The RNA-dependent DNA methylation pathway is required to restrict SPOROCYTELESS/NOZZLE expression to specify a single female germ cell precursor in Arabidopsis.

In higher plants, the female germline is formed from the megaspore mother cell (MMC), a single cell in the premeiotic ovule. Previously, it was reported that mutants in the RNA-dependent DNA methylation (RdDM) pathway might be involved in restricting the female germline to a single nucellus cell. We show that the DRM methyltransferase double mutant drm1drm2 also presents ectopic enlarged cells, consistent with supernumerary MMC-like cells. In wild-type ovules, MMC differentiation requires SPOROCYTELESS/NOZZLE (SPL/NZZ), as demonstrated by the spl/nzz mutant failing to develop an MMC. We address the poorly understood upstream regulation of SPL/NZZ in ovules, showing that the RdDM pathway is important to restrict SPL/NZZ expression. In ago9, rdr6 and drm1drm2 mutants, SPL/NZZ is expressed ectopically, suggesting that the multiple MMC-like cells observed might be attributable to the ectopic expression of SPL/NZZ. We show that the ovule identity gene, SEEDSTICK, directly regulates AGO9 and RDR6 expression in the ovule and therefore indirectly regulates SPL/NZZ expression. A model is presented describing the network required to restrict SPL/NZZ expression to specify a single MMC.

Translating auxin responses into ovules, seeds and yield: Insight from Arabidopsis and the cereals.

Grain production in cereal crops depends on the stable formation of male and female gametes in the flower. In most angiosperms, the female gamete is produced from a germline located deep within the ovary, protected by several layers of maternal tissue, including the ovary wall, ovule integuments and nucellus. In the field, germline formation and floret fertility are major determinants of yield potential, contributing to traits such as seed number, weight and size. As such, stimuli affecting the timing and duration of reproductive phases, as well as the viability, size and number of cells within reproductive organs can significantly impact yield. One key stimulant is the phytohormone auxin, which influences growth and morphogenesis of female tissues during gynoecium development, gametophyte formation, and endosperm cellularization. In this review we consider the role of the auxin signaling pathway during ovule and seed development, first in the context of Arabidopsis and then in the cereals. We summarize the gene families involved and highlight distinct expression patterns that suggest a range of roles in reproductive cell specification and fate. This is discussed in terms of seed production and how targeted modification of different tissues might facilitate improvements.

Progress on the paternal brain: theory, animal models, human brain research, and mental health implications.

With a secure foundation in basic research across mammalian species in which fathers participate in the raising of young, novel brain-imaging approaches are outlining a set of consistent brain circuits that regulate paternal thoughts and behaviors in humans. The newest experimental paradigms include increasingly realistic baby-stimuli to provoke paternal cognitions and behaviors with coordinated hormone measures to outline brain networks that regulate motivation, reflexive caring, emotion regulation, and social brain networks with differences and similarities to those found in mothers. In this article, on the father brain, we review all brain-imaging studies on PubMed to date on the human father brain and introduce the topic with a selection of theoretical models and foundational neurohormonal research on animal models in support of the human work. We discuss potentially translatable models for the identification and treatment of paternal mood and father-child relational problems, which could improve infant mental health and developmental trajectories with potentially broad public health importance.

Genetic and Phenotypic Analysis of Ovule Development in Arabidopsis.

The plant seed is a remarkable structure that represents the single most important energy source in global diets. The stages of reproductive growth preceding seed formation are particularly important since they influence the number, size, and quality of seed produced. The progenitor of the seed is the ovule, a multicellular organ that produces a female gametophyte while maintaining a range of somatic ovule cells to protect the seed and ensure it receives maternal nourishment. Ovule development has been well characterized in Arabidopsis using a range of molecular, genetic, and cytological assays. These can provide insight into the mechanistic basis for ovule development, and opportunities to explore its evolutionary conservation. In this chapter, we describe some of these methods and tools that can be used to investigate early ovule development and cell differentiation.

