Aging varies greatly within a single genus: A demographic study of Rhododendron spp. in botanic gardens.

PREMISE: There is mounting evidence that age matters in plant demography, but also indications that relationships between age and demographic rates may vary significantly among species. Age-based plant demographic data, however, are time-consuming to collect and still lacking for most species, and little is known about general patterns across species or what may drive differences. METHODS: We used individual birth and death records for 12 Rhododendron species from botanic gardens and conducted Bayesian survival trajectory analyses to assess how mortality changed with age. We calculated the demographic measures of aging rate, life-span equality, and life expectancy for each species, and assessed their relationships with the climatic conditions at species' sites of ancestral origin and with taxonomic group (subgenus). RESULTS: We found substantial among-species variation in survival trajectories, with mortality increasing, decreasing, or remaining constant with advancing age. Moreover, we found no relationships between demographic measures and ancestral climatic conditions but there were statistically significant differences among taxonomic groups in the rate of change in mortality with age (aging rate). CONCLUSIONS: We conclude that demographic consequences of aging can differ qualitatively, even among species in the same genus. In addition, taxonomic trends in aging rates indicate they may be genetically determined, though evolutionary drivers are still unclear. Furthermore, we suggest there is untapped potential in using botanic garden records in future studies on plant life history.

Data gaps and opportunities for comparative and conservation biology.

Biodiversity loss is a major challenge. Over the past century, the average rate of vertebrate extinction has been about 100-fold higher than the estimated background rate and population declines continue to increase globally. Birth and death rates determine the pace of population increase or decline, thus driving the expansion or extinction of a species. Design of species conservation policies hence depends on demographic data (e.g., for extinction risk assessments or estimation of harvesting quotas). However, an overview of the accessible data, even for better known taxa, is lacking. Here, we present the Demographic Species Knowledge Index, which classifies the available information for 32,144 (97%) of extant described mammals, birds, reptiles, and amphibians. We show that only 1.3% of the tetrapod species have comprehensive information on birth and death rates. We found no demographic measures, not even crude ones such as maximum life span or typical litter/clutch size, for 65% of threatened tetrapods. More field studies are needed; however, some progress can be made by digitalizing existing knowledge, by imputing data from related species with similar life histories, and by using information from captive populations. We show that data from zoos and aquariums in the Species360 network can significantly improve knowledge for an almost eightfold gain. Assessing the landscape of limited demographic knowledge is essential to prioritize ways to fill data gaps. Such information is urgently needed to implement management strategies to conserve at-risk taxa and to discover new unifying concepts and evolutionary relationships across thousands of tetrapod species.

Analysis of public discourse on heart transplantation in Japan using social network service data.

The clarification of public concerns regarding heart transplantation is important for improving low organ donation rates in Japan. In the present study, we used the Twitter data of 4986 tweets (between August 2015 and January 2016) and 1429 tweets (between April 2016 and May 2016) to analyze public discourse on heart transplantation in Japan and identify the reasons for low organ donation rates. We manually categorized all tweets relevant to heart transplantation into nine categories and counted the number of tweets in each category per month. During the study period, the most popular category of tweets was related to the media, followed by money (tweets questioning or even criticizing the high price of fundraising goals to go overseas for heart transplantations), while some tweets were misconceptions. We also conducted a sentiment analysis, which revealed that the most popular negative tweets were related to money, while the most positive tweets were related to reports on the favorable outcomes of recipients. Our results suggest that listening to concerns, providing correct information (particularly for some misconceptions), and emphasizing the outcomes of recipients will facilitate an increase in the number of people contemplating heart transplantation and organ donation.

Changes in localization of human discs large (hDlg) during keratinocyte differentiation are [corrected] associated with expression of alternatively spliced hDlg variants.

