Above and belowground traits impacting transpiration decline during soil drying in 48 maize (Zea mays) genotypes

BACKGROUND AND AIMS

Stomatal regulation allows plants to promptly respond to water stress. However, our understanding of the impact of above and belowground hydraulic traits on stomatal regulation remains incomplete. The objective of this study was to investigate how key plant hydraulic traits impact transpiration of maize during soil drying. We hypothesize that the stomatal response to soil drying is related to a loss in soil hydraulic conductivity at the root-soil interface, which in turn depends on plant hydraulic traits.

METHODS

We investigate the response of 48 contrasting maize (Zea mays) genotypes to soil drying, utilizing a novel phenotyping facility. In this context, we measure the relationship between leaf water potential, soil water potential, soil water content and transpiration, as well as root, rhizosphere and aboveground plant traits.

KEY RESULTS

Genotypes differed in their responsiveness to soil drying. The critical soil water potential at which plants started decreasing transpiration was related to a combination of above and belowground traits: genotypes with a higher maximum transpiration and plant hydraulic conductance as well as a smaller root and rhizosphere system closed stomata at less negative soil water potentials.

CONCLUSIONS

Our results demonstrate the importance of belowground hydraulics for stomatal regulation and hence drought responsiveness during soil drying. Furthermore, this finding supports the hypothesis that stomata start to close when soil hydraulic conductivity drops at the root-soil interface.

P993Incidence of atrial fibrillation early after cavotricuspid isthmus ablation

Background

Atrial fibrillation (AF) is a common finding in patients undergoing cavotricuspid isthmus ablation for isthmus dependent right atrial flutter (RAF). Little is known about the time of its occurrence.

Purpose

We aimed to investigate the incidence of AF early after RAF ablation in a well-defined, prospective cohort.

Methods

A total of 255 participants with RAF ablation from 5 centers and at least one completed follow-up were included. Structured clinical follow-up was performed at 3, 6 and 12 months including a 24 hour Holter-ECG. The endpoint was incidence of AF detected clinically or by Holter-ECG. Risk factors associated with the occurrence of AF were assessed using separate, univariate Cox proportional-hazards models.

Results

Mean age was 67 years, 80% were male and previous episodes of AF were known in 40%. Over a mean follow-up of 7.4 (±4.4) months AF was detected in 35 (13.7%) participants after RAF ablation (Figure A). After 3, 6 and 12 months AF was detected in 18 (7.1%), 30 (11.7%) and 34 (13.3%) patients. No difference in the incidence of AF after RAF ablation was found comparing patients with and without a history of AF (log-rank p value = 0.44) (Figure B). Comparing patients with and without AF during follow-up, there was no difference in age (68 vs 66 years, p = 0.36), sex (69 vs 81% male, p = 0.08), prior heart failure (29 vs 19%, p = 0.20), hypertension (43 vs 38%, p = 0.56) or left atrial volume (46.6 vs 39.6 ml, p = 0.10), but patients with previous AF had a lower left ventricular ejection fraction (LVEF) (45.7 vs 52.3%, p = 0.02). In separate, univariate Cox proportional-hazards models only increasing LVEF (Hazard ratio 0.97, 95% confidence interval (0.95; 0.99, p = 0.02)) was associated with a lower risk of incident AF after RAF ablation, but no other risk factor.

Conclusions

AF occurred in 13.7% of patients early after cavotricuspid isthmus ablation for RAF. There was no difference in the occurrence of AF between patients with and without previously known episodes of AF. Only impaired LVEF was associated with AF occurrence.

Abstract Figure

Non-equilibrium scale invariance and shortcuts to adiabaticity in a one-dimensional Bose gas

We present experimental evidence for scale invariant behaviour of the excitation spectrum in phase-fluctuating quasi-1d Bose gases after a rapid change of the external trapping potential. Probing density correlations in free expansion, we find that the temperature of an initial thermal state scales with the spatial extension of the cloud as predicted by a model based on adiabatic rescaling of initial eigenmodes with conserved quasiparticle occupation numbers. Based on this result, we demonstrate that shortcuts to adiabaticity for the rapid expansion or compression of the gas do not induce additional heating.

