Loneliness in the workplace: a mixed-method systematic review and meta-analysis

BACKGROUND

Loneliness is a risk factor for a range of mental and physical health problems and has gained increasing interest from policy-makers and researchers in recent years. However, little attention has been paid to loneliness at work and its implications for workers and employers.

AIMS

Identify workplace, health and personal factors associated with workplace loneliness.

METHODS

We searched five databases (PubMed, MEDLINE, EMBASE, PsycINFO and EBSCO Business Source Complete) for relevant articles published from 1 January 2000 to 23 February 2023. Quantitative data were synthesized using narrative synthesis and random-effects meta-analysis of correlation coefficients. Qualitative data were synthesized using thematic synthesis. Evidence quality was appraised using the Mixed-Methods Appraisal Tool.

RESULTS

We identified 49 articles meeting the inclusion criteria. Pooled results indicate that workplace loneliness was associated with lower job performance (r = -0.35, 95% CI -0.49, -0.21), reduced job satisfaction (r = -0.34, 95% CI -0.44, -0.24), worse worker-manager relationship (r = -0.31, 95% CI -0.38, -0.24) and elevated burnout (r = 0.39, 95% CI 0.25, 0.51). Qualitative results suggest links between loneliness and inadequate workplace social interactions and mental health problems. As most studies used cross-sectional data and few adjusted for potential confounders, the direction and robustness of the associations remain untested.

CONCLUSIONS

Our results indicate that loneliness is associated with poor occupational functioning and well-being among workers. Results also show that loneliness is associated with modifiable aspects of the work environment, suggesting that the workplace may offer a fruitful avenue for interventions targeting loneliness.

Association between genetic and socioenvironmental risk for schizophrenia during upbringing in a UK longitudinal cohort

BACKGROUND

Associations of socioenvironmental features like urbanicity and neighborhood deprivation with psychosis are well-established. An enduring question, however, is whether these associations are causal. Genetic confounding could occur due to downward mobility of individuals at high genetic risk for psychiatric problems into disadvantaged environments.

METHODS

We examined correlations of five indices of genetic risk [polygenic risk scores (PRS) for schizophrenia and depression, maternal psychotic symptoms, family psychiatric history, and zygosity-based latent genetic risk] with multiple area-, neighborhood-, and family-level risks during upbringing. Data were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally-representative cohort of 2232 British twins born in 1994-1995 and followed to age 18 (93% retention). Socioenvironmental risks included urbanicity, air pollution, neighborhood deprivation, neighborhood crime, neighborhood disorder, social cohesion, residential mobility, family poverty, and a cumulative environmental risk scale. At age 18, participants were privately interviewed about psychotic experiences.

RESULTS

Higher genetic risk on all indices was associated with riskier environments during upbringing. For example, participants with higher schizophrenia PRS (OR = 1.19, 95% CI = 1.06-1.33), depression PRS (OR = 1.20, 95% CI = 1.08-1.34), family history (OR = 1.25, 95% CI = 1.11-1.40), and latent genetic risk (OR = 1.21, 95% CI = 1.07-1.38) had accumulated more socioenvironmental risks for schizophrenia by age 18. However, associations between socioenvironmental risks and psychotic experiences mostly remained significant after covariate adjustment for genetic risk.

CONCLUSION

Genetic risk is correlated with socioenvironmental risk for schizophrenia during upbringing, but the associations between socioenvironmental risk and adolescent psychotic experiences appear, at present, to exist above and beyond this gene-environment correlation.

A time-sensitive analysis of the prognostic utility of vasopressor dose in septic shock

It is unclear whether the association between vasopressor dose and mortality is affected by duration of administration. We examined whether prognostication in septic shock is feasible through the use of daily median vasopressor doses. We undertook a single-centre retrospective cohort study. We included patients with a diagnosis of septic shock admitted to the intensive care unit at Queen Elizabeth Hospital, Birmingham, UK, between April 2016 and July 2019. The primary outcome measure was 90-day mortality. We defined vasopressor dose as the median norepinephrine equivalent dose (equivalent infusion rates of all vasopressors and inotropes) recorded for each day, for the first four days of septic shock. We divided patients into groups by vasopressor dose quintiles and calculated their 90-day mortality rate. We examined area under the receiver operator characteristic curves for prognostic ability. In total, 844 patients were admitted with septic shock and had a 90-day mortality of 43% (n = 358). Over the first four days, median vasopressor dose decreased in 93% of survivors and increased in 56% of non-survivors. The mortality rate associated with a given vasopressor dose quintile increased on sequential days of septic shock. The area under the receiver operator characteristic curves of daily median vasopressor dose against mortality increased from day 1 to day 4 (0.67 vs. 0.86, p < 0.0001). By day 4, a median daily vasopressor dose > 0.05 μg.kg^-1 .min^-1 had an 80% sensitivity and specificity for mortality. The prognostic utility of vasopressor dose improved considerably with shock duration. Prolonged administration of small vasopressor doses was associated with a high attributable mortality.

