Expanding the genomic encyclopedia of Actinobacteria with 824 isolate reference genomes

The phylum Actinobacteria includes important human pathogens like Mycobacterium tuberculosis and Corynebacterium diphtheriae and renowned producers of secondary metabolites of commercial interest, yet only a small part of its diversity is represented by sequenced genomes. Here, we present 824 actinobacterial isolate genomes in the context of a phylum-wide analysis of 6,700 genomes including public isolates and metagenome-assembled genomes (MAGs). We estimate that only 30%-50% of projected actinobacterial phylogenetic diversity possesses genomic representation via isolates and MAGs. A comparison of gene functions reveals novel determinants of host-microbe interaction as well as environment-specific adaptations such as potential antimicrobial peptides. We identify plasmids and prophages across isolates and uncover extensive prophage diversity structured mainly by host taxonomy. Analysis of >80,000 biosynthetic gene clusters reveals that horizontal gene transfer and gene loss shape secondary metabolite repertoire across taxa. Our observations illustrate the essential role of and need for high-quality isolate genome sequences.

Diversity and plant growth-promoting potential of (un)culturable bacteria in the Hedera helix phylloplane

Background

A diverse community of microbes naturally exists on the phylloplane, the surface of leaves. It is one of the most prevalent microbial habitats on earth and bacteria are the most abundant members, living in communities that are highly dynamic. Today, one of the key challenges for microbiologists is to develop strategies to culture the vast diversity of microorganisms that have been detected in metagenomic surveys.

Results

We isolated bacteria from the phylloplane of Hedera helix (common ivy), a widespread evergreen, using five growth media: Luria–Bertani (LB), LB01, yeast extract–mannitol (YMA), yeast extract–flour (YFlour), and YEx. We also included a comparison with the uncultured phylloplane, which we showed to be dominated by Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes. Inter-sample (beta) diversity shifted from LB and LB01 containing the highest amount of resources to YEx, YMA, and YFlour which are more selective. All growth media equally favoured Actinobacteria and Gammaproteobacteria, whereas Bacteroidetes could only be found on LB01, YEx, and YMA. LB and LB01 favoured Firmicutes and YFlour was most selective for Betaproteobacteria. At the genus level, LB favoured the growth of Bacillus and Stenotrophomonas, while YFlour was most selective for Burkholderia and Curtobacterium. The in vitro plant growth promotion (PGP) profile of 200 isolates obtained in this study indicates that previously uncultured bacteria from the phylloplane may have potential applications in phytoremediation and other plant-based biotechnologies.

Conclusions

This study gives first insights into the total bacterial community of the H. helix phylloplane, including an evaluation of its culturability using five different growth media. We further provide a collection of 200 bacterial isolates underrepresented in current databases, including the characterization of PGP profiles. Here we highlight the potential of simple strategies to obtain higher microbial diversity from environmental samples and the use of high-throughput sequencing to guide isolate selection from a variety of growth media.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02119-z.

Differential effect of silver nanoparticles on the microbiome of adult and developing planaria

Silver nanoparticles (AgNPs) are widely incorporated in household, consumer and medical products. Their unintentional release via wastewaters raises concerns on their environmental impact, particularly for aquatic organisms and their associated bacterial communities. It is known that the microbiome plays an important role in its host's health and physiology, e.g. by producing essential nutrients and providing protection against pathogens. A thorough understanding of the effects of AgNPs on bacterial communities and on their interactions with the host is crucial to fully assess AgNP toxicity on aquatic organisms. Our results indicate that the microbiome of the invertebrate Schmidtea mediterranea, a freshwater planarian, is affected by AgNP exposure at the tested 10 μg/ml concentration. Using targeted amplification of the bacterial 16S rRNA gene V3-V4 region, two independent experiments on the microbiomes of adult worms revealed a consistent decrease in Betaproteobacteriales after AgNP exposure, mainly attributed to a decrease in Curvibacter and Undibacterium. Although developing tissues and organisms are known to be more sensitive to toxic compounds, three independent experiments in regenerating worms showed a less pronounced effect of AgNP exposure on the microbiome, possibly because underlying bacterial community changes during development mask the AgNP induced effect. The presence of a polyvinyl-pyrrolidone (PVP) coating did not significantly alter the outcome of the experiments compared to those with uncoated particles. The observed variation between the different experiments underlines the highly variable nature of microbiomes and emphasises the need to repeat microbiome experiments, within and between physiological states of the animal.

Comparative Evaluation of Four Bacteria-Specific Primer Pairs for 16S rRNA Gene Surveys

Bacterial taxonomic community analyses using PCR-amplification of the 16S rRNA gene and high-throughput sequencing has become a cornerstone in microbiology research. To reliably detect the members, or operational taxonomic units (OTUs), that make up bacterial communities, taxonomic surveys rely on the use of the most informative PCR primers to amplify the broad range of phylotypes present in up-to-date reference databases. However, primers specific for the domain Bacteria were often developed some time ago against database versions that are now out of date. Here we evaluated the performance of four bacterial primers for characterizing complex microbial communities in explosives contaminated and non-contaminated forest soil and by in silico evaluation against the current SILVA123 database. Primer pair 341f/785r produced the highest number of bacterial OTUs, phylogenetic richness, Shannon diversity, low non-specificity and most reproducible results, followed by 967f/1391r and 799f/1193r. Primer pair 68f/518r showed overall low coverage and a bias toward Alphaproteobacteria. In silico, primer pair 341f/785r showed the highest coverage of the domain Bacteria (96.1%) with no obvious bias toward the majority of bacterial species. This suggests the high utility of primer pair 341f/785r for soil and plant-associated bacterial microbiome studies.

