At-Home Versus Onsite COVID-19 School-based Testing: A Randomized Noninferiority Trial

OBJECTIVES

Equitable access to coronavirus 2019 (COVID-19) screening is important to reduce transmission and maintain in-person learning for middle school communities, particularly in disadvantaged schools. Rapid antigen testing, and at-home testing in particular, could offer substantial advantages over onsite testing from a school district's perspective, but it is unknown if engagement in at-home testing can be initiated and sustained. We hypothesized that an at-home COVID-19 school testing program would be noninferior to an onsite school COVID-19 testing program with regard to school participation rates and adherence to a weekly screening testing schedule.

METHODS

We enrolled 3 middle schools within a large, predominantly Latinx-serving, independent school district into a noninferiority trial from October 2021 to March 2022. Two schools were randomized to onsite and 1 school to at-home COVID-19 testing programs. All students and staff were eligible to participate.

RESULTS

Over the 21-week trial, at-home weekly screening testing participation rates were not inferior to onsite testing. Similarly, adherence to the weekly testing schedule was not inferior in the at-home arm. Participants in the at-home testing arm were able to test more consistently during and before returning from school breaks than those in the onsite arm.

CONCLUSIONS

Results support the noninferiority of at-home testing versus onsite testing both in terms of participation in testing and adherence to weekly testing. Implementation of at-home COVID-19 screening testing should be part of schools' routine COVID-19 prevention efforts nationwide; however, adequate support is essential to ensure participation and persistence in regular at-home testing.

Occupational asthma in teachers

BACKGROUND

Work-related asthma symptoms are common in teachers and teaching assistants, there are few studies evaluating their causes.

AIMS

To identify causes of occupational asthma in teachers and teaching assistants referred to the Birmingham Occupational Lung Disease clinic 2000-20 using evaluation of serial Peak Expiratory Flow (PEF) records.

METHODS

Teachers and teaching assistants with possible occupational asthma were asked to record PEF 2-hourly at home and work for 4 weeks. Their records were evaluated with the Oasys programme. Those with a positive score for any of the three scores (area between curves (ABC), timepoint and Oasys score from discriminant analysis) were included. Repeat records were made as indicated to help identify the cause and the effects of remedial actions.

RESULTS

Thirty-eight teachers or teaching assistants met the inclusion criteria with all three Oasys scores positive in 24, 2/3 scores in nine and 1/3 in five. The building was the likely cause in 17 (in new builds particularly acrylates from carpet adhesives and in old buildings mould and construction dust), bystander exposure to agents in the schools in 12 (cleaning agents, acrylates from photocopiers and chloramines from indoor pools) and materials used in the classroom in 9 (most commonly MDF in design and technology classes). We illustrate how the PEF records helped identify the cause.

CONCLUSIONS

Oasys analysis of PEF records is a useful method of evaluating occupational asthma in teachers and identified difficult to confirm causes where successful remediation or redeployment was achieved.

Development of an At-Home COVID-19 Test Results-Reporting System for a School District Primarily Serving Underrepresented Minority Groups, San Diego, CA, 2021-2022

School-sponsored at-home COVID-19 testing benefits users, school administrators, and surveillance efforts, although reporting results remains challenging. Users require simple systems with tailored posttest guidance, and administrators need timely positive test information. We built a system to serve these needs and to collect data for our Rapid Acceleration of Diagnostics-Underserved Populations Return to School Program study in San Diego County, California, from October 2021 through January 2022. We describe this system and our participant outreach strategies and outline a replicable model for at-home results reporting. (Am J Public Health. 2022;112(S9):S883-S886. https://doi.org/10.2105/AJPH.2022.307073).

Emotional labour and aboriginal maternal infant care workers: The invisible load

BACKGROUND

The term 'emotional labour' has been used to describe the competing demands on midwives to empathize with clients whilst maintaining a level of professional detachment. Previous research indicates that when individuals experience difficulty managing these emotions, burnout may result. Aboriginal health care workers often have roles with large emotional demands, as they are relied upon heavily to engage clients in care. However, the concept of emotional labour has received little attention in relation to this group.

AIM

To explore potential sources of emotional labour for Aboriginal Maternal Infant Care workers in a maternity care program for Aboriginal women in South Australia. The program involves these workers providing care for women in partnership with midwives.

METHODS

We employed a phenomenological approach. Thirty in-depth interviews were conducted with staff and clients of the program. Recorded interviews were transcribed and coded and emerging themes identified.

