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Advances in assembling microbial genomes have led to growth of reference genome databases, which have been transformative for applied and basic microbiome research. Here we show that published microbial genome databases from humans, mice, cows, pigs, fish, honeybees, and marine environments contain significant sequencing-adapter contamination that systematically reduces assembly accuracy and contiguousness. By removing the adapter-contaminated ends of contiguous sequences and reassembling MGnify reference genomes, we improve the quality of assemblies in these databases., (© 2024. The Author(s).)

Shotgun metagenomic sequencing provides valuable insights into microbial communities, but the high cost of library preparation with standard kits and protocols is a barrier for many. New methods such as Hackflex use diluted commercially available reagents to greatly reduce library preparation costs. However, these methods have not been systematically validated for metagenomic sequencing. Here, we evaluate Hackflex performance by sequencing metagenomic libraries from known mock communities as well as mouse fecal samples prepared by Hackflex, Illumina DNA Prep, and Illumina TruSeq methods. Hackflex successfully recovered all members of the Zymo mock community, performing best for samples with DNA concentrations <1 ng/μL. Furthermore, Hackflex was able to delineate microbiota of individual inbred mice from the same breeding stock at the same mouse facility, and statistical modeling indicated that mouse ID explained a greater fraction of the variance in metagenomic composition than did library preparation method. These results show that Hackflex is suitable for generating inventories of bacterial communities through metagenomic sequencing., Competing Interests: None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Society for Microbial Ecology.)

Mammalian species harbor compositionally distinct gut microbial communities, but the mechanisms that maintain specificity of symbionts to host species remain unclear. Here, we show that natural selection within house mice ( Mus musculus domesticus ) drives deterministic assembly of the house-mouse gut microbiota from mixtures of native and non-native microbiotas. Competing microbiotas from wild-derived lines of house mice and other mouse species ( Mus and Peromyscus spp.) within germ-free wild-type (WT) and Rag1 -knockout ( Rag1 -/- ) house mice revealed widespread fitness advantages for native gut bacteria. Native bacterial lineages significantly outcompeted non-native lineages in both WT and Rag1 -/- mice, indicating home-site advantage for native microbiota independent of host adaptive immunity. However, a minority of native Bacteriodetes and Firmicutes favored by selection in WT hosts were not favored or disfavored in Rag1 -/- hosts, indicating that Rag1 mediates fitness advantages of these strains. This study demonstrates home-site advantage for native gut bacteria, consistent with local adaptation of gut microbiota to their mammalian species.

Vertebrates harbour gut microbial communities containing hundreds of bacterial species, most of which have never been cultivated or isolated in the laboratory. The lack of cultured representatives from vertebrate gut microbiotas limits the description and experimental interrogation of these communities. Here, we show that representatives from >50% of the bacterial genera detected by culture-independent sequencing in the gut microbiotas of fence lizards, house mice, chimpanzees, and humans were recovered in mixed cultures from frozen faecal samples plated on a panel of nine media under a single growth condition. In addition, culturing captured >100 rare bacterial genera overlooked by culture-independent sequencing, more than doubling the total number of bacterial sequence variants detected. Our approach recovered representatives from 23 previously uncultured candidate bacterial genera, 12 of which were not detected by culture-independent sequencing. Results identified strategies for both indiscriminate and selective culturing of the gut microbiota that were reproducible across vertebrate species. Isolation followed by whole-genome sequencing of 161 bacterial colonies from wild chimpanzees enabled the discovery of candidate novel species closely related to the opportunistic pathogens of humans Clostridium difficile and Hungatella hathewayi. This study establishes culturing methods that improve inventories and facilitate isolation of gut microbiota constituents from a wide diversity of vertebrate species., (© 2021 John Wiley & Sons Ltd.)

The importance of diversity and cellular specialization is clear for many reasons, from population-level diversification, to improved resiliency to unforeseen stresses, to unique functions within metazoan organisms during development and differentiation. However, the level of cellular heterogeneity is just now becoming clear through the integration of genome-wide analyses and more cost effective Next Generation Sequencing (NGS). With easy access to single-cell NGS (scNGS), new opportunities exist to examine different levels of gene expression and somatic mutational heterogeneity, but these assays can generate yottabyte scale data. Here, we model the importance of heterogeneity for large-scale analysis of scNGS data, with a focus on the utilization in oncology and other diseases, providing a guide to aid in sample size and experimental design.

Leukemia, specifically acute myeloid leukemia (AML), is a common malignancy that can be differentiated into multiple subtypes based on leukemogenic history and etiology. Although genetic aberrations, particularly cytogenetic abnormalities and mutations in known oncogenes, play an integral role in AML development, epigenetic processes have been shown as a significant and sometimes independent dynamic in AML pathophysiology. Here, we summarize how tumors evolve and describe AML through an epigenetic lens, including discussions on recent discoveries that include prognostics from epialleles, changes in RNA function for hematopoietic stem cells and the epitranscriptome, and novel epigenetic treatment options. We further describe the limitations of treatment in the context of the high degree of heterogeneity that characterizes acute myeloid leukemia.

