Molecular characterization of SARS-CoV-2 Omicron clade and clinical presentation in children

Since its emergence, SARS-CoV-2 Omicron clade has shown a marked degree of variability and different clinical presentation compared with previous clades. Here we demonstrate that at least four Omicron lineages circulated in children since December 2021, and studied until November 2022: BA.1 (33.6%), BA.2 (40.6%), BA.5 (23.7%) and BQ.1 (2.1%). At least 70% of infections concerned children under 1 year, most of them being infected with BA.2 lineages (n = 201, 75.6%). Looking at SARS-CoV-2 genetic variability, 69 SNPs were found to be significantly associated in pairs, (phi <  - 0.3 or > 0.3 and p-value < 0.001). 16 SNPs were involved in 4 distinct clusters (bootstrap > 0.75). One of these clusters (A23040G, A27259C, T23617G, T23620G) was also positively associated with moderate/severe COVID-19 presentation (AOR [95% CI] 2.49 [1.26-4.89] p-value: 0.008) together with comorbidities (AOR [95% CI] 2.67 [1.36-5.24] p-value: 0.004). Overall, these results highlight the extensive SARS-CoV-2 Omicron circulation in children, mostly aged < 1 year, and provide insights on viral diversification even considering low-abundant SNPs, finally suggesting the potential contribution of viral diversification in affecting disease severity.

Increase in invasive group A streptococcal infections in Milan, Italy: a genomic and clinical characterization

Background

Group A Streptococcus (GAS) causes multiple clinical manifestations, including invasive (iGAS) or even life-threatening (severe-iGAS) infections. After the drop in cases during COVID-19 pandemic, in 2022 a sharp increase of GAS was reported globally.

Methods

GAS strains collected in 09/2022-03/2023 in two university hospitals in Milan, Italy were retrospectively analyzed. Clinical/epidemiological data were combined with whole-genome sequencing to: (i) define resistome/virulome, (ii) identify putative transmission chains, (iii) explore associations between emm-types and clinical severity.

Results

Twenty-eight isolates were available, 19/28 (67.9%) from adults and 9/28 (32.1%) from pediatric population. The criteria for iGAS were met by 19/28 cases (67.9%), of which 11/19 (39.3%) met the further criteria for severe-iGAS. Pediatric cases were mainly non-invasive infections (8/9, 88.9%), adult cases were iGAS and severe-iGAS in 18/19 (94.7%) and 10/19 (52.6%), respectively. Thirteen emm-types were detected, the most prevalent being emm1 and emm12 (6/28 strains each, 21.4%). Single nucleotide polymorphism (SNP) analysis of emm1.0 and emm12.0 strains revealed pairwise SNP distance always >10, inconsistent with unique transmission chains. Emm12.0-type, found to almost exclusively carry virulence factors speH and speI, was mainly detected in children and in no-iGAS infections (55.6 vs. 5.3%, p = 0.007 and 66.7 vs. 0.0%, p < 0.001, respectively), while emm1.0-type was mainly detected in severe-iGAS (0.0 vs. 45.5%, p = 0.045).

Conclusions

This study showed that multiple emm-types contributed to a 2022/2023 GAS infection increase in two hospitals in Milan, with no evidence of direct transmission chains. Specific emm-types could be associated with disease severity or invasiveness. Overall, these results support the integration of classical epidemiological studies with genomic investigation to appropriately manage severe infections and improve surveillance.

The mef(A)/msr(D)-carrying streptococcal prophage Φ1207.3 encodes an SOS-like system, induced by UV-C light, responsible for increased survival and increased mutation rate

Bacterial SOS response is an inducible system of DNA repair and mutagenesis. Streptococci lack a canonical SOS response, but an SOS-like response was reported in some species. The mef(A)-msr(D)-carrying prophage Ф1207.3 of Streptococcus pyogenes contains a region, spanning orf6 to orf11, showing homology to characterized streptococcal SOS-like cassettes. Genome-wide homology search showed the presence of the whole Φ1207.3 SOS-like cassette in three S. pyogenes prophages, while parts of it were found in other bacterial species. To investigate whether this cassette confers an SOS-mutagenesis phenotype, we constructed Streptococcus pneumoniae R6 isogenic derivative strains: (i) FR172, streptomycin resistant, (ii) FR173, carrying Φ1207.3, and (iii) FR174, carrying a recombinant Φ1207.3, where the SOS-like cassette was deleted. These strains were used in survival and mutation rate assays using a UV-C LED instrument, for which we designed and 3D-printed a customized equipment, constituted of an instrument support and swappable-autoclavable mini-plates and lids. Upon exposure to UV fluences ranging from 0 to 6,400 J/m2 at four different wavelengths, 255, 265, 275, and 285 nm, we found that the presence of Φ1207.3 SOS-like cassette increases bacterial survival up to 34-fold. Mutation rate was determined by measuring rifampicin resistance acquisition upon exposure to UV fluence of 50 J/m2 at the four wavelengths by fluctuation test. The presence of Φ1207.3 SOS-like cassette resulted in a significant increase in the mutation rate (up to 18-fold) at every wavelength. In conclusion, we demonstrated that Φ1207.3 carries a functional SOS-like cassette responsible for an increased survival and increased mutation rate in S. pneumoniae. IMPORTANCE Bacterial mutation rate is generally low, but stress conditions and DNA damage can induce stress response systems, which allow for improved survival and continuous replication. The SOS response is a DNA repair mechanism activated by some bacteria in response to stressful conditions, which leads to a temporary hypermutable phenotype and is usually absent in streptococcal genomes. Here, using a reproducible and controlled UV irradiation system, we demonstrated that the SOS-like gene cassette of prophage Φ1207.3 is functional, responsible for a temporary hypermutable phenotype, and enhances bacterial survival to UV irradiation. Prophage Φ1207.3 also carries erythromycin resistance genes and can lysogenize different pathogenic bacteria, constituting an example of a mobile genetic element which can confer multiple phenotypes to its host.

