Molting hormone titer changes and their significance during development of the colorado beetle, Leptinotarsa decemlineata

Molting hormone (MH) titer in whole animal extracts of Leptinotarsa decemlineata was determined by chemical extraction and the Musca test (1 MU = 3.5 ng ecdysterone) during the developmental span from newly-ecdysed fourth instar larva to an adult 3 days after eclosion. Within the 17-day period, 21 age groups were chosen to estimate the MH titer. Two peaks of MH titer were detected, one in the post-feeding larval stage and the other during the pupal and pharate adult stage. MH activity was first detected in 2-day-old post-feeding larvae, and reached a maximum of 23.5 MU/g tissue on the third day. It began to decline on 3.5 days, and fell to 5.5 MU/g tissue on 4.5 days, the time of larval-pupal ecdysis. In the pupal and pharate adult stage MH rose after the first day and increased to a maximum of 91.5 MU/g tissue on the third day. The titer again declined on the fourth day, and became undetectable one day before adult emergence and in adults 3 days after emergence. MH was demonstrated to be produced by isolated larval abdomens. A peak of 11.5 MU/g tissue was detected in 7-day post-ligation preparations. The titer decreased to 6.9 MU/g tissue in 10-day post-ligation preparations, which was the time of the ecdysis. The finding raises questions concerning the rôle of MH synthesis by other tissues in relation to the function of the prothoracic glands during insect development.     

Phylogenetic Exploration of Nosocomial Transmission Chains of 2009 Influenza A/H1N1 among Children Admitted at Red Cross War Memorial Children’s Hospital,Cape Town,South Africa in 2011

Traditional modes of investigating influenza nosocomial transmission have entailed a combination of confirmatory molecular diagnostic testing and epidemiological investigation. Common hospital-acquired infections like influenza require a discerning ability to distinguish between viral isolates to accurately identify patient transmission chains. We assessed whether influenza hemagglutinin sequence phylogenies can be used to enrich epidemiological data when investigating the extent of nosocomial transmission over a four-month period within a paediatric Hospital in Cape Town South Africa. Possible transmission chains/channels were initially determined through basic patient admission data combined with Maximum likelihood and time-scaled Bayesian phylogenetic analyses. These analyses suggested that most instances of potential hospital-acquired infections resulted from multiple introductions of Influenza A into the hospital, which included instances where virus hemagglutinin sequences were identical between different patients. Furthermore, a general inability to establish epidemiological transmission linkage of patients/viral isolates implied that identified isolates could have originated from asymptomatic hospital patients, visitors or hospital staff. In contrast, a traditional epidemiological investigation that used no viral phylogenetic analyses, based on patient co-admission into specific wards during a particular time-frame, suggested that multiple hospital acquired infection instances may have stemmed from a limited number of identifiable index viral isolates/patients. This traditional epidemiological analysis by itself could incorrectly suggest linkage between unrelated cases, underestimate the number of unique infections and may overlook the possible diffuse nature of hospital transmission, which was suggested by sequencing data to be caused by multiple unique introductions of influenza A isolates into individual hospital wards. We have demonstrated a functional role for viral sequence data in nosocomial transmission investigation through its ability to enrich traditional, non-molecular observational epidemiological investigation by teasing out possible transmission pathways and working toward more accurately enumerating the number of possible transmission events.     

Aging shifts mitochondrial dynamics toward fission to promote germline stem cell loss

Changes in mitochondrial dynamics (fusion and fission) are known to occur during stem cell differentiation; however, the role of this phenomenon in tissue aging remains unclear. Here, we report that mitochondrial dynamics are shifted toward fission during aging of Drosophila ovarian germline stem cells (GSCs), and this shift contributes to aging‐related GSC loss. We found that as GSCs age, mitochondrial fragmentation and expression of the mitochondrial fission regulator, Dynamin‐related protein (Drp1), are both increased, while mitochondrial membrane potential is reduced. Moreover, preventing mitochondrial fusion in GSCs results in highly fragmented depolarized mitochondria, decreased BMP stemness signaling, impaired fatty acid metabolism, and GSC loss. Conversely, forcing mitochondrial elongation promotes GSC attachment to the niche. Importantly, maintenance of aging GSCs can be enhanced by suppressing Drp1 expression to prevent mitochondrial fission or treating with rapamycin, which is known to promote autophagy via TOR inhibition. Overall, our results show that mitochondrial dynamics are altered during physiological aging, affecting stem cell homeostasis via coordinated changes in stemness signaling, niche contact, and cellular metabolism. Such effects may also be highly relevant to other stem cell types and aging‐induced tissue degeneration.     