A time-course transcriptome analysis of two cassava varieties that are either resistant or susceptible to cassava brown streak disease (CBSD) was conducted using RNASeq, after graft inoculation with Ugandan cassava brown streak virus (UCBSV). From approximately 1.92 billion short reads, the largest number of differentially expressed genes (DEGs) was obtained in the resistant (Namikonga) variety at 2 days after grafting (dag) (3887 DEGs) and 5 dag (4911 DEGs). At the same time points, several defense response genes (encoding LRR-containing, NBARC-containing, pathogenesis-related, late embryogenesis abundant, selected transcription factors, chaperones, and heat shock proteins) were highly expressed in Namikonga. Also, defense-related GO terms of 'translational elongation', 'translation factor activity', 'ribosomal subunit' and 'phosphorelay signal transduction', were overrepresented in Namikonga at these time points. More reads corresponding to UCBSV sequences were recovered from the susceptible variety (Albert) (733 and 1660 read counts per million (cpm)) at 45 dag and 54 dag compared to Namikonga (10 and 117 cpm respectively). These findings suggest that Namikonga's resistance involves restriction of multiplication of UCBSV within the host. These findings can be used with other sources of evidence to identify candidate genes and biomarkers that would contribute substantially to knowledge-based resistance breeding.

Damaraland mole-rats (Fukomys damarensis) are among a small number of eusocial mammals. Eusociality is a social system where only a few individuals within a colony engage in direct reproduction, while remaining subordinate members are non-breeders and support reproductive efforts of breeding individuals. Inbreeding avoidance precludes mating between subordinate siblings and between offspring and parents. Interestingly, non-breeders readily attempt to mate with unrelated opposite-sex individuals. This is unusual since the non-breeding females do not attain puberty while in their natal colony. Based on this finding, the present study investigated the role of the gonads in the regulation of mating behaviors in this species and identified the mechanism of inbreeding avoidance. Gonadal-intact and gonadectomized non-breeders from different colonies were removed from their colonies and tested for the expression of sexual behavior. Results indicated that gonadal status had only minor effects on the expression of sexual behavior in either males or females. In a second experiment, sexual behaviors were absent between opposite-sex siblings so long as they had frequent contact with each other; however, following 5 weeks of separation, sexual behavior between these siblings was robustly expressed. Thus, Damaraland mole-rats avoid establishing mating relationships with familiar individuals but will readily mate with unfamiliar individuals of the opposite sex, with genetic relatedness apparently playing little role. The initiation of sexual behavior in Damaraland mole-rats does not require the presence of the gonads, but does require that the members of the pair have not been in contact with one another for at least several weeks., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Naked mole-rats are highly social rodents that live in large groups and exhibit a strict reproductive and social hierarchy. Only a few animals in each colony breed; the remainder are non-reproductive and are socially subordinate to breeders. We have examined androgen receptor immunoreactive (AR+) cells in brain regions comprising the recently described social decision-making network in subordinate and breeder naked mole-rats of both sexes. We find that subordinates have a significantly higher percentage of AR+ cells in all brain regions expressing this protein. By contrast, there were no significant effects of sex and no sex-by-status interactions on the percentage of AR+ cells. Taken together with previous findings, the present data complete a systematic assessment of the distribution of AR protein in the social decision-making network of the eusocial mammalian brain and demonstrate a significant role for social status in the regulation of this protein throughout many nodes of this network., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Sexual differentiation of the mammalian nervous system has been studied intensively for over 25 years. Most of what we know, however, comes from work on relatively non-social species in which direct reproduction (i.e., production of offspring) is virtually the only route to reproductive success. In social species, an individual's inclusive fitness may include contributions to the gene pool that are achieved by supporting the reproductive efforts of close relatives; this feature is most evident in eusocial organisms. Here, we review what is known about neuroendocrine mechanisms, sexual differentiation, and effects of social status on the brain and spinal cord in two eusocial mammals: the naked mole-rat and Damaraland mole-rat. These small rodents exhibit the most rigidly organized reproductive hierarchy among mammals, with reproduction suppressed in a majority of individuals. Our findings suggest that eusociality may be associated with a relative lack of sex differences and a reduced influence of gonadal hormones on some functions to which these hormones are usually tightly linked. We also identify neural changes accompanying a change in social and reproductive status, and discuss the implications of our findings for understanding the evolution of sex differences and the neuroendocrinology of reproductive suppression.

