Prevalence of Previous COVID-19 Infection, COVID-19 Vaccination Receipt, and Intent to Vaccinate Among the US Workforce

Objective:

As COVID-19 vaccines become more accessible to all people in the United States, more employees are returning to the workforce or switching to in-person work. However, limited information is available on vaccination coverage and intent among the US workforce.

Methods:

We used data from the US Census Bureau’s Household Pulse Survey, fielded during April 14–May 24, 2021 (N = 218 787), to examine the prevalence of previous COVID-19 infection, vaccination receipt, and intent to vaccinate by essential worker status and employment type. In addition, we analyzed factors associated with vaccination receipt and reasons for not getting vaccinated.

Results:

More than 15% of the US workforce had a previous diagnosis of COVID-19, and 73.6% received ≥1 dose of COVID-19 vaccine; however, 12.4% reported that they probably will not or definitely will not get vaccinated. Vaccination coverage (range, 63.8%-78.3%) was lowest and non-intent to get vaccinated (12.9%-21.7%) was highest among self-employed adults across all essential and nonessential worker groups. Factors associated with receipt of vaccination were age, race, Hispanic ethnicity, educational attainment, annual household income, health insurance status, and previous COVID-19 diagnosis. The main reasons for not getting vaccinated were concerns about possible side effects and waiting and seeing if the vaccine is safe.

Conclusion:

Identifying and addressing disparities in COVID-19 vaccination coverage in the US workforce can protect groups with low vaccine coverage and increase understanding of reasons for vaccine hesitancy. Educating employees about the vaccine and its potential side effects, promoting a culture of health and safety in the workplace, and building social norms around vaccination can help create a safe work environment for all employees and their families.

Prior COVID-19 Infection, Mental Health, Food and Financial Insecurity, and Association With COVID-19 Vaccination Coverage and Intent Among College-Aged Young Adults, US, 2021

INTRODUCTION

More than 700,000 COVID-19 cases have been linked to American colleges and universities since the beginning of the pandemic. However, studies are limited on the effects of the pandemic on college-aged young adults and its association with their COVID-19 vaccination status and intent.

METHODS

Using the Census Bureau's Household Pulse Survey (HPS), a large, nationally representative survey fielded from April 14 through May 24, 2021, we assessed the effects of the pandemic (COVID-19 infection, mental health, food and financial security) on COVID-19 vaccination coverage (≥1 dose) and intentions toward vaccination among college-aged young adults in the United States (N = 6,758). We examined factors associated with vaccination coverage and intent, and reasons for not getting vaccinated.

RESULTS

Approximately one-fifth (19.6%) of college-aged young adults had a previous diagnosis of COVID-19, 43.5% and 39.1% reported having anxiety or depression, respectively, 10.9% reported that they sometimes or often did not have enough food to eat, and 22.6% and 12.3% found it somewhat or very difficult, respectively, to pay for household expenses. Of college-aged young adults, 63.1% had received at least 1 dose of the COVID-19 vaccine, 15.4% probably would be vaccinated or were unsure about getting the vaccine, and 14.0% probably will not or definitely will not get vaccinated. Adults who were non-Hispanic Black (vs non-Hispanic White) or had food or financial insecurities (vs did not) were less likely to be vaccinated or intend to be vaccinated. Among adults who probably will not or definitely will not be vaccinated, more than one-third said that they did not believe a vaccine was needed.

CONCLUSION

Ensuring high and equitable vaccination coverage among college-aged young adults is critical for safely reopening in-person learning and resuming prepandemic activities.

Queensland’s multi-year Wet and Dry periods: implications for grazing enterprises and pasture resources

Year-to-year variability in rainfall has long been recognised as a major issue in managing livestock enterprises across Australia’s grazing lands. Extension products documenting rainfall variability have been developed over the last 30 years and have been keenly sought by producers and their advisors. This paper describes multi-year rainfall variability from 1889 to 2020 and provides the basis for classifying the 131 years of rainfall into 18 discrete Wet (7), Average (2) and Dry (9) periods as presented in the ‘Queensland’s Extended Wet and Dry Periods’ poster. The classification was consistent with: analysis of fluctuations and trends in the long-term time series of reported livestock numbers; drought declarations for government assistance; and documented periods of pasture resource degradation and recovery. Rainfall during the nine Wet and Average periods was +18% above the long-term average annual rainfall (LTAAR), in contrast to the Dry periods with −17% below LTAAR. Wet periods (including Average) were on average 7 years in duration, ranging from 5 to 9 years. Dry periods were on average 8 years in duration and ranged from 5 to 13 years. Detailed analysis of the effects of the El Niño Southern Oscillation (ENSO) phenomenon indicated that: (a) the Wet/Dry periods were dominated by different frequencies and amounts of rainfall in La Niña/El Niño years; (b) rainfall in ENSO neutral years was generally above and below average rainfall for the Wet or Dry periods respectively; (c) the frequency of ENSO year-types was less important than the overall rainfall surplus (or deficit) in La Niña (or El Niño) years within the Wet (or Dry) periods respectively; and (d) the timing of Wet and Dry periods was correlated with indices of quasi-decadal and inter-decadal variability in components (sea surface temperatures and atmospheric pressures) of the global climate system. Climatic risk assessment systems for grazing management at multi-year timescales are yet to be developed.

