Nomenclature of prokaryotic 'Candidatus' taxa: establishing order in the current chaos

In the mid-1990s, the category 'Candidatus' was established for putative taxa of as yet uncultivated prokaryotes. The status of 'Candidatus' is not formally included in the rules of the International Code of Nomenclature of Prokaryotes. Thus, 'Candidatus' names do not have standing in the nomenclature. Curated annotated lists of 'Candidatus' names (not including phyla) have been published since 2020. By April 2021, about 2700 names of 'Candidatus' taxa had been published. The International Committee on Systematics of Prokaryotes recently rejected proposals to allow gene sequence data as nomenclatural types. An alternative code for naming uncultivated microorganisms (the 'SeqCode') is now being developed for naming the majority of prokaryotes that are as yet uncultivated. In the opinion of the author, there is no need for such a code, as the existing system, with nomenclature quality control also for 'Candidatus' names, fulfills the needs. Computer programs such as GAN which generates large numbers of correctly formed names from the short lists of Latin and Greek word elements and Protologger that produce descriptions directly from genome sequences will become important in the future for automated naming and description of large numbers of 'Candidatus' taxa from metagenomic and single cell genome data. However, the formation of interesting and meaningful names is encouraged whenever possible.

P–441 Semen quality and cryopreservation in adolescent transgender females

Study question

What are the semen quality and cryopreservation outcomes among adolescent transgender females at the time of fertility preservation (FP) before initiating gender-affirming hormone (GAH) treatment?

Summary answer

Semen quality is strongly reduced among adolescent transgender females before hormone therapy and their stored sperm samples are suitable for intracytoplasmic sperm injection (ICSI).

What is known already

The age of individuals seeking treatment for gender affirmation has fallen sharply in recent years and many of them are adolescents. Estrogen, the primary treatment for transgender women, is known to impair semen quality and fertility potential. Sperm cryopreservation enables young transgender females to circumvent GAH therapy-related fertility impairment and have genetically related children. There are recent data on semen quality among adult transgender women who preserve fertility before exposure to GAH therapy, but little is known about pubertal transgender female adolescents.

Study design, size, duration

This retrospective cohort study included 26 adolescent transgender females who underwent FP between June 2013 and October 2020.

Participants/materials, setting, methods

Before initiating gonadotropin-releasing hormone agonists solely or with GAH treatment, 25 adolescent transgender females were referred to FP in our Fertility Institute of a tertiary university-affiliated medical center. Pre-freezing semen parameters were compared to WHO 2010 reference values. Post-thaw semen parameters were used to determine adequate assisted reproductive technology (ART). A multivariate linear regression analysis was performed to assess the impact of selected medical and lifestyle factors on the semen quality of our study participants.

Main results and the role of chance

The mean age at which adolescent transgender females underwent sperm cryopreservation was 16.2 ± 1.38 years. The median values of all semen parameters in our study group were significantly lower compared to the WHO data on semen quality in the general population of unscreened men, including volume (1.46 ml vs 3.2 ml, respectively, P = 0.001 ), sperm concertation (28*106/ml vs 64*106/ml, P < 0.001), total sperm number (28.2*106 vs 196*106, P < 0.001), total motility (51.6% vs 62%, P < 0.001), and normal morphology (2% vs 14%, P < 0.001). The frequency of semen abnormalities was teratozoospermia 72%, hypospermia 52%, oligozoospermia 28%, and azoospermia 4%. The median post-thaw total motile count was 0.17*106 per vial, and the quality was adequate only for ICSI in 87.7% of the thawed semen samples. Attention-deficit/hyperactivity disorder (ADHD) diagnosis, history of depression/anxiety, medication for ADHD, and antidepressant drugs were found to correlate with hypospermia. No correlation was found between the time of FP, body mass index, autistic spectrum disorder diagnosis, cannabis use, testis tucking, or the levels of follicle-stimulating hormone, estradiol, and testosterone on the semen parameters.

Limitations, reasons for caution

Because no normal values of semen in adolescents are available and the absence of a matched control group, we used WHO 2010 semen data as reference values, and they may not be representative of the adolescent population.

Wider implications of the findings: Although adolescent transgender females have poor semen quality and limited stored semen samples suitable for advanced ART interventions, even before starting GAH therapy, we highly recommend sperm cryopreservation before initiating GAH treatment and thereby prevent further impairment of sperm quality associated with the hormonal treatment.