Naked mole-rats are highly social rodents that live in large colonies characterized by a rigid social and reproductive hierarchy. Only one female, the queen, breeds. Most colony members are non-reproductive subordinates that work cooperatively to rear the young and maintain an underground burrow system. Little is known about the neurobiological basis of the complex sociality exhibited by this species. The neuropeptide oxytocin (Oxt) modulates social bonding and other social behaviors in many vertebrates. Here we examined the distribution of Oxt immunoreactivity in the brains of male and female naked mole-rats. As in other species, the majority of Oxt-immunoreactive (Oxt-ir) cells were found in the paraventricular and supraoptic nuclei, with additional labeled cells scattered throughout the preoptic and anterior hypothalamic areas. Oxt-ir fibers were found traveling toward and through the median eminence, as well as in the tenia tecta, septum, and nucleus of the diagonal band of Broca. A moderate network of fibers covered the bed nucleus of the stria terminalis and preoptic area, and a particularly dense fiber innervation of the nucleus accumbens and substantia innominata was observed. In the brainstem, Oxt-ir fibers were found in the periaqueductal gray, locus coeruleus, parabrachial nucleus, nucleus of the solitary tract, and nucleus ambiguus. The high levels of Oxt immunoreactivity in the nucleus accumbens and preoptic area are intriguing, given the link in other rodents between Oxt signaling in these regions and maternal behavior. Although only the queen gives birth or nurses pups in a naked mole-rat colony, most individuals actively participate in pup care.

Naked mole-rats are eusocial rodents that live in large subterranean colonies in which one queen breeds with one to three males. All other animals are nonbreeding subordinates. The external features of male and female subordinates, including their genitalia, are remarkably monomorphic, as is their behavior. Because vasopressin (VP) is associated with social behaviors and sex differences in other species, its distribution in naked mole-rats was of interest. We used immunohistochemistry to examine VP in the brains of subordinate and breeding naked mole-rats of both sexes. As in other mammals, VP-immunoreactive (-ir) somata were found in the paraventricular (PVN) and supraoptic nuclei (SON) and VP-ir projections from these nuclei ran through the internal and external zone of the median eminence. However, naked mole-rats had very few VP-ir cells in the bed nucleus of the stria terminalis (BST) and none in the suprachiasmatic nucleus (SCN); the extensive network of fine-caliber VP-ir fibers usually seen in projection sites of the BST and SCN were also absent. Equally unexpected was the abundance of large-caliber VP-ir fibers in the dorsomedial septum. VP immunoreactivity was generally similar in all groups, with the exception of VP-ir cell number in the dorsomedial hypothalamus (DMH). Breeders had a population of labeled cells in the DMH that was absent, or nearly absent, in subordinates. Future studies on the function of VP in these areas are needed to determine how the atypical distribution of VP immunoreactivity relates to eusociality and the unusual physiology of naked mole-rats.

Naked mole-rats (Heterocephalus glaber) are fossorial, eusocial rodents that live in colonies which typically include 60-80 individuals. Generally, only one of the females and 1-3 of the males in a colony are reproductives. The reproductives engage in mutual genital nuzzling behavior that is rarely exhibited by subordinates (non-reproductives). Thus, genital nuzzling may represent a mechanism of bonding and/or specific recognition between reproductive individuals. We investigated whether gonadal hormones are involved in the maintenance of genital nuzzling behavior and mating behaviors in isolated pairs of mole-rats and also in established breeding pairs of mole-rats within colonies. We also explored whether sex hormone deprivation would alter the strict partner preference for performance of nuzzling within colonies. Our results indicate (a) considerable variation between pairs in the frequency of nuzzling, (b) a reduction in the frequency of nuzzling following castration of the male and restoration of the 'baseline' frequency after replacement of testosterone in castrated males, (c) the failure of either castration or combined castration and ovariectomy to eliminate genital nuzzling in established pairs, and (d) the exhibition of nuzzling behavior by some of the subordinates in all three experimental colonies beginning several weeks after gonadectomy of both of the reproductives. No cases of lordosis behavior were seen during the approximately 109 h of behavioral observations. This is not surprising, since female mole-rats have an approximately 30-day ovulatory cycle, and lordosis only occurs during a peri-ovulatory period of a few hours. A total of 44 cases of mounting behavior were recorded; all these involved breeding males in colonies or males from isolated pairs, and all occurred when males were either gonad-intact or castrated with testosterone replacement. Thus, in contrast to nuzzling behavior, male sex behavior appeared to be eliminated during androgen deprivation.

Nitric oxide (NO) is emerging as an important signalling molecule with diverse physiological functions in plants. In the current study, changes in gene expression in response to 0.1 mm and 1.0 mm sodium nitroprusside (SNP), a donor of NO, were studied in Arabidopsis using the whole genome ATH1 microarray, representing over 24,000 genes. We observed 342 up-regulated and 80 down-regulated genes in response to NO treatments. These included 126 novel genes with unknown functions. Most of these changes were specific to NO treatment, as we observed a reverse trend when the plants were treated with NO scavenger, 2-[4-carboxyphenyl]-4,4,5,5-tetramethylimidazoline-1-oxy-3-oxide (c-PTIO). Hierarchical clustering revealed 162 genes showing a dose-dependent increase in signal from 0.1 mm SNP to 1.0 mm SNP treatment. We observed the up-regulation of several genes encoding disease-resistance proteins, WRKY proteins, transcription factors, zinc finger proteins, glutathione S-transferases, ABC transporters, kinases and biosynthetic genes of ethylene, jasmonic acid, lignin and alkaloids. This report provides an insight into the molecular basis for the seemingly diverse biological functions of NO in plants. Interestingly, about 2.0% of the genes in Arabidopsis responded to NO treatment, about 10% of which were transcription factors. NO may also influence the plant's signal transduction network as indicated by the transcriptional activation of several protein kinases, including a mitogen-activated protein (MAP) kinase. We identified many genes previously not shown to be associated with NO responses in plants, and this is the first report of NO responsive genes based on a whole genome microarray.