Alternative spliced variants of the human discs large (hDlg) tumour suppressor are characterized by combinations of insertions. Here, using insertions I2- and I3-specific antibodies, we show that I2 and I3 variants have distinct distributions in epidermal and cervical epithelia. In skin and cervix, I3 variants are found in the cytoplasm. Cytoplasmic localization of I3 variants decreases as cervical keratinocytes differentiate, concomitant with relocalization to the cell periphery. I2 variants are found at the cell periphery of differentiated epidermal and cervical keratinocytes. Nuclear localization of I2 variants was evident in both tissues, with concentration of nuclear I2 variants in basal and parabasal cervical keratinocytes. A prominent nuclear localization of hDlg in cells of hyperproliferative layers of psoriatic lesions, but not in mature differentiated keratinocytes, together with I2 redistribution in differentiating keratinocytes, suggests that nuclear hDlg functions may be pertinent to growth of undifferentiated cells. Supporting our findings in squamous tissues, a decrease of nuclear hDlg and an increase of membrane-bound and cytoplasmic hDlg upon calcium-induced keratinocyte differentiation were not concomitant processes. Furthermore, we confirm that the exit of I2 variants from the nucleus is linked to stimulation of epithelial differentiation. The dynamic redistribution of hDlg also correlated with a marked increase in the expression of I3 variants while the level of I2 variants showed only a moderate decrease. Because changes in the intracellular distribution of hDlg splice variants, and in their expression levels, correlate with changes in differentiation state we hypothesize that the different hDlg isoforms play distinct roles at various stages of epithelial differentiation.

Unraveling the molecular mechanisms of hair and nail genodermatoses.

Inherited hair and nail diseases have long been considered a group of rare and obscure disorders with a largely unknown genetic basis. In the postgenomic era, a large portion of the genes that are responsible for these genetic disorders has been identified, yielding new insights into the complex molecular pathways that regulate the development and biological function of epidermal appendages. This article reviews the recent progress accomplished in this field and discusses the novel clinical and experimental observations in several hair and nail genodermatoses.

Gene characterization of sciellin (SCEL) and protein localization in vertebrate epithelia displaying barrier properties.

Sciellin is a precursor of the cornified envelope of mammalian stratified epithelia characterized by a central core of nonidentical repeats. We characterized the genomic structure of human sciellin and showed that each homologous repeat was encoded by one exon. We also characterized mouse sciellin and showed that mouse sciellin and human sciellin (HGMW-approved symbol SCEL) share a similar gene organization and protein expression pattern. This one exon/one repeat organization is unique among other cornified envelope precursors characterized by homologous repeats. We identified an alternatively spliced isoform of human sciellin, absent in mouse, characterized by an additional repeat at the beginning of the core domain. During embryonic development, the accumulation of sciellin transcript and the accumulation of sciellin protein in the epidermis correlated with the activation of markers of terminal differentiation in epidermis. Mouse sciellin was also identified in simple epithelia with barrier properties, lending further support to its importance in epithelial function.

Dexamethasone reduces the inflammatory response to cardiopulmonary bypass in children.

BACKGROUND: A randomized, prospective, double-blind study of 29 children was performed to evaluate the hypothesis that dexamethasone administration prior to cardiopulmonary bypass would decrease the inflammatory mediator release and improve the postoperative clinical course. METHODS: Fifteen children received dexamethasone (1 mg/kg intravenously) and 14 (controls) received saline solution 1 hour prior to CPB. Serial blood analyses for interleukin-6, tumor necrosis factor-alpha, complement component C3a, and absolute neutrophil count were performed. Postoperative variables evaluated included temperature, supplemental fluids, alveolar-arterial oxygen gradient, and days of mechanical ventilation. RESULTS: Dexamethasone caused an eightfold decrease in interleukin-6 levels and a greater than threefold decrease in tumor necrosis factor-alpha levels after CPB (p < 0.05). Complement component C3a and absolute neutrophil count were not affected by dexamethasone. The mean rectal temperature for the first 24 hours postoperatively was significantly lower in the group given dexamethasone than in the controls (37.2 degrees +/- 0.4 degrees C versus 37.7 degrees +/- 4 degrees C; p = 0.007). Dexamethasone-treated patients required less supplemental fluid during the first 48 hours (22 +/- 28 mL/kg versus 47 +/- 34 mL/kg; p = 0.04). Compared with controls, dexamethasone-treated children had significantly lower alveolar-arterial oxygen gradients during the first 24 hours (144 +/- 108 mm Hg versus 214 +/- 118 mm Hg; p = 0.02) and required less mechanical ventilation (median duration, 3 days versus 5 days; p = 0.02). CONCLUSIONS: Dexamethasone administration prior to CPB in children leads to a reduction in the postbypass inflammatory response as assessed by cytokine levels and clinical course.