Trial registration number

Not applicable

Maternal mediation strategies during interaction with toddlers- a comparison of dyads with autism spectrum disorder (ASD) and dyads with typical development (TD)

Introduction

During interactions with toddlers, mothers use various mediation strategies to encourage mutual play. Such mediation skills play an important role in the development of toddlers’ communicative skills. Autism Spectrum Disorder (ASD) introduces challenges to this interaction.

Objectives

To study the use of maternal strategies during interaction with ASD and TD toddlers at early lexical levels.

Methods

Nine ASD and fifteen TD dyads participated. Toddlers were matched by lexical levels. The mean age in the ASD was 31.5 months and in TD - 17 months. Each dyad was video-recorded three times, during naturalistic interaction. Mothers’ verbal mediation strategies were divided into five main communicative categories.

Results

1. Exact repetition of toddler’s utterances was similarly used and increased in both groups across the three visits (f (2,44)=3.77, p< 0.05). 2. Significant differences were found between the two groups regarding strategies associated with control of the interaction eg mothers of toddlers with ASD (MASD) made more frequent attempts to redirect their child’s attention (F (1,22)= 74.56, p<0.01). 3. MASD had higher indices of overall talkativeness (F (1,22)= 5.43, p<0.05); use of nonverbal means (F(1,22)= 9,51, p<0.01); simultaneous use of different means of communication (F (1,22)=19.8, p<0.01).

Conclusions

Our results highlight that in some respects, maternal mediation strategies reflect the child’s lexical level. However, our main finding is a distinct interaction style expressed in MASD’s elevated use of verbal and nonverbal mediation strategies. This, in hope of maintaining continuous interaction that could not be otherwise achieved due to their toddlers’ difficulties

Disclosure

No significant relationships.

Between Abnormal "Otherness" to Groundbreaking "Uniqueness": The Family-Construction Process of the GLBT Family

The GLBT family is a new postmodern phenomenon demonstrating the accomplishments of marginal groups seeking acceptance within mainstream society. The article is based on a qualitative phenomenological study conducted in Israel during 2012, providing a theoretical model combining a vast number of GLBT parenting options ranging from surrogacy, sperm donation, adoption, and co-parenting. The research consisted of 50 personal interviews that concentrated on the family experiences of couples of gay men and lesbian woman who opted to bring a child into their families. Analysis of the data points to a process of empowerment where societal norms in respect to gender, parenting, and family are deconstructed and then reconstructed. The theoretical model conceptualizes three parenting challenges that highlight the respondent's family experience: "Otherness," belonging, and self-actualization. Research shows that every period of family life addresses a different segment, where one of the three challenges becomes the dominant experience.

Influence of emulsifier structure on lipid bioaccessibility in oil-water nanoemulsions

The influence of several nonionic surfactants (Tween-20, Tween-40, Tween-60, Span-20, Span-60, or Span-80) and anionic surfactants (sodium lauryl sulfate, sodium stearoyl lactylate, and sodium stearyl fumarate) showed drastic differences in the rank order of lipase activity/lipid bioaccessibility. The biophysical composition of the oil and water interface has a clear impact on the bioaccessibility of fatty acids (FA) by altering the interactions of lipase at the oil-water interface. It was found that the bioaccessibility was positively correlated with the hydrophilic/lipophilic balance (HLB) of the surfactant and inversely correlated to the surfactant aliphatic chain length. Furthermore, the induction time in the jejunum increased as the HLB value increased and decreased with increasing aliphatic chain length. The rate of lipolysis slowed in the jejunum with increasing HLB and with increasing aliphatic chain length.

Bacterioruberin and salinixanthin carotenoids of extremely halophilic Archaea and Bacteria: a Raman spectroscopic study

Laboratory cultures of a number of red extremely halophilic Archaea (Halobacterium salinarum strains NRC-1 and R1, Halorubrum sodomense, Haloarcula valismortis) and of Salinibacter ruber, a red extremely halophilic member of the Bacteria, have been investigated by Raman spectroscopy using 514.5nm excitation to characterize their carotenoids. The 50-carbon carotenoid α-bacterioruberin was detected as the major carotenoid in all archaeal strains. Raman spectroscopy also detected bacterioruberin as the main pigment in a red pellet of cells collected from a saltern crystallizer pond. Salinibacter contains the C40-carotenoid acyl glycoside salinixanthin (all-E, 2'S)-2'-hydroxy-1'-[6-O-(methyltetradecanoyl)-β-d-glycopyranosyloxy]-3',4'-didehydro-1',2'-dihydro-β,ψ-carotene-4-one), for which the Raman bands assignments of are given here for the first time.