We report on a rapid high-frequency somatic embryogenesis and plant regeneration protocol for Zea mays. Maize plants were regenerated from complete shoot meristem (3-4 mm) explants via organogenesis and somatic embryogenesis. In organogenesis, the shoot meristems were directly cultured on a high-cytokinin medium comprising 5-10 mg x L(-1) 6-benzylaminopurine (BAP). The number of multiple shoots produced per meristem varied from six to eight Plantlet regeneration through organogenesis resulted in just four weeks. Callus was induced in five days of incubation on an auxin-modified Murashige and Skoog (MS) medium. Prolific callus, with numerous somatic embryos, developed within 3-4 weeks when cultured on an auxin medium containing 5 mg 2,4-dichlorophenoxyacetic acid x L(-1). The number of multiple shoots varied from three to six per callus. Using R23 (Pioneer, Hi-Bred, Johnston, Iowa), the frequency of callus induction was consistently in excess of 80% and plant regeneration ranged between 47 and 64%. All regenerated plantlets survived in the greenhouse and produced normal plants. Each transgenic plant produced leaves, glumes, and anthers that uniformly expressed green fluorescent protein (GFP). The GFP gene segregated in the pollen. Based on this data it is concluded that the transgenics arose from single-cell somatic embryos. The rate of transfer DNA (T-DNA) transfer to complete shoot meristems of Zea mays was high on the auxin medium and was independent of using super-virulent strains of Agrobacterium.

Siberian hamsters exhibit seasonal, photoperiod influenced cycles of reproductive activity, body size, pelage characteristics, and thermoregulatory behavior. Laboratory populations generally exhibit inter-individual variability in expression of photoperiod responsiveness, with a subset of individuals that fail to show the species typical responses to short photoperiod. This variability is partly explained by a genetic component, as it has been possible to increase the number of short-day nonresponders by artificial selection. Responsiveness to short photoperiod is also substantially influenced by photoperiod history in this species; hamsters that have been raised under long (16L) or very long (18L) day lengths are less likely to exhibit winter-type responses to short days as compared to hamsters raised under an intermediate (14L) day length. In the present experiment, we examined effects of age and early photoperiod history in a strain of Siberian hamsters that had been selected for short-day nonresponsiveness. Hamsters transferred into short photoperiod on the day of birth were uniform in exhibiting winter-type responses. However, hamsters raised until 25 days of age in either continuous illumination or in 16L exhibited variation in responsiveness when subsequently moved into short photoperiod. We conclude that virtually all hamsters of the short-day nonresponsive strain are born responsive to short days. Subsequent development of resistance to potential short day effects is dependent on age and/or photoperiod history., (Copyright 2003 Wiley-Liss, Inc.)

A relationship has been established between the expression of apomixis in natural polyploids of Tripsacum dactyloides and fertility as measured by percent seed set. Thus, fertility may be reliably used as a defining phenotype for apomixis when scoring the progeny from diploid (2n = 2x = 36) x tetraploid (2n = 4x = 72) crosses in Tripsacum. By exploiting the relationship between apomixis and fertility, as defined by seed set, analyses were performed on a set of related second-generation triploid populations segregating for apomixis. These populations were derived from sexual (diploid) x apomictic (tetraploid) crosses. Six out of 25 genome-dispersed restriction fragment length polymorphism (RFLP) markers co-segregate with fertility. Five of these markers were previously reported and include: php20855, tda48, tda53, umc62, and umc83, and are linked to Tripsacum genetic linkage groups F, I, H, L, and A, respectively. Significantly, we report here the syntenic relationships of the maize chromosome intervals to Tripsacum that segregate for numerous meiosis-specific and fertility-associated genes. Utilizing RFLP locus comparative mapping based on conservation of chromosome (genic) regions between related species, it may be concluded that the genes controlling fertility have been preserved in both Tripsacum and maize. A sixth marker, umc166, has also been shown to co-segregate with fertility and is conserved in both grass species. Specifically, umc166 is linked to Tripsacum linkage group D and, by syntenic comparison, to the short arm of maize chromosome 5. Encoded within this marked interval is the gene Ameiotic1 (Am1) whose function is required for the initiation of meiosis in both micro- and megaspore mother cells and whose absence of expression in the female is, in all likelihood, a prerequisite for the expression of apomixis.