A Whole-Genome Sequencing-Based Approach for the Characterization of Klebsiella pneumoniae Co-Producing KPC and OXA-48-like Carbapenemases Circulating in Sardinia, Italy

BACKGROUND

Whole-genome sequencing (WGS) provides important information for the characterization, surveillance, and monitoring of antimicrobial resistance (AMR) determinants, particularly in cases of multi- and extensively drug-resistant microorganisms. We reported the results of a WGS analysis carried out on carbapenemases-producing Klebsiella pneumoniae, which causes hospital-acquired infections (HAIs) and is characterized by a marked resistance profile.

METHODS

Clinical, phenotypic, and genotypic data were collected for the AMR surveillance screening program of the University Hospital of Sassari (Italy) during 2020-2021. Genomic DNA was sequenced using the Illumina Nova Seq 6000 platform. Final assemblies were manually curated and carefully verified for the detection of antimicrobial resistance genes, porin mutations, and virulence factors. A phylogenetic analysis was performed using the maximum likelihood method.

RESULTS

All 17 strains analyzed belonged to ST512, and most of them carried the blaKPC-31 variant blaOXA-48-like, an OmpK35 truncation, and an OmpK36 mutation. Phenotypic analysis showed a marked resistance profile to all antibiotic classes, including β-lactams, carbapenems, aminoglycosides, fluoroquinolone, sulphonamides, and novel β-lactam/β-lactamase inhibitors (BL/BLI).

CONCLUSION

WGS characterization revealed the presence of several antibiotic resistance determinants and porin mutations in highly resistant K. pneumoniae strains responsible for HAIs. The detection of blaKPC-31 in our hospital wards highlights the importance of genomic surveillance in hospital settings to monitor the emergence of new clones and the need to improve control and preventive strategies to efficiently contrast AMR.

Genomic Characterization of Carbapenem-Resistant Acinetobacter baumannii (CRAB) in Mechanically Ventilated COVID-19 Patients and Impact of Infection Control Measures on Reducing CRAB Circulation during the Second Wave of the SARS-CoV-2 Pandemic in Milan, Italy

COVID-19 has significantly affected hospital infection prevention and control (IPC) practices, especially in intensive care units (ICUs). This frequently caused dissemination of multidrug-resistant organisms (MDROs), including carbapenem-resistant Acinetobacter baumannii (CRAB). Here, we report the management of a CRAB outbreak in a large ICU COVID-19 hub Hospital in Italy, together with retrospective genotypic analysis by whole-genome sequencing (WGS). Bacterial strains obtained from severe COVID-19 mechanically ventilated patients diagnosed with CRAB infection or colonization between October 2020 and May 2021 were analyzed by WGS to assess antimicrobial resistance and virulence genes, along with mobile genetic elements. Phylogenetic analysis in combination with epidemiological data was used to identify putative transmission chains. CRAB infections and colonization were diagnosed in 14/40 (35%) and 26/40 (65%) cases, respectively, with isolation within 48 h from admission in 7 cases (17.5%). All CRAB strains belonged to Pasteur sequence type 2 (ST2) and 5 different Oxford STs and presented blaOXA-23 gene-carrying Tn2006 transposons. Phylogenetic analysis revealed the existence of four transmission chains inside and among ICUs, circulating mainly between November and January 2021. A tailored IPC strategy was composed of a 5-point bundle, including ICU modules' temporary conversion to CRAB-ICUs and dynamic reopening, with limited impact on ICU admission rate. After its implementation, no CRAB transmission chains were detected. Our study underlies the potentiality of integrating classical epidemiological studies with genomic investigation to identify transmission routes during outbreaks, which could represent a valuable tool to ensure IPC strategies and prevent the spread of MDROs. IMPORTANCE Infection prevention and control (IPC) practices are of paramount importance for preventing the spread of multidrug-resistant organisms (MDROs) in hospitals, especially in the intensive care unit (ICU). Whole-genome sequencing (WGS) is seen as a promising tool for IPC, but its employment is currently still limited. COVID-19 pandemics have posed dramatic challenges in IPC practices, causing worldwide several outbreaks of MDROs, including carbapenem-resistant Acinetobacter baumannii (CRAB). We present the management of a CRAB outbreak in a large ICU COVID-19 hub hospital in Italy using a tailored IPC strategy that allowed us to contain CRAB transmission while preventing ICU closure during a critical pandemic period. The analysis of clinical and epidemiological data coupled with retrospective genotypic analysis by WGS identified different putative transmission chains and confirmed the effectiveness of the IPC strategy implemented. This could be a promising approach for future IPC strategies.