Experimental studies of the role of the little raven (Corvus mellori) in surveillance for West Nile virus in Australia

OBJECTIVE

To study the potential role of an Australian corvid, the little raven (Corvus mellori), in the surveillance for exotic West Nile virus (WNV) in Australia.

METHOD

In a series of trials, little ravens were infected with WNV (strain 4132 New York 1999) and Kunjin virus (strain K42886) by the intramuscular route. They were observed for 20 days during which blood and swab samples were taken for virus isolation. Tissue samples were taken from ravens humanely killed during the acute infection period, and at the termination of the trials, for virus isolation, histopathology and immunohistochemistry.

RESULTS

Ravens infected with WNV became mildly ill, but all recovered and seroconverted. Blood virus titres peaked around 3 to 4 days after inoculation at levels between 10(3.0) to 10(7.5) plaque forming units/mL. Virus or viral antigen was detected in spleen, liver, lung, kidney, intestine, testis and ovary by virus isolation and/or immunohistochemistry. WNV was detected in oral and cloacal swabs from 2 to 7 days post inoculation. The molecular and pathogenic characteristics of the inocula were consistent with them being of high virulence, as expected for this isolate. Ravens infected with Kunjin virus developed viraemia and seroconverted, although they did not develop disease.

CONCLUSIONS

Little ravens do not develop severe disease in response to virulent WNV infection and for this reason may not be important sentinel hosts in the event of an outbreak of WNV, as in North America. However, as they have relatively high viraemias, they may be able to support virus cycles.

[Mediators of inflammation's clinical relevance in multiple myeloma]

Multiple myeloma is a blood disease characterized amongst other things by at least 10% plasmocytes in the bone marrow. The illness is always lethal. The Salmon & Durie classification is well established to evaluate the prognosis. Other parameters are under study in order to supplement it, among them mediators of inflammation such as CRP and LDH. A 5-year study assessing these 2 parameters and their clinical relevance is presented.

Effective prevention of sports injuries: a model integrating efficacy, efficiency, compliance and risk-taking behaviour

In 1992 van Mechelen et al published a "sequence of prevention model" based on a four-step process. This model has been widely used to implement preventive measures in response to sports injuries. However, the execution of this model has been shown to lack validity in determining the success of a preventive measure. A modified model has therefore been proposed which incorporates additional steps that enable the inclusion of external factors with a significant effect on the outcome of a prevention intervention. This expansion of van Mechelen's model leads to a more global model in which the compliance level and risk-taking behaviour of the individual and the assessment of efficiency of the stakeholders have a key influence on the preventive measure. This model gives a better insight into the different processes in injury prevention that can be used by clinicians, coaches and managers to decide whether to implement a preventive measure programme.

Efficacy and safety of denileukin diftitox (Dd) in a phase III, double-blind, placebo-controlled study of CD25+ patients with cutaneous T-cell lymphoma (CTCL)

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Background: ONTAK®(Dd), a genetically engineered fusion protein combines the enzymatically active domain of diphtheria toxin with the sequence of interleukin-2 (IL-2), designed to target IL-2 receptor expressing malignancies. Dd received FDA accelerated approval for the treatment of CTCL in patients with the CD25 component of the IL-2 receptor. Methods: The confirmatory placebo- controlled L4389–11 phase III trial evaluated 9 and 18μg/kg/d Dd in 144 patients with CD25(+) CTCL. Patients (=3 prior treatments, stages Ia - III) received Dd or placebo IV for up to 8 cycles, consisting of Dd once daily for 5 days every 3 weeks. Tumor burden in skin, blood and lymph nodes and a physician's global (PGA) were assessed relative to baseline and before every treatment cycle beginning with cycle 2. Confirmation of tumor response required two more consecutive cycles (3 observations). Investigator assessments were ratified by an independent Drug Evaluation Review Committee. Results: Initial analysis of activity and benefit shown below. Both Dd treatment arms were greatly superior to placebo in a dose dependent fashion. Population demographics were the same across treatment arms (median age 59 years, 55% male). Randomization was stratified by disease status at baseline, 67% were = stage IIa, 33% were =stage IIb. Response between stage groups within each arm did not differ significantly. Many responses were confirmed after 5 or more cycles. AEs were similar to those in previous Dd studies. The only significantly different Grade 3/4 adverse event was nausea (2% in Placebo and 15% in 18μg/kg/d). No differences in serious adverse events among treatment arms were observed. The frequency of AEs and SAEs markedly decrease after the first two cycles of treatment. Conclusions: This is the largest randomized, placebo controlled trial conducted in CTCL, providing clear evidence for efficacy and clinical benefit for Dd.