FINDINGS

This workforce undertakes extensive emotional labour. Key sources include the cultural and family obligations they have to clients, complex social needs of many clients, and potential for community backlash when poor perinatal outcomes occur. A lack of respect for the role within the workplace further contributes to these experiences.

CONCLUSION

This study found that the responsibilities inherent to the role as both cultural broker and carer create significant emotional labour for workers. Recommendations to address this and enhance the sustainability of this workforce include: recognition and valuing of emotional work by management and other staff, enhancing cultural awareness training, and building stress-relieving activities into the workplace.

Short-term respiratory effects of cleaning exposures in female domestic cleaners

Symptoms of obstructive lung disease in domestic cleaners have been related to the use of bleach and other irritant cleaning products. The short-term effects of cleaning exposures on respiratory symptoms and peak expiratory flow (PEF) were investigated in domestic cleaners with respiratory disorders. In a panel study, 43 female domestic cleaners with a recent history of asthma and/or chronic bronchitis completed a 2-week diary, collecting information on respiratory symptoms, PEF and cleaning exposures. Mixed regression models were used to assess daily changes in symptoms and PEF associated with specific cleaning exposures. The probability of having work-related asthma was individually assessed by a computerised diagnostic system and an occupational asthma expert. Lower respiratory tract symptoms were more common on working days and were predominantly associated with exposure to diluted bleach, degreasing sprays/atomisers and air fresheners. Associations with upper respiratory tract symptoms and PEF were less apparent. Eleven (30%) subjects scored positively for work-related asthma. It is concluded that exposure to certain irritant cleaning products aggravates lower respiratory tract symptoms in female domestic cleaners with asthma or chronic bronchitis.

Oral oestrogen and combined oestrogen/progestogen therapy versus placebo for hot flushes

BACKGROUND

Hot flushes and night sweats are common symptoms experienced by menopausal women. Hormone therapy (HT), containing oestrogens alone or oestrogens together with progestogens in a cyclic or continuous regimen, is often recommended for their alleviation.

OBJECTIVES

To examine the effect of oral HT compared to placebo on these vasomotor symptoms and the risk of early onset side-effects.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders Group and Subfertility Group trials register (searched May 2002). This register is based on regular searches of MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, the handsearching of 20 relevant journals and conference proceedings, and searches of several key grey literature sources. We also contacted all relevant pharmaceutical companies, The Journal of the International Menopause Society and Climacteric.

SELECTION CRITERIA

Double-blind, randomised, placebo-controlled trials of oral HT for at least three months duration.

DATA COLLECTION AND ANALYSIS

Study quality and outcome data were assessed independently. Random effects models were considered appropriate due to the variety of trial methodologies. The meta-analyses were explored for sensitivity to trial quality and therapy duration. Symptom frequency and severity were assessed separately, together with withdrawals and side-effects. Frequency data were analysed using the Weighted Mean Difference (WMD) between treatment and placebo outcomes. For severity data, odds ratios were estimated from the proportional odds model. From 115 references originally identified, 24 trials meeting the selection criteria were included in the review. Study participants totaled 3,329. Trial duration ranged from three months to three years.

MAIN RESULTS

There was a significant reduction in the weekly hot flush frequency for HT compared to placebo (WMD -17.92, 95% CI -22.86 to -12.99). This was equivalent to a 75% reduction in frequency (95% CI 64.3 to 82.3) for HT relative to placebo. Symptom severity was also significantly reduced compared to placebo (OR 0.13, 95% CI 0.07 to 0.23). Withdrawal for lack of efficacy occurred significantly more often on placebo therapy (OR 10.51, 95% CI 5.00 to 22.09). Withdrawal for adverse events, commonly breast tenderness, oedema, joint pain and psychological symptoms, was not significantly increased (OR 1.25, 95% CI 0.83 to 1.90), although the occurrence of any adverse events was significantly increased for HT (OR 1.41, 95% CI 1.00 to 1.99). In women who were randomised to placebo treatment, a 57.7% (95% CI 45.1 to 67.7) reduction in hot flushes was observed between baseline and end of study.