An online system for calculating and delivering long-term carrying capacity information for Queensland grazing properties. Part 2: modelling and outputs

A combination of field data and models have been used to estimate long-term carrying capacity (LTCC) of domestic livestock in Queensland grazing lands. These methods have been synthesised and coupled with recent developments in science and information technology to provide a fully-automated approach of modelling LTCC through the FORAGE online system. In this study, the GRASP model was used to simulate pasture growth with parameter sets and safe pasture utilisation rates defined for 225 land types across Queensland. Distance to water points was used to assess the accessibility of pastures to livestock. Spatial analysis classified the property into unique areas based on paddock, land type and distance to water points, which estimated pasture growth, pasture utilisation and accessibility at a sub-paddock scale. Thirteen foliage projective cover (FPC) classes were used in modelling the pasture system to deal with the non-linear relationship between tree and grass interactions. As ‘proof of concept’, remotely-sensed individual-date green ground cover data were used to optimise the GRASP model parameters to improve the model performance, and a Monte Carlo analysis provided uncertainty estimates for model outcomes. The framework provides an efficient and standardised method for estimating LTCC. To test the system, LTCCs from 43 ‘benchmark’ properties were compared with simulated LTCCs, and 65% of the modelled LTCCs were within ± 25% of the benchmark LTCCs. Due to uncertainties in model inputs at the property scale and in model simulation, the modelled LTCC should be used as a starting point for further refinement of actual property LTCC.

Factors affecting patient flow in a neurosurgery department

INTRODUCTION

Patient flow is the process by which movement of patients and clinical productivity is achieved. The objectives of this study were to implement and evaluate the NHS Improvement SAFER patient flow bundle, evaluate the impact of the Red2Green initiative, and assess the impact of frailty on patient flow.

MATERIALS AND METHODS

All patients admitted to a neurosurgery unit from 1 September to 30 November 2017 were included. Using guidance set out by NHS, data were prospectively collected from daily ward lists and patient notes, including demographics, admission and discharge details, length of stay, anticipated discharge date, red days with reasons and frailty (Rockwood Clinical Frailty Scale). NHS reference costs were used for cost analyses.

RESULTS

A total of 420 patients (55% elective) were included, totalling 3909 bed days. All patients received daily senior reviews before midday, and anticipated discharge dates were set at daily multidisciplinary team meetings. Ten per cent of patients were discharged before midday. There were 21% (837) red days, significantly more (76%) for emergency patients (639 vs 198 elective; P < 0.001); 63% red days were attributed to awaiting a bed in a local hospital; 25% (106) patients were classed as frail (50 elective), which was associated with a significantly longer length of stay (17.3 vs 6; P < 0.01), and more red days (615 vs 222; p<0.01). Considering excess bed charges and lost revenue (with penalties), red days cost over £1 million per year.

CONCLUSIONS

SAFER has identified areas for improvement in patient flow, with obvious cost implications. It has created a platform for discussion within the referral network and identified a role for a geriatric liaison service.

FP1-4 Factors affecting patient flow in a neurosurgery department

Objectives

The objectives of this study were to audit the NHS Improvement SAFER patient flow bundle, evaluate the impact of the Red2Green initiative, and assess the impact of frailty on patient flow.

Design

A prospective review over a 3 month period.

Subjects

All patients admitted to a Neurosurgery Unit from 01/09/2017 to 30/11/2017 were included.

Methods

Data were prospectively collected from daily ward lists and patient notes, including demographics, admission/discharge details, length of stay (LOS), expected discharge date, red days with reasons, and frailty (Rockwood Clinical Frailty Scale). NHS Improvement Reference Costs were used for cost analyses.