Pituitary metastases: presentation and outcomes from a pituitary center over the last decade

PURPOSE

Highlight and characterize manifestations, diagnostic/management approaches and outcomes in a contemporary cohort of patients with pituitary metastases (PM) from a large European pituitary center-over 10 years.

METHODS

Retrospective review of PM cases between 1/2009 and 12/2018. Clinical, laboratory, imaging data at PM detection and during follow-up were analysed.

RESULTS

18 cases were identified (14 females; median age at diagnosis 61.5 years). Most common primary malignancies were lung (39%) and breast (32%). Most frequent presenting manifestation was visual dysfunction (50%). Gonadotrophin, ACTH, TSH deficiency were diagnosed in 85%, 67%, 46% of cases, respectively; diabetes insipidus (DI) was present in 17%. 33% of cases were detected during investigation for symptoms unrelated to PM. PM management included radiotherapy (44%), transsphenoidal surgery (17%), transsphenoidal surgery and radiotherapy (6%) or monitoring only (33%). One-year survival was 49% with median survival from PM detection 11 months (range 2-47).

CONCLUSIONS

In our contemporary series, clinical presentation of PM has evolved; we found increased prevalence of anterior hypopituitarism, decreased rates of DI and longer survival compared with older literature. Increased availability of diagnostic imaging, improvements in screening and recognition of pituitary disease and longer survival of patients with metastatic cancer may be contributing factors.

Sleeping with one eye open: loneliness and sleep quality in young adults

BACKGROUND

Feelings of loneliness are common among young adults, and are hypothesized to impair the quality of sleep. In the present study, we tested associations between loneliness and sleep quality in a nationally representative sample of young adults. Further, based on the hypothesis that sleep problems in lonely individuals are driven by increased vigilance for threat, we tested whether past exposure to violence exacerbated this association.

METHOD

Data were drawn from the Environmental Risk (E-Risk) Longitudinal Twin Study, a birth cohort of 2232 twins born in England and Wales in 1994 and 1995. We measured loneliness using items from the UCLA Loneliness Scale, and sleep quality using the Pittsburgh Sleep Quality Index. We controlled for covariates including social isolation, psychopathology, employment status and being a parent of an infant. We examined twin differences to control for unmeasured genetic and family environment factors.

RESULTS

Feelings of loneliness were associated with worse overall sleep quality. Loneliness was associated specifically with subjective sleep quality and daytime dysfunction. These associations were robust to controls for covariates. Among monozygotic twins, within-twin pair differences in loneliness were significantly associated with within-pair differences in sleep quality, indicating an association independent of unmeasured familial influences. The association between loneliness and sleep quality was exacerbated among individuals exposed to violence victimization in adolescence or maltreatment in childhood.

CONCLUSIONS

Loneliness is robustly associated with poorer sleep quality in young people, underscoring the importance of early interventions to mitigate the long-term outcomes of loneliness. Special care should be directed towards individuals who have experienced victimization.

First estimates of the probability of survival in a small-bodied, high-elevation frog (Boreal Chorus Frog, Pseudacris maculata), or how historical data can be useful

In an era of shrinking budgets yet increasing demands for conservation, the value of existing (i.e., historical) data are elevated. Lengthy time series on common, or previously common, species are particularly valuable and may be available only through the use of historical information. We provide first estimates of the probability of survival and longevity (0.67–0.79 and 5–7 years, respectively) for a subalpine population of a small-bodied, ostensibly common amphibian, the Boreal Chorus Frog (Pseudacris maculata (Agassiz, 1850)), using historical data and contemporary, hypothesis-driven information–theoretic analyses. We also test a priori hypotheses about the effects of color morph (as suggested by early reports) and of drought (as suggested by recent climate predictions) on survival. Using robust mark–recapture models, we find some support for early hypotheses regarding the effect of color on survival, but we find no effect of drought. The congruence between early findings and our analyses highlights the usefulness of historical information in providing raw data for contemporary analyses and context for conservation and management decisions.

Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer

Context:

In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer.

Objectives:

To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial.

Methods:

Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made.

Results:

The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients.

Conclusions:

This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions.

Pedestrian deaths in children--potential for prevention

The National Paediatric Mortality Database was reviewed for the six year period 1st January 2006 to 31st December 2011 and all pedestrian deaths extracted, after review of available data the deaths were categorized as either traffic or non-traffic related. There were 45 child pedestrian fatalities in the period examined. Traffic related deaths accounted for 26 (58%) vs. 19 (42%) non-traffic related. Analysis of the deaths showed there was a male preponderance 28 (62%), weekend trend 22 (49%) with an evening 16 (35%) and summer peak 20 (44%). The highest proportion of deaths occurred in the 1-4 year age group 24 (53%), with 13 (28%) due to low speed vehicle rollovers, mainly occurring in residential driveways 8 (61%). Child pedestrian fatalities are highly preventable through the modification of risk factors including behavioural, social and environmental. Preventative action needs to be addressed, particularly in relation to non-traffic related deaths i.e, low speed vehicle rollovers.