A case of SARS-CoV-2 Omicron reinfection resulting in a significant immunity boost in a paediatric patient affected by B-cell acute lymphoblastic leukemia

BACKGROUND

Since its emergence in November 2021, SARS-CoV-2 Omicron clade has quickly become dominant, due to its increased transmissibility and immune evasion. Different sublineages are currently circulating, which differ in mutations and deletions in regions of the SARS-CoV-2 genome implicated in the immune response. In May 2022, BA.1 and BA.2 were the most prevalent sublineages in Europe, both characterized by ability of evading natural acquired and vaccine-induced immunity and of escaping monoclonal antibodies neutralization.

CASE PRESENTATION

A 5-years old male affected by B-cell acute lymphoblastic leukemia in reinduction was tested positive for SARS-CoV-2 by RT-PCR at the Bambino Gesù Children Hospital in Rome in December 2021. He experienced a mild COVID-19 manifestation, and a peak of nasopharyngeal viral load corresponding to 15.5 Ct. Whole genome sequencing identified the clade 21 K (Omicron), sublineage BA.1.1. The patient was monitored over time and tested negative for SARS-CoV-2 after 30 days. Anti-S antibodies were detected positive with modest titre (3.86 BAU/mL), while anti-N antibodies were negative. 74 days after the onset of the first infection and 23 days after the last negative test, the patient was readmitted to hospital with fever, and tested positive for SARS-CoV-2 by RT-PCR (peak of viral load corresponding to 23.3 Ct). Again, he experienced a mild COVID-19. Whole genome sequencing revealed an infection with the Omicron lineage BA.2 (21L clade). Sotrovimab administration was started at the fifth day of positivity, and RT-PCR negativity occurred 10 days later. Surveillance SARS-CoV-2 RT-PCR were persistently negative, and in May 2022, anti-N antibodies were found positive and anti-S antibodies reached titres > 5000 BAU/mL.

CONCLUSIONS

By this clinical case, we showed that SARS-CoV-2 reinfection within the Omicron clade can occur and can be correlated to inadequate immune responses to primary infection. We also showed that the infection's length was shorter in the second respect to first episode, suggesting that pre-existing T cell-mediated immunity, though not preventing re-infection, might have limited the SARS-CoV-2 replication capacity. Lastly, Sotrovimab treatment retained activity against BA.2, probably accelerating the viral clearance in the second infectious episode, after which seroconversion and increase of anti-S antibodies titres were observed.

Streptococcus pyogenes Φ1207.3 Is a Temperate Bacteriophage Carrying the Macrolide Resistance Gene Pair mef(A)-msr(D) and Capable of Lysogenizing Different Streptococci

Streptococcus pyogenes prophage Φ1207.3 (formerly Tn1207.3) carries the mef(A)-msr(D) resistance genes, responsible for type M macrolide resistance. To investigate if Φ1207.3 is a functional bacteriophage, we transferred the element from the original S. pyogenes host in a prophage-free and competence-deficient S. pneumoniae strain. Pneumococcal cultures of the Φ1207.3-carrying lysogen were treated with mitomycin C to assess if Φ1207.3 enters the lytic cycle. Mitomycin C induced a limited phage burst and a growth impairment, resulting in early entrance into the stationary phase. To determine if Φ1207.3 is able to produce mature phage particles, we prepared concentrated supernatants recovered from a mitomycin C-induced pneumococcal culture by sequential centrifugation and ultracentrifugation steps. Negative-staining transmission electron microscopy (TEM) of supernatants revealed the presence of phage particles with an icosahedral, electron-dense capsid and a long, noncontractile tail, typical of a siphovirus. Quantification of Φ1207.3 was performed by quantitative PCR (qPCR) and semiquantitatively by TEM. PCR quantified 3.34 × 104 and 6.06 × 104 excised forms of phage genome per milliliter of supernatant obtained from the untreated and mitomycin C-treated cultures, respectively. By TEM, we estimated 3.02 × 103 and 7.68 × 103 phage particles per milliliter of supernatant. The phage preparations of Φ1207.3 infected and lysogenized pneumococcal recipient strains at a frequency of 7.5 × 10-6 lysogens/recipient but did not show sufficient lytic activity to form plaques. Phage lysogenization efficiently occurred after 30 min of contact of the phages with the recipient cells and required a minimum of 103 phage particles. IMPORTANCE Bacteriophages play an important role in bacterial physiology and genome evolution. The widespread use of genome sequencing revealed that bacterial genomes can contain several different integrated temperate bacteriophages, which can constitute up to 20% of the genome. Most of these bacteriophages are only predicted in silico and are never shown to be functional. In fact, it is often difficult to induce the lytic cycle of temperate bacteriophages. In this work, we show that Φ1207.3, a peculiar bacteriophage originally from Streptococcus pyogenes, which can lysogenize different streptococci and carries the macrolide resistance mef(A)-msr(D) gene pair, is capable of producing mature virions, but only at a low level, while not being able to produce plaques. This temperate phage is probably a partially functional phage, which seems to have lost lytic characteristics to specialize in lysogenization. While we are not used to conceiving phages separately from lysis, this behavior could actually be more frequent than expected.