Life cycles,phenology and genetic structure of endangered Megacrania tsudai Shiraki (Phasmatodea: Phasmatidae): Male individuals from a geographic parthenogenesis species

Megacrania tsudai, a peripherally distributed member of Megacrania, requires conservation in Taiwan; it has limited distribution in Taiwan and its eastern offshore islands. It feeds on screw pines (Pandanus odoratissimus) in nature and has demonstrated a specific defensive mechanism involving actinidine secretion from the prothoracic gland. However, details of its distribution area, life cycle and developmental phenology remain largely unknown. In this study, a field survey and review of published works revealed M. tsudai distribution in coastal zones and along river shores near estuaries. At room temperature, the egg period was 128 days. The development of the first to sixth instars required 17, 26, 27, 26, 34 and 43 days, respectively, on average; and a generation cycle required approximately 204 days. The phenology of the mesonotal granules was recorded. Moreover, genetic analysis of the mitochondrial cytochrome oxidase I (COI), 16S ribosomal DNA (16S rDNA) and the nuclear ribosomal spacer indicated the occurrence of genetic drift. Therefore, the rearing procedures proposed in this study for the primary and last instars of M. tsudai can facilitate its conservation. Megacrania tsudai was previously recorded as parthenogenetic; however, two male individuals were fostered unexpectedly. The male body length was 91 mm, which is shorter than the female length (120 mm). During mating, the male climbs onto the female's back and protrudes its genitalia downward. Geographical parthenogenesis is likely the reproductive strategy among peripheral M. tsudai; however, the rarely found M. tsudai male could be an intermediate link of reproductive strategy in the transition from tychoparthenogenesis to parthenogenesis.     

Evaluation of park management based on "Installation-Management Permission" in TEN-SHIBA,Tennoji Park,Osaka City: focus on park users and financial effects

The park management (PM) that evolved from the park-renewal project based on Installation-Management Permission (IMP) in Tennoji Park, a major urban park in Osaka City, Japan is evaluated herein. The PM of Tennoji Park is composed of 'hard' and 'soft' tasks. The process and characteristics of the hard tasks, i.e., the park-renewal project including the construction of a significant landmark, the lawn plaza (named 'TEN-SHIBA') and convenience facilities with various service functions are analyzed. The details and outcomes of the soft tasks including cleaning, security, and lawn/planting management plus events held on the TEN-SHIBA plaza are also clarified. The PM results and financial effects of the introduction of IMP in TEN-SHIBA are evaluated based on both the park users' characteristics obtained by a questionnaire, an observation survey of the park users, and a data analysis of the track record. Based on a comparison with Sumiyoshi Park, an urban park similar to TEN-SHIBA but without the introduction of IMP, it was found that young females were the predominant users of TEN-SHIBA, and the average staying time on the lawn plaza was 2 min. longer than that in Sumiyoshi park. Together these results suggest the effectiveness of IMP for PM based on the TEN-SHIBA experience. It also appears that placing a plaza in the center of a park and providing facilities and various events by private business operators can generate profits; this might be effective for future PM hard tasks, while various and continuous soft task efforts remain essential.

     

Neurovascular abnormalities in brain disorders: highlights with angiogenesis and magnetic resonance imaging studies

The coupling between neuronal activity and vascular responses is controlled by the neurovascular unit (NVU), which comprises multiple cell types. Many different types of dysfunction in these cells may impair the proper control of vascular responses by the NVU. Magnetic resonance imaging, which is the most powerful tool available to investigate neurovascular structures or functions, will be discussed in the present article in relation to its applications and discoveries. Because aberrant angiogenesis and vascular remodeling have been increasingly reported as being implicated in brain pathogenesis, this review article will refer to this hallmark event when suitable.     

Role of cognitive parameters in dengue hemorrhagic fever and dengue shock syndrome

Dengue is becoming recognized as one of the most important vector-borne human diseases. It is predominant in tropical and subtropical zones but its geographical distribution is progressively expanding, making it an escalating global health problem of today. Dengue presents with spectrum of clinical manifestations, ranging from asymptomatic, undifferentiated mild fever, dengue fever (DF), to dengue hemorrhagic fever (DHF) with or without shock (DSS), a life-threatening illness characterized by plasma leakage due to increased vascular permeability. Currently, there are no antiviral modalities or vaccines available to treat and prevent dengue. Supportive care with close monitoring is the standard clinical practice. The mechanisms leading to DHF/DSS remains poorly understood. Multiple factors have been attributed to the pathological mechanism, but only a couple of these hypotheses are popular in scientific circles. The current discussion focuses on underappreciated factors, temperature, natural IgM, and endotoxin, which may be critical components playing roles in dengue pathogenesis.     

A HT/PEXEL Motif in Toxoplasma Dense Granule Proteins is a Signal for Protein Cleavage but not Export into the Host Cell

Apicomplexan parasites, such as Toxoplasma gondii and Plasmodium, secrete proteins for attachment, invasion and modulation of their host cells. The host targeting (HT), also known as the Plasmodium export element (PEXEL), directs Plasmodium proteins into erythrocytes to remodel the host cell and establish infection. Bioinformatic analysis of Toxoplasma revealed a HT/PEXEL‐like motif at the N‐terminus of several hypothetical unknown and dense granule proteins. Hemagglutinin‐tagged versions of these uncharacterized proteins show co‐localization with dense granule proteins found on the parasitophorous vacuole membrane (PVM). In contrast to Plasmodium, these Toxoplasma HT/PEXEL containing proteins are not exported into the host cell. Site directed mutagenesis of the Toxoplasma HT/PEXEL motif, RxLxD/E, shows that the arginine and leucine residues are permissible for protein cleavage. Mutations within the HT/PEXEL motif that prevent protein cleavage still allow for targeting to the PV but the proteins have a reduced association with the PVM. Addition of a Myc tag before and after the cleavage site shows that processed HT/PEXEL protein has increased PVM association. These findings suggest that while Toxoplasma and Plasmodium share similar HT/PEXEL motifs, Toxoplasma HT/PEXEL containing proteins interact with but do not cross the PVM .     