REVIEWERS' CONCLUSIONS

Oral HT is highly effective in alleviating hot flushes and night sweats. Therapies purported to reduce such symptoms must be assessed in blinded trials against a placebo or a validated therapy because of the large placebo effect seen in well conducted randomised controlled trials, and also because during menopause symptoms may fluctuate and after menopause symptoms often decline. Withdrawals due to side-effects were only marginally increased in the HT groups despite the inability to tailor HT in these fixed dose trials. Comparisons of hormonal doses, product types or regimens require analysis of trials with these specific "within study" comparisons.

Oral estrogen replacement therapy versus placebo for hot flushes: a systematic review

OBJECTIVE

To examine the effectiveness of oral hormone replacement therapy (HRT) with regard to hot flushes and night sweats, which are vasomotor symptoms commonly experienced by menopausal women.

METHODS

Double-blind, randomized, placebo-controlled trials of oral HRT for at least 3 months' duration and reporting vasomotor outcomes were identified using a search strategy developed by the Menstrual Disorders Group and Subfertility Group of the Cochrane Collaboration. Twenty-one trials meeting the selection criteria were included in the review. Study participants totalled 2511. Trial duration ranged from 3 months to 3 years.

RESULTS

There was a significant reduction in the weekly hot flush frequency for HRT compared with placebo (weighted mean difference -17.46, 95% confidence interval (CI) -24.72 to -10.21). This was equivalent to a 77% reduction in frequency (95% CI 58.2-87.5) for HRT relative to placebo. Symptom severity was also significantly reduced compared with placebo (odds ratio (OR) 0.13, 95% CI 0.08-0.22). Withdrawal for lack of efficacy occurred significantly more often with placebo therapy (OR 17.25, 95% CI 8.23-36.15). Withdrawal for adverse events, commonly breast tenderness, edema, joint pain and psychological symptoms, was not significantly increased for HRT (OR 1.38, 95% CI 0.87-2.21). In women who were randomized to placebo treatment, a 50.8% (95% CI 41.7-58.5) reduction in hot flushes was observed between baseline and the end of the study.

CONCLUSIONS

Oral HRT is highly effective in alleviating hot flushes and night sweats. Owing to the marked effect seen with placebo treatment, it is important to compare therapies purported to alleviate vasomotor symptoms with a placebo or an established therapy.

Oral oestrogen replacement therapy versus placebo for hot flushes

BACKGROUND

Hot flushes and night sweats are common symptoms experienced by menopausal women. Hormone replacement therapy (HRT), containing oestrogens alone or oestrogens together with progestogens in a cyclic or continuous regimen, is often recommended for their alleviation.

OBJECTIVES

To examine the effect of oral HRT compared to placebo on these vasomotor symptoms and the risk of early onset side-effects.

SEARCH STRATEGY

As developed by the Menstrual Disorders Group and Subfertility group of the Cochrane Collaboration.

SELECTION CRITERIA

Double-blind, randomised, placebo-controlled trials of oral HRT therapy for at least three months duration.

DATA COLLECTION AND ANALYSIS

Study quality and outcome data were assessed independently. Random effects models were considered appropriate due to the variety of trial methodologies. The meta-analyses were explored for sensitivity to trial quality and therapy duration. Symptom frequency and severity were assessed separately, together with withdrawals and side-effects. Frequency data were analysed using the Weighted Mean Difference (WMD) between treatment and placebo outcomes. For severity data, odds ratios were estimated from the proportional odds model. From 99 references originally identified, 21 trials meeting the selection criteria were included in the review. Study participants totalled 2,511. Trial duration ranged from three months to three years.

MAIN RESULTS

There was a significant reduction in the weekly hot flush frequency for HRT compared to placebo (WMD -17.46, 95% CI -24.72, -10.21). This was equivalent to a 77% reduction in frequency (95% CI 58.2, 87.5) for HRT relative to placebo. Symptom severity was also significantly reduced compared to placebo (OR 0.13, 95% CI 0.08, 0.22). Withdrawal for lack of efficacy occurred significantly more often on placebo therapy (OR 17.25, 95% CI 8.23, 36.15). Withdrawal for adverse events, commonly breast tenderness, oedema, joint pain and psychological symptoms, was not significantly increased for HRT therapy (OR 1.38, 95% CI 0.87, 2.21). In women who were randomised to placebo treatment, a 50.8% (95% CI 41.7, 58.5) reduction in hot flushes was observed between baseline and end of study.