Predicted transmembrane proteins with homology to Mef(A) are not responsible for complementing mef(A) deletion in the mef(A)-msr(D) macrolide efflux system in Streptococcus pneumoniae

Objectives

In streptococci, the type M resistance to macrolides is due to the mef(A)–msr(D) efflux transport system of the ATP-Binding cassette (ABC) superfamily, where it is proposed that mef(A) codes for the transmembrane channel and msr(D) for the two ATP-binding domains. Phage ϕ1207.3 of Streptococcus pyogenes, carrying the mef(A)–msr(D) gene pair, is able to transfer the macrolide efflux phenotype to Streptococcus pneumoniae. Deletion of mef(A) in pneumococcal ϕ1207.3-carrying strains did not affect erythromycin efflux. In order to identify candidate genes likely involved in complementation of mef(A) deletion, the Mef(A) amino acid sequence was used as probe for database searching.

Results

In silico analysis identified 3 putative candidates in the S. pneumoniae R6 genome, namely spr0971, spr1023 and spr1932. Isogenic deletion mutants of each candidate gene were constructed and used in erythromycin sensitivity assays to investigate their contribution to mef(A) complementation. Since no change in erythromycin sensitivity was observed compared to the parental strain, we produced double and triple mutants to assess the potential synergic activity of the selected genes. Also these mutants did not complement the mef(A) function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05856-6.

Chromosomal integration of Tn5253 occurs downstream of a conserved 11-bp sequence of the rbgA gene in Streptococcus pneumoniae and in all the other known hosts of this integrative conjugative element (ICE)

Background

Tn5253, a composite Integrative Conjugative Element (ICE) of Streptococcus pneumoniae carrying tet(M) and cat resistance determinants, was found to (i) integrate at specific 83-bp integration site (attB), (ii) produce circular forms joined by a 84-bp sequence (attTn), and (iii) restore the chromosomal integration site. The purpose of this study is to functionally characterize the attB in S. pneumoniae strains with different genetic backgrounds and in other bacterial species, and to investigate the presence of Tn5253 attB site into bacterial genomes.

Results

Analysis of representative Tn5253-carryng transconjugants obtained in S. pneumoniae strains with different genetic backgrounds and in other bacterial species, namely Streptococcus agalactiae, Streptococcus gordonii, Streptococcus pyogenes, and Enterococcus faecalis showed that: (i) Tn5253 integrates in rbgA of S. pneumoniae and in orthologous rbgA genes of other bacterial species, (ii) integration occurs always downstream of a 11-bp sequence conserved among streptococcal and enterococcal hosts, (iii) length of the attB site corresponds to length of the duplication after Tn5253 integration, (iv) attB duplication restores rbgA CDS, (v) Tn5253 produced circular forms containing the attTn site at a concentration ranging between 2.0 × 10⁻⁵ to 1.2 × 10⁻² copies per chromosome depending on bacterial species and strain, (vi) reconstitution of attB sites occurred at 3.7 × 10⁻⁵ to 1.7 × 10⁻² copies per chromosome. A database search of complete microbial genomes using Tn5253 attB as a probe showed that (i) thirteen attB variants were present in the 85 complete pneumococcal genomes, (ii) in 75 pneumococcal genomes (88.3 %), the attB site was 83 or 84 nucleotides in length, while in 10 (11.7 %) it was 41 nucleotides, (iii) in other 19 bacterial species attB was located in orthologous rbgA genes and its size ranged between 17 and 84 nucleotides, (iv) the 11-bp sequence, which correspond to the last 11 nucleotides of attB sites, is conserved among the different bacterial species and can be considered the core of the Tn5253 integration site.

Conclusions

A functional characterization of the Tn5253 attB integration site combined with genome analysis contributed to elucidating the potential of Tn5253 horizontal gene transfer among different bacterial species.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13100-021-00253-z.