Detection on four continents of dengue fever cases related to an ongoing outbreak in Luanda, Angola, March to May 2013

In April 2013, ten cases of dengue fever in travellers returning from Luanda, Angola, to five countries on four continents, were reported to the globally distributed GeoSentinel Surveillance network. Dengue virus serotype 1 was identified in two cases. The findings indicate that a major dengue outbreak is currently ongoing in Luanda. This report illustrates how cases from an emerging arboviral epidemic focus can spread internationally and highlights the risk of dissemination of a vector-borne disease into receptive areas

A randomized, double blind, placebo-controlled trial of pioglitazone in combination with riluzole in amyotrophic lateral sclerosis

Background

Pioglitazone, an oral anti-diabetic that stimulates the PPAR-gamma transcription factor, increased survival of mice with amyotrophic lateral sclerosis (ALS).

Methods/Principal Findings

We performed a phase II, double blind, multicentre, placebo controlled trial of pioglitazone in ALS patients under riluzole. 219 patients were randomly assigned to receive 45 mg/day of pioglitazone or placebo (one: one allocation ratio). The primary endpoint was survival. Secondary endpoints included incidence of non-invasive ventilation and tracheotomy, and slopes of ALS-FRS, slow vital capacity, and quality of life as assessed using EUROQoL EQ-5D. The study was conducted under a two-stage group sequential test, allowing to stop for futility or superiority after interim analysis. Shortly after interim analysis, 30 patients under pioglitazone and 24 patients under placebo had died. The trial was stopped for futility; the hazard ratio for primary endpoint was 1.21 (95% CI: 0.71–2.07, p = 0.48). Secondary endpoints were not modified by pioglitazone treatment. Pioglitazone was well tolerated.

Conclusion/Significance

Pioglitazone has no beneficial effects on the survival of ALS patients as add-on therapy to riluzole.

Trial Registration

Clinicaltrials.gov NCT00690118.

Growth in human immunodeficiency virus type 1-infected children treated with protease inhibitors

To determine the long-term impact of antiretroviral treatment (ART) including a protease inhibitor (PI) on growth in children infected with the human immunodeficiency virus type I (HIV-1), a prospective multi-centre study was conducted in Switzerland on HIV-1-infected children treated with ritonavir (350 mg/m2 twice a day) or nelfinavir (20-30 mg/kg three times a day) in addition to two nucleoside reverse transcriptase inhibitors. Length or height of HlV-1-infected children from before (weeks -72, -48, -24, and 0) and after (weeks +24, +48, and +72) introducing a PI to the ART were compared. To allow for age- and gender-independent assessment, values were expressed in standard deviations from the mean. Complete data sets on body length were available for 44 children after 72 weeks of treatment with a PI. Preceding initiation of a PI, there was an overall decline in growth to -0.3 SD. Following start of a PI, an increase in growth was noted from weeks 0 to +24 (+0.33 SD, P=0.02) and from weeks +48 to +72 (+0.21 SD, P=0.03). The increase in growth was restricted to children with stunting before a PI was introduced (P=0.03), and was more marked in children younger than 3 years of age.

CONCLUSION

children infected with human immunodeficiency virus type 1 showed catch-up growth after addition of a protease inhibitor to their antiretroviral treatment, but this phenomenon was observed almost exclusively in children under 3 years of age.

Application of hydrophobic anion-exchange phases in capillary electrochromatography

Capillary electrochromatography (CEC) requires stationary phases that enable appropriate electroosmotic propel under various conditions. Analyte retention can be controlled through hydrophobic or electrostatic interaction with the packing material. The development and characterization of new strong anion-exchange materials with additional hydrophobic moieties (SAX/C18 mixed-mode phases) is described. The synthesis was based on polymer encapsulation of porous silica. The phases were systematically characterized by means of elemental analyses, HPLC frontal analyses and CEC experiments. The studies focused on the influence of various parameters (e.g., pH, kind of buffer, capillary wall) on the electroosmotic flow (EOF). Phases with high anion-exchange capacity generated a fast and constant EOF over a wide pH range. Long-time stability of EOF and hydrophobic retention under CEC conditions were demonstrated within the course of 100 consecutive injections. The applicability of the SAX/C18 phases in appropriate buffer systems is demonstrated for neutral, acidic and basic compounds.