REVIEWER'S CONCLUSIONS

Oral HRT is highly effective in alleviating hot flushes and night sweats. Therapies purported to reduce such symptoms must be assessed in blinded trials against a placebo or a validated therapy. Withdrawals due to side-effects were only marginally increased in the HRT groups despite the inability to tailor HRT in these fixed dose trials. Comparisons of hormonal doses, product types or regimens require analysis of trials with these specific "within study" comparisons.

Substituted 2-aminopyridines as inhibitors of nitric oxide synthases

A series of substituted 2-aminopyridines was prepared and evaluated as inhibitors of human nitric oxide synthases (NOS). 4,6-Disubstitution enhanced both potency and specificity for the inducible NOS with the most potent compound having an IC50 of 28 nM.

Development and dissemination of minimum standards of care for asthma

Asthma is a common illness in children and adults that is often associated with suboptimal outcomes, despite the existence and distribution of carefully considered national and international guidelines for diagnosis and treatment. The need to improve asthma care in North Texas motivated a coalition of health plans, employers, hospitals, academic medical centers, providers, and benefit consultants to collaborate in developing and implementing Minimum Standards of Care for Asthma. To gain consensus, the North Central Texas HEDIS Coalition used a panel of regional asthma experts and surveyed a large number of primary-care providers to construct a one-page document that was ultimately approved by regional stakeholders in healthcare participating in this coalition and also by specialty organizations in Texas. Adopting a minimum standard guideline, developed and supported by multiple stakeholders, may represent a more realistic intermediate goal when implementing "best practice" guidelines is limited by practical barriers.

School-based asthma management policies and practices: a regional survey

Children with asthma may spend as much as one-third of their weekdays in the school setting. As one effort to evaluate and improve asthma care in the Dallas/Fort Worth area, the North Central Texas HEDIS Coalition surveyed 36 independent school districts (ISDs). Twenty-nine ISDs, representing 679,631 children, responded to questions on school health personnel, identification and monitoring of students with asthma, staff training in asthma care, policies for students carrying asthma medications, and campus smoking policies. Key findings were more positive than expected and included the following: (a) training in asthma management is fairly extensive, (b) students in 26 ISDs are allowed, upon physician request, to carry medihalers, and (c) smoking on school property is illegal in Texas. However, the absence of a fully developed strategy for implementing the survey findings may have hindered the continuous quality improvement efforts among schools, health plans, providers, and the community that could have evolved from this project.

Magnesium for preventing preterm birth after threatened preterm labour

BACKGROUND

Magnesium therapy is sometimes continued after an episode of threatened preterm labour in an attempt to prevent the onset of further preterm contractions.

OBJECTIVES

The objective of this review was to assess the effects of magnesium maintenance therapy on preventing preterm birth after threatened preterm labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register.

SELECTION CRITERIA

Randomised controlled trials of magnesium therapy given to women after threatened preterm labour.

DATA COLLECTION AND ANALYSIS

Trial quality assessment and data extraction were done independently by two reviewers.

MAIN RESULTS

Two trials were included. Both were of poor quality and neither study included any long-term follow up of infants. The incidence of preterm birth or perinatal mortality was not reduced by magnesium maintenance therapy compared to alternative therapy or no treatment.

REVIEWER'S CONCLUSIONS

There is not enough evidence to show that magnesium maintenance therapy is effective in preventing preterm birth after an episode of threatened preterm labour.

Age-of-acquisition and cumulative frequency have independent effects

Lewis (1999) argued that effects of age of acquisition (AoA) are entirely attributable to cumulative frequency. He reported an instance-based model in which the number of instances of the stimulus stored in memory predicts reaction time. We note four aspects of the literature on AoA that cannot be explained by this instance-based approach. Firstly, an effect of AoA has been observed in the absence of an effect of frequency. Secondly, an effect of AoA has been observed when cumulative frequency has been controlled. Thirdly, the effect of AoA is dependent on task. Fourthly, the effect of word frequency is dependent on stimulus modality. Lewis reported an experiment in which participants make a decision based on identity-specific semantic information to celebrity faces to demonstrate an effect of the number of instances in memory, which he interpreted as an effect of AoA. We note that effects of AoA have been found in lexical and perceptual tasks, but to date all attempts to demonstrate an advantage for early-acquired items in semantic classification tasks have failed. We conclude that the effects of AoA cannot be attributed solely to the effects of cumulative frequency.

