Specificity and sensibility of the Spanish version of the COMFORT Behaviour Scale for assessing pain, grade of sedation and withdrawal syndrome in the critically ill paediatric patient. Multicentre COSAIP study (Phase 1)

AIM

The main aim of this investigation was to analyse the specificity and sensibility of the COMFORT Behaviour Scale (CBS-S) in assessing grade of pain, sedation, and withdrawal syndrome in paediatric critical care patients.

METHOD

An observational, analytical, cross-sectional and multicentre study conducted in Level III Intensive Care Areas of 5 children's university hospitals. Grade of sedation was assessed using the Spanish version of the CBS-S and the Bispectral Index on sedation, once per shift over one day. Grade of withdrawal was determined using the CBS-S and the Withdrawal Assessment Tool-1, once per shift over three days.

RESULTS

A total of 261 critically ill paediatric patients with a median age of 5.07 years (P25:0.9-P75:11.7) were included in this study. In terms of the predictive capacity of the CBS-S, it obtained a Receiver Operation Curve of .84 (sensitivity of 81% and specificity of 76%) in relation to pain; .62 (sensitivity of 21% and specificity of 78%) in relation to sedation grade, and .73% (sensitivity of 40% and specificity of 74%) in determining withdrawal syndrome.

CONCLUSIONS

The Spanish version of the COMFORT Behaviour Scale could be a useful, sensible and easy scale to assess the degree of pain, sedation and pharmacological withdrawal of critically ill paediatric patients.

COVID-19 in children and young adults with moderate/severe inborn errors of immunity in a high burden area in pre-vaccine era

Background

Information regarding inborn error of immunity (IEI) as a risk factor for severe COVID-19 is scarce. We aimed to determine if paediatric patients with moderate/severe IEI got COVID-19 at the same level as the general population, and to describe COVID-19 expression.

Material and methods

We included patients with moderate/severe IEI aged 0–21 years old: cross-sectional study (June2020) to determine the prevalence of COVID-19; prospective study (January2020-January2021) including IEI patients with COVID-19. Assays used: nasopharyngeal swab SARS-CoV-2 PCR and SARS-CoV-2-specific immunoglobulins.

Results

Seven from sixty-five patients tested positive (prevalence: 10.7% (7%–13%)) after the first SARS-COV-2 wave and 13/15 patients diagnosed with COVID-19 had an asymptomatic/mild course.

Conclusions

In our area, prevalence of COVID-19 in moderate/severe IEI paediatric patients after the first wave was slightly higher than in the general population. The majority of patients presented a benign course, suggesting a possible protective factor related with age despite IEI.

Specificity and sensibility of the Spanish version of the COMFORT Behaviour Scale for assessing pain, grade of sedation and withdrawal syndrome in the critically ill paediatric patient. Multicentre COSAIP study (Phase 1)

AIM

The main aim of this investigation was to analyse the specificity and sensibility of the COMFORT Behaviour Scale (CBS-S) in assessing grade of pain, sedation, and withdrawal syndrome in paediatric critical care patients.

METHOD

An observational, analytical, cross-sectional and multicentre study conducted in Level III Intensive Care Areas of 5 children's university hospitals. Grade of sedation was assessed using the Spanish version of the CBS-S and the Bispectral Index on sedation, once per shift over one day. Grade of withdrawal was determined using the CBS-S and the Withdrawal Assessment Tool-1, once per shift over three days.

RESULTS

A total of 261 critically ill paediatric patients with a median age of 5.07 years (P25:0.9-P75:11.7) were included in this study. In terms of the predictive capacity of the CBS-S, it obtained a Receiver Operation Curve of .84 (sensitivity of 81% and specificity of 76%) in relation to pain; .62 (sensitivity of 21% and specificity of 78%) in relation to sedation grade, and .73% (sensitivity of 40% and specificity of 74%) in determining withdrawal syndrome.