The environment in the provincial plan of Cremona, Italy

Recent Italian laws mandate the consideration of environmental factors in local plans, especially at the provincial level of government. The plan for the province of Cremona in northern Italy illustrates the integration of the environment in provincial-level planning. The Cremona plan was developed through an ecological planning approach that occurred from 1994 to 1998. As part of this process, the planning team designed an environmental sustainability index. This index was integrated with an environmental capability analysis. To improve the quality of the Cremona landscape, the planning team developed an ecological network. This network seeks to weave together the natural areas of the province, especially by connecting provincial parks to regional river parks throughout Lombardy. The experience of the Cremona provincial plan has implications for environmental management elsewhere in Italy, Europe, and abroad.

Community-acquired pneumonia in children due to Mycoplasma pneumoniae: diagnostic performance of a seminested 16S rDNA-PCR

A 16S rDNA-PCR assay for Mycoplasma pneumoniae applied to nasopharyngeal secretion (NPS) or pharyngeal swab (PS) from children with community-acquired pneumonia (CAP) was prospectively compared to serological tests including complement fixation (CF) test, a mu-capture enzyme immuno assay (EIA) for the detection of specific IgM, and an EIA for the detection of specific IgG. During a 24-months-period diagnosis of active M. pneumoniae infection was established in 32 (12.6%) of 253 patients for whom paired sera were available. In the acute phase, the sensitivities of PCR from NPS and PS, CF test, IgM EIA, and IgG EIA were 90.0%, 79.3%, 46.9%, 78.1%, and 59.4%, respectively. The corresponding specificities were 98.1%, 98.6%, 97.6%, 87.1%, and 72.4%, respectively. Thus, the 16S rDNA-PCR assay provides a highly sensitive and accurate tool for the rapid diagnosis of M. pneumoniae infection in children with CAP.

Nonaqueous capillary electrophoresis: a versatile completion of electrophoretic separation techniques

Nonaqueous capillary electrophoresis (NACE) is the application of a conductive electrolyte dissolved in either one organic solvent or a mixture of several organic solvents to carry out zone electrophoresis or related techniques in fused-silica capillaries. A complete review on the fundamentals, the optimization of analytical methods, practical considerations, and applications is given. To explain the differences to CE in aqueous media, a brief summary on solvent properties and molecular interactions in solutions introduces the reader into these fields. The use of additives to tune separation selectivity by means beyond a pure zone-electrophoretic mechanism is discussed in detail for organic media. Special detection techniques providing high potential for NACE are presented. Data on the precision of NACE methods and a list of relevant applications are included. More specialized applications like the determination of physicochemical constants in NACE or the setup of a semipreparative mode are described.

Long-term responses to treatment including ritonavir or nelfinavir in HIV-1-infected children. Pediatric AIDS Group of Switzerland

BACKGROUND

Knowledge concerning the long-term antiretroviral and immunological efficacy of protease inhibitors in children is limited.

PATIENTS AND METHODS

An open-label, prospective, multicenter clinical trial was conducted over a period of 72 weeks in Switzerland. 60 HIV-1 infected children (aged 0.3-16.9 years) naive to protease inhibitors were enrolled. Ritonavir or nelfinavir and at least one new nucleoside reverse transcriptase inhibitor were introduced into the current treatment regimen. HIV-1 RNA levels and CD4 cell counts were monitored after introducing the protease inhibitor, and the tolerability and safety of the drugs were assessed.

RESULTS

Dictated by chronological availability, 37 children received ritonavir and 23 nelfinavir. At baseline, children given ritonavir had higher mean plasma HIV-1 RNA levels (5.03 vs 4.63 log10 copies/ml; p = 0.001) and lower mean CD4 cell counts (277 vs 555 cells/microl; p = 0.009) than children given nelfinavir. Antiretroviral treatment (ART) naive children showed higher mean plasma HIV-1 RNA levels than non-naive (5.18 vs 4.64 log10 copies/ml; p = 0.02). The decline in plasma HIV-1 RNA levels 72 weeks after treatment with ritonavir and nelfinavir was -2.17 and -1.30 log10 copies/ml, respectively (p = 0.006) and in ART-naive vs non-naive patients -2.70 vs -1.39 log10 copies/ml (p < or = 0.01). 69% of ART-naive patients and 32% of non-naive patients achieved sustained plasma HIV-1 RNA levels < 400 copies/ml. Increases in CD4 cells were higher in ART-naive compared to non-naive patients (p < 0.04).