A New Molecular Phylogeny and a New Genus,Pendulorchis, of the Aerides–Vanda Alliance (Orchidaceae: Epidendroideae)

Background

The Aerides–Vanda alliance is a complex group in the subtribe Aeridinae (subfamily Epidendroideae, Orchidaceae). Some phylogenetic systems of this alliance have been previously proposed based on molecular and morphological analyses. However, several taxonomic problems within this alliance as well as between it and its allies remain unsolved.

Methodology/Principal Findings

We utilized ITS and five plastid DNA regions in this phylogenetic analysis. Consensus trees strongly indicate that the Aerides–Vanda alliance is monophyletic, and the 14 genera of this alliance can be grouped into the following clades with 14 subclades: 1. Aerides, comprising two subclades: Rhynchostylis and Aerides; 2. Ascocentropsis; 3. Papilionanthe; 4. Vanda, comprising five subclades: Neofinetia, Christensonia, Seidenfadenia, Ascocentrum, and Vanda–Trudelia, in which Vanda and Trudelia form a subclade; 5. Tsiorchis, comprising three subclades: Chenorchis, Tsiorchis, and two species of Ascocentrum; 6. Paraholcoglossum; and 7. Holcoglossum. Among the 14 genera, only Ascocentrum is triphyletic: two species of the Ascocentrum subclade, an independent subclade Ascocentrum subclade in the Tsiorchis clade; the Ascocentrum subclade in the Vanda clade; and one species in the Holcoglossum clade. The Vanda and Trudelia species belong to the same subclade. The molecular conclusion is consistent with their morphological characteristics.

Conclusions

We elucidate the relationship among the 14 genera of the Aerides–Vanda alliance. Our phylogenetic results reveal that the Aerides–Vanda alliance is monophyletic, but it can be divided into 14 genera. The data prove that Ascocentrum is triphyletic. Plants with elongate-terete leaves and small flowers should be treated as a new genus, Pendulorchis. Saccolabium himalaicum (Ascocentrum himalaicum) should be transferred to Pendulorchis. Ascocentrum pumilum, endemic to Taiwan, should be transferred to Holcoglossum. A new combination, Holcoglossum pumilum, was also established. Trudelia should not be recognized as an independent genus. Two new species, Pendulorchis gaoligongensis and Holcoglossum singchianum, were described as well.     

Regional Amyloid Deposition in Amnestic Mild Cognitive Impairment and Alzheimer's Disease Evaluated by [18F]AV-45 Positron Emission Tomography in Chinese Population

Background

To compare the neocortical amyloid loads among cognitively normal (CN), amnestic mild cognitive impairment (aMCI), and Alzheimer''s disease (AD) subjects with [¹⁸F]AV-45 positron emission tomography (PET).

Materials and Methods

[¹⁸F]AV-45 PET was performed in 11 CN, 13 aMCI, and 12 AD subjects to compare the cerebral cortex-to-whole cerebellum standard uptake value ratios (SUVRs) of global and individual volumes of interest (VOIs) cerebral cortex. The correlation between global cortical [¹⁸F]AV-45 SUVRs and Mini-Mental State Examination (MMSE) scores was analyzed.

Results

The global cortical [¹⁸F]AV-45 SUVRs were significantly different among the CN (1.08±0.08), aMCI (1.27±0.06), and AD groups (1.34±0.13) (p = 0.0003) with amyloidosis positivity rates of 9%, 62%, and 92% in the three groups respectively. Compared to CN subjects, AD subjects had higher SUVRs in the global cortical, precuneus, frontal, parietal, occipital, temporal, and posterior cingulate areas; while aMCI subjects had higher values in the global cortical, precuneus, frontal, occipital and posterior cingulate areas. There were negative correlations of MMSE scores with SUVRs in the global cortical, precuneus, frontal, parietal, occipital, temporal, posterior cingulate and anterior cingulate areas on a combined subject pool of the three groups after age and education attainment adjustment.

Conclusions

Amyloid deposition occurs relatively early in precuneus, frontal and posterior cingulate in aMCI subjects. Higher [¹⁸F]AV-45 accumulation is present in parietal, occipital and temporal gyri in AD subjects compared to the aMCI group. Significant correlation between MMSE scores and [¹⁸F]AV-45 SUVRs can be observed among CN, aMCI and AD subjects.