Increased cord serum inflammatory markers in small-for-gestational-age neonates

OBJECTIVE

The pathological picture in ischemic tissue injury shares features with the inflammatory response. Hypoxia-mediated induction of interleukin-6 (IL-6) could set in motion the mechanisms limiting inflammation in ischemia. Intrauterine growth restriction (IUGR) represents a human model of chronic fetal hypoxia. The purpose of this study was a first-time exploration to determine whether cord blood obtained at the delivery of small-for-gestational-age (SGA) infants has increased concentrations of inflammatory markers.

STUDY DESIGN

Cord blood was collected from 20 SGA (term and near-term) infants and 20 appropriate-for-gestational-age (AGA) controls. Infants exposed to maternal smoking, diabetes, maternal chronic diseases, or alcohol or drug use were excluded. Both groups had Apgar score ≥7 at 1 min with a normal cord pH (>7.25). Cord-serum cytokines and thrombopoietin (TPO) levels were measured by enzyme linked immunosorbent assay. C-reactive protein (CRP) was measured using a turbidometric immunoassay.

RESULT

SGA infants had a significantly smaller birth weight than AGA controls, with a smaller gestation age by 1 week. There were significant elevations in IL-6, tumor necrosis factor (TNF-α), CRP and TPO in the SGA compared with the AGA group, which persisted in multiple regression analysis even after gestational age was taken into account.

CONCLUSION

As hypothesized, significant increases in the cord blood concentrations of known inflammatory markers were found in SGA infants compared with the controls.

Increased cord serum inflammatory markers in small-for-gestational-age neonates

OBJECTIVE

The pathological picture in ischemic tissue injury shares features with the inflammatory response. Hypoxia-mediated induction of interleukin-6 (IL-6) could set in motion the mechanisms limiting inflammation in ischemia. Intrauterine growth restriction (IUGR) represents a human model of chronic fetal hypoxia. The purpose of this study was a first-time exploration to determine whether cord blood obtained at the delivery of small-for-gestational-age (SGA) infants has increased concentrations of inflammatory markers.

STUDY DESIGN

Cord blood was collected from 20 SGA (term and near-term) infants and 20 appropriate-for-gestational-age (AGA) controls. Infants exposed to maternal smoking, diabetes, maternal chronic diseases, or alcohol or drug use were excluded. Both groups had Apgar score ≥7 at 1 min with a normal cord pH (>7.25). Cord-serum cytokines and thrombopoietin (TPO) levels were measured by enzyme linked immunosorbent assay. C-reactive protein (CRP) was measured using a turbidometric immunoassay.

RESULT

SGA infants had a significantly smaller birth weight than AGA controls, with a smaller gestation age by 1 week. There were significant elevations in IL-6, tumor necrosis factor (TNF-α), CRP and TPO in the SGA compared with the AGA group, which persisted in multiple regression analysis even after gestational age was taken into account.

CONCLUSION

As hypothesized, significant increases in the cord blood concentrations of known inflammatory markers were found in SGA infants compared with the controls.

Quantum yields for oxygenic and anoxygenic photosynthesis in the cyanobacterium Oscillatoria limnetica

A comparison of the quantum yield spectra of the oxygenic (H(2)O as the electron donor) with the anoxygenic (H(2)S as the electron donor) photosynthesis of the cyanobacterium, Oscillatoria limnetica reveals that anoxygenic photosynthesis is driven by photosystem I only. The highest quantum yields of the latter (maximum; 0.059 CO(2) molecules/quantum of absorbed light) were obtained with wavelengths which preferentially excite photosystem I (<550, >650) in which chlorophyll a and carotenoids are the major pigments. The addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea had no effect on anoxygenic photosynthesis, and no enhancement in quantum efficiency was observed by a superimposition of light preferentially exciting photosystem II.Oxygenic photosynthesis efficiently utilizes only a narrow range of the absorption spectrum (550-650 nm) where light is provided in excess to photosystem II via phycocyanin. The quantum yield (0.033 CO(2) molecules/quantum of absorbed light) is lower than the theoretical yield by a factor of 3, possibly due to inefficient light transfer from photosystem II to I. Thus, 3-fold enhancement of oxygenic photosynthesis by superimposition of photosystem I light, and low quantum yields for anoxygenic photosynthesis, were obtained in this region. These results are consonant with the suggestion that such a cyanobacterium represents an intermediate stage in phototrophic evolution.