Exploring heterogeneity in clinical trials with latent class analysis.

Case-mix is common in clinical trials and treatment effect can vary across different subgroups. Conventionally, a subgroup analysis is performed by dividing the overall study population by one or two grouping variables. It is usually impossible to explore complex high-order intersections among confounding variables. Latent class analysis (LCA) provides a framework to identify latent classes by observed manifest variables. Distal clinical outcomes and treatment effect can be different across these classes. This paper provides a step-by-step tutorial on how to perform LCA with R. A simulated dataset is generated to illustrate the process. In the example, the classify-analyze approach is employed to explore the differential treatment effects on distal outcomes across latent classes.

Reversal of opsonic deficiency in surgical, trauma, and burn patients by infusion of purified human plasma fibronectin. Correlation with experimental observations.

Plasma fibronectin deficiency has been documented in critically ill surgical, trauma, and burn patients. Human plasma fibronectin was isolated by gelatin-Sepharose affinity chromatography and evaluated with respect to its opsonic activity following pasteurization, its in vivo clearance kinetics, and its short-term influence on cardiovascular hemodynamics in postoperative septic sheep. Six patients with low plasma fibronectin levels were also evaluated with respect to temporal changes of immunoreactive fibronectin and opsonic activity following infusion of fibronectin at a dose calculated to elevate the plasma fibronectin level to 400 micrograms/ml. With utilization of three different in vitro radioisotopic phagocytic assays, i.e., liver slice assay, peritoneal macrophage monolayer assay, and Kupffer cell monolayer assay, retention of opsonic activity by fibronectin following pasteurization was documented. The normal biphasic kinetics associated with plasma clearance of fibronectin were also not altered by pasteurization. In postoperative septic sheep with hemodynamic instability, intravenous infusion of 500 mg of purified human fibronectin initiated no abnormal hemodynamic response. Indeed, as compared with placebo, the infusion of fibronectin into the postoperative septic sheep resulted in a more stable systemic vascular resistance and pulmonary vascular resistance with a higher arterial pressure. It also elevated immunoreactive fibronectin levels (p less than 0.05) and increased opsonic activity (p less than 0.05). Surgical, trauma, and burn patients (ages 18 to 80 years) with low plasma fibronectin levels (160 to 236 micrograms/ml) manifested no disturbance in cardiovascular, respiratory, or hematologic parameters following fibronectin infusion (590 to 988 mg per patient), but did display an early increase of opsonic activity. This standardized, pasteurized, and opsonically active preparation of purified human plasma fibronectin (5.0 mg/ml after reconstitution) has utility for future randomized clinical trials in injured patients with sepsis.

Nontuberculous mycobacterial lung disease. Substantiation of a less aggressive approach.

A nonsurgical, less aggressive, less toxic chemotherapeutic protocol for the management of nontuberculous mycobacterial (NTB) pulmonary infections has been uniformly applied to patients in our institution between 1972 and 1985. Forty-three nonimmunocompromised patients with active lung disease caused by Mycobacterium avium-intracellulare (MAI) (n = 26), M kansasii (n = 16), and M xenopi (n = 1) were identified retrospectively. Eighteen MAI patients were treated with three or four antituberculosis agents resulting in sputum conversion and clinical improvement in 12 (67 percent). Additionally, 11 out of 16 (69 percent) patients completing therapy or still undergoing therapy for persistent MAI disease, achieved sputum conversion and clinical improvement after prolonged therapy (3.6 +/- 0.5 years [SEM]). When M kansasii was identified as the etiologic agent, all patients were treated with four or fewer antituberculosis agents and 14 out of 16 patients (88 percent) achieved sputum conversion and clinical improvement throughout the follow-up period. We conclude that the use of three or four chemotherapeutic agents in the treatment of NTM lung disease provides an excellent probability of successful outcome even in MAI infections.

Realizing the promise: delivering pulmonary continuing medical education over the Internet.