Siberian hamsters are photoperiodic rodents that typically exhibit several physiological changes when exposed to a short-day photoperiod. However, development of the winter phenotype in short days is largely conditional on prior photoperiod history: Hamsters that have been reared in an exceptionally long day length (18 L) do not usually exhibit the winter phenotype after transfer to short days, whereas animals reared under "moderately" long days (16 L) are more variable in responsiveness to subsequent short-day exposure, with 20% to 30% generally failing to exhibit winter-type responses. Hamsters reared exclusively in an "intermediate" day length (14 L) are almost uniformly responsive to short photoperiod. In the present study, the authors examine the influence of photoperiod history on short-day responsiveness in a breeding line of hamsters that has been subjected to artificial selection for resistance to the effects of short days. The results demonstrate that photoperiod history is an important determinant of short-day responsiveness in both random-bred (UNS) hamsters and animals artificially selected and bred for nonresponsiveness to short photoperiod (PNR). The PNR hamsters have a reduced requirement for long-day exposure to evoke a state of unresponsiveness to short days. The results are discussed in relation to possible significance for the origin of population and species differences in photoperiod responsiveness.

Naked mole-rats (Heterocephalus glaber) are fossorial, eusocial mammals that live in colonies averaging about 70 individuals. Metabolic regulation is of particular interest in this species because it is one of only two naturally occurring small mammals that are hairless. Further, relative to other small mammals, naked mole-rats exhibit low body temperature (Tb) and weak capacity to maintain Tb above the ambient temperature (Ta). The present study examined effects of Ta, norepinephrine (NE), and chronic food restriction on O2 consumption (as a measure of metabolism) in naked mole-rats. Studies were performed in both awake and anesthetized animals. Metabolic rate decreased with increasing T. over the range of 23-34 degrees C in awake mole-rats, whereas in anesthetized animals rates of O2 consumption were very low over this entire range of Ta and tended to increase with increasing Ta. Injections of NE led to rapid increases in metabolic rate at all Tas in anesthetized subjects and also at Ta = 34 degrees C in awake mole-rats. However, at Tas of 29 and 23 degrees C, awake subjects given NE showed little stimulation of O2 consumption beyond the already elevated baseline rates observed at these Tas. During chronic restriction of food to 60-70% of their normal daily consumption mole-rats exhibited decreased rates of metabolism; metabolic rate was not altered following several hours of acute food deprivation. Food consumption remained somewhat decreased after a period of chronic food restriction, even when animals were returned to ad lib conditions. However, body weights returned to prerestriction values, despite the continued reduction in ad lib food intake. These observations suggest that mole-rats may be capable of long-lasting metabolic adaptations as a means to cope with restricted food supply. These findings are discussed in relation to adaptation of this fossorial species to a habitat where food has a patchy distribution. Naked mole-rats, with their several unusual thermoregulatory and behavioral features, provide an intriguing model for studies of mammalian metabolic regulation.

We compared the change in passive respiratory system compliance (Crs) and resistance (Rrs) after albuterol aerosol treatment administered by either low-flow nebulizer (NEB) or a metered dose inhaler (MDI) and spacer into a ventilator circuit. We hypothesized that albuterol delivered to ventilated infants older than 7 days of life by an MDI and a spacer would improve Crs more than albuterol delivered by a low-flow nebulizer. The treatments were administered 6 hr apart to premature infants with Crs < or = 0.8 mL/cm H2O per kg, requiring ventilation after 7 days of age. Patients served as their own controls and treatment order was randomized. Eighteen studies were performed in eight infants before and 1 and 3 hr after treatment. Differences between methods were compared by analyses of variance. Mean (range) birth weight and study age were 888 (619-1,283) g and 12 (7-29) days, respectively. Mean respiratory system compliance increased by 34% with MDI and by 11% with NEB at 1 hr after treatment (P < 0.02). By 3 hr after treatment, Crs returned to baseline with both methods of aerosol delivery. There was no significant difference in Rrs between the two methods at 1 and 3 hr after treatment. We conclude that albuterol delivered by MDI improves Crs more than low-flow NEB in ventilated premature infants.

A wide variety of organisms exhibit circadian rhythms, regulated by internal clocks that are entrained primarily by the alternating cycle of light and darkness. There have been few studies of circadian rhythms in fossorial species that inhabit a microenvironment where day-night variations in most environmental parameters are minimized and where exposure to light occurs only infrequently. In this study, daily patterns of locomotor activity and body temperature (Tb) were examined in adult blind mole-rats (Spalax ehrenbergi). These fossorial rodents lack external eyes but possess rudimentary ocular structures that are embedded in the Harderian glands and covered by skin and fur. Most individual mole-rats exhibited circadian rhythms of locomotor activity, but some animals were arrhythmic. Individuals that did exhibit robust rhythms of locomotor activity also showed rhythms of Tb. In most cases, Tb was highest during the phase of intense locomotor activity. Locomotor activity rhythms could be entrained to light:dark cycles, and several mole-rats exhibited entrainment to non-24-h light cycles (T-cycles) with period lengths ranging from T = 23 h to T = 25 h. Some individuals also showed entrainment to daily cycles of ambient temperature. There was considerable interindividual variation in the daily patterns of locomotor activity among mole-rats in virtually all the conditions of environmental lighting and temperature employed in this study. Thus, whereas it appears likely that photic cues have a significant role in the entrainment of circadian rhythms in mole-rats, the amount of variability in rhythm patterns among individuals appears to be much greater than for most species that have been studied.