Disbalancing Envelope Stress Responses as a Strategy for Sensitization of Escherichia coli to Antimicrobial Agents

Disbalancing envelope stress responses was investigated as a strategy for sensitization of Escherichia coli to antimicrobial agents. Seventeen isogenic strains were selected from the KEIO collection with deletions in genes corresponding to the σ^E, Cpx, Rcs, Bae, and Psp responses. Antimicrobial activity against 20 drugs with different targets was evaluated by disk diffusion and gradient strip tests. Growth curves and time-kill curves were also determined for selected mutant-antimicrobial combinations. An increase in susceptibility to ampicillin, ceftazidime, cefepime, aztreonam, ertapenem, and fosfomycin was detected. Growth curves for Psp response mutants showed a decrease in optical density (OD) using sub-MIC concentrations of ceftazidime and aztreonam (ΔpspA and ΔpspB mutants), cefepime (ΔpspB and ΔpspC mutants) and ertapenem (ΔpspB mutant). Time-kill curves were also performed using 1xMIC concentrations of these antimicrobials. For ceftazidime, 2.9 log₁₀ (ΔpspA mutant) and 0.9 log₁₀ (ΔpspB mutant) decreases were observed at 24 and 8 h, respectively. For aztreonam, a decrease of 3.1 log₁₀ (ΔpspA mutant) and 4 log10₁₀ (ΔpspB mutant) was shown after 4–6 h. For cefepime, 4.2 log₁₀ (ΔpspB mutant) and 2.6 log₁₀ (ΔpspC mutant) decreases were observed at 8 and 4 h, respectively. For ertapenem, a decrease of up to 6 log₁₀ (ΔpspB mutant) was observed at 24 h. A deficient Psp envelope stress response increased E. coli susceptibility to beta-lactam agents such as cefepime, ceftazidime, aztreonam and ertapenem. Its role in repairing extensive inner membrane disruptions makes this pathway essential to bacterial survival, so that disbalancing the Psp response could be an appropriate target for sensitization strategies.

Modelling Thirty-day Mortality in the Acute Respiratory Distress Syndrome (ARDS) in an Adult ICU

Variables predicting thirty-day outcome from Acute Respiratory Distress Syndrome (ARDS) were analysed using Cox regression structured for time-varying covariates. Over a three-year period, 1996–1998, consecutive patients with ARDS (bilateral chest X-ray opacities, PaO2/FiO2 ratio of <200 and an acute precipitating event) were identified using a prospective computerized data base in a university teaching hospital ICU.

The cohort, 106 mechanically ventilated patients, was of mean (SD) age 63.5 (15.5) years and 37% were female. Primary lung injury occurred in 45% and 24% were postoperative. ICU-admission day APACHE II score was 25 (8); ARDS onset time from ICU admission was 1 day (median: range 0-16) and 30 day mortality was 41% (95% CI: 33%-51%). At ARDS onset, PaO2/FiO2 ratio was 92 (31), 81% had four-quadrant chest X-ray opacification and lung injury score was 2.75 (0.45). Average mechanical ventilator tidal volume was 10.3 ml/ predicted kg weight. Cox model mortality predictors (hazard ratio, 95% CI) were: APACHE II score, 1.15 (1.09-1.21); ARDS lag time (days), 0.72 (0.58-0.89); direct versus indirect injury, 2.89 (1.45-5.76); PaO2/FiO2 ratio, 0.98 (0.97-0.99); operative versus non-operative category, 0.24 (0.09-0.63). Time-varying effects were evident for PaO2/FiO2 ratio, operative versus non-operative category and ventilator tidal volume assessed as a categorical predictor with a cut-point of 8 ml/kg predicted weight (mean tidal volumes, 7.1 (1.9) vs 10.7 (1.6) ml/kg predicted weight). Thirty-day survival was improved for patients ventilated with lower tidal volumes.

Survival predictors in ARDS were multifactorial and related to patient-injury-time interaction and level of mechanical ventilator tidal volume.

Development and validation of an equine nerve block simulator to supplement practical skills training in undergraduate veterinary students

Lameness is the most common presenting complaint in equine practice. Performing diagnostic nerve blocks is an integral part of any lameness work-up, and is therefore an essential skill for equine practitioners. However, the opportunities for veterinary students to practice this skill are limited. The aim of this study was to design and validate an equine nerve block simulator. It was hypothesised that the simulator would improve students' ability and enhance their confidence in performing nerve blocks. A simulator was built using an equine forelimb skeleton and building foam. Wire wool targets were placed under the foam in the positions corresponding to the anatomical location of the most palmar digital, abaxial and low four-point nerve blocks and attached to an electrical circuit. The circuit became complete when the operator placed a needle in the correct position and immediate audible feedback with a buzzer was provided. To validate the simulator, it was compared with two established teaching methods: cadaver training and theoretical training with a hand-out. Cadaver-trained students achieved the best results (73 per cent correct blocks), compared with simulator-trained students (71 per cent correct blocks), and a hand-out trained group (58 per cent correct blocks). Feedback obtained with a questionnaire showed that students enjoyed simulator training more, and that they felt more confident in performing diagnostic nerve blocks than the other two groups. The equine nerve block simulator provides a safe, cost-effective method to supplement the teaching of diagnostic analgesia to undergraduate veterinary students.