Sudden unexplained death in childhood. An audit of the quality of autopsy reporting

Cases of sudden unexplained death in childhood (SUDC) in Ireland in children aged > 1 year and < 5 years were examined in order to assess the quality of autopsy reporting. All SUDC cases are notified to and documented by the National Sudden Infant Death Register (NSIDR) in Ireland along with all cases of sudden infant death syndrome (SIDS) referring to sudden infant deaths less than one year of age. The database of the NSIDR in Ireland was interrogated and cases of SIDS and SUDC were compared over a fifteen-year period (1995-2009). SIDS cases whose autopsies were conducted in the same hospital in the same year as the index SUDC case were used for comparison. The autopsy report for each case was examined and modified Rushton (MR) score(s1) calculated. MR scores were compared along with the number of paediatric pathology prosectors and the year of autopsy examination between the two groups. 45 cases were registered as SUDC (age 52 - 152 weeks) between 1995-2009. Autopsy reports were available for 43/45 (95%) of these. 43 SIDS cases from the same year and site of autopsy were used for comparison. Overall MR scores were higher in the SIDS cases, with 29/43 (67%) cases obtaining the minimum arbitrary score (MAS) of > 300 compared to 25/43 (58%) of SUDC cases. Paediatric pathologists in specialist centres carried out similar numbers of SIDS autopsies and SUDC autopsies (46% SIDS, 44% SUDC). Autopsies carried out by paediatric pathologists in specialist centres met the MAS in 19/21 (90%) SIDS cases and 18/19 (95%) SUDC cases. Based on our findings we recommend referral of all SUDC cases to specialist centres for optimal autopsy examination and investigation, and that cases of sudden unexpected death in children over 1 year of age are investigated according to the same guidelines as are used for unexpected death under one year of age.

Maternal smoking and alcohol consumption during pregnancy as risk factors for sudden infant death

A population based case control study was conducted to examine alcohol consumption and maternal smoking during pregnancy and the risk of SIDS in an Irish population. Each SIDS case (n = 287) was compared with control infants (n = 832) matched for date and place of birth for infants born from 1994 to 2001. Conditional logistic regression was used to investigate differences between Cases and Controls establishing Odds Ratio's (OR) and 95% Confidence Intervals (CI). Mothers who smoked were 3 times more likely to have a SIDS Case, and a dose response effect was apparent, with mothers smoking 1-10 cigarettes/day OR 2.93 (CI 1.50-5.71), and those smoking > 10 cigarettes/day OR 4.36 (CI 2.50-7.61). More Case mothers consumed alcohol during pregnancy than Control mothers and, within drinkers, the amount of alcohol consumed was also greater (p < 0.05). A dose response with frequency of drinking was apparent. The adjusted odds ratio for those consuming alcohol in all three trimesters was 3.59 (CI:1.40-9.20). Both of these risk factors are modifiable and need to be incorporated into antenatal education from a SIDS point of view.

Assessing the effect of foreign travel and protection by BCG vaccination on the spread of tuberculosis in a low incidence country, United Kingdom, October 2008 to December 2009

Binary file ES_Abstracts_Final_ECDC.txt matches

Assessing the effect of foreign travel and protection by BCG vaccination on the spread of tuberculosis in a low incidence country, United Kingdom, October 2008 to December 2009

The contribution of travel to high incidence countries and the impact of the discontinuation of universal Bacillus Calmette–Guérin (BCG) vaccination to there cent rise in tuberculosis (TB) in the United Kingdom remain unclear. An outbreak in a college presented an opportunity to assess these. A cohort of students answered a questionnaire assessing risk factors for TB.Participants were screened with an interferon gamma release assay (IGRA). Unadjusted and adjusted odds ratios (OR) were calculated using logistic regression.Among 2,284 students, 400 (17.5%) were diagnosed with TB infection. A higher risk was noted for travel to a high incidence area in the past two years (OR: 1.39;95% confidence interval (CI): 1.04–1.89) and among those with the greatest exposure to the index case(OR: 3.94; 95% CI: 2.60–5.97). There was no association between BCG and risk of infection (OR: 1.05; 95%CI: 0.80–1.39). The lack of a protective effect by BCG on TB infection supports the discontinuation of universal vaccination. The association with foreign travel suggests the need to assess the cost-effectiveness of serial IGRA testing and treatment of positive persons among returning travellers.

N-terminal pro-B-type natriuretic peptide: a measure of significant patent ductus arteriosus

BACKGROUND

B-type natriuretic peptide (BNP) is a marker for ventricular dysfunction secreted as a pre-prohormone, pro-B-type natriuretic peptide (proBNP), and cleaved into BNP and a biologically inactive fragment, N-terminal pro-B-type natriuretic peptide (NT-proBNP). Little is known about the clinical usefulness of NT-proBNP in preterm infants.