Results

420 patients (55% elective) were included, total 3909 bed days. All patients received a daily senior review before midday, and EDDs were set at daily MDT meetings. 10% patients were discharged before midday. There were 21% (837) red days, significantly more (76%) for emergency patients (639 vs 198 elective; p<0.001). 63% red days were attributed to awaiting a bed in a local hospital. 25% (106) patients were classed as frail (50 elective), which was associated with a significantly longer LOS (17.3 vs 6; p<0.01), and more red days (615 vs 222; p<0.01). Considering bed costs and lost revenue (with penalties), red days cost is estimated at over £1M per year.

Conclusions

SAFER has identified areas for improvement in patient flow, with obvious cost implications. It has created a platform for discussion within the referral network, and identified a role for a geriatric liaison service.

Paradoxical upgrading reaction in extra-pulmonary tuberculosis: association with vitamin D therapy

SETTING:

Glasgow, Scotland, UK.

BACKGROUND:

Paradoxical reactions in tuberculosis (TB) are a notable example of our incomplete understanding of host-pathogen interactions during anti-tuberculosis treatment.

OBJECTIVES:

To determine risk factors for a TB paradoxical reaction, and specifically to assess for an independent association with vitamin D use.

DESIGN:

Consecutive human immunodeficiency virus (HIV) negative adult patients treated for extra-pulmonary TB were identified from an Extended Surveillance of Mycobacterial Infections database. In our setting, vitamin D was variably prescribed for newly diagnosed TB patients. A previously published definition of paradoxical TB reaction was retrospectively applied to, and data on all previously described risk factors were extracted from, centralised electronic patient records. The association with vitamin D use was assessed using multivariate logistic regression.

RESULTS:

Of the 249 patients included, most had TB adenopathy; 222/249 had microbiologically and/or histologically confirmed TB. Vitamin D was prescribed for 57/249 (23%) patients; 37/249 (15%) were classified as having paradoxical reactions. Younger age, acid-fast bacilli-positive invasive samples, multiple disease sites, lower lymphocyte count and vitamin D use were found to be independent risk factors.

CONCLUSION:

We speculate that vitamin D-mediated signalling of pro-inflammatory innate immune cells, along with high antigenic load, may mediate paradoxical reactions in anti-tuberculosis treatment.

Lenses and Lessons: Using three different research perspectives in early childhood education research

In contemporary Western research, collaboration is held in high esteem. This developing practice is chal¬lenging particularly for researchers who follow varying theoretical approaches. However although a challeng¬ing endeavour, when viewing the one data set with different lenses, there are various lessons that can be shared. A key aspect of this paper is involved researchers' different analytical perspectives in one data set to learn more about each other's research insights, rather than become instant expert in other's approaches. The interview data reported in this paper originates from a larger study researching parents' experience of using early child¬hood education and care (ECEC) in Australia. Here we analyse and report on two shared interview excerpts and use three different research lenses for analysis; phenomenographic study, conversational analysis and cul¬tural-historical theory. The finding of this paper demonstrates that applying different lenses provide different interpretations, including strengths, limitations and opportunities. In this paper we argue that collaborative research practices enhance our understanding of varying research approaches and the scope, quality, transla¬tion of research and the researchers' capacity are enhanced.

Simple merging technique for improving resolution in qualitative single image phase contrast tomography

For dynamic samples and/or for simple ease-of-use experiments, single-image phase contrast tomography is a very effective method for the 3D visualization of materials which would otherwise be indiscernible in attenuation based x-ray imaging. With binary samples (e.g. air-material) and monochromatic wavefields a transport-of-intensity (TIE)-based phase retrieval algorithm is known to retrieve accurate quantitative maps of the phase distribution. For mixed material samples and/or white beam radiation the algorithm can still produce useful qualitative tomographic reconstructions with significantly improved area contrast. The stability of the algorithm comes with a recognized associated loss of spatial resolution due to its essential behaviour as a low-pass filter. One possible answer to this is an image fusion technique that merges the slices reconstructed from raw phase contrast images and those after phase retrieval, where the improved contrast may be acquired without the associated loss of high-frequency information. We present this technique as a simple few-parameter Fourier method, which is easily tunable and highly compatible with current reconstruction steps.

Risk of venous thromboembolism in patients treated for bacterial infection in the community with outpatient parenteral antimicrobial therapy

BACKGROUND

It is recommended that venous thromboembolism (VTE) prophylaxis be considered for patients receiving outpatient parenteral antimicrobial therapy (OPAT), but there is no published data to quantify VTE risk in this patient group.