No significant financial relationships to disclose.

[Table: see text]

Novel treatment of chronic severe hand dermatitis with bexarotene gel

BACKGROUND

Hand dermatitis is an eczematous inflammation of the hands that is related to occupation or to routine activities. It often becomes chronic, and in some patients may become severe and disabling. Topical corticosteroids are effective treatment, particularly for milder forms, but they often lose effectiveness with time and can produce skin atrophy.

OBJECTIVES

To evaluate bexarotene gel topical therapy for safety, tolerability and efficacy in patients with chronic hand dermatitis.

METHODS

A phase I-II open-label randomized clinical study of bexarotene gel, alone and in combination with a low- and a mid-potency steroid, was conducted in 55 patients with chronic severe hand dermatitis at two academic clinics.

RESULTS

Patients using bexarotene gel monotherapy reached a 79% response rate for > or = 50% clinical improvement and a 39% response rate for > or = 90% clearance of hands. Adverse events possibly related to treatment in all patients were stinging or burning (15%), flare of dermatitis (16%) and irritation (29%). Thirteen patients (24%) withdrew early, including two for related adverse events and five for inadequate response.

CONCLUSIONS

Bexarotene gel appears to be safe, tolerated by most patients, with useful therapeutic activity in chronic severe hand dermatitis.

Accidents don't just happen!

Risk management is a systematic approach to monitoring processes and systems to ensure that patients receive their care in a safe environment. The NHS management executive (1993) states that risk management should not lead to defensive practices but should be used to pinpoint deficiencies in a positive way, using mistakes as an opportunity for learning and to eliminate errors in the future.

Anti-bullying interventions at school: aspects of programme adaptation and critical issues for further programme development

Recently, a growing interest in problems at school of peer aggression and victimization was observed. As a result, intervention strategies appropriate for this kind of problem were required. The Norwegian anti-bullying intervention that was developed and evaluated by Olweus (1992) in the region of Bergen was considered to be a good model for other countries to implement interventions against peer aggression within the school environment. It was therefore adapted to the educational settings of other countries. This paper aims to discuss the adaptation processes of the Bergen anti-bullying programme and to give guidelines to advance further programme development. For this, the DFE Sheffield Bullying Project (Smith and Sharp, 1994), the Anti-bullying Intervention in Toronto schools (Pepler et al., 1994) and the Flemish anti-bullying project (Stevens and Van Oost, 1994) were considered in the analyses. Discussion of the adaptation processes of the Bergen model programme revealed that the adapted interventions largely succeeded in incorporating the core components of the Bergen model programme, taking into account the characteristics of the implementation environment. This suggests that for bully/victim interventions, the dilemma of programme fidelity and programme adaptation could be solved adequately. However, from a health promotion perspective, some critical issues for programme improvement were observed. Three suggestions for change were made, indicating that anti-bullying actions at schools may benefit from: (i) a clear overview of the learning objectives, specified per target population; (ii) more attention to parental involvement and family interventions; and (iii) additional information about the adoption processes of the anti-bullying interventions within schools.

Prenatal care needs, availability, accessibility, use, and satisfaction: a comparison of military women within and outside the continental United States

This article presents the results of a survey distributed to military women within and outside the continental United States (CONUS and OCONUS) who had received prenatal care and delivered at one of six Army, Navy, or Air Force military facilities. This comparative descriptive study was undertaken to determine from the mothers' perspective (1) their needs, availability, accessibility, use, satisfaction, and preferences for prenatal care services, and (2) if prenatal care and birth outcomes were significantly different for CONUS versus OCONUS women. Both groups reported a high degree of satisfaction with services, clinics/offices, and health care staff. Significant group differences were reported in transportation, length of travel time, and cost of traveling, with the CONUS group reporting greater problems with each. For both groups, quality and consistency of health care were the two most important factors in their preference of provider. More than 20% of the mothers reported receiving no information on some of the common concerns of pregnancy. There were no significant group differences with regard to infant birth weight or length of hospital stay.

Past violence and substance use disorder and subsequent violence towards others: six year analysis of the Assaulted Staff Action Program (ASAP)

Recent research has begun to document evidence of associations between past violence toward others, untreated personal victimization, and substance use disorder and later acts of violence toward others. This appears true for many types of individuals, including psychiatric patients who have been victims of violence. This six-year retrospective study sought to evaluate these possible associations in assaultive psychiatric patients. Data were gathered in the context of the Assaulted Staff Action Program (ASAP), a crisis intervention program for staff victims of patient assault. Both histories of violence (violence toward others and/or personal victimization) and substance use disorder in assaultive psychiatric patients were individually and jointly examined and found to be associated with subsequent assaults by these patients. Increased levels of both past violence toward others, personal victimization, and substance use disorder were associated with the largest increased frequency of subsequent assault. The implications and possible links to emergency mental health services are discussed [International Journal of Emergency Mental Health, 2(4), 241-247].