OBJECTIVE

To evaluate the usefulness of plasma NT-proBNP in diagnosing haemodynamically significant patent ductus arteriosus (hsPDA) in neonates and examine some factors that might affect this.

METHODS

Infants born at <34 weeks' gestational age (GA) and <2 kg birth weight (BW) were prospectively enrolled within 6-12 hours of birth. Plasma NT-proBNP levels were measured on days 1, 3, 5 and 10 with simultaneous echocardiography done to detect hsPDA and assess ventricular function. Significant PDA was diagnosed by large ductal flow with left to right shunt on colour Doppler, measuring >1.6 mm on two-dimensional echocardiography, along with clinical features of PDA.

RESULTS

Forty-nine infants were analysed. Median GA was 30 weeks (range 24-33) and median BW 1220 g (range 550-1950). Eighteen infants with hsPDA had higher day 3 plasma NT-proBNP values (median 32 907 pg/ml; range 11 396-127 155) (p<0.001) than controls (median 3147 pg/ml; range 521-10 343). Infants who developed sepsis had higher day 10 plasma NT-proBNP levels. Area under receiver operator characteristic curve for detection of hsPDA, by day 3 NT-proBNP value, was significant 0.978 (95% CI 0.930 to 1.026). NT-proBNP was predictive of hsPDA (sensitivity 100%; specificity 95%) at a cut-off value of 11 395 pg/ml.

CONCLUSION

Plasma NT-proBNP level on day 3 is a good marker for hsPDA in preterm infants. Serial measurements of NT-proBNP may be useful in assessing the clinical course of PDA.

A general practice-based prevalence study of epilepsy among adults with intellectual disabilities and of its association with psychiatric disorder, behaviour disturbance and carer stress

BACKGROUND

Although the elevated occurrence of epilepsy in people with intellectual disabilities (ID) is well recognized, the nature of seizures and their association with psychopathology and carer strain are less clearly understood. The aims were to determine the prevalence and features of epilepsy in a community-based population of adults with ID, and to explore whether the presence of epilepsy was associated with greater psychopathology or carer strain.

METHODS

Data were collected on the age, gender, place of residence, adaptive and challenging behaviour, social abilities and psychiatric status of 318 adults from 40 general practices, together with the degree of malaise and strain of family carers. For participants with epilepsy, a nurse collected information on seizures, investigations, treatment and carer concerns by interview. Association between epilepsy and psychiatric morbidity, challenging behaviour and caregiver malaise or strain, was explored by comparing those with epilepsy with a comparison group matched on adaptive behaviour.

RESULTS

Fifty-eight participants (18%) had epilepsy: 26% were seizure free, but 34% had extremely poorly controlled seizures. Earlier onset and seizure frequency were associated with adaptive behaviour. Carer concerns were related to seizure frequency and a history of injury. There were no significant differences in psychopathology, carer malaise or caregiver strain between the matched epilepsy and non-epilepsy groups.

CONCLUSIONS

This study supports the high occurrence and chronicity of epilepsy among people with ID. While psychopathology and carer strain is common within this population, underlying disability-related factors appear to be more important than the presence of epilepsy per se.

The pathology of frozen shoulder

We treated 22 patients with a diagnosis of primary frozen shoulder resistant to conservative treatment by manipulation under anaesthetic and arthroscopic release of the rotator interval, at a mean time from onset of 15 months (3 to 36). Biopsies were taken from this site and histological and immunocytochemical analysis was performed to identify the types of cell present. The tissue was characterised by the presence of fibroblasts, proliferating fibroblasts and chronic inflammatory cells. The infiltrate of chronic inflammatory cells was predominantly made up of mast cells, with T cells, B cells and macrophages also present. The pathology of frozen shoulder includes a chronic inflammatory response with fibroblastic proliferation which may be immunomodulated.

A case of a cilioretinal artery supplying the entire retina

The cilioretinal artery commonly supplies a small area of the retina, usually the macula. It can serve a valuable purpose in preserving the central vision in central retinal artery occlusion. We describe a case, where the total retinal circulation is from the cilioretinal artery in one eye and an abnormal central retinal artery branching in the other eye. The clinical relevance of cilioretinal artery in the eye is discussed.

An 8 year study of risk factors for SIDS: bed-sharing versus non-bed-sharing

BACKGROUND

It is unclear if it is safe for babies to bed share with adults. In Ireland 49% of sudden infant death syndrome (SIDS) cases occur when the infant is bed-sharing with an adult.

OBJECTIVE

To evaluate the effect of bed-sharing during the last sleep period on risk factors for SIDS in Irish infants.

DESIGN

An 8 year (1994-2001) population based case control study of 287 SIDS cases and 831 controls matched for date, place of birth, and sleep period. Odds ratios and 95% confidence intervals were calculated by conditional logistic regression.