AIM AND METHOD

The aim of this retrospective cohort study was to establish VTE incidence in patients managed through an OPAT service and assess utility of a common VTE prediction score normally used for inpatients. Consecutive episodes of OPAT between May 2009 and May 2012 were included. Patients on long-term anti-coagulants, those with an established indication for extended, outpatient VTE prophylaxis (i.e. patients referred to OPAT following hip or knee arthroplasty) were excluded. The Padua VTE Prediction Score was retrospectively applied to the cohort. The primary outcome was incidence of symptomatic VTE during or up to 90 days after completion of OPAT treatment.

RESULTS

There were 780 included patient episodes; 105 (13.5%) patients had a Padua VTE risk score >3; no patients received pharmacological VTE prophylaxis during OPAT treatment. During or up to 90 days following OPAT, two proximal lower limb DVTs were diagnosed, giving VTE incidence of 2/780 (0.26%, 95% CI: 0.03-0.92%), and there were eight deaths of which none were suspected to be related to VTE. There was one intracranial haemorrhage associated death.

CONCLUSION

This retrospective cohort study found a low incidence of VTE in OPAT patients, and does not support routine application of inpatient VTE prophylaxis algorithms to patients treated for infection in the community.

Unraveling wetting transition through surface textures with X-rays: liquid meniscus penetration phenomena

In this report we show that synchrotron X-ray radiography is a powerful method to study liquid-air interface penetration through opaque microtextured surface roughness, leading to wetting transition. We investigate this wetting phenomenon in the context of sessile drop evaporation, and establish that liquid interface sinking into the surface texture is indeed dictated by the balance of capillary and Laplace pressures, where the intrinsically three-dimensional nature of the meniscus must be accounted for. Air bubble entrapment in the texture underneath impacting water drops is also visualized and the mechanisms of post-impact drop evaporation are discussed.

Inhibition of neointimal hyperplasia in a rabbit vein graft model following non-viral transfection with human iNOS cDNA

Vein graft failure caused by neointimal hyperplasia (IH) after coronary artery bypass grafting with saphenous veins is a major clinical problem. The lack of safe and efficient vectors for vascular gene transfer has significantly hindered progress in this field. We have developed a Receptor-Targeted Nanocomplex (RTN) vector system for this purpose and assessed its therapeutic efficacy in a rabbit vein graft model of bypass grafting. Adventitial delivery of β-Galactosidase showed widespread transfection throughout the vein wall on day 7, estimated at about 10% of cells in the adventitia and media. Vein grafts were then transfected with a plasmid encoding inducible nitric oxide synthase (iNOS) and engrafted into the carotid artery. Fluorescent immunohistochemistry analysis of samples from rabbits killed at 7 days after surgery showed that mostly endothelial cells and macrophages were transfected. Morphometric analysis of vein graft samples from the 28-day groups showed approximately a 50% reduction of neointimal thickness and 64% reduction of neointimal area in the iNOS-treated group compared with the surgery control groups. This study demonstrates efficacy of iNOS gene delivery by the RTN formulation in reducing IH in the rabbit model of vein graft disease.

X-ray mosaic nanotomography of large microorganisms

Full-field X-ray microscopy is a valuable tool for 3D observation of biological systems. In the soft X-ray domain organelles can be visualized in individual cells while hard X-ray microscopes excel in imaging of larger complex biological tissue. The field of view of these instruments is typically 10(3) times the spatial resolution. We exploit the assets of the hard X-ray sub-micrometer imaging and extend the standard approach by widening the effective field of view to match the size of the sample. We show that global tomography of biological systems exceeding several times the field of view is feasible also at the nanoscale with moderate radiation dose. We address the performance issues and limitations of the TOMCAT full-field microscope and more generally for Zernike phase contrast imaging. Two biologically relevant systems were investigated. The first being the largest known bacteria (Thiomargarita namibiensis), the second is a small myriapod species (Pauropoda sp.). Both examples illustrate the capacity of the unique, structured condenser based broad-band full-field microscope to access the 3D structural details of biological systems at the nanoscale while avoiding complicated sample preparation, or even keeping the sample environment close to the natural state.

The 4th Annual Ontario Thoracic Cancer Conference at Niagara-on-the-Lake

The 4th annual Ontario Thoracic Cancer Conference at Niagara-on-the-Lake focused on the themes of innovations in the management of lung cancer, controversies in the management of esophageal cancer, and molecular targeted therapies in lung cancer. This conference summary highlights the presentations and provides clinicians with a referenced update on these topics.