Topical treatment of cutaneous lesions of acquired immunodeficiency syndrome-related Kaposi sarcoma using alitretinoin gel: results of phase 1 and 2 trials

OBJECTIVE

To evaluate the efficacy and safety of topical alitretinoin gel (9-cis-retinoic acid [LGD1057], Panretin gel; Ligand Pharmaceuticals, Inc, San Diego, Calif) in cutaneous Kaposi sarcoma (KS).

DESIGN

Open-label, within-patient, controlled, dose-escalating phase 1 and 2 clinical trials. In all patients, 1 or more cutaneous KS lesions were treated with alitretinoin gel, and at least 2 other lesions served as untreated controls for up to 16 weeks. Alitretinoin (0.05% or 0.1% gel) was applied twice daily for the first 2 weeks and up to 4 times daily thereafter, if tolerated.

SETTING

Nine academic clinical centers.

PATIENTS

One hundred fifteen patients with biopsy-proven acquired immunodeficiency syndrome (AIDS)-related KS.

MAIN OUTCOME MEASURES

AIDS Clinical Trials Group response criteria.

RESULTS

Statistically significant clinical responses were observed in 31 (27%) of 115 patients for the group of treated index lesions compared with 13 (11%) for the group of untreated control lesions (P<.001). Responses occurred with low CD4(+) lymphocyte counts (<200 cells/microL) and in some patients with refractory response to previous systemic anti-KS therapy. The incidence of disease progression was significantly lower for treated index lesions compared with untreated control lesions (39/115 [34%] vs 53/115 [46%]; P =.02). Alitretinoin gel generally was well tolerated, with 90% of treatment-related adverse events confined to the application site and only mild or moderate in severity.

CONCLUSIONS

Alitretinoin gel has significant antitumor activity as a topical treatment for AIDS-related KS lesions, substantially reduces the incidence of disease progression in treated lesions, and is generally well tolerated.

Exploration of facilitators and barriers to prenatal care among military women

Early and regular prenatal care has been shown to decrease the incidence of adverse pregnancy outcomes; however, little research has examined it experientially from the mother's perspective. The purpose of this qualitative study was to explore the experience of prenatal care from the military mother's perspective. Using purposive sampling, 16 women who had recently given birth were interviewed. The data were analyzed using a qualitative descriptive research methodology to elicit categories of substantive concepts, ideas, or themes. Data explored in this study included availability, use and satisfaction with prenatal care services, and barriers, preferences, and recommendations.

Bullying in Flemish schools: an evaluation of anti-bullying intervention in primary and secondary schools

BACKGROUND

The positive of the Norwegian anti-bullying programme (Olweus, 1992) stimulated other countries to tackle bully/victim problems. However, outcome studies found rather low levels of effect or even inconsistent results.

AIMS

The purpose of the present study was to evaluate behavioural effectiveness of a school-based anti-bullying approach within Flemish schools. In addition, specific attention was given to the relationship between outcome findings and external support.

SAMPLE

A total of 18 schools, comprising 1104 primary and secondary school children were recruited for this study. Students ranged in age from 10 to 16 years.

METHOD

For this study, an experimental pre-test/post-test design was used which included a control group. Three groups were established. The first group, Treatment with Support, involved students from schools that implemented a school-based anti-bullying intervention with additional support from the research group. The second group, Treatment without Support, also involved students from schools that implemented a school-based anti-bullying programme. However, in contrast with those falling under the first condition, this group of schools could not appeal to the research group for additional help. The last group involved students from schools that did not implement the anti-bullying programme and served as a Control condition. Repeated measures analyses of variance were carried out.

RESULTS

The findings regarding the effects of the school-based anti-bullying intervention programme on the extent of bullying and victimisation showed a mixed pattern of positive changes in primary schools and zero outcomes in secondary schools. The findings regarding the effects of external support revealed limited outcomes.

CONCLUSIONS

The outcomes of the evaluation study confirm that a school-based anti-bullying intervention strategy can be effective in reducing problems with bullying, especially within primary schools. It was argued that the developmental characteristics of secondary school students interfered with the programme outcomes. In addition, the findings revealed no extra effects of specific training sessions.

The effects of an anti-bullying intervention programme on peers' attitudes and behaviour

This study aimed to evaluate the effect of an anti-bullying intervention programme on peers' attitudes towards bullying and their attempts to solve bully/victim conflicts. An experimental pre-test/post-test design with a control group was used. For secondary school students, positive outcomes were observed at post-test 1 on attitudes and on actual rates of intervention. However, the effects had disappeared at post-test 2. For primary school students, significant differences were found at post-test 2, showing a smaller decline in seeking teacher's help and in heightening students' support for victims. Students' competence to solve bully/victim problems in relation to their general pro-social development is discussed.