Accumulation of trehalose and sucrose in cyanobacteria exposed to matric water stress

The drought-resistant cyanobacteria Phormidium autumnale, strain LPP(4), and a Chroococcidiopsis sp. accumulated trehalose, sucrose, and both trehalose and sucrose, respectively, in response to matric water stress. Accumulated sugar concentrations reached values of up to 6.2 mug of trehalose per mug of chlorophyll in P. autumnale, 6.9 mug of sucrose per mug of chlorophyll in LPP(4), and 4.1 mug of sucrose and 3.2 mug of trehalose per mug of chlorophyll in the Chroococcidiopsis sp. The same sugars were accumulated by these cyanobacteria in similar concentrations under osmotic water stress. Cyanobacteria that did not show drought resistance (Plectonema boryanum and Synechococcus strain PCC 7942) did not accumulate significant amounts of sugars when matric water stress was applied.

Prohepcidin concentrations and erythroid progenitors in cord blood of appropriate versus small for gestational age neonates

OBJECTIVE

Prohepcidin (Pro-Hep), synthesized in the liver, is the prohormone of hepcidin (Hep), which reduces iron absorption in the gut; its synthesis is enhanced by inflammation and is reduced during hypoxia. We aimed to study the hypothesis that infants born small for gestational age (SGA) have reduced cord blood concentrations of Pro-Hep.

STUDY DESIGN

Cord blood was collected from 20 SGA (term and near term >35 week gestation) infants and 20 appropriate for gestational age (AGA) controls. We excluded infants exposed to maternal chronic diseases, smoking, diabetes, alcohol or drug use. Both groups had a 1 min Apgar score above or equal to 7 and had normal cord blood pH (above 7.25). ELISA was used to determine serum concentrations of Pro-Hep and erythropoietin (EPO). Circulating CD71(+)/CD45(-)/SSC(low) cells were measured by flow cytometry as an index of erythroid progenitors.

RESULT

There were no significant differences between groups in terms of hemoglobin concentrations, and Pro-Hep. In contrast, EPO levels and circulating CD71(+)/CD45(-)/SSC(low) erythroid progenitors were significantly higher in the SGA group. These differences remained significant even after controlling for gestational age and gravidity.

CONCLUSION

Contrary to EPO upregulation during intrauterine growth restriction (IUGR), and higher concentrations of circulating erythroid progenitors, Pro-Hep concentration is not affected by IUGR.

Birth size and coronary heart disease risk score in young adulthood. The Atherosclerosis Risk in Young Adults (ARYA) study

Data of the Atherosclerosis Risk in Young Adults (ARYA) study were used to investigate the association between birth size and the absolute risk for coronary heart disease in healthy young adults. The cohort study comprises 750 (46.9% men) subjects born between 1970 and 1973. Birth characteristics were obtained from school health records. At young adulthood, blood pressure, anthropometry and fasting lipid levels were measured. Questionnaires were taken about smoking and diabetes. The young adult 10-year risk for coronary heart disease was calculated using the Framingham risk score. The overall 10-year risk for coronary heart disease was 1.6% (standard deviation (SD) 1.9), 3.0% (SD 1.9) in men and 0.3% (SD 0.2) in women. Using linear regression it was shown that a SD lower birth weight (=0.54 kg) was associated with 0.1% greater risk in the overall population (95% confidence interval (CI): -0.19, -0.004). Similarly, a lower ponderal index at birth was associated with an 0.11% higher risk (95% CI: -0.21, -0.002). These relations were stronger in men. Lower birth length was related with an increased risk in women (-0.02% risk/SD birth length; 95% CI: -0.04, 0.0001). These results suggest that small birth size is associated with an increased risk score for coronary artery disease in young adulthood.

The cytoskeletal network controls c-Jun translation in a UTR-dependent manner

The cytoskeleton is a dynamic network that undergoes restructuring during various cellular events, influencing cell proliferation, differentiation, and apoptosis. Here, we report that accumulation of c-Jun, a member of the AP1 family of transcription factors that play a key role in normal and aberrant cell growth, dramatically increases upon depolymerization of the cytoskeleton, and that, unexpectedly, this increase is controlled translationally. Depolymerization of the actin or microtubule network induces an increase in c-Jun accumulation with no corresponding increase in c-Jun mRNA or in the half-life of the c-Jun protein, but rather in the translatability of its transcript. This increase is mediated by the untranslated regions (UTRs) of c-Jun mRNA, and is not dependent on activated mitogen-activated protein kinase pathways. This novel mechanism of c-Jun regulation might be relevant to physiological conditions in which c-Jun plays a pivotal role.