STUDY OBJECTIVES: Continuing medical education (CME) is meant to bridge the gap between new scientific observations and clinical practice. However, traditional CME has not been effective at altering the behaviors of physicians. One reason for this failure of traditional CME programs may be their inflexibility. In traditional CME, the clinician does not choose the topic, the pace of the program, or the place of learning, and the CME material cannot be easily delivered to the point of care where the clinician needs the information. Computers and computer networks have the potential to accomplish these goals. CME has begun to appear on the Internet; however, there have been few evaluations of its usefulness, acceptance, and effectiveness. Over the last 18 months, we have developed three on-line pulmonary CME programs, and we have delivered them on the Virtual Hospital, the University of Iowa's digital health sciences library on the Internet. We report our initial experience with this CME material. DESIGN: We measured the frequency with which the Internet-delivered CME is accessed by monitoring page accessions and by using a log file analysis program (Analog 1.2.3; University of Cambridge Statistical Laboratory; Cambridge, UK). In addition, we collected all completed CME examinations and evaluation forms submitted by registered users. MEASUREMENTS AND RESULTS: We have found that the frequency with which the Internet-delivered CME is accessed has continued to increase with time (2.3-fold increase over 18 months), that evaluations of technical and content issues are strongly favorable, and that some clinicians have been willing to pay to receive CME through the medium of the Internet. CONCLUSIONS: We feel that with adequate peer review and quality control, physicians will use the Internet-delivered CME. However, several obstacles to wide use remain. These obstacles include issues regarding training in using the Internet for physicians, reluctance of physicians to participate in on-line commerce, and the current unavailability of CME to be delivered in small-grained quantities to the point of care. As these issues are addressed, we feel that on-line CME will represent an increasingly important CME medium for clinicians.

The relationship between alveolar macrophage TNF, IL-1, and PGE2 release, alveolitis, and disease severity in sarcoidosis.

A mononuclear cell alveolitis, comprised in part of activated macrophages, is thought to precede granuloma formation and fibrosis in pulmonary sarcoidosis. Tumor necrosis factor-alpha (TNF), interleukin 1-beta (IL-1), and prostaglandin E2 (PGE2) are potent mediators released by activated alveolar macrophages. To determine if alveolar macrophage TNF, IL-1, and PGE2 release was associated with clinically progressive pulmonary sarcoidosis, we obtained alveolar macrophages from bronchoalveolar lavage of 68 patients with biopsy specimen-confirmed sarcoidosis, cultured the macrophages in the presence and absence of lipopolysaccharide (10 mg/L) for 24 h, and measured TNF (enzyme-linked immunosorbent assay), IL-1 (enzyme-linked immunosorbent assay), and PGE2 (radioimmunoassay) release. Alveolar macrophages from most patients with sarcoidosis spontaneously released TNF, IL-1, and PGE2. The amounts of these mediators released (either spontaneously or following lipopolysaccharide stimulation) did not positively correlate with the numbers of any of the cells in bronchoalveolar lavage fluid, the clinical status of disease (stable vs deterioration), steroid usage, or cigarette smoking. The relative release of each of the individual mediators, however, was highly correlated with the release of the other mediators. The studies suggest that these markers of alveolar macrophage activation from a single bronchoalveolar lavage are poor indicators of clinically progressive disease.

Outcome of subjects with idiopathic pulmonary fibrosis who fail corticosteroid therapy. Implications for further studies.