The current prospective study examined how characteristic beliefs about mood affect illness and symptom reporting. Using the Trait Meta-Mood Scale, 134 undergraduate (76 females and 58 males) reported their beliefs about attention to, clarity, and reparability of mood. Self-reported stress, illness, and symptoms were collected at three times following assessment of trait meta-mood, during times of general stress, and immediately prior to a class examination. Results indicate that, at increasing levels of distress, those who believe in greater attention to mood were more likely to report physical symptoms. In addition, those individuals who said that they generally make efforts to maintain positive mood were less likely to report illness than those less likely to engage in mood repair. The findings suggest that a person's general manner of evaluating or appraising mood is an important moderator of the relation between distress and symptom and illness reporting.

This study examines measures of the glottal airflow waveform, the electroglottographic signal (EGG), amplitude differences between peaks in the acoustic spectrum, and observations of the spectral energy content of the third formant (F3), in terms of how they relate to one another. Twenty females with normal voices served as subjects. Both group and individual data were studied. Measurements were made for the vowel in two speech tasks: strings of the syllable /pae/and sustained phonation of /ae/, which were produced at two levels of vocal effort: comfortable and loud voice. The main results were: 1. Significant differences in parameter values between /pae/and/ae/were related to significant differences in the sound pressure level (SPL). 2. An "adduction quotient," measured from the glottal waveform at a 30% criterion, was sensitive enough to differentiate between waveforms reflecting abrupt versus gradual vocal fold closing movements. 3. DC flow showed weak or nonsignificant relationships with acoustic measures. 4. The spectral content in the third formant (F3) in comfortable loudness typically consisted of a mix of noise and harmonic energy. In loud voice, the F3 spectral content typically consisted of harmonic energy. 5. Significant differences were found in all measures between tokens with F3 harmonic energy and tokens with F3 noise, independent of loudness condition. 6. Strong relationships between flow- and EGG-adduction quotients suggested that these signals can be used to complement each other. 7. The amplitude difference between spectral peaks of the first and third formant (F1-F3) was found to add information about abruptness of airflow decrease (flow declination) that may be lost in the glottal waveform signal due to low-pass filtering. The results are discussed in terms of how an integrated use of these measures can contribute to a better understanding of the normal vocal mechanism and help to improve methods for evaluating vocal function.

Used a prospective approach to examine the relation of prenatal parental anxiety to pediatric utilization in the first year. 31 firstborn children and their parents participated in the study. These families were primarily Caucasian, college-educated, middle-class couples who had been married an average of 4.3 years at the prenatal time period. They were first seen in their home during the second trimester of pregnancy. At that time, each parent independently completed the Life Events Survey and the Speilberger Trait Anxiety Inventory. At 12 months, each parent completed the Marital Relationship Inventory. Data on pediatric services utilization were derived from complete medical records when the child reached 12 months of age. Frequency counts for unscheduled acute care and well baby care visits were used as the primary dependent variables. As expected, prenatal reports of high maternal anxiety predicted an increased incidence of unscheduled acute care visits in the infancy period. The findings implicate physiological mechanisms and extend earlier work on psychosocial influences of pediatric services utilization to the infancy period, a time when children experience their greatest incidence of illness and patterns of medical care use become established.

For years, affect researchers have debated about the true dimensionality of mood. Some have argued that positive and negative moods are largely independent and can be experienced simultaneously. Others claim that mood is bipolar, that joy and sorrow represent opposite ends of a single dimension. The 3 studies presented in this article suggest that the evidence that purportedly shows the independence of seemingly opposite mood states, that is, low correlations between positive and negative moods, may be the result of failures to consider biases due to random and nonrandom response error. When these sources of error are taken into account using multiple methods of mood assessment, a largely bipolar structure for affect emerges. The data herein speak to the importance of a multi-method approach to the measurement of mood.

During the double-blind, multicenter trials of the synthetic surfactant Exosurf Neonatal, we measured pulmonary mechanics at 28 days of age in 30 surfactant- or placebo-treated infants. In the 20 surfactant-treated and 10 air-treated infants studied, there were no differences in lung compliance or resistance at 28 days of age. These observations suggest that improvements in pulmonary function reported early in the neonatal course after the administration of exogenous surfactant are not detectable at 28 days of age.

Moving beyond a focus on children's conceptions of causation, the study sought to (a) identify and evaluate additional dimensions along which young children's conceptions of illness might be organized and (b) to discover how young children also understand health concepts related to nutrition and routine preventive medical examination. 27 healthy preschool children, ages 4-6 were interviewed about their conceptions of common illness, knowledge of basic nutrition, and understanding of medical procedures and instruments associated with a standard pediatric examination. The findings demonstrated that children understand five characteristics of illness representations, which have also been identified in adults. They include causation, identity, consequence, time line, and cure. Associations among illness dimensions, concepts of nutrition, and knowledge about routine medical examinations were also found and are discussed in terms of their implications for future research.