Yeast diversity in hypersaline habitats

Thus far it has been considered that hypersaline natural brines which are subjected to extreme solar heating, do not contain non-melanized yeast populations. Nevertheless we have isolated yeasts in eight different salterns worldwide, as well as from the Dead Sea, Enriquillo Lake (Dominican Republic) and the Great Salt Lake (Utah). Among the isolates obtained from hypersaline waters, Pichia guilliermondii, Debaryomyces hansenii, Yarrowia lipolytica and Candida parapsilosis are known contaminants of low water activity food, whereas Rhodosporidium sphaerocarpum, R. babjevae, Rhodotorula laryngis, Trichosporon mucoides, and a new species resembling C. glabrata were not known for their halotolerance and were identified for the first time in hypersaline habitats. Moreover, the ascomycetous yeast Metschnikowia bicuspidata, known to be a parasite of the brine shrimp, was isolated as a free-living form from the Great Salt Lake brine. In water rich in magnesium chloride (bitterns) from the La Trinitat salterns (Spain), two new species provisionally named C. atmosphaerica - like and P. philogaea - like were discovered.

Determinants of augmentation index in young men: the ARYA study

BACKGROUND

There is an increasing interest in the augmentation index (AIx), the proportion of the central pulse pressure resulting from peripheral arterial wave reflection, which has been related to cardiovascular disease risk and mortality. Most of the data on the AIx have been collected in patients with established cardiovascular disease. In contrast, data in the young are scarce. However, as AIx might be used to evaluate cardiovascular disease risk already at an early age, we aimed to study determinants of AIx in a population of healthy young men.

MATERIALS AND METHODS

Three hundred and thirty males (mean age of 28 years) of the Atherosclerosis Risk in Young Adults study (ARYA-study) were studied in this cross sectional, population-based study. Anthropometrics and risk factors for cardiovascular disease were determined and AIx was estimated by radial applanation tonometry. The data were analysed using linear regression models.

RESULTS

Augmentation index was associated with age, height (inverse), heart rate (inverse) and mean arterial pressure (positive). After adjustment for these determinants, smoking (beta = 0.31%/pack years, 95% CI [0.06; 0.55]) and LDL-cholesterol (beta = 1.28%/(mmol L(-1)), 95% CI [0.04; 2.51]) were statistically significant related to AIx.

CONCLUSIONS

This study among young adult males shows that smoking and LDL-cholesterol are positively related to AIx. These findings support the view that AIx may be used as a marker for early vascular damage and cardiovascular disease risk.

The Atherosclerosis Risk in Young Adults (ARYA) study: rationale and design

INTRODUCTION

Despite recent advances in treatment, cardiovascular disease (CVD) is still health problem number one in western societies. Aiming at specific prevention strategies for high-risk individuals and shifting the available prevention programs towards younger age groups might increase the success of primary prevention. However, before addressing age-specific prevention programs, more insight in the determinants of early vascular damage and increased cardiovascular risk is warranted as well as insight in determinants increased cardiovascular risk, including vascular damage, at an early age. The Atherosclerosis Risk in Young Adults (ARYA) study was specifically designed to address this issue.

OBJECTIVES

The ARYA study started off with studies evaluating (1) whether it is possible to predict cardiovascular risk at young adulthood by routinely measured adolescent data, and (2) evaluating the role of birth characteristics and adolescent characteristics to the development of vascular damage at young adulthood.

METHODS

The ARYA study comprises of two cohorts of young adults. The Utrecht cohort includes 750 young adults, aged 27-30 years. The Hague-cohort includes 261 young adults born between 1963 and 1968. Data on birth characteristics, growth in early infancy as well as adolescent anthropometry, blood pressure, lipids, body mass index were obtained from the original medical records of the Municipal Health Service. In 1999/2001, the extent of subclinical vascular damage was measured using carotid wall thickness and aortic stiffness. Also, data on adult cardiovascular risk profile, bone density and central blood pressure were assessed, fasting blood was drawn and timed overnight urine samples were collected.

CONCLUSION

The ARYA study is aimed to provide data on early determinants of cardiovascular risk, including vascular damage, at an early age. This knowledge enhances the understanding of atherosclerosis development and CVD risk and is needed to improve the available primary prevention programs.

Aortic stiffness and carotid intima-media thickness: two independent markers of subclinical vascular damage in young adults?

BACKGROUND

Previous reports have shown that carotid intima-media thickness (CIMT) and arterial stiffness are strong predictors of subsequent cardiovascular disease (CVD) morbidity and mortality, and are well related to an unfavourable cardiovascular risk profile in middle-aged and older subjects. These similarities suggest that arterial stiffness may play a role in the development of atherosclerosis or vice versa. However, studies show conflicting results and are limited to elderly subjects. To study this issue further, we evaluated the relation of arterial stiffness to subclinical atherosclerosis in 524 healthy young adults, aged 27-30 years.