To evaluate the outcome of subjects with idiopathic pulmonary fibrosis (IPF) whose conditions clinically deteriorate while receiving corticosteroid therapy, we studied 12 of these subjects (7 male, 5 female) who received subsequent therapy with intravenous (IV) pulse cyclophosphamide (CPX). Seven of the 12 study subjects died during the course of therapy. Six of these subjects died of respiratory failure, and one died of cholecystitis. Among those who died, the mean age at diagnosis was 63 years compared with 57 years in those who have continued to survive (p = 0.29). Smoking status and pack-years of cigarette smoking were similar between those subjects who died and those who continue to survive. However, subjects who died received CPX for a mean of 6 months, while subjects still living have received CPX for a mean of 16 months (p = 0.01). Subjects who died were given a CPX a mean of 64 months after the onset of symptoms, compared with a mean of 50 months for subjects who are still alive (p = 0.57). Interestingly, there were no significant differences in measures of pulmonary function between living and dead subjects. In fact, measures of lung function and gas exchange remained stable in both groups throughout the period of observation. These data suggest that (1) measures of lung function may not be a reliable indicator of patient mortality in end-stage IPF, and (2) while not statistically significant, these data raise the possibility that duration of symptomatic disease may play a role in the outcome of IPF patients receiving alternative therapeutic agents after failure of corticosteroid therapy. In future intervention trails, controlling entry criteria for duration of disease may prove helpful in determining the effects of these agents on the disease process. These data do not permit a determination of the effect of CPX in patients with IPF.

Sudden infant death with external airways covered: case-comparison study of 206 deaths in the United States.

OBJECTIVE: To study factors associated with sudden infant deaths occurring with the external airways (ie, nose and mouth) covered by bedding. DESIGN: Case-comparison study of infants dying with vs those dying without the external airways covered. SETTING: Death-scene investigation and reconstruction at the site of death using an infant mannequin; 18 metropolitan areas. PARTICIPANTS: Caregivers for a consecutive sample of infants who died of sudden infant death syndrome (SIDS). Complete data from 206 of 382 eligible cases. MAIN OUTCOME MEASURES: Among infants dying suddenly and unexpectedly, an analysis of whether sociodemographic risk factors for SIDS, sleep practices, or bedding increased the risk of dying with the external airways covered. RESULTS: Data were analyzed by using univariate and 2 types of multivariate risk analysis, logistic regression and latent class. Of the victims, 59 (29%) were found with the external airways covered. Conventional risk factors for SIDS did not affect the risk of death with the external airways covered. Factors increasing the risk of death with the external airways covered included prone sleep position (odds ratio [OR], 2.86) and using soft bedding (OR, 5.28), such as comforters (OR, 2.46) and pillows (OR, 3.31). Infants at low risk for death with the external airways covered slept in the prone position, but rarely on a pillow, comforter, or other bedding that allowed a pocket to form beneath the face. All 9 infants who were positioned supine or on one side for sleep and found with the external airways covered had turned and were found dead in the prone position. CONCLUSIONS: Sudden infant deaths with the external airways covered were common in the United States when most infants slept prone. Soft bedding, including pillows and comforters, increased the risk that an infant who died would be found with the external airways covered. Therefore, these items should not be placed near infants, regardless of the sleep position.

Bronchoalveolar lavage in interstitial lung disease: effect of volume of fluid infused.

To evaluate the effect of varying infusate volume on the results of bronchoalveolar lavage (BAL) in patients with interstitial lung disease, 55 patients underwent 58 BAL during which both a 100- and 250-ml lavage was performed in the same lobe of the lung. Although the percent of the fluid that was returned and the total numbers of cells were greater in the 250- vs. the 100-ml lavage, there were no significant differences in cell differentials or numbers of cells per milliliter between the 100- and 250-ml BAL. We conclude that infusate volume does not affect cell differentials or numbers of cells per milliliter of bronchoalveolar lavage fluid in patients with interstitial lung disease.

Plasma fibronectin levels during cardiopulmonary bypass.