Hot spot mutations in keratin 2e suggest a correlation between genotype and phenotype in patients with ichthyosis bullosa of Siemens.

Ichthyosis bullosa of Siemens (IBS) is a rare disorder of cornification characterized by blister formation in the upper suprabasal layers of the epidermis. Molecular analysis of IBS has identified mutations in the keratin 2e (K2e) gene, which is located in the type II keratin gene cluster on chromosome 12q. We have studied two IBS families and have identified heterozygous point mutations in codon 493 of the K2e gene in both families. Whereas a non-conservative amino acid substitution at position 117 of the 2B region of K2e (E117K) was associated with a severe phenotype in family 1, family 2 showed mild clinical features as a result of a conservative substitution (E117D). These data suggest a phenotype-genotype correlation in these families.

Fatal hypermagnesemia in a child treated with megavitamin/megamineral therapy.

We report a case of fatal hypermagnesemia resulting from the unsupervised use of high doses of magnesium oxide administered as part of a regimen of megavitamin and megamineral therapy to a child with mental retardation, spastic quadriplegia, and seizures. The treatment regimen was given at the recommendation of a dietician working as a private nutritional consultant without the involvement or notification of the child's pediatrician. Hypermagnesemia is an uncommon but serious side effect of the use of magnesium containing compounds. These compounds are widely used as laxatives and dietary supplements, and serious side effects are uncommon when used in appropriate dosages and with adequate supervision. The use of alternative medical therapies, including megavitamin/megamineral therapy, is widespread. Many patients use alternative medicine or seek care from alternative medicine practitioners without the recommendation or knowledge of their primary physicians. Despite unproved benefit, many alternative therapies may be safe. However, unsupervised use of generally safe treatments can result in serious side effects. This case report serves to illustrate the characteristic pathophysiologic changes of severe hypermagnesemia, an entity rarely seen in pediatric practice, and more importantly, it alerts primary care and subspecialty pediatricians to be aware of and monitor the use of alternative medical therapies in their patients.

Myocardial injury in children with respiratory syncytial virus infection.

OBJECTIVE: Respiratory syncytial virus (RSV) infection is associated with a number of extrapulmonary manifestations, including a sepsis-like syndrome characterized by any combination of hypothermia, fever, apnea, hypovolemia, and myocardial dysfunction. We hypothesized that RSV can have a direct injurious effect on the myocardium of infants and children that can be detected by the presence of cardiac troponin I (cTnI), a highly sensitive and specific marker of myocardial injury, in the blood of patients infected with the virus. DESIGN: Serial cTnI measurements were obtained from patients admitted with documented RSV infection to the pediatric intensive care unit (PICU). PARTICIPANTS: Data were collected and analyzed from 22 RSV infected patients and 11 control patients. RESULTS: Elevated levels of cTnI were detected in 54.5% (12/22) of the study population during their PICU admission. The average cTnI level was significantly higher in the RSV infected group than in controls. There was a significant association between the presence of a positive troponin assay and the occurrence of a cardiovascular event, the need for inotropic support, and the requirement of mechanical ventilation. Patients who required inotropic support had a significantly higher cTnI level than the rest of the study population. CONCLUSION: A large percentage of children admitted to the PICU with RSV infection have myocardial damage as detected by the use of commercially available troponin assays. Additionally, in a portion of these patients, this damage is clinically significant, leading to cardiovascular instability and the need for inotropic support.