CONCLUSION

The antiretroviral and immunologic benefits of protease inhibitors are more profound in ART-naive than in non-naive children.

Instrumentation for capillary electrochromatography

One of the reasons for the immense interest in capillary electrochromatography (CEC) is its feature to combine chromatographic selectivity with the high efficiency and the miniaturization potential of capillary electrophoresis (CE). The capability of commercial CE instruments to run CEC has enforced the readiness of users and researchers to work on this separation technique. Nevertheless, to fully exploit the potential of CEC, a routine CE device can certainly not fulfill all requirements. Two different approaches have been made to overcome this problem. The first was to modify commercial CE instruments for various demands. Pressurization of the packed capillary to prevent "air" bubble formation, gradient elution capabilities and thermostating devices allowing a greater flexibility in column designs have been implemented in CE instruments of several manufacturers. A completely different approach is the development of modular laboratory-made instrumentation dedicated to special CEC requirements. In order to increase mobile phase velocity and thus the speed of analysis the availability of voltages higher than 30 kV was accomplished in some of these devices. Gradient elution was achieved by either coupling of gradient LC systems or an electroosmotic generation of the changing eluent composition. When a pressure gradient is applied between both column ends in addition to the voltage gradient, a hybrid between capillary HPLC and CEC results. This chromatographic mode is named pressure-assisted electrochromatography (PEC). Either CE instruments equipped with additional HPLC pumps or modular laboratory-made devices are suitable for PEC. In CEC, sensitivity for UV detection is rather poor due to the short optical path length for on-column detection in capillary separation techniques. A special cell design with enhanced light path is presented and further principles like, e.g., fluorescence detection and coupling to mass spectrometry are discussed.

On-line determination of mercury in river water at the German monitoring station Schnackenburg/Elbe

A monitor is described which provides the on-line determination of mercury in river water at concentrations from 20 to 1000 ng/L. The measurement includes an on-line digestion with Br-/BrO3- and UV-radiation. Each determination is controlled by an on-line addition of 50 and 100 ng/L mercury carried out by pre-dilution of a 500 and 1000 ng/L stock solution using sequential injection analysis (SIA). One cycle of analysis takes 20 min and results in nine signals. A five days stand-alone operation has been performed successfully. Details are also published at web page: "http/www.rzbd.fh-hamburg.de/-prmercol".

Prospective evaluation of amplification-boosted ELISA for heat-denatured p24 antigen for diagnosis and monitoring of pediatric human immunodeficiency virus type 1 infection

The performance in pediatric human immunodeficiency virus type 1 (HIV-1) infection of a signal-amplification boosted ELISA for HIV-1 p24 antigen in plasma after heat-mediated immune complex dissociation was prospectively compared with polymerase chain reaction-based procedures. Diagnostic sensitivity and specificity of the p24 antigen test were 100% and 99.2%, respectively. Quantification revealed RNA in 85.7% and p24 antigen in 87.4% of 230 samples from 25 infected children. Concentrations of these indices in individual samples correlated (P<.0001). Introduction or modification of antiretroviral treatment showed concordant responses of RNA and p24 antigen in 39 (90.7%) of 43 instances. The treatment-induced changes in concentrations of RNA were higher than those of p24 antigen in 11 instances. In 1 instance, however, the concentration change of p24 antigen was greater than that of RNA (P=. 002). Variation of RNA concentrations was more marked than that of p24 antigen (P=.002). The p24 antigen test was equivalent to PCR for diagnosing and monitoring pediatric HIV-1 infection.

M band proteins myomesin and skelemin are encoded by the same gene: analysis of its organization and expression

The complete exon-intron organization of the murine gene encoding sarcomeric myomesin has been determined. The gene is composed of 38 exons and 37 introns, spanning approximately 105 kb of DNA. Intron positions and phases are essentially identical to those identified in M-protein. They are related to the modular structure of myomesin, which is composed almost entirely of immunoglobulin and fibronectin type III domains. Nearly all repeats follow a two exon-one domain structure. The start and end of each domain are defined by introns in phase I, while internal introns are more divergent in position and very rarely use phase I. Genomic Southern blotting and reverse transcription-polymerase chain reaction revealed that differential splicing of a single exon gives rise to two polypeptides, described in the literature as myomesin and skelemin, respectively. A single transcriptional start point was detected in both skeletal and cardiac muscle. Analysis of the presumptive promoter region revealed several potential regulatory elements. CAT expression assays using promoter deletion constructs identified three regions that seem to be important for the muscle-specific transcriptional activation of the myomesin gene. These results provide the basis for a comparative analysis of the regulation of myomesin and M-protein genes in vivo.