Laparoscopic and thoracoscopic esophagomyotomy for children with achalasia

BACKGROUND

Minimally invasive esophagomyotomy, consisting of a laparoscopic or thoracoscopic approach, has become a preferred surgical treatment for adults with achalasia. This multicenter study reports on the clinical status of children who have undergone minimally invasive esophagomyotomy for achalasia.

METHODS

Symptomatology for achalasia was assessed in 22 pediatric patients who underwent minimally invasive esophagomyotomy for achalasia between 1995 and 2000. All patients were evaluated for duration of hospitalization, postoperative resumption of feeds, postoperative complications, and symptomatic relief. Participants were assigned pre-and postoperative symptom severity scores ranging from 0 (no symptoms) to 3 (severe).

RESULTS

The median age of the 10 females and 12 males at time of surgery was 11.3 years +/- 3.4 (standard deviation). Transabdominal laparoscopic esophagomyotomy with fundoplication was performed in 18 patients, and thoracoscopic esophagomyotomy without fundoplication was performed in 4. Two patients required conversion from transabdominal laparoscopic esophagomyotomy to open esophagomyotomy because of intraoperative esophageal perforation. The mean duration of postsurgical follow-up was 17 +/- 16 (standard deviation) months (range, 1-54 months). Mean duration of hospitalization (days +/- standard error or mean) was less for transabdominal laparoscopic esophagomyotomy than for converted open esophagomyotomy (2.7 +/- 0.3 vs. 9.0 +/- 3.0 days; P < 0.05) or for thoracoscopic esophagomyotomy (4.8 +/- 1.7 days; P = not significant). Mean time to resumption of soft feedings (days +/- standard error or mean) occurred sooner after transabdominal laparoscopic esophagomyotomy than after converted open esophagomyotomy (2.0 +/- 0.2 vs. 5.5 +/- 0.5 days; P < 0.001) or after thoracoscopic esophagomyotomy (4.0 +/- 1.3 days; P = not significant). Patients experienced significant pre-to postoperative improvement in mean severity score with regard to dysphagia (2.6 vs. 0.4; P < 0.001) and regurgitation (1.7 vs. 0.2; P < 0.001).

CONCLUSIONS

Minimally invasive esophagomyotomy can provide excellent symptomatic relief from dysphagia and regurgitation for children with achalasia.

First person account: schizophrenia, medication, and outpatient commitment

The article that follows is part of the Schizophrenia Bulletin's ongoing First Person Account series. We hope that mental health professionals-the Bulletin's primary audience--will take this opportunity to learn about the issues and difficulties confronted by consumers of mental health care. In addition, we hope that these accounts will give patients and families a better sense of not being alone in confronting the problems that can be anticipated by persons with serious emotional difficulties. We welcome other contributions from patients, ex-patients, or family members. Our major editorial requirement is that such contributions be clearly written and organized, and that a novel or unique aspect of schizophrenia be described, with special emphasis on points that will be important for professionals. Clinicians who see articulate patients with experiences they believe should be shared might encourage these patients to submit their articles to Schizophrenia Bulletin, First Person Accounts, EEI Communications, 66 Canal Center Plaza, Suite 200, Alexandria, VA 22314.-The Editors.

Erythroid Kruppel-like factor (EKLF) coordinates erythroid cell proliferation and hemoglobinization in cell lines derived from EKLF null mice

Erythroid Kruppel-like factor (EKLF) is a transcription factor of the C2H2 zinc-finger class that is essential for definitive erythropoiesis. We generated immortal erythroid cell lines from EKLF(-/-) fetal liver progenitor cells that harbor a single copy of the entire human beta-globin locus and then reintroduced EKLF as a tamoxifen-inducible, EKLF-mutant estrogen receptor (EKLF-ER) fusion protein. Addition of tamoxifen resulted in enhanced differentiation and hemoglobinization, coupled with reduced proliferation. Human beta-globin gene expression increased significantly, whereas gamma-globin transcripts remained elevated at levels close to endogenous mouse alpha-globin transcript levels. We conclude that EKLF plays a role in regulation of the cell cycle and hemoglobinization in addition to its role in beta-globin gene expression. The cell lines we used will facilitate structural and functional analyses of EKLF in these processes and provide useful tools for the elucidation of nonglobin EKLF target genes.

The mutagenic potential of acetonitrile in the bone marrow and peripheral blood of the mouse

Acetonitrile was tested for its ability to induce clastogenic or aneugenic effects through the induction of micronucleated polychromatic erythrocytes (MNPCE) in mouse bone marrow and peripheral blood. Groups of NMRI mice, five males and five females, were administered a single i.p. dose of acetonitrile, corresponding to the maximum tolerated dose (MTD), 100 or 125 mg/kg body wt for males and females, respectively. Bone marrow was sampled at 18, 24 or 36 h after treatment, while peripheral blood was sampled before and 24, 48, 72 and 96 h after treatment. Positive controls were administered cyclophosphamide (65 mg/kg i.p.). Acetonitrile did not increase the incidence of MNPCE in either bone marrow or peripheral blood in male mice or in peripheral blood in females. A small, but statistically significant (P: < 0.05), increase was observed in female bone marrow 36 h after administration, but since this was within the range of the control data it is not considered to be of biological significance. Cyclophosphamide increased the incidence of MNPCE in bone marrow and peripheral blood of both sexes. It is concluded that acetonitrile is neither clastogenic nor aneugenic in the bone marrow of the mouse at the MTD.