Immunohistochemical localization of caspase-3 correlates with clinical outcome in B-cell diffuse large-cell lymphoma.

Although B-cell diffuse large-cell lymphoma (DLCL) can respond to chemotherapy and radiotherapy, a large number of patients are still resistant to treatment. Caspase-3 is an enzyme crucial to the apoptotic process and may be important in the clinical outcome of these patients. The pattern of caspase-3 expression was studied in 54 cases of DLCL using immunohistochemistry and quantitative reverse-transcription PCR. Tumor cells displayed both a diffuse cytosolic and a punctate cytosolic staining for caspase-3. Kaplan-Meier survival curves indicated that tumor cells with a diffuse cytosolic expression of caspase-3 correlated with a poor prognosis (P > 0.0004). In addition, a punctate cellular localization was associated with complete response to treatment (P = 0.011). Cases with a small percentage of lymphoma cells expressing caspase-3 also tended to show poor survival (P > 0.09). Levels of caspase-3 mRNA were not significant (P > 0.17), although a weak trend was observed similar to the immunohistochemical analysis. The pattern of expression of caspase-3 was also assessed with respect to terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) positivity in both reactive lymph nodes and B-cell DLCL cases. Our results suggest that TUNEL-positive cells are not caspase-3-positive and that there is no correlation between DLCL cases with a high degree of DNA fragmentation and caspase-3 immunostaining. Furthermore, a survival curve indicated that a high TUNEL positivity was associated with a poor survival probability (P < 0.02) and a poor response to treatment (P = 0.04). These results confirm the dynamic nature of caspase-3 expression in DLCL and suggests that the pattern of expression of the enzyme has prognostic significance.

Ectopic expression of the nude gene induces hyperproliferation and defects in differentiation: implications for the self-renewal of cutaneous epithelia.

Nude mice are characterized by the absence of visible hair, epidermal defects, and the failure to develop a thymus. This phenotype results from loss-of-function mutations in Whn (Hfh11), a winged-helix transcription factor. In murine epidermis and hair follicles, endogenous whn expression is induced as epithelial cells initiate terminal differentiation. Using the promoter for the differentiation marker involucrin, transgenic mice that ectopically express whn in stratified squamous epithelia, hair follicles, and the transitional epithelium of the urinary tract were generated. Transgenic epidermis and hair follicles displayed impaired terminal differentiation and a subset of hair defects, such as delayed growth, a waved coat, and curly whiskers, correlated with decreased transforming growth factor (TGF)-alpha expression. The exogenous Whn protein also stimulated epithelial cell multiplication. In the epidermis, basal keratinocytes exhibited hyperproliferation, though transgene expression was restricted to suprabasal, postmitotic cells. Hair follicles failed to enter telogen (a resting period) and remained continuously in an abnormal anagen (the growth phase of the hair cycle). Ureter epithelium developed severe hyperplasia, leading to the obstruction of urine outflow and death from hydronephrosis. Though an immune infiltrate was present occasionally in transgenic skin, the infiltrate was not the primary cause of the epithelial hyperproliferation, as the immune reaction was not observed in all affected transgenics, and the transgene induced identical skin and urinary tract abnormalities in immunodeficient Rag1-null mice. Given the effects of the transgene on cell proliferation and TGFalpha expression, the results suggest that Whn modulates growth factor production by differentiating epithelial cells, thereby regulating the balance between proliferative and postmitotic populations in self-renewing epithelia.

Identification of sporadic mutations in the helix initiation motif of keratin 6 in two pachyonychia congenita patients: further evidence for a mutational hot spot.