RESULTS

The risk associated with bed-sharing was three times greater for infants with low birth weight for gestation (UOR 16.28 v 4.90) and increased fourfold if the combined tog value of clothing and bedding was > or =10 (UOR 9.68 v 2.34). The unadjusted odds ratio for bed-sharing was 13.87 (95% CI 9.58 to 20.09) for infants whose mothers smoked and 2.09 (95% CI 0.98 to 4.39) for non-smokers. Age of death for bed-sharing and sofa-sharing infants (12.8 and 8.3 weeks, respectively) was less than for infants not sharing a sleep surface (21.0 weeks, p<0.001) and fewer bed-sharing cases were found prone (5% v 32%; p = 0.001).

CONCLUSION

Risk factors for SIDS vary according to the infant's sleeping environment. The increased risk associated with maternal smoking, high tog value of clothing and bedding, and low z scores of weight for gestation at birth is augmented further by bed-sharing. These factors should be taken into account when considering sleeping arrangements for young infants.

A fluorescence polarization assay for inhibitors of Hsp90

Hsp90 encodes a ubiquitous molecular chaperone protein conserved among species which acts on multiple substrates, many of which are important cell-signaling proteins. Inhibition of Hsp90 function has been promoted as a mechanism to degrade client proteins involved in tumorigenesis and disease progression. Several assays to monitor inhibition of Hsp90 function currently exist but are limited in their use for a drug discovery campaign. Using data from the crystal structure of an initial hit compound, we have developed a fluorescence polarization assay to monitor binding of compounds to the ATP-binding site of Hsp90. This assay is very robust (Z' > 0.9) and can detect affinity of compounds with IC50s to 40 nM. We have used this assay in conjunction with cocrystal structures of small molecules to drive a structure-based design program aimed at the discovery and optimization of a novel class of potent Hsp90 inhibitors.

Workload and short-term outcome of babies weighing 2,500 grams or more at birth admitted to the paediatric unit of the Rotunda Hospital

BACKGROUND

Audit is important in ensuring adequate use of resources and maintaining optimum standards of care. Most of the emphasis in neonatal audit is focused on very low birth weight infants. However, term and near-term infants account for a significant proportion of the workload in neonatal units and warrant regular audit. In addition, audit of these infants may be useful as a marker of the organisation of the perinatal service.

METHODS

A retrospective audit was performed of all infants with birth weights greater than or equal to 2,500 grams admitted to the neonatal department in the first week of life over a two-year period, examining mode of delivery, level of care, duration of stay, diagnosis and short-term outcome.

RESULTS

Eight hundred and seventy infants were admitted greater than or equal to 2,500 grams birth weight, 54% of all neonatal admissions, during the study period. Six hundred and eighty seven of these infants were admitted in the first week of life and were included in the study; this was 5.8% of infants born with a birth weight 2500 grams or more. Infants born by caesarean section were twice as likely to require admission (9.8%) compared with infants born by vaginal delivery (4.5%). The median length of stay was 3 days (3 hours to 45 days). One hundred and six (15.4%) infants required level 1 or level 2 care. One hundred and eleven infants received normal care, only. Most of these infants were admitted for maternal or social reasons. Other common reasons for admission were jaundice, respiratory disease, neonatal abstinence syndrome and congenital abnormality. Forty-one infants required transfer to another hospital, most commonly for surgical or cardiac conditions. Six infants died after admission. However, only one normally formed infant delivered in our hospital died prior to discharge or transfer. One infant was born at home and four infants who had a lethal congenital abnormality are known to have died following transfer.

CONCLUSION

Term and near-term infants account for a significant proportion of neonatal admissions and deserve regular audit. Many admissions are potentially avoidable. Survival for infants weighing 2,500 grams or greater is excellent. Only one normally formed infant died following admission during the study period. The number of "social" admissions of "well" infants highlighted by this study reflects poorly on the services available for well infant whose mothers are unable to care for them for whatever reason. We recommend regular audit of these infants in order to ensure efficient use of neonatal resources and to ensure optimum levels of neonatal intensive care.

Impact of human immunodeficiency virus type 1 gp41 amino acid substitutions selected during enfuvirtide treatment on gp41 binding and antiviral potency of enfuvirtide in vitro

Enfuvirtide (ENF), a novel human immunodeficiency virus type 1 (HIV-1) fusion inhibitor, has potent antiviral activity against HIV-1 both in vitro and in vivo. Resistance to ENF observed after in vitro passaging was associated with changes in a three-amino-acid (aa) motif, GIV, at positions 36 to 38 of gp41. Patients with ongoing viral replication while receiving ENF during clinical trials acquired substitutions within gp41 aa 36 to 45 in the first heptad repeat (HR-1) of gp41 in both population-based plasma virus sequences and proviral DNA sequences from isolates showing reduced susceptibilities to ENF. To investigate their impact on ENF susceptibility, substitutions were introduced into a modified pNL4-3 strain by site-directed mutagenesis, and the susceptibilities of mutant viruses and patient-derived isolates to ENF were tested. In general, susceptibility decreases for single substitutions were lower than those for double substitutions, and the levels of ENF resistance seen for clinical isolates were higher than those observed for the site-directed mutant viruses. The mechanism of ENF resistance was explored for a subset of the substitutions by expressing them in the context of a maltose binding protein chimera containing a portion of the gp41 ectodomain and measuring their binding affinity to fluorescein-labeled ENF. Changes in binding affinity for the mutant gp41 fusion proteins correlated with the ENF susceptibilities of viruses containing the same substitutions. The combined results support the key role of gp41 aa 36 to 45 in the development of resistance to ENF and illustrate that additional envelope regions contribute to the ENF susceptibility of fusion inhibitor-naïve viruses and resistance to ENF.