CONCLUSIONS

The Spanish version of the COMFORT Behaviour Scale could be a useful, sensible and easy scale to assess the degree of pain, sedation and pharmacological withdrawal of critically ill paediatric patients.

Grade of sedation in the critically ill paediatric patient and its correlation with sociodemographic and clinical variables. Multicentre COSAIP study

AIMS

To determine the grade of sedation in the critically ill paediatric patient using Biespectral Index Sensor (BIS) and to analyse its relationship with sociodemographic and clinical patient variables.

METHODS

Observational, analytical, cross-sectional and multicentre study performed from May 2018 to January 2020 in 5 Spanish paediatric critical care units. Sex, age, reason for admission, presence of a chronic pathology, type and number of drugs and length of stay were the sociodemographic and clinical variables registered. Furthermore, the grade of sedation was assessed using BIS, 11per shift over 24hours.

RESULTS

A total of 261 paediatric patients, 53.64% of whom were male, with a median age of 1.61 years (0.35-6.55), were included in the study. Of the patients, 70.11% (n=183) were under analgosedation and monitored using the BIS sensor. A median of BIS values of 51.24±14.96 during the morning and 50.75±15.55 during the night were observed. When comparing BIS values and sociodemographic and clinical paediatric variables no statistical significance was detected.

CONCLUSIONS

Despite the limitations of the BIS, investigations and the present study show that BIS could be a useful instrument to assess grade of sedation in critically ill paediatric patients. However, further investigations which determine the sociodemographic and clinical variables involved in the grade of paediatric analgosedation, as well as studies that contrast the efficacy of clinical scales like the COMFORT Behaviour Scale-Spanish version, are required.

LUCAS (lung ultrasonography in cardiac surgery) score to monitor pulmonary edema after congenital cardiac surgery in children

Aim: Cardiopulmonary bypass (CPB) generates a systemic capillary leak syndrome with pulmonary edema. Lung ultrasound (LUS) could be useful to monitor it. Primary objective was to compare sensitivity, specificity, positive and negative predictive values of chest X-ray and LUS to detect pulmonary edema using a new score (LUCAS). Secondary objectives were to evaluate correlation between LUCAS score and respiratory and inotropic support.Methods: Prospective intervention study including patients <2 months admitted to the Pediatric Intensive Care Unit after CPB. LUS was performed with a lineal probe, screening 3 points in each lung (parasternal, anterolateral and posterior area), pre and post-CPB. Pulmonary edema was evaluated clinically, through LUCAS score and with X-ray.Results: 17 patients were included. LUS achieved higher sensitivity than X-ray to detect pulmonary edema (91.7 versus 44.0%) and greater predictive negative value (88.2 versus 53.3%). There was correlation between higher LUCAS score prior to surgery and longer mechanical ventilation. High values of LUCAS score after surgery correlated with longer CPB time, inotropic support, and FiO₂ need.Conclusion: LUS detected pulmonary edema better than chest X-ray, with greater sensitivity and negative predictive value. LUCAS score was useful to predict more inotropic support and longer mechanical ventilation.Key notesCardiopulmonary bypass during cardiac surgery, generates a systemic capillary leak syndrome with pulmonary edema.In this prospective study performed in the Pediatric Intensive Care Unit, lung ultrasound detected pulmonary edema better than X-ray, with greater sensitivity and negative predictive value.LUCAS score was useful to predict more inotropic support and longer mechanical ventilation.

Early surfactant replacement guided by lung ultrasound in preterm newborns with RDS: the ULTRASURF randomised controlled trial