Mapping of a myosin-binding domain and a regulatory phosphorylation site in M-protein, a structural protein of the sarcomeric M band

The myofibrils of cross-striated muscle fibers contain in their M bands cytoskeletal proteins whose main function seems to be the stabilization of the three-dimensional arrangement of thick filaments. We identified two immunoglobin domains (Mp2-Mp3) of M-protein as a site binding to the central region of light meromyosin. This binding is regulated in vitro by phosphorylation of a single serine residue (Ser76) in the immediately adjacent amino-terminal domain Mp1. M-protein phosphorylation by cAMP-dependent kinase A inhibits binding to myosin LMM. Transient transfection studies of cultured cells revealed that the myosin-binding site seems involved in the targeting of M-protein to its location in the myofibril. Using the same method, a second myofibril-binding site was uncovered in domains Mp9-Mp13. These results support the view that specific phosphorylation events could be also important for the control of sarcomeric M band formation and remodeling.

Structure and expression of the gene encoding murine M-protein, a sarcomere-specific member of the immunoglobulin superfamily

The complete exon-intron organization of the murine gene encoding M-protein, a structural protein of sarcomeric myofibrils, was determined. The gene is composed of 37 exons and 36 introns, spanning approximately 75 kb of DNA. Intron positions are related to the modular structure of M-protein, which is composed essentially of immunoglobulin and fibronectin type III domains. Almost all repeats follow a two exon-one domain structure. The beginning and end of each domain are defined by introns in phase I; internal introns are more divergent in position and very rarely use phase I. A single transcriptional start point was detected in both skeletal and cardiac muscle. Analysis of the prospective promoter region revealed several potential regulatory elements. CAT expression assays using promoter deletion constructs identified three regions that seem to be most important for the muscle-specific transcription activation of the M-protein gene. These results provide the first complete characterization of a gene for a member of the intracellular branch of the immunoglobulin superfamily.

Cardiopulmonary bypass primes polymorphonuclear leukocytes

Polymorphonuclear leukocyte (PMN) superoxide (.O2-) production has been implicated in the pathogenesis of cardiopulmonary bypass (CPB)-related end organ injury. PMN "priming" has been described as an event which enhances the release of .O2- following a second, activating insult. We hypothesized that PMN priming occurs during CBP and is temporally related to the plasma level of complement (C3a), interleukin (IL)-6, and IL-8. PMNs were isolated from 10 CPB patients pre-bypass (preCPB), 5 min after protamine administration (PROT), and at 6 and 24 h post-CPB. PMN .O2- production was measured by a cytochrome c reduction assay in the presence or absence of either phorbol 12-myristate-13-acetate (PMA, 0.4 microgram/ml) or N-formyl-methionyl-leucyl-phenylalanine (FMLP, 1 microM) and also after priming with 2000 nM platelet-activating factor (PAF) followed by activation with either PMA or FMLP. Plasma levels of C3a, IL-6, and IL-8 were determined by enzyme-linked immunosorbent assay. PMA-activated PMN .O2- production was significantly elevated at 6 h post-CPB compared to pre-CPB levels (11.04 +/- 0.9 vs 7.62 +/- 0.57, P = 0.009), indicating that CPB is associated with in vivo PMN priming. When PMNs were primed in vitro with PAF and then activated with PMA or FMLP, .O2- release at 6 h post-CPB was also significantly greater than pre-CPB levels (16.04 +/- 0.74 vs 12.2 +/- 0.92, P = 0.038; and 17.33 +/- 1.38 vs 13.33 +/- 1.35, P < 0.05), indicating that CPB acts synergistically with PAF to prime PMNs. Levels of C3a rose significantly over pre-CPB levels at PROT (P = 0.001), and IL-6 and IL-8 rose over pre-CPB levels at 6 h post-CPB (P = 0.01 and P = 0.006, respectively). These findings demonstrate that CPB not only directly primes PMNs, but also potentiates priming of PMNs by PAF. This "primed" PMN state, which coincided with the increased plasma levels of inflammatory mediators, may suggest a mechanism of predisposition to organ dysfunction following CPB.