Marriage and mental illness

I have not read anything regarding persons who marry while living with serious, persistent mental illness. I married in the 1960s when persistent mental illness was considered a "nervous breakdown" and not an ongoing disease. With this article, I want to educate and explore thought in other persons who might share the same problems I experienced. I want to give a voice to the isolation I felt while married, coping with my illness. I felt so different from other married women with my closeted illness. I have two beautiful daughters who suffered a tragedy in their young lives when I became ill, yet our love seems to have survived and our relationship each day grows. With this article I want to give a voice to one marriage and mental illness. I want someone who reads this to say, "Yes, I feel like that; I know I'm not alone."

Patients' experiences of having an underwater seal chest drain: a replication study

The nursing management of patients who have a chest drain in situ has received little attention. The findings of a single small-scale study previously indicated that such patients' needs for information are not always fully met and pain control is inadequate. This small-scale study was replicated to produce broadly similar findings in a second hospital 2 years later. Despite some differences in the approach to management it was apparent that patients were still not well prepared pre-operatively and there was scope for improving pain control. All the patients reported considerable discomfort and pain of moderate to severe intensity. The type of pain described is typical of deep somatic/visceral pain.

Marine radioactivity assessment of Mururoa and Fangataufa atolls

The International Atomic Energy Agency (IAEA) carried out an international project. 'The Study of the Radiological Situation at the Atolls of Mururoa and Fangataufa' with the aim of assessing the present and future radiological situation at the atolls and making recommendations for either monitoring or remedial actions if they are deemed necessary. The paper concentrates on marine radioactivity aspects and gives an estimation of present radionuclide concentrations in water, sediment and biota of the Mururoa and Fangataufa lagoons and the surrounding ocean. The dominant radionuclide in both lagoons is Pu in sediments (the total inventory is approximately 30 TBq). A decline in radionuclide concentrations has been observed in recent years in lagoon water, with the exception of 3H and 90Sr, for which a contribution from underground sources is to be expected. Radionuclide concentrations in biota from the lagoons and the surrounding ocean are low and consistent with previous measurements. The observed radionuclide concentrations in both lagoons imply that no radiological risk exists for hypothetical inhabitants of Mururoa and Fangataufa Atolls.

Mitochondrial neurogastrointestinal encephalomyopathy: diagnosis by rectal biopsy

A 14-year-old girl with the mitochondrial neurogastrointestinal encephalopathy syndrome had an 8-year history of intestinal pseudoobstruction with abdominal pain, persistent vomiting, gastric and duodenal dilatation, and duodenal diverticulosis. The child appeared chronically malnourished and had severe growth failure. Multisystem involvement was evident with the presence of ptosis, external ophthalmoplegia, muscle wasting, peripheral neuropathy, and diffuse white matter disease seen on magnetic resonance imaging. Lactic acidosis and increased cerebrospinal fluid protein were observed. Mitochondrial enzyme analysis of fresh-frozen skeletal muscle revealed a respiratory chain defect. Molecular genetic studies showed multiple mitochondrial DNA deletions. Pathologic findings in the intestine included atrophy of the external layer of the muscularis propria and an increased number of abnormal-appearing mitochondria in ganglion and smooth-muscle cells. Microvesicular steatosis was observed in liver, skeletal, and gastrointestinal smooth muscle, and Schwann cells of peripheral nerve. Brightly eosinophilic inclusions in the cytoplasm of gastrointestinal ganglion cells were visible by light microscopy, which were confirmed to be megamitochondria by ultrastructural studies. This is the first report of abnormal mitochondria observed in intestinal ganglion and smooth-muscle cells in this syndrome.

Trichloroacetic acid: investigation into the mechanism of chromosomal damage in the in vitro human lymphocyte cytogenetic assay and the mouse bone marrow micronucleus test