This study aimed to investigate whether using lung ultrasound (LUS) scores in premature newborns with respiratory distress syndrome (RDS) allows for earlier surfactant therapy (within the first 3 h of life) than using FiO₂ criteria. This was a randomised, non-blinded clinical trial conducted in a neonatal intensive care unit. The inclusion criteria were newborns with a gestational age of ≤ 32 weeks and RDS. Patients meeting the inclusion criteria were randomly assigned to two groups: the ultrasound group, administered surfactant based on LUS score and/or FiO₂ threshold, and the control group, guided by FiO₂ only. Fifty-six patients were included. The ultrasound group received surfactant earlier (1 h of life vs. 6 h, p < 0.001), with lower FiO₂ (25% vs. 30%, p = 0.016) and lower CO₂ (48 vs. 54, p = 0.011). After surfactant treatment, newborns in the ultrasound group presented a greater SpO₂ (p = 0.001) and SpO₂/FiO₂ ratio (p = 0.012).Conclusions: LUS score allowed an earlier surfactant therapy, reduced oxygen exposure early in life and a better oxygenation after the treatment. This early surfactant replacement may lead to reduced oxygen exposure. What is Known: • Lung ultrasound scores predict the need for surfactant therapy in premature newborns. What is New: • This study shows that using lung ultrasound scores improves the timeliness of surfactant replacement compared with using FiO₂ alone.

Impact of a modification of the clinical practice guide of the American Academy of Pediatrics in the management of severe acute bronchiolitis in a pediatric intensive care unit

OBJECTIVE

To describe the characteristics and evolution of patients with bronchiolitis admitted to a pediatric intensive care unit, and compare treatment pre- and post-publication of the American Academy of Pediatrics clinical practice guide.

DESIGN

A descriptive and observational study was carried out between September 2010 and September 2017.

SETTING

Pediatric intensive care unit.

PATIENTS

Infants under one year of age with severe bronchiolitis.

INTERVENTIONS

Two periods were compared (2010-14 and 2015-17), corresponding to before and after modification of the American Academy of Pediatrics guidelines for the management of bronchiolitis in hospital.

MAIN VARIABLES

Patient sex, age, comorbidities, severity, etiology, administered treatment, bacterial infections, respiratory and inotropic support, length of stay and mortality.

RESULTS

A total of 706 patients were enrolled, of which 414 (58.6%) males, with a median age of 47 days (IQR 25-100.25). Median bronchiolitis severity score (BROSJOD) upon admission: 9 points (IQR 7-11). Respiratory syncytial virus appeared in 460 (65.16%) patients. The first period (2010-14) included 340 patients and the second period (2015-17) 366 patients. More adrenalin and hypertonic saline nebulizations and more corticosteroid treatment were administered in the second period. More noninvasive ventilation and less conventional mechanical ventilation were used, and less inotropic support was needed, with no significant differences. The antibiotherapy rate decreased significantly (P=.003).

CONCLUSIONS

Despite the decrease in antibiotherapy, the use of nebulizations and glucocorticoids in these patients should be limited, as recommended by the guide.

Photoemission and photoionization time delays and rates

Ionization and, in particular, ionization through the interaction with light play an important role in fundamental processes in physics, chemistry, and biology. In recent years, we have seen tremendous advances in our ability to measure the dynamics of photo-induced ionization in various systems in the gas, liquid, or solid phase. In this review, we will define the parameters used for quantifying these dynamics. We give a brief overview of some of the most important ionization processes and how to resolve the associated time delays and rates. With regard to time delays, we ask the question: how long does it take to remove an electron from an atom, molecule, or solid? With regard to rates, we ask the question: how many electrons are emitted in a given unit of time? We present state-of-the-art results on ionization and photoemission time delays and rates. Our review starts with the simplest physical systems: the attosecond dynamics of single-photon and tunnel ionization of atoms in the gas phase. We then extend the discussion to molecular gases and ionization of liquid targets. Finally, we present the measurements of ionization delays in femto- and attosecond photoemission from the solid-vacuum interface.

Outbreak of brainstem encephalitis associated with enterovirus-A71 in Catalonia, Spain (2016): a clinical observational study in a children's reference centre in Catalonia

OBJECTIVES

To describe the characteristics of an outbreak of brainstem encephalitis and encephalomyelitis related to enterovirus (EV) infection in Catalonia (Spain), a setting in which these manifestations were uncommon.