The 4th Annual Ontario Thoracic Cancer Conference at Niagara-on-the-Lake

The 4th annual Ontario Thoracic Cancer Conference at Niagara-on-the-Lake focused on the themes of innovations in the management of lung cancer, controversies in the management of esophageal cancer, and molecular targeted therapies in lung cancer. This conference summary highlights the presentations and provides clinicians with a referenced update on these topics.

Time to pregnancy and semen parameters: a cross-sectional study among fertile couples from four European cities

BACKGROUND

In fertile populations, little is known about the association between semen parameters and time to pregnancy (TTP).

METHODS

Pregnant women from Copenhagen, Edinburgh, Paris and Turku who conceived without medical intervention were asked for their TTP (942 couples), and their partners provided a semen sample. The proportion of morphologically normal sperm and the multiple anomalies index (MAI, ratio of the total number of anomalies to the number of abnormal sperm) were centrally estimated. We estimated rate ratios for the occurrence of a pregnancy by a discrete survival model, adjusted for sexual activity and female factors affecting fecundity.

RESULTS

Increasing sperm concentration influenced TTP up to 55 x 10(6)/ml. The proportion of morphologically normal sperm influenced TTP up to 39% according to David's criteria, and this association held among the subjects with a sperm concentration >55 x 10(6)/ml. For strict criteria, the threshold value was 19% normal sperm. An increase of 0.5 in MAI was associated with an adjusted rate ratio for the occurrence of a pregnancy of 0.68 (95% confidence interval: 0.54-0.85).

CONCLUSIONS

These results highlight the importance of sperm morphology parameters and indicate that the effect of proportion of normal sperm on TTP may be independent of sperm concentration.

Regional differences in waiting time to pregnancy among fertile couples from four European cities

BACKGROUND

A previous European study found a longer time to pregnancy (TTP) among fertile women from Paris compared with women from other Western European countries. A co-ordinated, cross-sectional study of pregnant couples from Denmark (Copenhagen), France (Paris), Scotland (Edinburgh) and Finland (Turku) was therefore undertaken to assess differences in waiting TTP among couples from these cities.

METHODS

Pregnant women were invited to participate when they showed up for their first antenatal visit in one of the four centres. Inclusion criteria included that their partner was 20-45 years of age and born in the country in which he was currently living and that the pregnancy was achieved without fertility treatment. Both partners filled in a questionnaire and the man underwent a physical examination and delivered a semen sample (Turku: n = 237, Copenhagen: n = 302, Edinburgh: n = 212, Paris: n = 191).

RESULTS

French couples had a decreased probability of conception compared with couples from the other three countries, although only after adjustment for confounders. No significant differences between couples from the three other countries were found.

CONCLUSION

The observed geographical differences in TTP remain unexplained and were not due to differences in semen quality, but may be caused by varying exposures to environmental factors or psychological distress. In addition, selection bias due to the low participation rates cannot be ruled out. Future studies examining the causes for geographical differences in TTP are needed.

Chronic exercise reduces sympathetic nerve activity in rabbits with pacing-induced heart failure: A role for angiotensin II

BACKGROUND

Chronic exercise (EX) improves the quality of life and increases the survival of patients with chronic heart failure (CHF). Because sympathetic nerve activity is elevated in the CHF state, it is possible that EX is beneficial in this disease due to a decrease in sympathetic outflow.

METHODS AND RESULTS

We evaluated arterial baroreflex function and resting renal sympathetic nerve activity (RSNA) in EX normal and CHF rabbits before and after angiotensin II type 1 (AT(1)) receptor blockade. Four groups of rabbits were studied: a normal non-EX group, a normal EX group, a CHF non-EX group, and a CHF EX group. EX lowered resting RSNA in rabbits with CHF but not in normal rabbits. In addition, EX increased arterial baroreflex sensitivity in the CHF group (heart rate slope: CHF 1. 7+/-0.3 bpm/mm Hg, EX CHF 4.9+/-0.3 bpm/mm Hg; P:<0.01; RSNA slope: CHF 2.2+/-0.2%max/mm Hg, EX CHF 5.7+/-0.4%max/mm Hg; P:<0.01. AT(1) receptor blockade enhanced baroreflex sensitivity in the non-EX CHF rabbits but had no effect in EX CHF rabbits. Concomitant with this effect, EX lowered the elevated plasma angiotensin II concentration in the CHF group. A significant positive correlation was observed between sympathetic nerve activity and plasma angiotensin II.