Late luteal rescue in the baboon (Papio cynocephalus)

Numerous studies have used human chorionic gonadotrophin (HCG) administration to study the response of the primate ovary to gonadotrophin stimulation. These studies are generally performed in the luteal phase with very few studies of the follicular phase. We have studied the effect of both HCG and gonadotrophin releasing hormone (GnRH) agonist administered at the early follicular phase in normally cycling baboons (Papio cynocephalus). Five baboons were treated with increasing doses of HCG for 5 consecutive days starting on day 1 of the cycle and three untreated baboons served as controls. Follicular and luteal phase lengths were determined and serum samples were assayed for progesterone, oestradiol and 17alpha-OH progesterone. In a separate study, six baboons were treated with GnRH agonist (WY-40972) on days 2-6 of the cycle and saline-treated baboons served as controls (n = 5). Mean peak progesterone concentrations (+/- SE) during the treatment interval were 3.88+/-0.56 ng/ml in HCG-treated baboons compared to 0.19+/-0.07 ng/ml in controls (P < 0.001). A similar significant increase (P < 0.001) in serum 17alpha-OH progesterone concentrations was also observed (6.13+/-1.12 ng/ml versus 1.13+/-0.49 ng/ml). In association with the increase in luteal steroids there was also a significant prolongation of menstrual cycle length from 32.7+/-1.2 days in controls to 46.8+/-4.9 days in HCG-treated baboons (P < 0.05), which involved prolongation of the follicular phase (16.7+/-1.2 days to 29.0+/-4.6 days; P < 0.05) with no difference in luteal phase length or progesterone concentrations. In GnRH agonist-treated baboons, mean (+/- SE) cycle length was prolonged to 46.3+/-1.6 days and in saline-treated controls was 32.8+/-0.8 days (P < 0.001), again this was completely represented by the change in follicular phase length, from 13.4+/-0.7 days in controls to 27.2+/-2.1 days in agonist-treated baboons (P < 0.001). In contrast, there was no significant difference in luteal phase length between these two groups (19.4+/-0.7 versus 19.2+/-1.0 days). The prolongation of the follicular phase was accompanied by significant increases in both progesterone (P < 0.01) and oestradiol (P < 0.01) during GnRH agonist treatment above control concentrations. Luteal phase concentrations of these hormones were not different from controls. These results demonstrate the previously unreported finding that gonadotropin stimulation will rescue the corpus luteum in the next follicular phase.

Maternal acceptability of a dietary intervention designed to lower children's intake of saturated fat and cholesterol: the Dietary Intervention Study in Children (DISC)

OBJECTIVE

This report examined the acceptability to mothers of a dietary educational and behavioral intervention for preadolescent children with elevated levels of serum low-density lipoprotein cholesterol (LDL-C) who were enrolled in the Dietary Intervention Study in Children (DISC).

DESIGN

DISC is a randomized, controlled clinical trial. Subjects were randomly assigned to either an intervention or usual-care (control) group.

SUBJECTS/SETTING

To be eligible for the study, participants were required to have the average of 2 fasting LDL-C values fall between the 80th and 98th sex-specific percentiles. Three hundred thirty-four 8-to 10-year-old children and their families were randomly assigned to an intervention group, and 329 were assigned to a usual-care (control) group. This study examined data from 232 subjects in the intervention group. Data were collected at 6 intervention sites around the United States.

INTERVENTION

Those assigned to the intervention group participated in a multidisciplinary dietary intervention that included a series of group and individual sessions over a 3-year period. Children and their caretakers were taught to follow a nutritionally adequate diet that was low in total fat, saturated fat, and cholesterol and high in polyunsaturated fat.

MAIN OUTCOME MEASURES

Three nonconsecutive 24-hour diet recalls were collected at baseline and at 1 year by trained and certified dietitians. A questionnaire designed to assess diet acceptability was administered at months 4, 8, 11, and 15. Demographic measures were collected at the onset of the study.

STATISTICAL ANALYSIS PERFORMED

Statistical procedures included factor analysis and regression analysis.

RESULTS

Regression analysis suggested that perceived effectiveness of the dietary intervention and mothers' having few concerns about disadvantages of the diet were significantly related to higher overall fat intake in children in one-parent families. Maternal willingness to implement the diet was significantly related to lower saturated fat intake.

APPLICATIONS/CONCLUSIONS

In attempts to change eating behavior of children, interest and cooperation of the parents are essential to achieving successful results. These analyses further suggest that maternal acceptability translates into willingness to implement the diet and may facilitate changes that are associated with reduced saturated fat intake in children.

Effects of diet and sexual maturation on low-density lipoprotein cholesterol during puberty: the Dietary Intervention Study in Children (DISC)

BACKGROUND

The Dietary Intervention Study in Children (DISC) is a multicenter, randomized, controlled clinical trial designed to examine the efficacy and safety of a dietary intervention to reduce serum LDL cholesterol (LDL-C) in children with elevated LDL-C.

METHODS AND RESULTS

The effects of dietary intake of fat and cholesterol and of sexual maturation and body mass index (BMI) on LDL-C were examined in a 3-year longitudinal study of 663 boys and girls (age 8 to 10 years at baseline) with elevated LDL-C levels. Multiple linear regression was used to predict LDL-C at 3 years. For boys, LDL-C decreased by 0.018 mmol/L for each 10 mg/4.2 MJ decrease in dietary cholesterol (P<.05). For girls, no single nutrient was significant in the model, but a treatment group effect was evident (P<.05). In both sexes, BMI at 3 years and LDL-C at baseline were significant and positive predictors of LDL-C levels. In boys, the average LDL-C level was 0.603 mmol/L lower at Tanner stage 4+ than at Tanner stage 1 (P<.01). In girls, the average LDL-C level was 0.274 mmol/L lower at Tanner stage 4+ than at Tanner stage 1 (P<.05).