Plasma fibronectin, also called cold-insoluble globulin, is a cryoprecipitable glycoprotein with both opsonic and adhesive activities. It binds to collagen, actin, and heparin and can form soluble as well as cryoprecipitable complexes in the cold. Fibronectin augments particulate phagocytosis by the reticuloendothelial system and can influence lung vascular permeability. Plasma fibronectin deficiency is temporally associated with respiratory failure in septic surgical, trauma, and burn patients. We measured plasma fibronectin and albumin levels in nine adults undergoing elective cardiopulmonary bypass to determine whether dilution alone could account for the changes in plasma fibronectin. Plasma fibronectin concentration decreased 17% with the surgical trauma of opening of the chest and placement of the vascular cannulas. On heparinization and initiation of cardiopulmonary bypass, plasma fibronectin fell an additional 48% (P less than 0.001), whereas albumin concentration (corrected for albumin in the pump prime) fell only 25% (P less than 0.001), emphasizing that dilution was not the only mechanism contributing to the decline in plasma fibronectin. Fibronectin levels began to increase after discontinuation of cardiopulmonary bypass and in association with diuresis, but unexpectedly they remained subnormal until 4 days postoperation. Thus the decline in fibronectin concentration with cardiopulmonary bypass may be due to dilution as well as opsonic consumption and possible complexing with heparin in the cold.

Determinants of bronchoalveolar lavage cellularity in idiopathic pulmonary fibrosis.

To investigate factors that determine bronchoalveolar lavage (BAL) cellularity in patients with idiopathic pulmonary fibrosis (IPF), we compared BAL cells in patients with IPF (n = 83) to both nonsmoking (n = 111) and smoking (n = 19) normal volunteers. Patients with IPF had higher concentrations of BAL total cells and alveolar macrophages than nonsmoking volunteers and more BAL neutrophils and eosinophils than normal volunteers regardless of smoking status. Among patients with IPF, the numbers of alveolar macrophages, neutrophils, or eosinophils were strongly associated with either smoking status or pack-years of cigarette smoking. In fact, after accounting for cigarette smoking, using multivariate analysis, the only additional factors that were found to be associated with BAL cellularity were age (macrophages and eosinophils) and the percent predicted forced expired volume in 1 s (neutrophils). Additional multivariate models failed to identify a significant relationship between BAL cellularity and either the type of immunosuppressive therapy or other physiological measures of lung function. We conclude that cigarette smoking strongly influences BAL cellularity in patients with IPF. These findings suggest that cigarette smoking may have a role in the pathogenesis of IPF or may adversely affect the prognosis in patients with IPF.

Determinants of restrictive lung function in asbestos-induced pleural fibrosis.

We evaluated whether restrictive lung function among asbestos-exposed individuals with pleural fibrosis was caused by radiographically inapparent parenchymal inflammation and/or parenchymal fibrosis. All 24 study participants were sheet metal workers who were nonsmokers with normal parenchyma on posteroanterior chest radiograph. These subjects had either normal pleura (n = 7), circumscribed plaques (n = 9), or diffuse pleural thickening (n = 8). After controlling for age, years in the trade, and pack-years of smoking, we found that sheet metal workers with diffuse pleural thickening had a lower forced vital capacity (P less than 0.001), total lung capacity (P less than 0.01), and CO-diffusing capacity of the lung (P less than 0.05) than those with normal pleura. Similarly, sheet metal workers with circumscribed plaques were found to have a reduced forced vital capacity; however, because of the small number of study subjects, this difference (regression coefficient = -11.0) was only marginally significant (P = 0.06). Although circumscribed plaque and diffuse pleural thickening were both associated with a lymphocytic alveolitis and a higher prevalence of parenchymal fibrosis on high-resolution computerized tomography (HRCT) scan, neither a lymphocytic alveolitis nor the finding of parenchymal fibrosis on HRCT scan influenced the relationship between pleural fibrosis and restrictive lung function. We conclude that pleural fibrosis is associated with restrictive lung function and abnormally low diffusion that appears to be independent of our measures of parenchymal injury (chest X-ray, bronchoalveolar lavage, and HRCT scan).(ABSTRACT TRUNCATED AT 250 WORDS)

Conceptualizing oral health and oral health-related quality of life.