METHODS

Clinical and microbiological data were analysed from patients with neurological symptoms associated with EV detection admitted to a reference paediatric hospital between April and June 2016.

RESULTS

Fifty-seven patients were included. Median age was 27.7 months (p25-p75 17.1-37.6). Forty-one (72%) were diagnosed with brainstem encephalitis, seven (12%) with aseptic meningitis, six (11%) with encephalitis, and three (5%) with encephalomyelitis (two out of three with cardiopulmonary failure). Fever, lethargy, and myoclonic jerks were the most common symptoms. Age younger than 12 months, higher white-blood-cell count, and higher procalcitonin levels were associated with cardiopulmonary failure. Using a PAN-EV real-time PCR, EV was detected in faeces and/or nasopharyngeal aspirate in all the patients, but it was found in cerebrospinal fluid only in patients with aseptic meningitis. EV was genotyped in 47 out of 57 and EV-A71 was identified in 40 out of 47, being the only EV type found in patients with brainstem symptoms. Most of the detected EV-A71 strains were subgenogroup C1. Intravenous immunoglobulins were used in 34 patients. Eight cases (14%) were admitted to the intensive care unit. All the patients but three, those with encephalomyelitis, showed a good clinical course and had no significant sequelae. No deaths occurred.

CONCLUSIONS

The 2016 outbreak of brainstem encephalitis in Catalonia was associated with EV-A71 subgenogroup C1. Despite the clinical manifestations of serious disease, a favourable outcome was observed in the majority of patients.

Attosecond beamline with actively stabilized and spatially separated beam paths

We describe a versatile and compact beamline for attosecond spectroscopy. The setup consists of a high-order harmonic source followed by a delay line that spatially separates and then recombines the extreme-ultraviolet (XUV) and residual infrared (IR) pulses. The beamline introduces a controlled and actively stabilized delay between the XUV and IR pulses on the attosecond time scale. A new active-stabilization scheme combining a helium-neon-laser and a white-light interferometer minimizes fluctuations and allows to control delays accurately (26 as rms during 1.5 h) over long time scales. The high-order-harmonic-generation region is imaged via optical systems, independently for XUV and IR, into an interaction volume to perform pump-probe experiments. As a consequence of the spatial separation, the pulses can be independently manipulated in intensity, polarization, and frequency content. The beamline can be combined with a variety of detectors for measuring attosecond dynamics in gases, liquids, and solids.

Photoelectron spectrometer for attosecond spectroscopy of liquids and gases

A new apparatus for attosecond time-resolved photoelectron spectroscopy of liquids and gases is described. It combines a liquid microjet source with a magnetic-bottle photoelectron spectrometer and an actively stabilized attosecond beamline. The photoelectron spectrometer permits venting and pumping of the interaction chamber without affecting the low pressure in the flight tube. This pressure separation has been realized through a sliding skimmer plate, which effectively seals the flight tube in its closed position and functions as a differential pumping stage in its open position. A high-harmonic photon spectrometer, attached to the photoelectron spectrometer, exit port is used to acquire photon spectra for calibration purposes. Attosecond pulse trains have been used to record photoelectron spectra of noble gases, water in the gas and liquid states as well as solvated species. RABBIT scans demonstrate the attosecond resolution of this setup.

Exclusive breastfeeding and its effect on growth of Malawian infants: results from a cross-sectional study

BACKGROUND

For the optimal nutrition of children under 2 years of age, it is considered important that they be exclusively breastfed for the first 6 months before being given complementary food.

AIMS AND OBJECTIVES

A cross-sectional nutritional baseline survey was undertaken in 2011 in the Kasungu and Mzimba Districts of Malawi to assess the nutritional status of children under 2 years of age and its determinants in order to prepare a nutrition education intervention programme. The intention of this study was to assess the nutritional status of infants aged 0-<6 months with regard to food intake.

METHODS

Interviews were conducted on randomly selected families with children under 2 years; anthropometric measurements were obtained from mothers and their children. Only infants between 0 and <6 months were selected for analysis (n  =  196). An ANCOVA test was performed on age of the infant with mothers' height and weight as covariates.