CONCLUSIONS

In pubertal children, sexual maturation, BMI, dietary intervention (in girls), and dietary cholesterol (in boys) were significant in determining LDL-C. Sexual maturation was the factor associated with the greatest difference in LDL-C. Clinicians screening for dyslipidemia or following dyslipidemic children should be aware of the powerful effects of pubertal change on measurements of lipoproteins.

The impact of the ageing population on intensive care provision

This paper explores the impact of the ageing population on the health service and intensive care provision. The concept of rationing is discussed. The paper concludes that age alone is not a reliable prediction of outcome (e.g. length of stay; mortality). The review highlights the lack of literature available offering a comparison of costs associated with intensive care management of the elderly.

Immunogenicity of a fusion protein linking the beta subunit carboxyl terminal peptide (CTP) of human chorionic gonadotropin to the B subunit of Escherichia coli heat-labile enterotoxin (LTB)

Human chorionic gonadotropin (hCG) is currently under investigation as an antigenic target in both anti-cancer and anti-fertility vaccines. Formulations studied to date show promise in clinical trials for both applications yet are expensive to produce and require frequented administration in order to maintain an effective antibody titer. We have engineered a fusion protein consisting of Escherichia coli heat-labile enterotoxin subunit B (LTB) genetically linked at its C terminus via a nine amino acid linker to the 37 amino acid carboxyl terminal peptide (CTP) of the hCG beta chain. This LTB-CTP fusion protein is stably expressed in bacteria and forms pentamers of full-length protein subunits. Purified LTB-CTP protein hCG-specific antibodies in mice without additional adjuvants.

Baseline characteristics of participants in phase II of the Trials of Hypertension Prevention (TOHP II). Trials of Hypertension Prevention (TOHP) Collaborative Research Group

Phase II of the Trials of Hypertension Prevention (TOHP II) is a multicenter, controlled clinical trial designed to test whether weight loss, a reduced sodium intake, or a combination of weight loss and a reduced sodium intake will lower blood pressure (BP) and prevent the occurrence of hypertension. The study population consists of middle-aged, moderately overweight individuals with a diastolic BP between 83 and 89 mm Hg. Of the 2382 randomized participants, 816 (34%) are female and 494 (21%) are from a racial or ethnic minority background. At baseline, mean dietary intakes of sodium, based on measurements of 24-hour urinary excretion, were 199 mmol/d in men and 154 mmol/d in women. The average body mass index was 30.9 kg/m2. Across the four randomized groups, there was no substantial imbalance in the distribution of baseline variables; however, the mean age in the four groups was slightly but significantly different (range: 43.2 to 44.2 years, P = 0.02). A comparison of baseline characteristics of TOHP II participants with those of participants in three other primary prevention trials reveals a high level of mean dietary sodium intake in each study. Data reported in this article indicate that any subsequent differences in BP among the randomized groups are unlikely to result from maldistribution of known confounding variables at baseline. Finally, because of the high prevalence of overweight and excessive sodium intake in the United States, results from TOHP II should be broadly applicable to the general population.

Are emergency department patients more likely to answer alcohol questions in a masked health questionnaire?

The development of approaches to screening of hospital patients for harmful drinking frequently encounters resistance from both patients and hospital staff. A contributing factor could be the discomfort both feel about talking specifically about drinking. One approach to reducing this discomfort has been to mask concern about alcohol consumption into a general focus on other health and lifestyle issues. One-hundred and eighty-two patients admitted to an emergency department were presented randomly with either a straight alcohol screening questionnaire or a general health and lifestyle questionnaire with alcohol questions embedded amongst items on smoking exercise and diet. The number of returns was equal for both questionnaires which suggests the masked questionnaire does not improve the acceptability of alcohol screening in hospital environments.

Peptide vaccines incorporating a 'promiscuous' T-cell epitope bypass certain haplotype restricted immune responses and provide broad spectrum immunogenicity

An ideal peptide vaccine should contain both B- and T-cell epitopes. Recognition of antigen by B cells is highly dependent on the three-dimensional conformation of the antigen whereas T cells recognize antigen only after it has been processed to release a peptide fragment which is bound to the major histocompatibility complex (MHC) class II molecule. However, T cells provide 'help' to B cells displaying the same processed, MHC-restricted form of the antigen, demonstrating that the T-cell response to a protein antigen is under genetic control. Thus, strategies for co-inclusion of T cell 'helper' epitopes with the B-cell determinant elicit immune responses that are in most cases genetically restricted to only one or a few alleles of the MHC with limited activity across divergent MHC class II haplotypes. This genetically restricted T cell stimulatory activity of peptides is a serious obstacle and consequently such constructs would be of limited practical value as a vaccine targeted to a majority of an outbred population. In the study described here, we have engineered two peptides to encompass the sequences from the universally immunogenic tetanus toxoid (TT) epitope and the contraceptive vaccine candidate lactate dehydrogenase C4 (LDH-C4). We demonstrate the feasibility of using 'promiscuous' T-cell epitopes colinearly constructed with a defined B-cell epitope to induce high titer antipeptide IgG antibodies specific for native protein antigen LDH-C4 in several inbred strains of mice, outbred mice and rabbits. There appears to be a strong correlation between the capacity for the hybrid peptides to be stimulatory for the corresponding T cells in C57BL/6 (H-2b) and C3H/HeJ (H-2k) mice and their ability to be immunogenic. This correlation, however, appears to break down in H-2d strains of mice since no antibodies were detected in BALB/c and barely detectable levels of antibodies in B10.D2 although activated T cells were detectable. Conversely, high titers of antipeptide antibodies are elicited in some strains (B10.BR (H-2k); C57BL/10 (H-2b) without detectable IL-2 responses. Finally, we show that a determinant which was previously restricted to H-2k can be rendered immunogenic in H-2b with the 'promiscuous' TT epitope. Thus, certain haplotype-restricted immune responses can be bypassed, setting forth the ground work for the design of a universal vaccine by broadening the effective response in a larger number of individuals typical of the genetically diverse outbred human population.