How reliable are SIDS rates?

There is increasing concern with using SIDS as a diagnosis, especially where the postmortem examination reveals additional findings that may be contributory to the death exclusion. This report shows how varying the criteria for a diagnosis of SIDS significantly alters the SIDS rate in Ireland.

The palaeoecology of the micromammals from the late middle Pleistocene site of Hoedjiespunt 1 (Cape Province, South Africa)

The palaeontological site of Hoedjiespunt 1 (HDP1) represents a fossilized hyaena lair. A rich mammalian fauna, including four hominid teeth, has been recovered from the site. Micromammals were recovered from the same sediments as the larger fauna. Taphonomic analysis suggests that the micromammal assemblages from HDP1 were accumulated by a barn owl. The barn owl produces micromammal assemblages that provide a broad sample of micromammals, within a certain size range, living in the hunting area of the owl. There are size-related and other biases inherent in the prey selection of this predator, and owls may roost in one area and hunt in another however, the barn owl has frequently been found to provide a better indication of micromammals living within an area than trapping. The micromammals from HDP1 were used to reconstruct the microhabitats in the vicinity of the site. Two taxonomic habitat indexes were used to assess the environment and dominant habitat types at Hoedjiespunt 1. The variability and adaptability of many of the southern African micromammals complicates interpretation of the results, however, it appears that the micromammals from the HDP1 fossil assemblages utilized habitats of open, scrub vegetation, and rocky and sandy areas. It is suggested that the environment was not markedly different from today, but it may have been relatively more arid. A comparison between HDP1 and other fossil sites in the area dating from the terminal Pleistocene to the Holocene indicates that HDP1 is lacking certain species that are common to all the other west coast fossil sites. There is some discrepancy in the environment indicated by the large mammals as compared that indicated by to the micromammals at the site. It is suggested that this discrepancy may reflect the fact that an owl is likely to have hunted in the vicinity of the hyaena den, probably in the more open areas around the roost site, whereas the macrofauna, accumulated by the further-ranging brown hyaena (Hyaena brunnea), represents environments from further afield.

Observation of structural anisotropy and the onset of liquidlike motion during the nonthermal melting of InSb

The melting dynamics of laser excited InSb have been studied with femtosecond x-ray diffraction. These measurements observe the delayed onset of diffusive atomic motion, signaling the appearance of liquidlike dynamics. They also demonstrate that the root-mean-squared displacement in the [111] direction increases faster than in the [110] direction after the first 500 fs. This structural anisotropy indicates that the initially generated fluid differs significantly from the equilibrium liquid.

Time-resolved measurements of the structure of water at constant density

Dynamical changes in the structure factor of liquid water, S(Q,t), are measured using time-resolved x-ray diffraction techniques with 100 ps resolution. On short time scales following femtosecond optical excitation, we observe temperature-induced changes associated with rearrangements of the hydrogen-bonded structure at constant volume, before the system has had time to expand. We invert this data to extract transient changes in the pair correlation function associated with isochoric heating effects, and interpret these in terms of a decrease in the local tetrahedral ordering.

Atomic-Scale Visualization of Inertial Dynamics

The motion of atoms on interatomic potential energy surfaces is fundamental to the dynamics of liquids and solids. An accelerator-based source of femtosecond x-ray pulses allowed us to follow directly atomic displacements on an optically modified energy landscape, leading eventually to the transition from crystalline solid to disordered liquid. We show that, to first order in time, the dynamics are inertial, and we place constraints on the shape and curvature of the transition-state potential energy surface. Our measurements point toward analogies between this nonequilibrium phase transition and the short-time dynamics intrinsic to equilibrium liquids.

Perinatal factors influencing survival in extremely low-birthweight infants

The majority of deaths in normally formed infants occur in extremely low birth weight infants (< 1000 g). Survival rates for these infants have improved greatly but still vary from centre to centre and accurate local outcome figures are important for counselling parents and upholding standards of care. In the Rotunda Hospital, Dublin, over the 6 year period from 1 January 1990 to 31 December 1995, there were 34 474 deliveries over 500 g birthweight. One hundred and twenty-six of these were normally formed infants between 500 g and 999 g. Our objective was to analyse the factors influencing survival in these extremely low birthweight (ELBW) infants. Overall survival in the group was 63%. The most significant factors influencing survival to 28 days were gestation and birthweight. Survival increased from 33% at 24 weeks to 100% at 28 weeks' gestation and from 29% at 500-599 g to 87% at 900-999 g birthweight. Having controlled for gestational age, none of the following variables had a significant effect on survival: year of birth; gender; multiple pregnancy; 1-minute Apgar score; maternal age; parity; use of antenatal steroids; a history of antepartum haemorrhage, pre-eclamptic toxaemia or prolonged rupture of membranes. A 5-min Apgar score > 5 increased the chance of survival by 3.97 (95% CI: 1.46- 10). Both mode of delivery and incidence of chorioamnionitis had an influence on survival which varied according to the gestational age. A larger cohort of survivors would illustrate the effect of these variables more clearly.

