Autochthonous Leishmania siamensis in Horse, Florida, USA

TO THE EDITOR: Leishmania siamensis, a recently described species, was identified as the cause of autochthonous visceral leishmaniasis in 2 men in southern Thailand (1,2). Cutaneous leishmaniasis has been reported in horses in Europe and South America. Lesions in horses are solitary or multiple nodules that are often ulcerated and most commonly occur on the head, pinnae, legs, and neck. Other clinical signs are usually absent. In South America, biochemical characterization has identified L. braziliensis in horses (3). Leishmaniasis has been reported in horses in Puerto Rico (4), and equine leishmaniasis has been described, but no reports have been published, in the United States. L. infantum has been reported in equine cutaneous leishmaniasis in Europe (5). A report from central Europe recently identified an organism with 98% nucleotide identity over the ITS (internal transcribed spacer) 1 region to L. siamensis as the cause of cutaneous leishmaniasis in 4 horses (6). L. siamensis was also identified in a case of cutaneous bovine leishmaniasis in Switzerland (7).     

Three methods for evaluation of left atrial volume.

AIM: To compare and contrast 3 different echocardiographic methods used to measure left atrial (LA) volume: biplane area length (AL), biplane modified Simpson (SIMP), and prolate ellipse (PE) methods. METHODS AND RESULTS: A review of consecutive patients who presented to our outpatient echocardiography laboratory for a resting transthoracic study between April 2006 and May 2006 was performed. Echocardiograms were reexamined and LA volume measured using the AL, SIMP, and PE methods. Of 102 consecutive patients evaluated, 97 had a measure of LA volume using all 3 methods. A significant difference in the measurement of mean +/- SD LA volume was noted among the 3 different methods: 37 +/- 16 mL/m(2) for AL, 34 +/- 14 mL/m(2) for SIMP, and 27 +/- 12 mL/m(2) for PE. The PE method yielded routinely smaller values compared with either the AL or SIMP method (P < 0.001). Differences increased with increased LA volume. The SIMP method derived consistently smaller (<5 mL/m(2)) values than those of the AL method, consistent across the full range of LA volumes. CONCLUSION: Significant differences exist among these 3 commonly used methods for measuring LA volume. Standardization of the measurement of LA volume is recommended.     

Mutations in Mlph, encoding a member of the Rab effector family, cause the melanosome transport defects observed in leaden mice

The d, ash, and ln coat color mutations provide a unique model system for the study of vesicle transport in mammals. All three mutant loci encode genes that are required for the polarized transport of melanosomes, the specialized, pigment-containing organelles of melanocytes, to the neighboring keratinocytes and eventually into coat hairs. Genetic studies suggest that these genes function in the same or overlapping pathways and are supported by biochemical studies showing that d encodes an actin-based melanosome transport motor, MyoVa, whereas ash encodes Rab27a, a protein that localizes to the melanosome and is postulated to serve as the MyoVa receptor. Here we show that ln encodes melanophilin (Mlph), a previously undescribed protein with homology to Rab effectors such as granuphilin, Slp3-a, and rabphilin-3A. Like all of these effectors, Mlph possesses two Zn(2+)-binding CX(2)CX(13,14)CX(2)C motifs and a short aromatic-rich amino acid region that is critical for Rab binding. However, Mlph does not contain the two Ca(2+)-binding C(2) domains found in these and other proteins involved in vesicle transport, suggesting that it represents a previously unrecognized class of Rab effectors. Collectively, our data show that Mlph is a critical component of the melanosome transport machinery and suggest that Mlph might function as part of a transport complex with Rab27a and MyoVa.     

When the brain goes diving: glial oxidative metabolism may confer hypoxia tolerance to the seal brain

Deep diving mammals have developed strategies to cope with limited oxygen availability when submerged. These adaptations are associated with an increased neuronal hypoxia tolerance. Brain neurons of the hooded seal Cystophora cristata remain much longer active in hypoxic conditions than those of mice. To understand the cellular basis of neuronal hypoxia tolerance, we studied neuroglobin and cytochrome c in C. cristata brain. Neuroglobin, a respiratory protein typically found in vertebrate neurons, displays three unique amino acid substitutions in hooded seal. However, these substitutions unlikely contribute to a modulation of O₂ affinity. Moreover, there is no significant difference in total neuroglobin protein levels in mouse, rat and seal brains. However, in terrestrial mammals neuroglobin resided exclusively in neurons, whereas in seals neuroglobin is mainly located in astrocytes. This unusual localization of neuroglobin is accompanied by a shift in the distribution of cytochrome c. In seals, this marker for oxidative metabolism is mainly localized in astrocytes, whereas in terrestrial mammals it is essentially found in neurons. Our results indicate that in seals aerobic ATP production depends significantly on astrocytes, while neurons rely less on aerobic energy metabolism. This adaptation may imbue seal neurons with an increased tolerance to hypoxia and potentially also to reactive oxygen species, and may explain in part the ability of deep diving mammals to sustain neuronal activity during prolonged dives.     