To learn if increasing inspiratory time would improve pulmonary function in mechanically ventilated babies with chronic lung disease, we measured lung mechanics and alveolar ventilation at three inspiratory times: 0.4, 0.6, and 0.8 s. Nine babies were studied. Their mean birth weight was 875 g (range, 570-1,100 g), gestational age 27 (24-34) weeks, and age 7 (4-12) weeks. Their mean oxygen requirement was 40% (29-53), ventilator rate 33/min (20-40), and mean airway pressure 8 (5-10) cmH2O. Ventilator rate was kept constant; therefore expiratory time decreased and mean airway pressure and I:E ratio increased at longer inspiratory times. At 0.6 s and 0.8 s, when compared to 0.4 s, significant increases occurred in tidal volume (10.4, 10.1, and 8.4 mL/kg, respectively), dynamic lung compliance (0.68, 0.68, and 0.53 mL/cmH2O/kg, respectively), and alveolar ventilation (6.0, 6.3, and 4.7 mL/kg/breath, respectively). Airway resistance, anatomical dead space to tidal volume ratio, and functional residual capacity were similar at the three inspiratory times. Our findings suggest that an inspiratory time greater than or equal to 0.6 s (compared to 0.4 s) increases the effectiveness of mechanical ventilation for babies with chronic lung disease.

Virulent strains of the soil bacterium Agrobacterium tumefaciens infect dicotyledonous plants and elicit a profound neoplastic response which results in crown gall formation (18). The inciting agent has been shown to be a high molecular weight plasmid (Ti) a section of which, the T-DNA, integrates into the host plant's genome (4, 28, 30). Although transformation of this kind was presumed to be limited to dicots, the detection of enzyme activities linked to the expression of T-DNA has been demonstrated in monocots from the families Liliaceae and Amaryllidaceae (10, 11).In this communication, we present evidence that a member of the commercially important Gramineae also is subject to A. tumefaciens directed transformation. This conclusion is based on two observations. First, seedlings of Zea mays that have had the bacteria introduced into wound sites defined by a region which includes the scutellar node and mesocotyl express the activity of enzymes whose synthesis is associated with the translation of T-DNA transcripts. Specifically, strain specific lysopine dehydrogenase activity has been detected in B6 infected material, whereas nopaline dehydrogenase activity is reported only in those plants inoculated with C58N. Second, the detection of either of these activities in extracts made from infected maize plants requires that the assaulting bacterial strain be competent with respect to the transfer of T-DNA. The vir (-) strains, JK195 and 238MX, are not, and transformation does not seem to occur. In this connection, the corresponding opine synthase activities are not observed.

Protein-calorie malnutrition, as determined by anthropometric measures and laboratory tests, was assessed in 17 preoperative patients with colorectal cancer and 47 control patients. The cancer patients had significant deficits in visceral protein and skeletal muscle and no deficit in fat stores. Greater attention should be given to preoperative nutritional assessment and to the correction of protein deficits.

Scanning electron microscope studies demonstrated that cells of Agrobacterium tumefaciens strains attach to cells on the cut surfaces of corn and wheat seedlings and to gladiolus disks. Bacterial cells attached to these monocots in the same manner as they attached to the dicots tested. Of the strains tested, A66 and T37 covered more of the cut surfaces of these monocots in a nonrandom fashion than did cells of other isolates. These bacteria attached to cells of intact monocotyledonous plants and had the greatest affinity for tissues located within the vascular bundles. They attached in large numbers to cells in these areas in all three monocots tested.

To see if continuous distending pressure (CPD) given by nasal prongs increases work of breathing, we measured the mechanics of breathing, minute ventilation, and blood gases in nine infants with both nasal prong and face mask CDP. Minute ventilation was 16% larger (P less than .02), work of breathing was 94% higher (P less than .01), and the mean PaO2 was 8 mm Hg lower (P less than .03) with the nasal prongs. There was no difference in pH or PaCO2. We speculate that CDP given by nasal prongs may increase the risk of respiratory failure in the premature infant already compromised with hyaline membrane disease.

Evaluation of advanced cardiac life support performance requires a consistent assessment process. This study compares a new objective method of evaluation to the currently used method to determine if this objective method improves evaluator concordance on critical errors and whether or not this method is reasonable when compared to the current evaluation method. The design compared two experienced evaluator groups consisting of two evaluators in each group, with one group utilizing written guidelines and the other without these guidelines. Each evaluator independently reviewed student performances on 36 videotaped simulations. Results indicate that evaluators with the written guidelines identified critical errors more often than evaluators without these guidelines (30 versus 20 of 36 cases). When the critical errors observed by the no guideline evaluators were compared to the written guidelines, the critical errors were consistent with the written guidelines in 32 of 36 cases. These results suggest that written guidelines improve evaluator identification of critical errors observed and are reasonable when compared to two experienced evaluators without these guidelines.