A multivariate "time based" analysis of SIDS risk factors

AIMS

To investigate the influence of analytical design on the variability of published results in studies of sudden infant death syndrome (SIDS).

METHODS

The results of a prospective case-control study, of 203 cases of SIDS, and 622 control infants are presented. All variables significant on univariate analysis were included in a multivariate model analysed in nine stages, starting with sociodemographic variables, then sequentially and cumulatively adding variables relating to pregnancy history, current pregnancy, birth, the interval from birth to the week prior to death, the last week, the last 48 hours, and the last sleep period. A ninth stage was created by adding placed to sleep prone for the last sleep period.

RESULTS

As additional variables are added, previously published SIDS risk factors emerged such as social deprivation, young maternal age, > or =3 previous live births, maternal smoking and drinking, urinary tract infection in pregnancy, reduced birth weight, and the infant having an illness, regurgitation, being sweaty, or a history of crying/colic in the interval from birth to the week before death, with co-sleeping and the lack of regular soother use important in the last sleep period. As the model progressed through stages 1-9, many significant variables became non-significant (social deprivation, young maternal age, maternal smoking and drinking) and in stage 9 the addition of placed to sleep prone for the last sleep period caused > or =3 previous live births and a reduced birth weight to become significant.

CONCLUSION

The variables found to be significant in a case-control study, depend on what is included in a multivariate model.

Routine day-case laparoscopic cholecystectomy

BACKGROUND

A prospective study was carried out to assess the feasibility of performing true day-case laparoscopic surgery in a district general hospital.

METHODS

All patients admitted consecutively under the care of one surgeon for laparoscopic cholecystectomy were included in the study. Selection criteria for a day-case procedure included an American Society of Anesthesiologists grade of I or II and the availability of a responsible carer at home. Patients were discharged 4-6 h after surgery with a standard analgesia pack and a contact number for advice. All patients were contacted by telephone on the day after discharge. A postal questionnaire was sent to the first 100 patients to assess satisfaction with the day-case process.

RESULTS

Of 357 patients admitted for laparoscopic cholecystectomy over a 24-month period, 154 (43.1 per cent) were operated on as day cases on a morning theatre list. Twenty-two patients required an overnight stay (14.3 per cent), three because of conversion to an open procedure. One patient was readmitted for neck pain. Eighty-two (92.1 per cent) of 89 patients were either satisfied or very satisfied with the day-case procedure.

CONCLUSION

This study has demonstrated a low rate of overnight stay (14.3 per cent) and readmission (1.9 per cent), and a high degree of patient satisfaction for day-case laparoscopic cholecystectomy.

Factors relating to the infant's last sleep environment in sudden infant death syndrome in the Republic of Ireland

AIM

To identify risk factors for sudden infant death syndrome (SIDS) in the sleeping environment of Irish infants.

METHODS

A five year population based case-control study with parental interviews conducted for each case and three controls matched for age, place of birth, and last sleep period. A total of 203 SIDS cases and 622 control infants born 1994-98 were studied.

RESULTS

In a multivariate analysis, co-sleeping significantly increased the risk of SIDS both as a usual practice (adjusted OR 4.31; 95% CI 1.07 to 17.37) and during the last sleep period (adjusted OR 16.47; 95% CI 3.73 to 72.75). The associated risk was dependent on maternal smoking (OR 21.84; 95% CI 2.27 to 209.89), and was not significant for infants who were > or =20 weeks of age (OR 2.63; 95% CI 0.49 to 70.10) or placed back in their own cot/bed to sleep (OR 1.07; 95% CI 0.21 to 5.41). The use of pillows, duvets, and bedding with tog value > or =10 were not significant risk factors when adjusted for the effects of confounding variables, including maternal smoking and social disadvantage. However, the prone sleeping position remains a significant SIDS risk factor, and among infants using soothers, the absence of soother use during the last sleep period also significantly increased the SIDS risk (OR 5.83; CI 2.37 to 14.36).

CONCLUSION

Co-sleeping should be avoided in infants who are <20 weeks of age, or whose mothers smoked during pregnancy. The prone position remains a factor in some SIDS deaths, and the relation between soother use and SIDS is a complex variable requiring further study.

The quality and value of sudden infant death necropsy reporting in Ireland

BACKGROUND

Infant necropsies are important for identifying cause of death. Recently issued guidelines have recommended investigations to be performed following sudden unexpected death in infants.