METHODS AND RESULTS

Aortic stiffness was assessed using pulse wave velocity (PWV) and CIMT was used as measure of subclinical atherosclerosis. The positive crude correlation between for mean arterial pressure adjusted PWV and CIMT (Pearson's correlation coefficient: 0.11; P=0.016) attenuated after adjustment for common determinants of both measurements like gender and age (partial correlation coefficient: 0.03; P=0.512). Furthermore, multivariate linear regression models showed that male gender, age and blood pressure were independent determinants of both CIMT and PWV while body mass index and LDL-cholesterol were independent determinants of CIMT only.

CONCLUSIONS

These observations suggest that in healthy young adults arterial stiffness and CIMT reflect two separate entities of vascular damage.

Change in body mass index from adolescence to young adulthood and increased carotid intima-media thickness at 28 years of age: The Atherosclerosis Risk in Young Adults study

Obesity has become a major health problem in Western societies by increasing the risk of atherosclerosis and cardiovascular disease. Although data on tracking of body mass index (BMI) are available, little is known about the impact of weight change over time on the development of vascular damage.

OBJECTIVE

To evaluate the relationship between adolescent BMI as well as change in BMI from adolescence into young adulthood and cardiovascular risk, as estimated by common carotid intima-media thickness (CIMT).

DESIGN

Cohort study.

SUBJECTS

A total of 750 healthy young adults, aged 27-30 y, who attended secondary school in Utrecht, the Netherlands.

MEASUREMENTS

Data on adolescent weight, height, blood pressure and puberty stage were available from the original school health records of the Municipal Health Service. At young adulthood, a questionnaire on cardiovascular risk factors was completed and fasting blood sample was drawn and common CIMT was measured.

RESULTS

One standard deviation (s.d.) increase in adolescent BMI was associated with 2.3 microm [95% confidence interval (CI): 1.3; 3.3] increase in mean common CIMT in young adults after adjustment for gender, adolescent age, adolescent blood pressure, puberty stage and lumen diameter. Further adjustment for adult cardiovascular risk factors did not change the relationship (linear regression coefficient=2.1 microm/s.d.; 95% CI: 1.0; 3.1). Adjustment for adult BMI attenuated the association (linear regression coefficient=0.9 microm/s.d.; 95% CI: -0.3; 2.2) as the majority of overweight and obese adolescents remained overweight or became obese young adults. Subjects who remained in the upper BMI distribution from adolescence into young adulthood had a significantly higher common CIMT compared to those who showed relative weight loss over time (mean difference 14.7 mum; P<0.001). These latter showed similar CIMT values as individuals with constant low BMI.

CONCLUSION

Adolescent BMI predicts cardiovascular risk, as estimated by common CIMT in young adulthood. Individuals who experience the largest increase in BMI and those who remain overweight over time have the thickest common CIMT.

In human epidermis, beta-defensin 2 is packaged in lamellar bodies

The skin presents a mechanical, as well as an immunological barrier to infection, and displays considerable innate immune capacity. Recently, cultured human keratinocytes were described to produce and export a microbicidal peptide human beta-defensin 2 (HBD-2). Immunogold was used to label ultrathin cryosections of stimulated, cultured human epidermis. HBD-2 was found to be stored in the lamellar bodies (LBs) of the stimulated keratinocytes of the spinous layer of the epidermis. HBD-2 was also found in the intercellular space. These findings suggest that HBD-2 is released with the contents of the LBs. Along with other investigations, our findings indicate that the lipid "permeability" barrier of the skin contains antimicrobial substances.

Survival of filamentous fungi in hypersaline Dead Sea water

A variety of filamentous fungi have recently been isolated from the Dead Sea (340 g/L total dissolved salts). To assess the extent to which such fungi can survive for prolonged periods in Dead Sea water, we examined the survival of both spores and mycelia in undiluted Dead Sea water and in Dead Sea water diluted to different degrees with distilled water. Mycelia of Aspergillus versicolor and Chaetomium globosum strains isolated from the Dead Sea remained viable for up to 8 weeks in undiluted Dead Sea water. Four Dead Sea isolates (A. versicolor, Eurotium herbariorum, Gymnascella marismortui, and C. globosum) retained their viability in Dead Sea water diluted to 80% during the 12 weeks of the experiment. Mycelia of all species survived for the full term of the experiment in Dead Sea water diluted to 50% and 10% of its original salinity. Comparison of the survival of Dead Sea species and closely related isolates obtained from other locations showed prolonged viability of the strains obtained from the Dead Sea. Spores of isolates obtained from the terrestrial shore of the Dead Sea generally proved less tolerant to suspension in undiluted Dead Sea water than spores of species isolated from the water column. Spores of the species isolated from the control sites had lost their viability in undiluted Dead Sea water within 12 weeks. However, with the exception of Emericella spores, which showed poor survival, a substantial fraction of the spores of Dead Sea fungal isolates remained viable for that period. The difference in survival rate between spores and mycelia of isolates of the same species points to the existence of adapted halotolerant and/or halophilic fungi in the Dead Sea.