CONCLUSIONS

These data strongly suggest that EX reduces the sympathoexcitatory state in the setting of CHF. Enhanced arterial baroreflex sensitivity may contribute to this reduction. In addition, EX lowers plasma angiotensin II concentration in CHF. These data further suggest that the lowering of angiotensin II may contribute to the decrease in sympathetic nerve activity after EX in the CHF state.

Early referral, diagnosis, and treatment of rheumatoid arthritis: evidence for changing medical practice

OBJECTIVES

To study the delay in starting disease modifying anti-rheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA), and any changes in medical practice between 1980 and 1997.

METHODS

198 consecutive RA patients attending the rheumatology clinics at a teaching hospital, for routine review, had their case sheet reviewed. The dates of symptom onset, general practitioner (GP) referral, first clinic appointment and first use of DMARD were recorded. Data were collected on the erythrocyte sedimentation rate, C reactive protein, rheumatoid factor, and the presence/absence of erosions at the first clinic assessment. Patients were split into four groups according to the date of their first clinic assessment-before 1986, 1987-9, 1990-3, and 1994-7.

RESULTS

There was a sharp drop in the delay between symptom onset and GP referral (before 1986, 21 months; 1987-89, 23 months; 1990-3, 7 months; 1994-7, 4 months, p<0.03), and in the delay between first assessment at the rheumatology clinic and the start of DMARD treatment (before 1986, 32 months; 1987-89, 21 months; 1990-1993, 8 months; 1994-7, 1 month, p<0.001). The number of patients given DMARD treatment within six months of symptom onset increased from 5% (before 1994) to 44% (1994-7). Seventy three per cent of patients waiting more than a year from symptom onset to first clinic appointment already had erosive change, compared with 34% of patients seen within a year.

CONCLUSIONS

Patients are being referred earlier in their disease, and DMARDs are prescribed sooner in the disease course. There has been a substantial increase in the proportion of patients treated with a DMARD within six months of symptom onset.

On the cellular mechanisms by which the bicarbonate ion mediates the extragenomic action of progesterone on human spermatozoa

Progesterone exerts an extragenomic action on human spermatozoa, inducing a rapid calcium transient in the acrosomal domain of these cells and enhancing their potential for fertilization. This response is known to exhibit an absolute dependence on the presence of extracellular bicarbonate, although the mechanisms underlying this interaction are not understood. In this study, bicarbonate was found to exert a dose-dependent impact on the ability of progesterone to promote sperm-oocyte fusion in the absence of any collateral effect on sperm motility. The loss of sperm function in bicarbonate-free medium was associated with a failure to produce reactive oxygen species, an impaired capacity to exhibit redox-associated changes in tyrosine phosphorylation, and an apparent incapacity to generate normal calcium transients on exposure to progesterone. These defects were not related to a cAMP deficiency but were associated with a significant fall in intracellular pH. If cytosolic pH was chemically buffered into the normal range, then the spermatozoa regained every element of their response to progesterone. These results emphasize the importance of an alkaline intracellular milieu for the extragenomic action of progesterone on human spermatozoa and stress the fundamental difference between intracellular and extracellular sources of bicarbonate in maintaining the proton balance within such cells.

Reactive oxygen species generation by human spermatozoa is induced by exogenous NADPH and inhibited by the flavoprotein inhibitors diphenylene iodonium and quinacrine

Human spermatozoa possess a specialized capacity to generate reactive oxygen species (ROS) that is thought to be of significance in the redox regulation of sperm capacitation (De Lamirande and Gagnon, 1993; Aitken et al., 1995). However, the mechanisms by which ROS are generated by these cells are not understood. In this study we have examined the possible significance of NADPH as a substrate for ROS production by human spermatozoa. Addition of NADPH to viable populations of motile spermatozoa induced a sudden dose-dependent increase in the rate of superoxide generation via mechanisms that could not be disrupted by inhibitors of the mitochondrial electron transport chain (antimycin A, rotenone, carbonyl cyanide m-chlorophenylhydrazone [CCCP], and sodium azide), diaphorase (dicoumarol) xanthine oxidase (allopurinol), or lactic acid dehydrogenase (sodium oxamate). However, NADPH-induced ROS generation could be stimulated by permeabilization and was negatively correlated with sperm function. Both NADH and NADPH were active electron donors in this system, while NAD+ and NADP+ exhibited little activity. Stereo-specificity was evident in the response in that only the beta-isomer of NADPH supported superoxide production. The involvement of a flavoprotein in the electron transfer process was indicated by the high sensitivity of the oxidase to inhibition by diphenylene iodonium and quinacrine. These results indicate that NAD(P)H can serve as an electron donor for superoxide generation by human spermatozoa and present a simple strategy for the production of motile populations of free radical generating cells with which to study the significance of these molecules in the control of normal and pathological sperm function.