A novel endothelial cell-based gene therapy platform for the in vivo delivery of apolipoprotein E

A major focus in gene therapy has been the use of recombinant viruses to deliver genes in vivo. Although this approach shows much promise, there are many safety concerns associated with the use of viral materials in the treatment of human diseases. Our alternative cell-based gene therapy approach utilizes endothelial cells (Pro 175) isolated from the murine embryonic yolk sac. These endothelial cells were evaluated for their potential use in gene therapy as a gene delivery platform. As a test model, we used these cells to deliver apolipoprotein E (apoE) in the murine apoE knockout atherosclerosis model. The lack of apoE protein in these animals results in high levels of serum cholesterol and formation of severe aortic plaques and lesions at a young age. After transplantation of the apoE secreting Pro 175 endothelial cells into apoE-deficient mice, serum cholesterol levels were measured at 2 week intervals. During the 3 months after the initiation of these experiments, levels of cholesterol in the animals having received the apoE secreting endothelial cells were statistically lower compared with the levels of age-matched controls having received non-secreting endothelial cells. Concomitant with cholesterol reduction, atherosclerotic aortic plaques were noticeably reduced in the experimental apoE+ animals. These results highlight the potential of these unique endothelial cells as an efficient delivery platform for somatic gene therapy.

The effect of age of acquisition on speed and accuracy of naming famous faces

Three experiments examined whether famous faces would be affected by the age at which knowledge of the face was first acquired (AoA). Using a multiple regression design, Experiment 1 showed that rated familiarity and AoA were significant predictors of the time required to name pictures of celebrities' faces and the accuracy of producing their names. Experiment 2 replicated an effect of AoA using a factorial design in which other attributes of the celebrities were matched. In both Experiments 1 and 2, several ratings had been collected from participants before naming latency data were collected. Experiment 3 investigated the accuracy and latency of naming celebrities without any prior exposure to the stimuli. An advantage for naming early acquired celebrities was observed even on the first presentation. The participants named the same celebrities in three subsequent presentations of the stimuli. The effect of AoA was not significant on the fourth presentation. The implications of these results for models of face naming and directions for future research are discussed.

On the relationship between reading, listening and speaking: it's different for people's names

Two experiments are reported that tested predictions derived from the framework of face, object, and word recognition proposed by Valentine, Brennen, and Brédart (1996). The findings were as follows: (1) Production of a celebrity's name in response to seeing the celebrity's face primed a subsequent familiarity decision to the celebrity's printed name. The degree of repetition priming observed was as great as that observed when a familiarity decision to the printed name was repeated in the prime and test phases of the experiment. (2) Making a familiarity decision to an auditory presentation of a celebrity's name primed a familiarity decision to the same celebrity's name presented visually. The magnitude of cross-modality priming was as great as the magnitude of within-modality repetition priming. This result for people's names contrasted with the effects observed in lexical decision tasks, in which no reliable cross-modality priming was observed. The results cannot be accounted for by previous models of face and name processing. They show a marked contrast between processing people's names and processing words. The results support the framework proposed by Valentine et al. (1996). The implications for models of speech production, perception, and reading are discussed, together with the potential of the methodology to elucidate our understanding of proper name processing.

Cost-effectiveness of initial therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors to treat hypercholesterolemia in a primary care setting of a managed-care organization

From January 1994 through May 1995, Prudential HealthCare-North Texas prospectively studied 299 member patients diagnosed with hypercholesterolemia for whom pharmacotherapy with one of four 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, also known as statins, was prescribed. The purpose of this study was to measure the relative cost-effectiveness (CE) of these drugs in a real-world setting. This study provides information to assist decision makers in managed-care organizations (MCO) in making formulary selections. The study used a prospective, randomized, balanced cohort design, examining patients who had been prescribed initial therapy with a statin drug as monotherapy. Costs (direct medical and indirect costs) and effectiveness (percent reduction in low-density lipoprotein cholesterol levels) were based on approximately the first 6 months of initial therapy. Both the MCO and patient perspectives were considered. In the base case, mean CE ratios were significantly lower for fluvastatin compared with lovastatin, pravastatin, and simvastatin from both the managed-care perspective and the patient perspective. Sensitivity analysis did not alter the CE conclusions, even under conditions of varying cost structures. Although differences were found in the effectiveness of lovastatin, pravastatin, and simvastatin measured in this study versus efficacy measured for these drugs in controlled clinical trials, sensitivity analysis suggests that these differences alone do not determine the superior CE of fluvastatin. Finally, this study supports the idea that well-designed formularies should consider drug CE (based on safety, effectiveness, and cost) and that integration of the pharmacy benefit management with other medical management is essential. These results provide evidence that fluvastatin may represent a more cost-effective formulary choice among statin products used for initial monotherapy of hypercholesterolemia.