Diversity of halophilic microorganisms: environments, phylogeny, physiology, and applications

The phylogenetic diversity of microorganisms living at high salt concentrations is surprising. Halophiles are found in each of the three domains: Archaea, Bacteria, and Eucarya. The metabolic diversity of halophiles is great as well: they include oxygenic and anoxygenic phototrophs, aerobic heterotrophs, fermenters, denitrifiers, sulfate reducers, and methanogens. The diversity of metabolic types encountered decreases with salinity. The upper salinity limit at which each dissimilatory process takes place is correlated with the amount of energy generated and the energetic cost of osmotic adaptation. Our understanding of the biodiversity in salt-saturated environments has increased greatly in recent years. Using a combination of culture techniques, molecular biological methods, and chemotaxonomic studies, we have obtained information on the nature of the halophilic Archaea as well as the halophilic Bacteria that inhabit saltern crystallizer ponds. Several halophilic microorganisms are being exploited in biotechnology. In some cases, such as the production of ectoine, the product is directly related to the halophilic behavior of the producing microorganism. In other cases, such as the extraction of beta-carotene from Dunaliella or the potential use of Haloferax species for the production of poly-beta-hydroxyalkanoate or extracellular polysaccharides, similar products can be obtained from non-halophiles, but halophilic microorganisms may present advantages over the use of non-halophilic counterparts.

Determinants of Staphylococcus aureus nasal carriage

Nasal carriage of Staphylococcus aureus has been identified as a risk factor for community-acquired and nosocomial infections. We screened 230 donors of diverse ethnic and socioeconomic backgrounds and identified 62 (27%) whose nasal secretions were colonized by S. aureus. In 18 donors in whom the various regions of the nasal luminal surface were separately sampled, the predominant region of S. aureus colonization was the moist squamous epithelium on the septum adjacent to the nasal ostium. Nasal fluid from carriers was defective in killing endogenous S. aureus and nasal carrier isolates of S. aureus but not a laboratory S. aureus strain. Transmission electron microscopy revealed that S. aureus isolates incubated in nasal fluid from carriers for 2 h at 37 degrees C were less damaged than those incubated in noncarrier fluid and were coated with an electron-dense layer. Compared with that from healthy donors and patients with acute rhinitis, nasal fluid from carriers contained elevated concentrations of the neutrophil-derived defensins human neutrophil peptides 1 to 3 (47- and 4-fold increases, respectively), indicative of a neutrophil-mediated inflammatory host response to S. aureus colonization. The concentration of the inducible epithelial antimicrobial peptide human beta-defensin 2 was also highly elevated compared to that in healthy donors, in whom the level was below the detection limit, or patients with acute rhinitis (sixfold increase). Thus, nasal carriage of S. aureus takes hold in nasal fluid that is permissive for colonization and induces a local inflammatory response that fails to clear the colonizing bacteria.

The taxonomic status of "Halobacterium marismortui" from the Dead Sea: a comparison with Halobacterium vallismortis

A Halobacterium strain, isolated by Ginzburg et al. from the Dead Sea in the late 1960's, often referred to as "Halobacterium marismortui" or "Halobacterium of the Dead Sea" (deposited in the American Type Culture Collection as ATCC 43049) was compared with Halobacterium (Haloarcula) vallismortis ATCC 29715. The strains appeared to be very closely related, as shown by the near identity of their 5S and 16S ribosomal RNA's, and a large number of other common properties. Distinct differences exist, however, in cell morphology, and in their potency to utilize different sugars and other compounds.

Cancer in children with celiac disease: a survey of the European Society of Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND

In adults, the relation between celiac disease (CD) and cancer has been long recognized. In children, only four cases of CD and cancer have been described in Europe. We made a new inventory of cases with CD and cancer in children that were known by the members of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition between 1989 and 1999.

METHODS

Postal inquiry was made of all European Society for Paediatric Gastroenterology, Hepatology and Nutrition members mentioned on the society's web page. The members were asked if they had seen a child with CD and cancer between 1989 and 1999 and if so, to supply additional clinical data. Also, information on working place, experience, and number of celiac patients under their care was requested.