Homeobox genes in the Ctenophora: identification of paired-type and Hox homologues in the atentaculate ctenophore, Beroë ovata

Homeobox-containing genes are a phylogenetically widespread family of transcription factors that can regulate cell fates during embryogenesis. Two distinct homeobox gene sequences are described for the atentaculate ctenophore Beroë, the first homeoboxes to be identified in this phylum. Beroë homeobox fragments were cloned in a survey of genomic DNA using polymerase chain reaction (PCR). Parsimony, neighbor-joining, and maximum likelihood methods were used to infer the orthology of the ctenophore sequences to specific homeoboxes from higher metazoans including Drosophila, Caenorhabditis elegans, and humans. Cteno-paired appears most closely related to paired-typed homeoboxes. This is the first evidence of a paired-type homeobox in one of the so-called diploblastic animals. Cteno-Hoxl appears most closely related to members of the Hox class, particularly Antennapedia.

Evidence of deteriorating semen quality in the United Kingdom: birth cohort study in 577 men in Scotland over 11 years

OBJECTIVE

To determine whether the quality of semen has changed in a group of over 500 Scottish men born between 1951 and 1973.

DESIGN

Retrospective review of data on semen quality collected in a single laboratory over 11 years and according to World Health Organisation guidelines.

SETTING

Programme of gamete biology research funded by Medical Research Council.

SUBJECTS

577 volunteer semen donors. Of these, 171 were born before 1959, 120 were born in 1960-4, 171 in 1965-9, and 115 in 1970-4.

MAIN OUTCOME MEASURES

Conventional criteria of semen quality including semen volume (ml), sperm concentration (10(6)/ml), overall motility (% motile), total number of sperm in the ejaculate (10(6)), and total number of motile sperm in the ejaculate (10(6)).

RESULTS

When the four birth cohort groups were compared a later year of birth was associated with a lower sperm concentration, a lower total number of sperm in the ejaculate, and a lower number of motile sperm in the ejaculate. The median sperm concentration fell from 98x10(6)/ml among donors born before 1959 to 78x10(6)/ml among donors born after 1970 (P=0.002). The total number of sperm in the ejaculate fell from 301x10(6) to 214x10(6) (P=0.0005), and the total number of motile sperm in the ejaculate fell from 169.7x10(6) to 129.0x10(6) (P=0.0065).

CONCLUSION

This study provides direct evidence that semen quality is deteriorating, with a later year of birth being significantly associated with a reduced number of sperm in adult life.

Prospective study of 210 consecutive cases of endocapsular phacoemulsification using the AMO SI-30NB 3-piece foldable lens

PURPOSE

To assess the acceptability of clinical outcome achieved with use of the SI-30NB lens, as well as the incidence of any lens related complications.

METHODS

This prospective study evaluated 210 consecutive eyes undergoing endocapsular phacoemulsification cataract surgery (EPECS), with implantation of the AMO SI-30NB foldable three-piece lens, commencing with the first patient in our practice receiving this implant. There was 99% follow-up for at least three months, with a mean of nine months, and a range of three to 14 months. Incisions were a maximum of 3.2 mm in size, and this allowed minimisation of astigmatism, and maximisation of early visual rehabilitation.

RESULTS

The final visual acuity results were excellent, with 95% of cases achieving corrected vision of 6/12 or better. All cases without pre-existing ocular pathology achieved corrected vision of 6/6, apart from a single case which achieved 6/9, but the patient died before follow-up. The lens-related complication rate was less than 1% (two patients). No decentration of any other implant occurred, and no patient complained of edge glare. There were no cases of iris chafing or pigment dispersion. Only three patients (1.4%) required Yag posterior capsulotomy in the first 14 months of the study. Central bag-bag fixation was achieved in 206 of the 210 cases in the study (98%).

CONCLUSION

The results achieved using the SI-30NB lens with a small incision phaco procedure were excellent. Lens-related complications occurred in only two cases and very few cases have had problems with posterior capsular opacification.

Ketamine inhibits glutamate-, N-methyl-D-aspartate-, and quisqualate-stimulated cGMP production in cultured cerebral neurons

BACKGROUND

Glutamatergic signaling has been linked to the recently discovered neurotransmitter/neuromodulator nitric oxide (NO), and several classes of anesthetics block some step in glutamatergic signaling. This study was designed to determine whether or not ketamine would prevent NO-dependent cGMP production stimulated by glutamate (GLU) and the GLU analogs NMDA, quisqualate (QUIS), and kainate (KAIN).