AIMS

To evaluate the quality and value of infant postmortem reporting.

METHODS

Postmortem reports from 1994-1996 and 1998-2000 in Ireland were evaluated using the National Sudden Infant Death Register. Scoring was by a modification of the Rushton system based on the extent of the postmortem data. The finding of additional pathological information was also assessed.

RESULTS

Of the 274 cases registered during the selection period, reports were available for 245. Overall quality of necropsy reporting was below the minimum accepted standard in 55.5%; 47% of the necropsies were performed in regional paediatric pathology centres. The quality of necropsies performed in regional centres was significantly higher than those performed elsewhere. Although 86% of the cases were defined as sudden infant death syndrome (SIDS; no cause of death found), the finding of additional pathological information was significantly related to the extent of the necropsy. There was a significant improvement in the quality of necropsies after the postmortem guidelines were issued.

CONCLUSIONS

The overall quality of sudden unexpected infant death necropsies in Ireland is less than adequate. A minimum accepted standard of necropsy is required before a diagnosis of SIDS can be made. Although standards have improved recently, this study highlights the need to adhere to published guidelines and the importance of auditing the effect of introducing practice guidelines on clinical practice to complete the audit loop.

Safety of home delivery compared with hospital delivery in The Eastern Region Health Authority in Ireland in the years 1999-2002

A comparison was made of deaths from intrapartum hypoxia of normally formed babies > 2.5 kg born at home (N = 346) and those born in hospitals (N = 61,215). If the intended place of birth is home the chance of dying due to intrapartum hypoxia is 1:70 (5 in 346). If the intended place of birth is hospital the chance of dying is 1:3600 (17 in 61,215). Although the sample size of home births is smaller, the difference is significant (< 0.01 level of significance). In view of the small number of home births, the need for ongoing monitoring of home births over a longer period is essential.

Sudden infant death syndrome--a defect in circulatory control?

The majority of Sudden Infant Death Syndrome (SIDS) infants die during sleep and especially during the overnight sleep period. Recent evidence from SIDS cases, which occurred while on a cardiorespiratory monitor at home, has suggested that the mechanism of death involves circulatory failure, with the development of a shock like state, associated with a progressive bradycardia in the presence of continued breathing movements. In this paper we explore the circulatory effects of sleep and in particular the down regulation of the baroreceptor reflex, associated with a reduction in vasomotor tone and a fall in central venous return, cardiac output and blood pressure. This sequence of events would be exacerbated by many of the known SIDS risk factors, namely the prone sleeping position, overheating and co-sleeping. Poor central venous return,with diminished cardic distension could induce a progressive bradycardia as occurs in adults with neuro-cardiogenic syncope. Alternatively a reduced cardiac output could result in the rapid onset of severe hypoxia through poor lung perfusion. The effects of sleep on circulatory control deserve further study in infants.

Ability of the V3 loop of simian immunodeficiency virus to serve as a target for antibody-mediated neutralization: correlation of neutralization sensitivity, growth in macrophages, and decreased dependence on CD4

To better define the effects of sequence variation and tropism on the ability of the simian immunodeficiency virus SIVmac V3 loop to act as a target of antibody-mediated neutralization, a series of experiments were performed. Three SIV strains, SIVmac239, SIVmac316, and SIVmac155/T3, each with defined differences in env sequence and tropism, were used to construct a panel of viruses chimeric for a portion of envelope that includes the V2 and V3 regions. Peptides with sequences corresponding to the V3 loops of the parental viruses were used to immunize rabbits. The polyclonal rabbit antibodies and plasma from SIVmac239-infected animals were then used to assess the neutralization sensitivity of the parental and chimeric viruses. One of the parental viruses, SIVmac316, which is able to replicate to high titer in alveolar macrophages and can infect cells in a CD4-independent fashion, was highly sensitive to neutralization by plasma from SIVmac-infected rhesus macaques, with average 50% neutralization titers of 1:20,480; this same strain was also sensitive to neutralization by the anti-V3 loop peptide sera. Other parental and chimeric viruses were less sensitive to neutralization with this same panel of antibodies, but as seen with SIVmac316, those viruses that were able to productively replicate in alveolar macrophages were more sensitive to antibody-mediated neutralization. To further define the amino acids involved in increased sensitivity to neutralization, a panel of viruses was constructed by changing envelope residues in SIVmac316 to the corresponding SIVmac239 amino acids. The increased neutralization sensitivity observed for SIVmac316 was mapped principally to three amino acid changes spread throughout gp120. In addition, the increased sensitivity to neutralization by V3-directed antibodies correlated with the ability of the various viruses to replicate to high levels in alveolar macrophage cultures and a CD4-negative cell line, BC7/CCR5. These results demonstrate that the V3 loop of SIVmac Env can act as an efficient target of neutralizing antibodies in a fashion that is highly dependent on sequence context. In addition, these studies suggest a correlation between decreased dependence on CD4 and increased sensitivity to antibody-mediated neutralization.