A matrix metalloproteinase-generated aggrecan neoepitope as a marker of skeletal maturation and aging in cartilage

OBJECTIVE

To quantify the matrix metalloproteinase-induced neoepitope F(M/V)DIPEN (Phe-[Met/Val]-Asp-Ile-Pro-Glu-Asn341) in guinea pig and rabbit cartilage during aging.

METHODS

Cartilage was taken from the stifle joint, nasal septum, and xiphoid process in guinea pigs and rabbits at selected ages. The cartilage was then extracted and evaluated for F(M/V)DIPEN levels by radioimmunoassay.

RESULTS

In the 3 tissues studied, there were major increases in F(M/V)DIPEN levels during skeletal maturation and aging in both the guinea pig and rabbit cartilage. Except for spontaneous osteoarthritis that develops in guinea pigs with aging, increases in the neoepitope were not correlated with arthritis pathology.

CONCLUSION

Increases in the level of F(M/V)DIPEN in cartilage occur as a result of skeletal maturation and aging. This physiologic accumulation of F(M/V)DIPEN in cartilage should be considered when using the neoepitope as a disease marker in arthritis.

Relationship of genetically transmitted alpha EEG traits to anxiety disorders and alcoholism

We tested the hypothesis that a heritable EEG trait, the low voltage alpha (LV), is associated with psychiatric disorders. Modest to moderate evidence for genetic linkage of both panic disorder and the low voltage alpha trait to the same region of chromosome 20q has recently been reported, raising the issue of whether there is a phenotypic correlation between these traits. A total of 124 subjects including 50 unrelated index subjects and 74 relatives were studied. Alpha EEG power was measured and EEG phenotypes were impressionistically classified. Subjects were psychiatrically interviewed using the SADS-L and blind-rated by RDC criteria. Alcoholics were four times more likely to be LV (including so-called borderline low voltage alpha) than were nonalcoholic, nonanxious subjects. Alcoholics with anxiety disorder are 10 times more likely to be LV. However, alcoholics without anxiety disorder were similar to nonalcoholics in alpha power. An anxiety disorder (panic disorder, phobia, or generalized anxiety) was found in 14/17 LV subjects as compared to 34/101 of the rest of the sample (P < 0.01). Support for these observations was found in the unrelated index subjects in whom no traits would be shared by familial clustering. Lower alpha power in anxiety disorders was not state-dependent, as indicated by the Spielberger Anxiety Scale. Familial covariance of alpha power was 0.25 (P < 0.01). These findings indicate there may be a shared factor underlying the transmissible low voltage alpha EEG variant and vulnerability to anxiety disorders with associated alcoholism. This factor is apparently not rare, because LV was found in approximately 10% of unrelated index subjects and 5% of subjects free of alcoholism and anxiety disorders.

How parents can help young visually-impaired children to communicate

A study of parents' strategies to communicate with their young visually-impaired children has implications for all health visitors working with young children, write Vanessa Moore and Helen McConachie. The study highlights the important role of naturally-occurring communicative exchanges between parent and young child in promoting language development.

Mössbauer characterization of the metal clusters in Azotobacter vinelandii nitrogenase VFe protein