Mutation of ornithine transcarbamylase (H136R) in a girl with severe intermittent orotic aciduria but normal enzyme activity

Ornithine transcarbamylase deficiency shows X-linked inheritance with partial dominant expression in carrier females. We studied a girl with intermittent severe orotic aciduria and mild hyperammonaemia despite apparently normal enzyme activity in the liver. Sequence analysis of all 10 exons of the ornithine transcarbamylase gene revealed a novel A-->G exchange (A502G) in exon 5 which changes His-136 to arginine in the ornithine transcarbamylase protein. Km values for carbamyl phosphate and ornithine determined in the patient's liver were comparable to those of wild-type enzyme but, unlike the wild-type enzyme, the mutant enzyme was unstable upon freezing and thawing. Electron microscopy revealed several giant mitochondria with paracrystalline inclusions. The results are compatible with the assumption that the mutant enzyme cannot form a functional complex with carbamyl phosphate synthetase and the ornithine carrier, resulting in decreased availability of substrates and diminished enzyme activity in vivo.

Lexipafant inhibits platelet activating factor enhanced neutrophil functions

Platelet activating factor (PAF) enhances polymorphonuclear leukocyte (PMN) superoxide (.O2-) production, CD11b expression, and elastase release, all essential components in the pathophysiology of multiple-organ failure. This study was designed to determine the effects of Lexipafant, a PAF receptor antagonist, on PAF-mediated PMN functions. PMNs from 10 healthy volunteers were isolated and pretreated with various concentrations of Lexipafant (0-100 microM). PMNs were then incubated for 5 min with 200 nM PAF for .O2- detection or 2000 nM PAF for elastase measurement and activated with 1 microM N-formylmethionylleucylphenylalanine. The mean rate of .O2- production was determined by a cytochrome c reduction assay (nmole .O2-/min/1.33 x 10(5) PMN +/- SEM). Elastase release was measured by the cleavage of the synthetic elastase substrate Meo-Suc-Ala-Ala-Pro-Val-pNA (mean elastolytic activity +/- SEM). In parallel experiments, PMNs were incubated with 200 nM PAF for 30 min following pre-treatment with Lexipafant and CD11b expression was determined by flow cytometry (mean fluorescence intensity +/- SEM). Statistical analysis was performed using repeated-measures ANOVA (P < 0.05). Lexipafant inhibited PAF-enhanced PMN .O2- generation, CD11b expression and elastase release in a dose dependent fashion. The IC50 of Lexipafant for .O2- production, CD11b expression, and elastase release was 0.046, 0.285, and 0.05 microM, respectively. Lexipafant attenuated the PAF-mediated upregulation of PMN .O2- production, CD11b expression, and elastase release in a dose dependent fashion. These data support the hypothesis that Lexipafant may reduce the severity of the inflammatory response to injury produced by PAF-enhanced activation of PMNs.

The structure of the sarcomeric M band: localization of defined domains of myomesin, M-protein, and the 250-kD carboxy-terminal region of titin by immunoelectron microscopy

The M band of vertebrate cross-striated myofibrils has remained an enigmatic structure. In addition to myosin thick filaments, two major structural proteins, myomesin and M-protein, have been localized to the M band. Also, titin is expected to be anchored in this structure. To begin to understand the molecular layout of these three proteins, a panel of 16 polyclonal and monoclonal antibodies directed against unique epitopes of defined sequence was assembled, and immunoelectron microscopy was used to locate the position of the epitopes at the sarcomere level. The results allow the localization and orientation of defined domains of titin, myomesin, and M-protein at high resolution. The 250-kD carboxy-terminal region of titin clearly enters the M band with the kinase domain situated approximately 52 nm from the central M1-line. The positions of three additional epitopes are compatible with the view that the titin molecule reaches approximately 60 nm into the opposite sarcomere half. Myomesin also seems to bridge the central M1-line and is oriented parallel to the long axis of the myofibril. The neighboring molecules are oriented in an antiparallel and staggered fashion. The amino-terminal portion of the protein, known to contain a myosin binding site, seems to adopt a specific three-dimensional arrangement. While myomesin is present in both slow and fast fibers, M-protein is restricted to fast fibers. It appears to be organized in a fundamentally different manner: the central portion of the polypeptide is around the M1-line, while the terminal epitopes seem to be arranged along thick filaments. This orientation fits the conspicuously stronger M1-lines in fast twitch fibers. Obvious implications of this model are discussed.