CSF monoamine levels in normal-weight bulimia: evidence for abnormal noradrenergic activity

Normal-weight bulimic patients have disturbed appetite, mood, and neuroendocrine function and often respond to antidepressants. Since these findings suggest abnormalities in brain monoaminergic pathways, the authors measured CSF monoamine concentrations in 27 normal-weight bulimic patients and 14 volunteers. Bulimic patients had a significantly lower mean CSF norepinephrine concentration. Levels of CSF 5-HIAA, the major serotonin metabolite, and CSF HVA, the major dopamine metabolite, were normal, although more frequent binge-eating in bulimic subjects was associated with a significantly lower CSF HVA level. Whether trait- or state-related, monoaminergic disturbances are part of this disorder's neurobiological syndrome. The lower CSF norepinephrine concentration suggests bulimia is not simply a variant of affective disorders.

Post-traumatic stress disorder among Special Forces Vietnam veterans

Fifty-seven Special Forces Vietnam Veterans were studied to determine if special selection and rigorous training affected the frequency and pattern of predictors of post-traumatic stress disorder (PTSD). No absolute immunity to PTSD was conferred. Frequency (25%) and predictors of PTSD were similar to those reported for other groups of Vietnam Veterans. Symptoms of PTSD were associated with poorer pre-service relationships, being wounded, being wounded after return from R&R, having friends missing in action, feeling guilt over the death of a friend, lack of emotional preparation to leave the unit or service, and failure to discuss feelings upon return from Vietnam.

A comparison of alprazolam with amitriptyline in the treatment of patients with neurotic or reactive depression. A report of a randomised, double blind study by a General Practitioner Working Party

104 patients suffering from neurotic or reactive depression were treated with either alprazolam or amitriptyline in randomised, double-blind fashion. Seventeen patients were either lost to follow-up or withdrawn before week 2 (13 due to side effects and 1 because she was feeling better). A further 7 patients did not comply with the protocol, giving a total of 24 patients whose data were not considered suitable for inclusion in the analysis of therapeutic assessments. Evaluation of the 80 patients (40 in each group) who completed at least 2 weeks of the 4-week study demonstrate that both treatments produced a statistically significant response rate. There was a more rapid effect in those patients who received amitriptyline, but there was no significant difference in response between the treatment groups after 4 weeks treatment. Analysis of safety and side effect data on 101 patients (50 treated with alprazolam and 51 with amitriptyline) shows no statistically significant difference in the overall number of side effects experienced in each group, although 11 of those patients who received amitriptyline withdrew because of adverse reactions before completing the study compared to 6 in the alprazolam group. These results suggest that alprazolam may be a useful treatment for patients with neurotic or reactive depression not requiring hospitalisation.

Sinus tachycardia in term infants preceding sudden infant death

The quantities of sinus tachycardia in 24-h recordings of the electrocardiogram from 16 full-term infants (greater than or equal to 37 weeks gestation) who were subsequently victims of the sudden infant death syndrome (SIDS), from 230 randomly selected age-matched full-term survivors and from 64 full-term survivors matched for age and birth weight were measured by computer and manual analysis techniques. Of 16 infants dying of SIDS, 7 had elevated levels of sinus tachycardia (greater than 95th centile in controls) (P less than 0.01). Although high levels of sinus tachycardia might be of value in identifying infants at high risk of SIDS, these encouraging findings must first be validated by further prospective studies.

Resource limitation in mountain goats: a test by experimental cropping

Changes are reported in the population dynamics and physical condition of mountain goats (Oreamnos americanus) following a reduction in their density at Olympic National Park, Washington, U.S.A. The goat population showed density-dependent responses in initial breeding ages and in litter size. Production and recruitment of kids were more variable at high densities, and these population attributes may show nonlinear density dependence. These shifts in dynamics were associated with increases in live weights and, possibly, in fat reserves. The density dependence shown was insufficient to compensate for removals that approximated the initial production of young, and goat numbers declined precipitously. The implications of these relationships to mountain goat ecology are examined.

