effort (esophageal pressure deflections) during obstructive events was not decreased by triazolam. We conclude that triazolam increases the arousal threshold to airway occlusion, but that this results in only modest prolongation of event duration and increased desaturation at a dose of 0.25 mg in a group of large sleep apnea patients.

Leukemia inhibitory factor (LIF) infusion stimulates skeletal muscle regeneration after injury: injured muscle expresses lif mRNA

Leukemia inhibitory factor (LIF) is known to stimulate myoblast growth in culture via direct receptor mediated mechanisms, but it does not suppress myoblast fusion in vitro. We show here that LIF is also effective in vivo, using a muscle crush model. Administration of LIF to the site of the crush results in an increased rate of regeneration of the injured muscle. LIF stimulates an increase in the size of the muscle fibers rather than an increase in total number. Perfusion of 125I-labelled LIF (125I-LIF) at the site of the crush leads to uptake of the great majority of 125I-LIF into the muscle, which suggests that LIF is acting directly at the site of injury. Further, following crush injury LIF mRNA synthesis commences in the muscle. These data provide evidence that LIF is acting as a natural trauma factor in vivo and is actively involved in muscle regeneration.

Composite dialysis access grafts

Hemodialysis access devices constructed of expanded polytetrafluoroethylene (ePTFE) require a maturation period of seven to 14 days before cannulation. Percutaneously placed dual-lumen catheters can be used for temporary access during this interval but are associated with significant short and long term complications. Access devices constructed of Plasma-TFE (pl-TFE) (Atrium, Hollis) conduits have been reported to tolerate cannulation immediately after placement, but long term patency is inferior to that of conventional ePTFE. To combine the immediate access advantages of pl-TFE and the long term patency of ePTFE, composite grafts were constructed, which consisted of 10 to 12 centimeters of pl-TFE and the remainder of ePTFE. The pl-TFE segment was made available for immediate access and the ePTFE segment after an appropriate maturation period. Thirty percent of composite grafts were cannulated on the day of placement and 83.8 percent were cannulated within 72 hours. No complications of early access of the pl-TFE segment occurred. These grafts were compared with a cohort of conventional ePTFE grafts for the occurrence of thrombosis, infection and pseudoaneurysm. No significant differences were noted. Event-free patency of the two groups was equal (327.7 versus 346.3 days, p = 0.282). Patency after an initial thrombotic episode was slightly better in the composite group. We conclude that composite dialysis access grafts can be cannulated immediately after placement and demonstrate long term performance at least equal to that of conventional ePTFE grafts. Use of the composite graft concept should be considered when immediate dialysis is needed and to avoid the use of temporary access catheters.

The determination of hemodialysis blood recirculation using blood urea nitrogen measurements

The determination of blood recirculation using blood urea nitrogen (BUN) measurements in hemodialysis patients is a standard technique. The accuracy and reproducibility of these calculations have never been determined. Two pairs of recirculation studies (study A and study B) were performed in 13 patients during a single dialysis treatment. Blood samples were analyzed for BUN and recirculation was calculated. The first recirculation study (study A) was performed within 1 hour of the initiation of dialysis, with a duplicate test of recirculation performed within 15 minutes. In study B, the dialyzer blood lines were reversed in an attempt to enhance blood recirculation. After 15 minutes, duplicate tests of recirculation were again performed. Calculated recirculations before the line reversal (study A) ranged from -3.3% to 11.9% in the first test and -2.9% to 12.2% in the second test. In study A, there was no correlation (P > 0.05, r = 0.09) between the first and second calculated recirculations. In study B, an increase in recirculation was observed. Calculated recirculations ranged from 16.3% to 53.5% for the first test and 5.4% to 58.1% for the second test. A significant relationship was observed in the calculated recirculation in study B (P < 0.05, r = 0.81). The results from the present study show that the use of BUN measurements may not provide a consistent indicator of access recirculation in a patient with a low recirculation. This lack of consistency should be considered when determining further clinical treatment.

Effects of leukaemia inhibitory factor and other cytokines on murine and human myoblast proliferation

It has been shown previously that leukaemia inhibitory factor (LIF) and transforming growth factor-alpha (TGF-alpha) stimulate proliferation of primary cultures of murine myoblasts. We now show that human myoblasts respond in a similar manner to LIF and TGF-alpha. These responses occur over a range of growth conditions. There are total additive effects in both human and murine myoblasts between LIF and TGF-alpha and LIF and fibroblast growth factor-beta (FGF-beta), but not between LIF and interleukin-6 (IL-6) or insulin-like growth factor 1 (IGF-1). The LIF response is initiated by a short exposure to the cytokine and is maintained for prolonged periods in its absence.