The diagnosis of asbestos-associated pulmonary fibrosis was established in 3 patients by finding ferruginous bodies in transbronchial lung biopsies. Ferruginous bodies may be difficult to identify in histologic preparations when they are not oriented parallel to the plane of tissue section or when camouflaged by anthracotic pigment. We describe a simple method to enhance diagnostic sensitivity by digesting biopsy tissue and examining the filtered residue for ferruginous bodies.

Physician performance was assessed in cardiopulmonary resuscitation (CPR) by the number and type of errors committed. In simulated arrests, physicians previously certified in advanced life support made fewer errors (5.6 vs 14.3, P = .007) than those not certified. Senior house staff made fewer errors than junior house staff (5.8 vs 10.9, P = .05). Guidelines for successful completion of these simulations were developed. This study indicates the need for continued physician education in CPR.

Hyperglycemic hyperosmolar coma is a life-threatening emergency with a mortality much higher than that of other forms of hyperosmolarity such as hypernatremia or diabetic ketoacidosis. Despite the differences in the three conditions, present evidence suggests that correction of hyperosmolarity should proceed slowly to avoid the seizures that may occur in all three conditions. This report describes a 9-month-old diabetic child who initially had hyperglycemic hyperosmolar coma and who is one of the youngest survivors of this syndrome in the American literature. This case report points out the limited understanding of the pathophysiology of this syndrome and the consequent problems of therapy.

We studied erythropoiesis in infants with the anemia of prematurity by counting the number of colonies derived from erythroid burst-forming units (BFU-E) in the blood of 11 premature infants before they received transfusions. Colony growth in blood from the infants was compared with growth in blood from adults and umbilical-cord blood from term infants, in the presence of erythropoietin, 0 to 2000 mU per milliliter. Addition of increasing concentrations of erythropoietin resulted in a stepwise increase in the number of colonies derived from BFU-E (P less than 0.0005) of all three groups of subjects. Cultures stimulated with 2000 mU of erythropoietin yielded 28.1 +/- 7.6, 88.0 +/- 19.4, and 121.0 +/- 22.5 bursts (mean +/- SE) per 10(5) cells plated in blood from adults, blood from premature infants, and cord blood, respectively. Although more BFU-E-derived colonies appeared when 200 or 2000 mU were present per milliliter in cultures of the infants' blood and cord blood, the intrinsic responsiveness of BFU-E to erythropoietin was similar in all groups. Although the mean hematocrit was 26 percent, mean serum erythropoietin concentrations (+/- SD) in the infants (20.7 +/- 10.0 mU per milliliter) were not significantly different from those in the adult controls (24.0 +/- 6.5). We conclude that progenitor cells committed to erythroid differentiation are present during the anemia of prematurity, and that the intrinsic responsiveness of the circulating BFU-E pool to erythropoietin is normal. These results implicate inadequate production of erythropoietin as the cause of the anemia of prematurity and suggest that recombinant erythropoietin might provide a therapeutic alternative to transfusion for symptomatic babies with this condition.

In experimental animals neurologic damage may occur during seizure activity whether the seizure is accompanied by motor activity and hypoxemia or whether the animal is paralyzed and normoxemic. These findings suggest that it may be important to detect seizure activity in the paralyzed neonate. Nine infants who were mechanically ventilated and paralyzed with pancuronium had their condition diagnosed as seizure activity. Vital signs were continuously monitored and six infants had either oxygen saturation or transcutaneous oxygen measured during seizure activity. For the group as a whole, rhythmic fluctuations in vital signs, cardiac rhythm, and oxygenation occurred every four minutes (range one to seven minutes) and lasted two minutes (range one to four minutes). In seven patients whose seizures were not accompanied by cardiac arrhythmias the following mean increases were noted: systolic arterial blood pressure, 15 mm Hg (range 7 to 36 mm Hg); heart rate, ten beats per minute (-11 to 30/min); oxygen saturation, 12% (range 4% to 20%); and transcutaneous oxygen, 31 mm Hg (range 14 to 45 mm Hg). Seizures in the two patients with cardiac arrhythmias were accompanied by a decrease in systolic arterial blood pressure of 27 mm Hg (range 15 to 40 mm Hg) and in oxygen saturation of 24% (range 20% to 28%). The presence of rhythmic fluctuation in vital signs and oxygenation should alert the physician to the possibility of seizure activity in the paralyzed neonate.

Agrobacterium tumefaciens was capable of directing the transformation of Gladiolus sp., a monocot genus belonging to the family Iridaceae. Only strains capable of transferring T-DNA formed tumors, sections of which could be cultured in phytohormone-free media. Opine synthase activities were also observed in homogenates made from these tumors.

The correlation of transcutaneous bilirubin measurements with serum bilirubin concentrations is not good enough to allow for accurate prediction of the serum values. To impose the jaundice meter's potential clinical usefulness, we evaluated 344 paired jaundice meter-serum bilirubin measurements in 125 infants, using new guidelines from the marketing company which were designed to identify which infants require serum bilirubin determinations rather than to predict the actual bilirubin values. Use of the new guidelines correctly assessed the need for serum determinations in most infants, but false positives and, more importantly, false negatives (missed high serum values) did occur.