RESULTS

Prevalence of stunting (infants' length-for-age Z-score (LAZ) <-2SD) was 39%, wasting (WLZ <-2SD) 2%, and underweight (WAZ <-2SD) 13%. Of the infants under 6 months, 43% were exclusively breastfed. Predominant breastfeeding and mixed breastfeeding were less common (21% and 36%, respectively). The ANCOVA confirmed the association between exclusive breastfeeding and LAZ and WAZ: exclusively breastfed infants had a higher mean (SE) LAZ (-1.13, 0.12) and WAZ (-0.41, 0.13) than infants not being exclusively breastfed (-1.59, 0.11, and -0.97, 0.11, respectively). There was no overall significant association between breastfeeding practice and WLZ.

CONCLUSION

Exclusive breastfeeding of infants under 6 months is associated with higher mean LAZ and WAZ. Promotion of exclusive breastfeeding in low-income countries is important in preventing growth retardation.

Ribavirin inhibits West Nile virus replication and cytopathic effect in neural cells

West Nile virus (WNV) is an emerging mosquito-borne pathogen that was reported for the first time in the Western hemisphere in August 1999, when an encephalitis outbreak in New York City resulted in 62 clinical cases and 7 deaths. WNV, for which no antiviral therapy has been described, was recently recovered from a pool of mosquitoes collected in New York City. In anticipation of the recurrence of WNV during the summer of 2000, an analysis was made of the efficacy of the nucleoside analogue ribavirin, a broad-spectrum antiviral compound with activity against several RNA viruses, for treatment of WNV infection. High doses of ribavirin were found to inhibit WNV replication and cytopathogenicity in human neural cells in vitro.

Expression and characterization of the Borna disease virus polymerase

Borna disease virus is the prototype of a new family, Bornaviridae, within the order Mononegavirales, that is characterized by nuclear transcription, splicing, low level replication, and neurotropism. The products of five open reading frames predicted from the genomic sequence have been confirmed; however, expression of the sixth, corresponding to the putative viral polymerase (L), has not been demonstrated. Here, we describe expression and characterization of a 190-kDa protein proposed to represent L. Expression of this protein from the third transcription unit of the viral genome is dependent on a splicing event that fuses a small upstream open reading frame in frame with the larger downstream continuous open reading frame. The protein is detected by serum antibodies from infected rats and is present in the nucleus, where it colocalizes with the phosphoprotein. L is also shown to be phosphorylated by cellular kinases and to interact with the viral phosphoprotein in coimmunoprecipitation studies. These findings are consistent with the identity of the 190-kDa protein as the viral polymerase and provide insights and describe reagents that will be useful for Bornavirus molecular biology and pathobiology.

Genetic analysis of West Nile New York 1999 encephalitis virus

Analysis of the genome of the flavivirus responsible for the 1999 New York City encephalitis epidemic cloned from human brain by reverse-transcription polymerase chain reaction Indicates its identity as a lineage I West Nile virus (WNV; WNV-NY1999) closely related to WNVs previously isolated In the Middle East.

[Neuromuscular pathology in a critical pediatric patient]

OBJECTIVE

To describe and provide diagnosis guidelines for the neuromuscular pathology of the pediatric critical patients, manifested as extubation difficulty, based in our experience.

CLINICAL CASES

A retrospective study has been performed on three patients in the Pediatric Intensive Care Unit that were diagnosed by using clinical, analytical and electromyographical findings. In the three patients the presence of the disorder was suspected due to the extubation difficulty and the hypotony. All them received vecuronium as neuromuscular blockage while dexamethasone was provided to one of them due to a nodal tachycardia. Myopathic causes were discarded in view of the normally of the muscular enzymes. The electromyography showed an axonal disorder in all three child. Neither lumbar puncture nor muscular biopsy were performed in any of them.