Trichloroacetic acid (TCA) was tested for its ability to induce chromosomal damage in cultured human peripheral blood lymphocytes and in bone marrow cells of male and female C57BL/6JfBL10/Alpk mice. Two in vitro cytogenetic assays were conducted with TCA. In the first TCA, as free acid, was added to whole blood cultures at final concentrations of 500, 2000 and 3500 micrograms/ml in the presence and absence of an auxiliary metabolic activation system (rat liver S9-mix). Statistically significant increases in the percentage of aberrant cells compared with solvent control values were observed in cultures treated with TCA at 2000 and 5000 mu/ml. Investigation into the effects of TCA on the pH of the culture medium revealed significant reductions in pH at both these TCA concentrations. Neutralized TCA was then tested at concentrations of 500, 2,000 and 5000 micrograms/ml, also in the presence and absence of S9-mix. No statistically or biologically significant increases in the percentage of aberrant cells were observed in any of these cultures. In the mouse micronucleus test, neutralized TCA was administered in two equal intraperitoneal doses 24 h apart to C57BL/6JfBL10/Alpk mice (337, 675 and 1080 mg/kg in males; 405, 810 and 1300mg/kg in females). These dose levels represent 25%, 50% and 80% of the median lethal dose (MLD) in this strain of mouse. Bone marrow samples were taken 6 and 24 h after the second dose and the chromosomal damage assessed by analysis of the bone marrow for micronuclei. No statistically or biologically significant increases in the incidence of micronucleated polychromatic erythrocytes compared with the solvent control dosed animals were observed in either sex at the 6 h sampling time or in the females at the 24 h sampling time. A small but statistically significant increase in micronucleated polychromatic erythrocytes was observed in male mice 24 h after a dose of 675 mg/kg (50% MLD). Since no increases were noted at the 25 or 80% MLD, and the levels recorded are within the range of the concurrent solvent control values, the small increase observed in the males at the 50% MLD is considered not to be biologically significant. Flow cytometric studies on suspensions of isolated liver cell nuclei revealed that changes in FITC binding (indicating altered chromatin conformation) were induced by pH changes alone and were not caused by neutralized TCA.(ABSTRACT TRUNCATED AT 400 WORDS)

Trial of anonymous versus confidential human immunodeficiency virus testing

Before December, 1986, all public human immunodeficiency virus (HIV) testing in Oregon was done confidentially (using names). In December, clients were offered the option of either anonymous or confidential services. As judged by questionnaire responses, the availability of anonymity increased overall demand for testing by 50%: 125% for homosexual/bisexual (gay) men, 56% for female prostitutes, 17% for intravenous drug users, and 32% for other clients. The number of gay clients who had tests increased from a mean of 42 per month during the 4 months before anonymity was available to 108 per month during the 4 months after, whereas, at public sites in Colorado or California and private sites in Oregon, the number of gay clients tested did not increase. Twice as many seropositive persons were identified during the 3 1/2 months after anonymity became available (n = 85) as in the 3 1/2 months before (n = 36). Thus, availability of anonymous HIV testing and counselling drew gay men who had not sought services under a confidential testing system.

Job analysis. National Certification Board: Perioperative Nursing, Inc, document

The document is the critical element in developing an exam that reflects current perioperative nursing practice. The test specifications ensure that each phase of perioperative nursing practice is adequately measured at a proficient level of care. In addition to developing test specifications, the NCB:PNI has recommended that A Job Analysis could be used in the following situations. 1. Nurse managers could use the document in refining job descriptions, evaluating employee performance, creating clinical ladder criteria, and establishing standards of patient care. 2. Perioperative nurse educators could use it in developing self-directed learning contracts, designing curriculum for students or staff development. 3. Researchers could use the document in justifying the existence of registered nurses in the OR. 4. Perioperative nurses could use it for peer review and self-evaluation.

Surgical treatment of familial polyposis. The ileal reservoir/anal pull-through

The success of the procedure is evaluated by the number of bowel movements the patient has in a 24-hour period. Nine or more in 24 hours is considered poor; the average postoperative patient has five to six. As the patient's functional results improve, he is generally more at ease in social and work environments. He can govern his own routine to a great extent, rather than being tied to the bathroom. Usually, the patient can return to work in about four weeks after the ileostomy takedown. Generally, these patients seem to be satisfied with the results of their surgery. One study noted that 92% of the patients studied stated they would not hesitate to have the same operation again if faced with the same options. For the first few months postoperatively, Billy was somewhat apprehensive that he would have an "accident." He did not report any, though. He also did not leak any stools, even at night. Now, more than a year after the surgery, Billy has about four to six bowel movements a day and continues to take psyllium hydrophilic mucilloid daily. He has occasional mild irritation of the perianal skin. He has also gained 15 pounds. Billy returned to college to complete his senior year six months postoperatively. He took a full course load and planned to graduate in August 1987 with a degree in computer science. He reported that, "I'm doing very well. I just forget I had surgery."

The pioneer spirit in first assisting

Unless RNs are willing to accept this responsibility, less trained people will be more than happy to do so. We have given away many of our technical skills in the past, such as allowing technicians to become firmly entrenched in the scrub role. I hope we don't let this opportunity slip through our hands because we have lost the pioneering spirit of our nursing heritage. Thirty years ago, the issue was whether or not nurses could take blood pressures. More recently, it has been whether nurses could use the defibrillator. Now both are accepted without a thought. Those of us who have chosen to expand our practice must be patient with our colleagues who have not had an opportunity to work through both sides of the issue, and encourage them to do so. There will be those who choose not to function in this role, and I believe that first assisting is not for everyone. But in order to have a choice, the option must be there.