Analysis of the heart rate and breathing patterns of infants destined to suffer sudden infant death syndrome: probability density function analysis

From a prospective study into the sudden infant death syndrome in which 24-h recordings of the ECG and respiratory waveform (abdominal wall movement) were made on a population of full-term infants, 22 recordings were obtained on 16 infants who subsequently suffered sudden infant death syndrome. The probability density function for the instantaneous heart rate and the breath to breath intervals and their randomly variabilities were calculated for these 22 recordings and for a control group of 324 infants randomly selected from the remainder of the population. A principal components analysis was then performed to classify the data and to make comparisons between infants. The infants in the analysis were divided into three postnatal age groups. No differences were found between the sudden infant death syndrome cases and the control group for the breath to breath intervals and its variability or for the instantaneous heart rate. Three sudden infant death syndrome cases lay outside the range of values for the heart rate variability at 6 wk of age.

Respiratory and heart rate patterns in infants destined to be victims of sudden infant death syndrome: average rates and their variability measured over 24 hours

From a prospective study in which 24 hour recordings of the electrocardiogram and respiratory activity (abdominal wall movement) were made on a population of full term infants, 22 recordings were obtained from 16 infants who later were victims of the sudden infant death syndrome. The average heart rate, average heart rate variability, average breath to breath interval, and average breath to breath interval variability over the whole of each recording for the 22 recordings were compared with those from a control group of 324 infants selected at random from the rest of the population. No significance was found in the number of recordings from those infants who suffered the sudden infant death syndrome which lay outside the 5th-95th percentile range of the control group for the four variables studied. In a group comparison no difference was found between the sudden infant death syndrome group and the controls either in terms of the respiratory variables studied or in terms of the average heart rate variability. The results did, however, suggest that there may be a group difference in terms of the average instantaneous heart rate.

High concentrations of furosemide inhibit serum binding of thyroxine

Serum samples taken from four patients who had low serum T4 concentrations (less than 2 micrograms/dl) during severe non-thyroidal illness were found to contain a heat-stable, dialyzable inhibitor of 125I T4 binding to plasma proteins. Inhibitory activity coincided with high dose furosemide treatment for oliguric renal failure. Inhibition was proportional to the serum furosemide concentration and the effect was reproduced in vitro by addition of furosemide to normal serum. The inhibitory effect diminished with serum dilution while maintaining the same relative concentration of furosemide. A time-course study in one patient demonstrated a close temporal relationship between high serum concentrations of furosemide and subnormal T4, associated with T3 resin uptake values compatible with increased occupancy of T4-binding globulin by a competitor. These findings demonstrate that furosemide in high concentrations can inhibit T4 binding in plasma and may be a factor contributing to the development of the low T4 state in critical illness.

"Unbound analog" radioimmunoassays for free thyroxin measure the albumin-bound hormone fraction

We have assessed the influence of albumin-bound thyroxin (T4) on apparent free T4 values obtained by two "unbound analog" free T4 methods (AmerlexR Free T4 and Clinical Assays one-step Free T4). We evaluated sera showing three different albumin anomalies: total hereditary analbuminemia, partially corrected analbuminemia, and familial dysalbuminemic hyperthyroxinemia, where abnormal albumin-binding of analog tracer is associated with high apparent free T4 values by these methods. In hereditary analbuminemia, free T4 was almost undetectable by both assays; in contrast, free T4 by equilibrium dialysis was normal. After addition of T4-free human serum albumin, the apparent free T4 concentration in total hereditary analbuminemia became normal by the analog methods. Immunoprecipitation of [125I]T4 and the unidentified labeled kit analogs by antiserum to human albumin was negligible in untreated total hereditary analbuminemia and approximately twice normal in familial dysalbuminemic hyperthyroxinemia. Therefore, alterations in tracer binding to albumin correlate with the apparent free T4 concentrations obtained by the analog methods. The interactions of the unidentified analog tracers and T4 with albumin are such that these techniques principally reflect the albumin-bound T4 moiety.

"Unbound analog" radioimmunoassays for free thyroxin measure the albumin-bound hormone fraction

We have assessed the influence of albumin-bound thyroxin (T4) on apparent free T4 values obtained by two "unbound analog" free T4 methods (AmerlexR Free T4 and Clinical Assays one-step Free T4). We evaluated sera showing three different albumin anomalies: total hereditary analbuminemia, partially corrected analbuminemia, and familial dysalbuminemic hyperthyroxinemia, where abnormal albumin-binding of analog tracer is associated with high apparent free T4 values by these methods. In hereditary analbuminemia, free T4 was almost undetectable by both assays; in contrast, free T4 by equilibrium dialysis was normal. After addition of T4-free human serum albumin, the apparent free T4 concentration in total hereditary analbuminemia became normal by the analog methods. Immunoprecipitation of [125I]T4 and the unidentified labeled kit analogs by antiserum to human albumin was negligible in untreated total hereditary analbuminemia and approximately twice normal in familial dysalbuminemic hyperthyroxinemia. Therefore, alterations in tracer binding to albumin correlate with the apparent free T4 concentrations obtained by the analog methods. The interactions of the unidentified analog tracers and T4 with albumin are such that these techniques principally reflect the albumin-bound T4 moiety.