The VFe protein of alternative nitrogenase, isolated from Azotobacter vinelandii, strain LS15 and designated as Av1', has been investigated by Mössbauer spectroscopy. The Mössbauer spectrum of the dithionite-reduced Av1', recorded at 4.2 K with a 60-millitesla magnetic field applied parallel to the gamma-beam, is a superposition of three spectral components: 1) a complex spectrum (the M component) with magnetic hyperfine structures attributed to the paramagnetic FeV cofactor, 2) a component (the P component) consisting of three quadrupole doublets identifiable as the Fe2+, D, and S doublets similar to those observed for the P cluster pairs in MoFe proteins, and 3) a minor (4% of total absorption) quadrupole doublet attributable to adventitiously bound iron. The observed 4.2-K parameters for the Fe2+ (delta EQ = 2.99 mm/s and delta = 0.64 mm/s), D (delta EQ = 0.75 mm/s and delta = 0.63 mm/s), and S (delta EQ = 1.2 mm/s and delta = 0.65 mm/s) iron sites and their temperature dependence are very similar to those observed for the P cluster pairs in the conventional MoFe proteins. Similar to those of the MoFe protein, strong field spectra indicate that these doublets are associated with a diamagnetic system. Their percent absorption intensities (Fe(2+)/D/S = 13.0:32.2:6.8) determined at 4.2 K after the removal of the contributions from the adventitiously bound iron are comparable to those of the P cluster pairs in MoFe proteins. These observations established that Av1' also contains P cluster pairs that are identical, in both composition and quantity, to those of the MoFe proteins; i.e. each molecule contains two P cluster pairs and each pair is formed by two Fe2+, five D, and one S iron sites. Considering that 52% absorption of the P component corresponding to two 8Fe clusters, the remaining 48% absorption determined for the M component is consistent with two 7Fe-containing FeV cofactors/molecule of Av1'. The fact that both P cluster pairs are found in the diamagnetic states implies that the S = 3/2 and S = 1/2 signals detected in earlier EPR measurements are associated with the FeV cofactor and suggests a spin mixture for the FeV cofactor in the dithionite-reduced Av1'.

Early expressive language of severely visually impaired children

This paper presents a comparison of the early language of nine blind and nine severely visually impaired children, with no other impairments, who were recruited from paediatric vision clinics in London and assessed in the second and third year of life using the Reynell-Zinkin Developmental Scales. Further information on milestones and content of early expressive language was obtained from parents' diary recordings of their children's emerging words. It is concluded that severely visually impaired children's expressive language tends to develop later than that of sighted children. The effect of children having even a small amount of vision could be discerned in their early words. The developmental course appears to be particularly variable for blind children, with implications for parental counselling.

Early expressive language of severely visually impaired children

This paper presents a comparison of the early language of nine blind and nine severely visually impaired children, with no other impairments, who were recruited from paediatric vision clinics in London and assessed in the second and third year of life using the Reynell-Zinkin Developmental Scales. Further information on milestones and content of early expressive language was obtained from parents' diary recordings of their children's emerging words. It is concluded that severely visually impaired children's expressive language tends to develop later than that of sighted children. The effect of children having even a small amount of vision could be discerned in their early words. The developmental course appears to be particularly variable for blind children, with implications for parental counselling.

Repetition priming and proper name processing. Do common names and proper names prime each other?

Three experiments are reported in which a repetition priming technique was used to investigate whether recognition of a person's surname which is also a known word (e.g. Baker) activates the lexical representation that mediates word recognition. Experiment 1 showed that a familiarity decision to familiar full names produced an effect of repetition priming on subsequent lexical decision to words that were presented in the initial task as surnames. Experiment 2 demonstrated that, conversely, a lexical decision primed subsequent familiarity decision to full names involving the same word. Experiment 3 showed that repeating the same decision during the initial and test phases did not produce a larger repetition priming effect than that obtained when the task at test differed from the prime task (name familiarity decision vs lexical decision or vice versa). The results are interpreted as support for the view that repetition priming is due to repeated activation of representations that are accessed by both common names and proper names.

Substance abuse among subjects screened out from an alcoholism research program

Three hundred and eight subjects were screened over the phone for admission to an inpatient alcohol treatment research unit. Using a structured interview, the prospective patients were asked questions regarding demographics, drinking history, previous treatments, physical health, family history, and a detailed history of past and present substance use. Drug use was studied as regular use versus no use or brief experimental use of five drug categories: cannabinoids, stimulants, sedatives, opiates, and hallucinogens. Fifty-one percent of the men and 48% of the women reported regular use of one or more of the drugs in addition to alcohol. For women, the amount of alcohol intake was positively correlated with use of stimulants (r = .32, p = .001), cannabinoids (r = .24, p = .019), sedatives (r = .30, p = .003), and hallucinogens (r = .30, p = .003). For men, correlations between the amount of alcohol intake and drug use were weaker but significant for stimulants (r = .21, p = .002), opiates (r = .15, p = .028), and hallucinogens (r = .15, p = .029). Women with alcoholic mothers displayed higher alcohol intake than women with nonalcoholic mothers (p = .02) and also showed more frequent use of most drugs. Although men with alcoholic fathers also showed greater alcohol intake compared to men with nonalcoholic fathers, the two groups did not differ in drug use. Younger subjects of both sexes were more likely to use cannabinoids, stimulants, opiates, and hallucinogens. Alcohol and sedative use was relatively constant across all age groups.