This investigation considers oral health from a health-related quality of life perspective using a multidimensional concept representing a combination of impairment, function, perceptions, and/or opportunity. A subset of dentate individuals aged 18 and older from a national probability sample of the U.S. was selected for the reported analysis with data available from personal interviews, self-administered questionnaires, and oral examinations. Impairment was represented by clinically assessed active diseases and sequelae of diseases and self-reported acute symptoms. Other domains are represented by self-reported problems with function, perception of control over oral health, satisfaction with teeth, value attributed to oral health, and opportunity to obtain dental care. Principal components analysis with varimax rotation provided a structure to interpret four factors: accumulated oral neglect, self-perceived symptoms and problems, reparable oral diseases, and oral health values and priorities. Approximately 50% of the variance was explained by these four factors. Factor-based scores, envisioned as an index or summary measure representing the combination of variables identified in each factor, were used to assess potential validity. Whites had lower levels of accumulated oral neglect, fewer symptoms, and less reparable oral disease, but similar oral health values, than non-whites. Level of formal education was associated with each of the four factor-based scores. Age was directly associated with accumulated oral neglect, but the youngest age group had significantly more reparable oral diseases. Individuals with a dental visit in the past two years had considerably less accumulated oral neglect, fewer self-perceived problems, less reparable oral disease, and higher values of oral health than those without a dental visit in the past two years. Ordinary least square regressions were performed on each of the four factor-based scores using eight sociodemographic and economic variables. All four regression models were significant, with only the education variable being significant across all models. These analyses provide no evidence for one unique factor representing oral health. Rather, a conceptual framework for oral health appears to be represented by a set of reasonably independent components, including two groups of clinically assessed oral health, which together more fully represent oral health than any one single variable. Conceptualizing and measuring oral health multidimensionally leads us closer to examining it as part of general health.

Evaluation of an Internet-based decision-support system for applying the ATS/CDC guidelines for tuberculosis preventive therapy.

Preventive therapy for patients infected with tuberculosis (TB) remains an important component of TB control. To guide physicians in applying preventive therapy, the American Thoracic Society and Centers for Disease Control (ATS/CDC) developed guidelines based on PPD reactivity and on pretest probability of infection. The guidelines have become complex, and many clinicians find them challenging to apply. The authors developed a computerized decision-support system to assist clinicians in applying the ATS/CDC guidelines. This tool, published on the World Wide Web using hypertext markup language, delivers patient-specific recommendations based on physician-delivered patient-specific information. Four local TB experts derived eight TB infection scenarios and validated the web-based tool, which was tested for effectiveness using general internal medicine residents, randomly divided into two groups. Group A (n = 12) used the web-based tool and group B (n = 17) used pre-existing understanding of the guidelines and/or written resources to determine the need for preventive therapy in the case scenarios. Group A correctly used therapy in 92/96 possible cases (95.8%), group B in only 77/136 (56.6%) (p < 0.001). Group A required a mean of three mouse-clicks and 1.5 minutes per scenario to reach their choices, and they rated the web-based tool both intuitive and effective. These data demonstrate that a computer-based decision-support system for applying TB treatment guidelines can be delivered over the Internet and provide an efficient and effective resource for clinicians.

A model intervention for elder abuse and dementia.

This article describes a 2-year collaborative project in Cleveland, OH, that improved the reporting and management of potential and suspected elder abuse situations involving persons with dementia. Educational curricula for cross-training, screening tools, and referral protocols were developed and tested for staff and volunteers in adult protective services and dementia care. A handbook for caregivers of persons with dementia was produced that enables caregivers to self-identify elder abuse risk and seek appropriate interventions to prevent abuse. Project organization, implementation, and evaluation are discussed along with strategies for replication in other communities.

Information criteria for pairwise comparisons.

A new approach is presented for the interpretation of differences among means and proportions. Post hoc techniques, such as Tukey's honestly significant difference procedure, have interpretive problems related to intransitive decisions and technical issues arising from unequal sample sizes or heterogeneity of variance. These concerns can be avoided by considering ordered subsets of means and by using information criterion to select among competing models. This paired-comparisons information-criterion (PCIC) approach is wholistic in nature and does not depend on interpreting a series of statistical tests. Simulation results suggest that a protected version of the PCIC procedure is desirable to minimize failures to detect the null case. This technique is illustrated for independent means, proportions, and means from repeated measures.