CONCLUSIONS

The three patients were diagnosed for a drug neuropathy (neuromuscular blocked and/or corticotheraphy). There were described another causes of the critical patient polyneuropathy in the literature, but we didn't find any of them.

Inhibition of Borna disease virus replication by ribavirin

The guanosine analogue ribavirin was tested for antiviral activity in two neural cell lines, human oligodendrocytes and rat glia, against Borna disease virus (BDV) strains V and He/80. Ribavirin treatment resulted in lower levels of virus and viral transcripts within 12 h. Addition of guanosine but not adenosine resulted in a profound reduction of the ribavirin effect. Ribavirin appears to be an effective antiviral agent for treatment of BDV infection in vitro. A likely mechanism for its activity is reduction of the intracellular GTP pool, resulting in inhibition of transcription and capping of BDV mRNAs.

Expression of human foamy virus reverse transcriptase involves a spliced pol mRNA

In human foamy virus (HFV) the reverse transcriptase is expressed independently of the Gag protein as a 127-kDa Pol precursor molecule. Evaluating the mechanism of Pol expression we identified a spliced mRNA which uses the main 5' splice donor and a splice acceptor site located in the gag gene. The significance of this spliced transcript for HFV Pol expression was studied by constructing a virus with a mutated splice acceptor site. This virus was unable to express detectable Pol proteins after transient transfection. Replication of the mutant was studied by a sensitive assay based on HFV transactivator-stimulated expression of an integrated lacZ gene under control of the HFV long terminal repeat. Whereas in the first 2 weeks after transfection the mutant replicated 3 to 5 order of magnitude less well than wild-type virus, extracellular titers obtained thereafter were similar to those of wild-type virus. This increase in replication competence was accompanied by a reversion of the mutated splice acceptor site. The results underlined the importance of the spliced pol transcript for HFV replication and pointed to a second mechanism of Pol expression. Indicator gene assays suggest that this other mechanism is likely to be a transactivator-dependent cryptic promoter in the gag gene which gives rise to Pol-encoding transcripts.

Foamy virus reverse transcriptase is expressed independently from the Gag protein

In the foamy virus (FV) subgroup of retroviruses the pol genes are located in the +1 reading frame relative to the gag genes and possess potential ATG initiation codons in their 5' regions. This genome organization suggests either a + 1 ribosomal frameshift to generate a Gag-Pol fusion protein, similar to all other retroviruses studied so far, or new initiation of Pol translation, as used by pararetroviruses, to express the Pol protein. By using a genetic approach we have ruled out the former possibility and provide evidence for the latter. Two down-mutations (M53 and M54) of the pol ATG codon were found to abolish replication and Pol protein expression of the human FV isolate. The introduction of a new ATG in mutation M55, 3' to the down-mutated ATG of mutation M53, restored replication competence, indicating that the pol ATG functions as a translational initiation codon. Two nonsense mutants (M56 and M57), which functionally separated gag and pol with respect to potential frame-shifting sites, were also replication-competent, providing further genetic evidence that FVs express the Pol protein independently from Gag. Our results show that during a particular step of the replication cycle, FVs differ fundamentally from all other retroviruses.

The mammalian transferrin-independent iron transport system may involve a surface ferrireductase activity