Aerosolized immunoglobulin treatment of respiratory syncytial virus infection in infants

BACKGROUND

Recent studies in animals with experimental respiratory syncytial virus (RSV) infection indicate that passive immunization by intranasal or intratracheal application of gamma-globulins (immunoglobulins) may be beneficial for treatment of infants with lower respiratory tract infection caused by RSV.

METHODS

We conducted a placebo-controlled, randomized multicenter study involving 68 infants with proven RSV infection admitted to 5 pediatric centers in Switzerland from November 1, 1992, through April 30, 1993. Treatment was carried out with aerosolized human IgG (Sandoglobulin) by assisted ventilation. On the day of hospital admission a single dose of 0.1 g of IgG per kg of body weight in a 5% solution or an identical amount of placebo, each delivered in 2 parts, was given.

RESULTS

The two groups did not differ substantially in their response to the aerosol received. The rate of improvement for symptoms of respiratory tract infection, oxygen requirement and length of hospital stay were comparable for both groups. There was a significant reduction (P < 0.05) in the frequency of apneic spells observed in the treatment group by Day 3 posttreatment. Aerosol therapy was generally well-tolerated in nonintubated infants, but some severe side effects (increased oxygen requirements in two patients, pneumothorax in one patient) were observed in two of three intubated and ventilated infants treated with IgG.

CONCLUSIONS

Aerosolized immunoglobulin in the dosage used had no substantial beneficial effect on RSV bronchiolitis. Despite these findings passive immunotherapy for treatment of RSV-induced lower respiratory tract infection deserves further evaluation before being discarded as ineffective.

Structure of the mouse arylsulfatase A gene and cDNA

The murine arylsulfatase A (ARSA) gene and cDNA have been cloned and sequenced. The gene is 3.8 kb long and contains eight exons. All intron/exon splice junctions conform to the GT/AG consensus sequence. The genomic structure is similar to that of the human gene. One major RNA species of 3.2 kb is transcribed. This RNA species has a 5' untranslated region of 638 nucleotides and terminates in a region around nucleotide 700 downstream of the termination codon. In addition, a rare mRNA species terminating at a polyadenylation signal 135 nucleotides downstream of the termination codon has been found. A larger transcript of 4 kb can be detected in liver. The size difference is due to initiation of transcription 5' of the cap site of the 3.2-kb mRNA species. The entire ARSA cDNA has been cloned by PCR from reverse-transcribed RNA. The coding sequence has 1518 nucleotides and predicts a protein of 506 amino acids. The nucleotide as well as the amino acid sequence is highly conserved among humans and mice.

Disseminated histoplasmosis in patients receiving low-dose methotrexate therapy for psoriasis

BACKGROUND

Low-dose methotrexate sodium therapy used for nonmalignant disease has been associated with a variety of opportunistic infections with pathogens occurring in patients with defective cellular immunity. This article describes the unusual development of disseminated histoplasmosis as a probable complication of immunosuppression resulting from use of methotrexate.

OBSERVATIONS

We report the cases of three patients in whom disseminated histoplasmosis developed while receiving low-dose methotrexate therapy for psoriasis. Disease manifestations were unusually severe in two of the three patients. All three cases were disseminated, and two cases resulted in illnesses requiring intensive medical treatment. Each patient responded appropriately to antifungal treatment, although one patient has required long-term suppressive treatment because of persistent Histoplasma antigenuria. These cases illustrate the risk for opportunistic fungal infections in patients receiving low-dose methotrexate therapy for nonmalignant diseases.

CONCLUSIONS

Histoplasma should be added to the list of pathogens to be suspected in patients receiving such therapy.

[Accidental ingestion of a battery]

A case of accidental battery ingestion by a three-year old boy is reported. The possible complications are local (i.e. necrosis of tissues by leakage of the alkaline electrolyte, by electrical injury or by impaction of the battery) and general (mercury poisoning). Large diameter batteries impacted in the oesophagus need prompt removal. When the battery is located in the stomach, two attitudes are discussed: some authors allow it to progress through the gastrointestinal tract spontaneously under radiological control, others recommend rapid removal by endoscopy or surgery in order to avoid the complications above described.