RESULTS

Fifty-six percent of the members responded. Sixteen members reported 22 cases of cancer and CD in children. One case had been reported in the literature previously. The tumors that were reported originated from the brain, thyroid, larynx, liver, small bowel, adrenal, lymphoreticular system, and the musculoskeletal system. There were no differences between members reporting a case and those who did not.

CONCLUSIONS

Twenty-one new cases of cancer and CD in children in Europe were found. Cancer and CD in children are underreported. A remarkable number of thyroid and small bowel cancers were found, suggesting a possible relation with CD. It is important to evaluate whether these findings are coincidental. All cases of cancer and CD in children should be reported to the literature.

The contribution of halophilic Bacteria to the red coloration of saltern crystallizer ponds(1)

Analysis of the pigments extracted from solar saltern crystallizer ponds in Santa Pola near Alicante and on the Balearic island of Mallorca, Spain, showed that 5-7.5% of the total prokaryotic pigment absorbance could be attributed to a novel carotenoid or carotenoid-like compound. This unidentified pigment was identical to the sole pigment present in Salinibacter ruber, the only described member of a newly discovered genus of red halophilic Bacteria related to the Cytophaga-Flavobacterium-Bacteroides group. On the basis of fluorescence in situ hybridization experiments it has been shown that Salinibacter is an important component of the microbial community of Spanish saltern ponds. The red color of saltern crystallizer ponds may thus not only be due to red halophilic Archaea and to beta-carotene-rich Dunaliella cells as previously assumed, but may contain a bacterial contribution as well. The Salinibacter pigment was not detected in samples collected from crystallizer ponds of the salterns of Eilat, Israel, and only traces of it may have been present in the Newark, CA, USA, salterns. The community structure of the prokaryote community inhabiting saltern crystallizers thus shows significant geographic variations. Polar lipid analyses of the biomass collected from the Santa Pola salterns showed that the total contribution of Salinibacter and other Bacteria to the total biomass was minor, the most important component of the community being halophilic Archaea.

Selenihalanaerobacter shriftii gen. nov., sp. nov., a halophilic anaerobe from Dead Sea sediments that respires selenate

We isolated an obligately anaerobic halophilic bacterium from the Dead Sea that grew by respiration of selenate. The isolate, designated strain DSSe-1, was a gram-negative, non-motile rod. It oxidized glycerol or glucose to acetate + CO2 with concomitant reduction of selenate to selenite plus elemental selenium. Other electron acceptors that supported anaerobic growth on glycerol were nitrate and trimethylamine-N-oxide; nitrite, arsenate, fumarate, dimethylsulfoxide, thiosulfate, elemental sulfur, sulfite or sulfate could not serve as electron acceptors. Growth on glycerol in the presence of nitrate occurred over a salinity range from 100 to 240 g/l, with an optimum at 210 g/l. Analysis of the 16S rRNA gene sequence suggests that strain DSSe-1 belongs to the order Halanaerobiales, an order of halophilic anaerobes with a fermentative or homoacetogenic metabolism, in which anaerobic respiratory metabolism has never been documented. The highest 16S rRNA sequence similarity (90%) was found with Acetohalobium arabaticum (X89077). On the basis of physiological properties as well as the relatively low homology of 16S rRNA from strain DSSe-1 with known genera, classification in a new genus within the order Halanaerobiales, family Halobacteroidaceae is warranted. We propose the name Selenihalanaerobacter shriftii. Type strain is strain DSSe-1 (ATCC accession number BAA-73).

Accuracy and cost-effectiveness of a new strategy to screen for celiac disease in children with Down syndrome

OBJECTIVES

To investigate the best approach to screen for celiac disease (CD) in patients with Down syndrome (DS).

STUDY DESIGN

One hundred thirty-seven children with DS were followed up longitudinally. CD screening was offered in 1994, 1996, and 1999 by determination of serum immunoglobulin A-anti-endomysium antibodies (AEA). The HLA-DQA1*0501/DQB1*02 allelic combination known to be strongly positively associated with CD was typed. All IgA-AEA-positive children were given the opportunity to undergo a small bowel biopsy: if villous atrophy was found, the diagnosis of CD was established.

RESULTS

CD was diagnosed in 11 (8%) children: 8 in 1994 and 3 in 1996. All of them carried the HLA-DQ alleles associated with CD. The presence of symptoms was not useful in discriminating which children could have CD.

CONCLUSIONS

Screening once in a lifetime is not enough to detect CD in patients with DS. We propose a new, accurate, and cost-sparing 2-step strategy for screening, based on selection of the individuals with potential CD by HLA-DQ typing and on longitudinal serologic CD screening in this selected group.