Pregnancy outcomes and community health: the POUCH study of preterm birth

In light of the social/ethnic disparity in preterm delivery (PTD) rates, the Pregnancy Outcomes and Community Health (POUCH) Study takes a broad view of the determinants of PTD by attempting to link underlying biological and psychosocial factors. The relationships between placental pathology, maternal biomarkers, and antecedent psychosocial factors are evaluated in three hypothesised pathways of PTD – one characterised primarily by infection, one by maternal vascular disease, and one by premature elevations in corticotropin releasing hormone in the absence of histological evidence of placental pathology. Within each pathway, an emphasis is placed on understanding the roles of stress and of maternal serum alpha-fetoprotein, an early biomarker associated with PTD. The POUCH Study enrols pregnant women from five Michigan communities. Information about these women and their environments is gathered through detailed interviews and collection of biological samples including hair, urine, saliva, blood, vaginal fluid, and vaginal smear at 15–26 weeks of gestation. We have chosen to focus on the second trimester – a time when pathological processes may have evolved to a detectable stage, but generally before the onset of biological changes that accompany labour. This focus is consistent with the long-range goal of early detection/intervention and prevention of PTD.     

Sex-specific mating pheromones in the nematode Panagrellus redivivus

Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes.     

Characterization of the Major Aroma-Active Compounds in Peel Oil of an HLB-Tolerant Mandarin Hybrid Using Aroma Extraction Dilution Analysis and Gas Chromatography-Mass Spectrometry/Olfactometry

Introduction

The main purposes of this study were to identity major peel oil odorants and determine which aroma compounds are primarily responsible for the overall aroma profile of a recently developed Huanglongbing (HLB)-tolerant mandarin hybrid.

Methods

The aroma-active compounds present in the recently developed mandarin hybrid peel oil were extracted by solvent-assisted flavor evaporation (SAFE) and then analyzed by gas chromatography-mass spectrometry/olfactometry (GC-MS/O) and aroma extract dilution analysis (AEDA).

Results

Thirty odor-active compounds in the flavor dilution (FD) factor range of 2 to 256 have been identified. On the basis of high FD factors, α-pinene, limonene, β-myrcene, linalool, and β-caryophyllene were characterized as the most essential aroma compounds at a FD factor ≥ 128, followed by γ-terpinene, β-pinene, terpinolene, p-dimethylstyrene, (E)-linalool oxide, decanal, β-cubebene, α-terpineol, and perilla aldehyde at a FD factor ≥ 16. Among all the detected aroma compounds, limonene was the most abundant compound (86.5 ± 2.8%), followed by γ-terpinene (5.3 ± 0.1%), β-myrcene (2.4 ± 0.1%), and α-pinene (1.2 ± 0.0%).

Conclusions

The compounds including α-pinene, limonene, β-myrcene, linalool, and β-caryophyllene were characterized as the most essential aromas. The sensory evaluation results indicated that the major attributes (FD ≥ 2) such as floral, lemon, peel-like, green, mint, and sweet were comparable to that of natural mandarin peel oil.

Implications

Based on the human perception, olfactometry and AEDA were used to determine the aroma-active compounds in the peel oil. Human perception also involved in aroma reconstitution to compare the re-engineering solution containing the essential aroma compounds with the natural mandarin oil.

     

Heterogeneity of glioblastoma with gliomatosis cerebri growth pattern on diffusion and perfusion MRI

Journal of Neuro-Oncology - Gliomatosis cerebri (GC) is a rare growth pattern of glioblastoma whose diffuse nature is reflected by unspecific, relatively uniform findings on conventional MRI. In...     

Current state of the Würzburg database for radiotherapy

Initially the data bank, which serves for the follow-up organization and for scientific studies, is briefly introduced. Then the possible analyses are described. Two types of possible evaluations can be distinguished. For the first type of evaluation, a subprogram has to be developed for every topic. A great number of questions can be answered by assembling the subprograms. These evaluations mostly dispose of a direct access to the data bank, so that the information desired is immediately available. For the second type of evaluation, the features of a group of patients have been determined with the aid of the data bank and have been stored then. A simple questioning language allows the establishment of any condition limiting the patient groups and its transmission to a statistical program package. Some examples are given to describe the possibilities of the statistical program developed especially for medical studies which makes it possible to perform analyses according to the life table method, too.