METHODS

Primary cultures of cortical neurons and glia (prepared from 16-day gestational rat fetuses) were used after 12-16 days in culture. Reactions were carried out in magnesium-free buffer containing 100 microM 3-isobutyl-1-methylxanthine, and cGMP content of cultures was used as a bioassay of NO production.

RESULTS

Cyclic GMP production stimulated by sodium nitroprusside (100 microM) occurred predominately in neurons and not in glia. Neurons were spontaneously active in these cultures; basal cGMP production was decreased by 50% in the presence of 1 microM tetrodotoxin (TTX). Glutamate (100 microM), NMDA (100 microM), QUIS (300 microM), and KAIN (100 microM) each increased cGMP content of neuronal cultures. L-NMMA (100 microM), a NO synthase inhibitor, prevented the stimulation of cGMP production by GLU or its analogs. Pretreatment with MK-801 (1 microM) or ketamine (10-100 microM) inhibited GLU-, NMDA-, and QUIS-stimulated cGMP production. Quisqualate-stimulated responses were the most sensitive to inhibition by ketamine and NMDA-stimulated responses were the least sensitive to inhibition. MK-801 and ketamine did not significantly inhibit KAIN-stimulated cGMP production. CNQX (10 microns) blocked KAIN-stimulated cGMP production only.

CONCLUSIONS

The authors' data demonstrate that ketamine inhibited NO synthesis stimulated by NMDA- and non-NMDA-receptor specific analogs. Our findings indicate that blockade of QUIS- as well as NMDA-subtypes of GLU- receptor may be important in the development of ketamine-induced anesthesia.

The entropion patch: a method of temporarily correcting involutional entropion with adhesive tape

A simply designed entropion patch provided effective temporary preoperative relief of the symptoms of lid malposition in lower lid involutional entropion in six patients. The patch is easily fashioned and used after appropriate instruction, with its design taking into account lid mechanics and the pathophysiology of involutional entropion.

Prospective evaluation of one surgeon's first 100 cases of endocapsular phacoemulsification cataract surgery

In this series of one surgeon's first 100 cases of endocapsular phacoemulsification cataract surgery (EPECS), believed to be the first truly prospective study of its kind, 86% of patients achieved corrected vision of 6/6 to 6/4; 96% achieved vision of 6/12 or better; and excluding those with pre-existing pathology, 99% achieved 6/12. Posterior capsular rupture occurred in 11 cases, with vitrectomy being required in eight cases. Detailed analysis of the 100 cases is provided.

Prospective study of short and ultrashort regimens of gonadotropin-releasing hormone agonist in an in vitro fertilization program

OBJECTIVE

To assess the usefulness of the ultrashort regimen of gonadotropin-releasing hormone agonist (GnRH-a) in ovulation induction in an in vitro fertilization (IVF) program.

DESIGN

A prospective randomized trial comparing short and ultrashort regimens of GnRH-a.

SETTING

Aberdeen Assisted Reproduction Unit.

PATIENTS

Forty-eight patients having IVF for the first time were randomized between the two protocols.

MAIN OUTCOME MEASURES

Response to ovarian stimulation and occurrence of spontaneous luteinizing hormone (LH) surges.

RESULTS

In ovulation induction, fertilization, and pregnancy rates the ultrashort regimen produces results that were no different to the short regimen but it did not always prevent an LH surge.

CONCLUSION

The ultrashort regimen can be a useful alternative for ovarian stimulation of patients undergoing IVF.

Mothers' concepts of normality, behavioural change and illness in their children

Several sociological models have been put forward to explain illness behaviour. However, little research has examined general practitioners' understanding of mothers' perceptions of their children's health and illness. The aim of this study was to attempt to understand the cultural context of children's illness. Mothers' concerns about their children's health and illnesses were examined by describing the mothers' own perceptions of alterations in their children's behaviour. The mothers' perceptions of normality appeared to underpin their negotiation of illness. The concept of normality was found to change over time, to be uniquely based on individual experience, to be related to health, and to a process of normalization. The mothers' perceived importance of children's behavioural changes are discussed: they may be precursors or results of illness, causes for concern in their own right, or a management problem for the household. Identifying and acknowledging the unique way in which mothers perceive health and illness in their children may lead to enhanced understanding and satisfaction for both the general practitioner and mother in the consultation process.