Mammalian cells accumulate iron from ferric citrate or ferric nitrilotriacetate through the activity of a transferrin-independent iron transport system [Sturrock, Alexander, Lamb, Craven and Kaplan (1990) J. Biol. Chem. 265, 3139-3145]. The uptake system might recognize and transport ferric-anion complexes, or cells may reduce ferric iron at the surface and then transport ferrous iron. To distinguish between these possibilities we exposed cells to either [59Fe]ferric citrate or ferric [14C]citrate and determined whether accumulation of iron was accompanied by the obligatory accumulation of citrate. In HeLa cells and human skin fibroblasts the rate of accumulation of iron was three to five times greater than that of citrate. Incubation of fibroblasts with ferric citrate or ferric ammonium citrate resulted in an enhanced accumulation of iron and citrate; the molar ratio of accumulation approaching unity. A similar rate of citrate accumulation, however, was observed when ferric citrate-incubated cells were exposed to [14C]citrate alone. Further studies demonstrated the independence of iron and citrate accumulation: addition of unlabelled citrate to cells decreased the uptake of labelled citrate without affecting the accumulation of 59Fe; iron uptake was decreased by the addition of ferrous chelators whereas the uptake of citrate was unaffected; reduction of ferric iron by ascorbate increased the uptake of iron but had no effect on the uptake of citrate. When HeLa cells were depleted of calcium, iron uptake decreased, but there was little effect on citrate uptake. These results indicate that transport of iron does not require the obligatory transport of citrate and vice versa. The mammalian transferrin-independent iron transport system appears functionally similar to iron transport systems in both the bacterial and plant kingdoms which require the activities of both a surface reductase and a ferrous metal transporter.

Regulation of iron uptake in Saccharomyces cerevisiae. The ferrireductase and Fe(II) transporter are regulated independently

Iron is required for the growth of Saccharomyces cerevisiae. High concentrations of iron, however, are toxic, forcing this yeast to tightly regulate its concentration of intracellular free iron. We demonstrate that S. cerevisiae accumulates iron through the combined action of a plasma membrane ferrireductase and an Fe(II) transporter. This transporter is highly selective for Fe(II). Several other transition metals did not inhibit iron uptake when these metals were present at a concentration 100-fold higher than the Km (0.15 microM) for iron transport. Pt(II) inhibited ferrireductase activity but not the ability of cells to transport iron that was chemically reduced to Fe(II). Incubation of cells in a synthetic iron-limited media resulted in the induction of both ferrireductase and Fe(II) transporter activities. In complex media, Fe(II) transport activity was regulated in response to media iron concentration, while the activity of the ferrireductase was not. When stationary phase cells were inoculated into fresh media, ferrireductase activity increased independent of the iron content of the media; in contrast, transporter activity varied inversely with iron levels. These results demonstrate that the ferrireductase and Fe(II) transporter are separately regulated and that iron accumulation may be limited by changes in either activity.

Regulation of the transferrin-independent iron transport system in cultured cells

Mammalian cells accumulate iron via the binding of transferrin to high affinity surface receptors, or through a transferrin-independent pathway which involves the uptake of iron-organic anion chelates by a membrane-based transport system. Previously we determined that the transferrin-independent transport system was present on a wide variety of cultured cells (Sturrock, A., Alexander, J., Lamb, J., Craven, C. M., and Kaplan, J. (1990) J. Biol. Chem. 265, 3139-3145). In this communication we demonstrate that the transferrin-independent iron uptake system is regulated differently than the transferrin-mediated pathway. The activity of the transferrin-independent system was unaffected by changes in cellular growth rate, induction of DNA synthesis and cell division, or depletion of cellular iron. Exposure of cells to ferric or ferrous iron, however, resulted in a time-dependent increase in transport activity, due to a change in Vmax with no change in Km. Increased transport activity was seen in a variety of cultured cell types, occurred in the presence of cycloheximide, and persisted for hours after removal of iron. The ability of other transition metals to induce changes in transport, or to compete with iron for accumulation by the transferrin-independent uptake system, was critically dependent on the composition of the media in which the cells were incubated. Metals such as Cu2+ or Zn2+, but not Cd2+ or Mn2+, when dissolved in a balanced salt solution buffered with 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, induced changes in the transferrin-independent iron transport system. The same metals which induced changes in transport were ineffective in media containing amino acids, ascorbate, or N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine. The Vmax of the transferrin-independent iron transport system was also elevated by increases in intracellular Ca2+. The effect of iron on transport activity, however, did not result from an iron-induced release of intracellular Ca2+. These results suggest a novel form of regulation in which the presence of extracellular iron induces the appearance of previously cryptic transporters and thus accelerates the clearance of potentially toxic molecules.