Pachyonychia congenita (PC) is a rare, autosomal dominant, ectodermal dysplasia characterized most distinctly by the presence of symmetric nail hypertrophy. In the Jadassohn-Lewandowsky form, or PC-1, additional cutaneous manifestations may include palmoplantar hyperkeratosis, hyperhidrosis, follicular keratoses, and oral leukokeratosis. Mutations have previously been identified in the 1A helix initiation motif of either keratin 6 or keratin 16 in patients with PC-1. In the current study, we have identified 2 sporadic, heterozygous mutations in the 1A helix region of the K6 isoform (K6a). The first mutation identified was a 3 base pair deletion (K6adelta N171). The second mutation was a C-to-A transversion resulting in an amino acid substitution (K6a N171K). These data, in combination with previous reports, provide further evidence that this location is a mutational hot spot.

TGF-beta3, but not TGF-beta1, protects keratinocytes against 12-O-tetradecanoylphorbol-13-acetate-induced cell death in vitro and in vivo.

We have examined the role that individual TGF-beta isoforms, and in particular TGF-beta3, play in control of epidermal homeostasis. Mice with a knockout mutation of the TGF-beta3 gene die a few hours after birth. A full-thickness skin grafting approach was used to investigate the postnatal development and homeostatic control of the skin of these mice. Grafted skin of mice with a disruption of the TGF-beta3 gene developed similarly to grafts of wild type and TGF-beta1 knockout animals. However, a strikingly different response was observed after acute treatment with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). When exposed to TPA, the grafted skin of wild type and TGF-beta1 knockout mice underwent a hyperplastic response similar to that of normal mouse skin. In marked contrast, TPA treatment of TGF-beta3 knockout grafts induced widespread areas of keratinocyte cell death. Analysis of cultured keratinocytes treated with purified TGF-beta isoforms revealed that TGF-beta3 plays a direct and specific function in protecting keratinocytes against TPA-induced cell death. The protective function of TGF-beta3 on TPA-induced cell death was not because of general suppression of the signaling pathways triggered by this agent, as ERK1/2 activation occurred to a similar if not greater extent in TGF-beta3-treated versus control keratinocytes. Instead, TGF-beta3 treatment led to a significant reduction in TPA-induced c-Jun N-terminal kinase activity, which was associated and possibly explained by specific counteracting effects of TGF-beta3 on TPA-induced disruption of keratinocyte focal adhesions.

Complete repair of Tetralogy of Fallot with absent pulmonary valve including the role of airway stenting.

Tetralogy of Fallot (TOF) with absent pulmonary valve (APV) represents an extreme form of tetralogy where pulmonary insufficiency and mild annular stenosis often results in massive pulmonary arterial (PA) dilatation. The aneurysmal left and right PAs often compress the adjacent trachea and bronchi, leading to airway obstruction and respiratory failure in infancy. Between 1991 and 1997, 11 patients underwent a single stage repair of TOF and APV using a valved (10 patients) or nonvalved (1 patient) homograft conduit and PA reduction arterioplasty. There was one (1/11 [9.1%) perioperative and one (9.1%) late death. Both deaths were related to airway complications. Morbidity associated with postoperative respiratory complications and ventilator-dependency due to underlying tracheobronchomalacia is an important problem. Intermediate follow-up shows a high incidence of reintervention for conduit stenosis and/or insufficiency and tracheobronchial compression. These infants also required multiple hospitalizations for recurrent respiratory infections secondary to their tracheobronchomalacia. Stenting of the right and left main bronchi with balloon expandable metallic stents is a new experimental therapy that has been useful in two recent patients with respiratory failure despite satisfactory intracardiac repair. It may provide an attractive alternative therapy to prolonged mechanical ventilation with positive end expiratory pressure in patients with severe tracheobronchomalacia. Complete repair with a valved homograft conduit and reduction pulmonary arterioplasty in infancy at the time of diagnosis is the procedure of choice for infants with TOF with APV. With this approach the patient outcome is essentially determined by their airway status and airway management.

cDNA cloning and characterization of sciellin, a LIM domain protein of the keratinocyte cornified envelope.