Non-invasive determination of recirculation in the patient on dialysis

Recirculation of blood flow occurs when the fistula flow rate is inadequate to support the desired dialyzer blood flow. The percentage recirculation is normally calculated using the blood urea nitrogen of blood samples from the two dialyzer blood lines and a peripheral blood sample. However, this method is time consuming, costly, and may not always give accurate measurements. A technique was developed to measure recirculation using the injection of saline into the venous dialysis line. For this technique, an optical detector is placed across the arterial dialysis tubing, and the light intensity, which is proportional to the hematocrit, is continually measured using a computerized data collection system. After a baseline data collection period, 10 ml of saline is injected into the venous dialysis line using the sampling port. The saline that appears in the arterial dialysis line as a result of recirculation will cause a dilution of the blood and an increase in light intensity. In vitro testing showed an excellent correlation between the area under the dilution curve and percentage recirculation. This technique will provide a quick, inexpensive, and reliable measurement of recirculation.

Elevated serum levels of interleukin-5 in patients with the syndrome of episodic angioedema and eosinophilia

The syndrome of episodic angioedema and eosinophilia is characterized by cyclic edema, marked peripheral blood eosinophilia, and eosinophil degranulation in the dermis. Using a sensitive immunoenzymetric method, we measured serum interleukin (IL)-5 levels in four patients with this syndrome. We also determined the percentage of activated T cells in the peripheral blood of a new patient before and during an attack. In the patient presented, IL-5 levels peaked several days before maximal eosinophilia and then declined. This patient's lymphocytes showed an increased percentage, 28% (normal 2% to 3%), of activated T cells staining for both CD3 and HLA-DR 10 days before maximal eosinophilia, but no increase at the time of peak eosinophilia. In serum from three previously reported cases, elevated serum IL-5 levels were found during attacks. After glucocorticoid administration, IL-5 levels became undetectable in three of the four patients. Production of IL-5 is likely an important determinant of the pathophysiology of this syndrome.

Outpatient vascular access surgery: impact of a dialysis unit-based surgical facility

The present report describes a novel approach to vascular access surgery based on the philosophy that a readily available operating room, staffed by nurses familiar with the unique problems of dialysis patients and their therapy, would reduce dialysis delays and maintain the quality of surgical care. Based on a 28-month experience with more than 1,000 access cases, we conclude that a traditional surgical setting is not necessary for either quality access graft placement or the management of access complications.

Comparison of rehabilitation in patients undergoing home dialysis. Continuous ambulatory or cyclic peritoneal dialysis vs home hemodialysis

Rehabilitation was assessed in 70 patients undergoing continuous ambulatory (CAPD; n = 67) or cyclic (CCPD; n = 3) peritoneal dialysis and 76 patients undergoing home hemodialysis (HHD). In the CAPD/CCPD group, there were more blacks (83% vs 53%) and diabetics (24% vs 8%). If patients too infirm to work were excluded, no statistically significant differences were found between those working for gain and in school (19% for CAPD/CCPD vs 32% for HHD); homemakers (16% for CAPD/CCPD vs 28% for HHD); and those not working (66% for CAPD/CCPD vs 41% for HHD). Although the CAPD/CCPD group had less formal education (8.9 +/- 3.7 years vs 10.9 +/- 2.2 years for HHD), illiteracy rates were similar (CAPD/CCPD, 16%; HHD, 7%). If unemployable (elderly and debilitated) patients were excluded, full rehabilitation was excellent in both groups (57% for CAPD/CCPD vs 65% for HHD), despite the greater number of blacks and diabetics in the CAPD group.

Effect of insulin on renal sodium handling in hypertensive rats

Spontaneously hypertensive rats have reduced peripheral insulin sensitivity. To determine whether hypertensive rats demonstrate reduced response to the antinatriuretic effect of insulin, urinary sodium excretion was determined in hypertensive and normotensive rats (n = 7 per group) before and during euglycemic insulin administration at two infusion rates (21 milliunits/kg load and 4 milliunits/kg/min or 85 milliunits/kg load and 8 milliunits/kg/min). Hypertensive and normotensive time controls received the vehicle for insulin administration. Mean arterial pressure was greater (p less than 0.05) and inulin clearance was less (p less than 0.05) in hypertensive than normotensive rats before insulin infusion. Baseline fractional sodium excretion was not different between groups. Low dose insulin infusion reduced (p less than 0.05) fractional sodium excretion from 0.81 +/- 0.43% to 0.31 +/- 0.07% in hypertensive rats and from 1.05 +/- 0.37% to 0.47 +/- 0.18% in normotensive rats. High dose insulin infusion reduced (p less than 0.05) fractional sodium excretion from 0.67 +/- 0.22% to 0.21 +/- 0.08% in hypertensive rats and from 0.81 +/- 0.15% to 0.30 +/- 0.09% in normotensive rats. Sodium excretion was unchanged in time controls. The reduction in sodium excretion was similar in both rat groups during low dose and high dose insulin infusions. Mean arterial pressure and inulin clearance were unchanged from baseline values during insulin infusion in all rat groups. Glucose requirement to maintain euglycemia was greater (p less than 0.05) in normotensive than hypertensive rats at both insulin infusion rates. Thus, while hypertensive rats have reduced sensitivity to the hypoglycemic effects of insulin, the antinatriuretic response to insulin is not different from that of normotensive rats.(ABSTRACT TRUNCATED AT 250 WORDS)