[Quantitative-morphometric characterization of the lung structure in congenital heart defects exemplified by Fallot disease and isolated ventricular septal defect]

The aim of this study was to investigate the possibility of determination of lung changes in congenital deformity of heart and vessels by the method of Weibel and Elias (1967) for count of points in the lung (volume of alveoli and interstitium). The results show that this method is suitable for the estimation of quantitative changes in Morbus Fallot. In order to decide the degree of arteriosclerosis an additional measurement of the wall thickness of lung vessels is necessary in cases of ventricular septal defect. The arteriosclerosis is an important factor for the secondary variations, especially of the right heart. A field of application of this method could be the praeoperative lung biopsy for the clarification of the question of operability.

Heme regulation of HeLa cell transferrin receptor number

The number of diferic transferrin receptors on HeLa cells decreases when cells are grown in iron-supplemented media. The experiments reported here suggest that heme is the iron-containing compound which serves as the signal for receptor number regulation. When HeLa cells were grown in the presence of hemin, transferrin receptor number decreased to a greater degree than when cells were grown in equivalent amounts of iron supplied as ferric ammonium citrate. Incubation of cells in conditions which increased cellular heme content resulted in a decrease in cellular transferrin receptors. Incubating cells with 5-aminolevulinic acid (thus bypassing the rate-limiting step in heme biosynthesis, 5-aminolevulinic acid synthase) led to a decrease in transferrin receptor number. Incubation of cells with an inhibitor of heme oxygenase, Sn-protoporphyrin IX, also led to a decrease in transferrin receptor number. When cellular heme content was decreased by inhibiting heme synthesis with succinylacetone (an inhibitor of 5-aminolevulinic acid dehydratase), or by depriving cells of iron with deferoxamine, an increase in HeLa cell transferrin receptor number was seen. When HeLa cells were incubated with inducers of heme oxygenase (CoCl2, SnCl2, Co-protoporphyrin IX), transferrin receptor number also increased. The effects of all compounds which alter transferrin receptor number were dependent on the concentration of the supplement, as well as the duration of the supplementation. These experiments suggest that intracellular heme content may be an important signal controlling transferrin receptor number.

[Analysis of therapeutic success and of obstetrical results in sterile marriages]

In the course of sterility therapy 375 pregnancies were observed in 296 patients. 63 women conceived twice or more. At the first visite the mean age of the patients was 25,8 years, the mean duration of sterility 2,7 years. A primary sterility was observed in 207 and a secondary sterility in 98 cases. The main therapeutic procedure was the induction of ovulation with FSH/LH releasing preparations (Clomiphen, Cyclofenil, Epimestrol) (40,3%), followed by the substitution therapy with human gonadotrophins (22,7%). 78 pregnancies ended by spontaneous and 4 by artificially induced abortion. The abortion rate in this study was 20,8 %, exceeding considerably the normal abortion rate. The rate of extrauterine pregnancies was also increased, being 2,4%. There was no significant difference in the abortion rate of pregnancies with or without induction of ovulation. The age at the time of conception and the duration of therapy had no significant influence on the rate of abortions. In 293 pregnancies the duration of gestation exceeded the 28th week. However, 33,1% of these pregnancies had complications that required hospitalisation. Almost 50% of the complications consisted of threatened abortion. The mean duration of gestation was reduced by 5 days, caused by a relatively high frequency of early births (16,9%). The mode of delivery of our patients was in 68,8% spontaneous delivery, in 16,2% caesarian section, in 15,0% forceps or vacuum extractions. This corresponds to the general mode of delivery of our hospital. Only after gonadotrophin therapy a higher caesarian section rate of 26,8% was noted. Out of the 310 live born children, 9,2% had a weight below 2500 g, owing to a multiple pregnancy rate of 4,1%. 4% of the children showed the signs of dystrophia. The perinatal mortality amounted to 5,1%. However, when the gonadotrophin induced multiple pregnancies are excluded, the rate is 2,7%. Only 2 cases of malformations were observed.