Sciellin is a precursor of the cornified envelopes of mammalian keratinizing tissues. We have cloned the cDNA encoding sciellin by screening a human keratinocyte expression library with a sciellin-specific monoclonal antibody. The composite cDNA of 2.35 kilobase pairs encodes a protein of 75.3 kDa with a pI of 10.09. The translated sequence has a central domain containing 16 repeats of 20 amino acids each that is rich in Gln and Lys residues, which are potential transglutaminase substrates, and a carboxyl domain, which contains a single LIM motif. Sciellin cDNA probes hybridize to bands of 3.4 and 4.4 kilobase pairs on Northern blots of cultured human keratinocyte RNA. The gene was mapped to human chromosome band 13q22 by fluorescence in situ hybridization. Radiation hybrid mapping demonstrated that sciellin is linked to the sequence tagged site marker WI-457 with a logarithm of the odds score of 7.77. In situ hybridization of human foreskin tissue sections demonstrated that sciellin is expressed in the stratum granulosum. Immunofluorescent staining with a polyclonal rabbit antibody made to a recombinant sciellin protein showed peripheral cytoplasmic localization in the upper cell layers of epidermis and in stratified squamous epithelia such as the oral cavity, esophagus, and vagina. Simple and columnar epithelia, with the exception of the amnion, showed no reaction.

Hair growth cycle affects hair follicle destruction by ruby laser pulses.

It has been shown that normal mode ruby laser pulses (694 nm) are effective in selectively destroying brown or black pigmented hair follicles in adult Caucasians. This study investigated how the various stages of the hair follicle growth cycle influence follicle destruction by ruby laser treatment, using a model of predictable synchronous hair growth cycles in the infantile and adolescent mice. A range of ruby laser pulse fluences was delivered during different stages of the hair growth cycle, followed by histologic and gross observations of the injury and regrowth of hair. Actively growing and pigmented anagen stage hair follicles were sensitive to hair removal by normal mode ruby laser exposure, whereas catagen and telogen stage hair follicles were resistant to laser irradiation. Selective thermal injury to follicles was observed histologically, and hair regrowth was fluence dependent. In animals exposed during anagen, intermediate fluences induced nonscarring alopecia, whereas high fluences induced scarring alopecia. The findings of this study suggest treatment strategies for optimal laser hair removal.

The amino-terminal domain of human STAT4. Overproduction, purification, and biophysical characterization.

The multifunctional signal transducer and activator of transcription (STAT) proteins relay signals from the cell membrane to the nucleus in response to cytokines and growth factors. STAT4 becomes activated when cells are treated with interleukin-12, a key cytokine regulator of cell-mediated immunity. Upon activation, dimers of STAT4 bind cooperatively to tandem interferon-gamma activation sequences (GAS elements) near the interferon-gamma gene and stimulate its transcription. The amino-terminal domain of STAT4 (STAT4(1-124)) is required for cooperative binding interactions between STAT4 dimers and activation of interferon-gamma transcription in response to interleukin-12. We have overproduced this domain of human STAT4 (hSTAT4(1-124)) in Escherichia coli and purified it to homogeneity for structural studies. The circular dichroism spectrum of hSTAT4(1-124) indicates that it has a well ordered conformation in solution. The translational diffusion constant of hSTAT4(1-124) was determined by nuclear magnetic resonance methods and found to be consistent with that of a dimer. The rotational correlation time (tauc) of hSTAT4(1-124) was estimated from 15N relaxation to be 16 ns; this value is consistent with a 29-kDa dimeric protein. These results, together with the number of signals observed in the two-dimensional 1H-15N heteronuclear single quantum coherence spectrum of uniformly 15N-labeled protein, indicate that hSTAT4(1-124) forms a stable, symmetric homodimer in solution. Cooperativity in native STAT4 probably results from a similar or identical interaction between the amino-terminal domains of adjacent dimers bound to DNA.