Outer surface protein polymorphisms linked to host‐spirochete association in Lyme borreliae

Lyme borreliosis is caused by multiple species of the spirochete bacteria Borrelia burgdorferi sensu lato. The spirochetes are transmitted by ticks to vertebrate hosts, including small‐ and medium‐sized mammals, birds, reptiles, and humans. Strain‐to‐strain variation in host‐specific infectivity has been documented, but the molecular basis that drives this differentiation is still unclear. Spirochetes possess the ability to evade host immune responses and colonize host tissues to establish infection in vertebrate hosts. In turn, hosts have developed distinct levels of immune responses when invaded by different species/strains of Lyme borreliae. Similarly, the ability of Lyme borreliae to colonize host tissues varies among different spirochete species/strains. One potential mechanism that drives this strain‐to‐strain variation of immune evasion and colonization is the polymorphic outer surface proteins produced by Lyme borreliae. In this review, we summarize research on strain‐to‐strain variation in host competence and discuss the evidence that supports the role of spirochete‐produced protein polymorphisms in driving this variation in host specialization. Such information will provide greater insights into the adaptive mechanisms driving host and Lyme borreliae association, which will lead to the development of interventions to block pathogen spread and eventually reduce Lyme borreliosis health burden.     

Influence of restraining devices on patterns of pediatric facial trauma in motor vehicle collisions

In the Commonwealth of Pennsylvania, it is required that all children under the age of 4 years be restrained by an infant seat or car seat appropriate for their age and weight. Furthermore, all individuals riding in the front seat must be restrained by a seatbelt. This study examined the relationship between patterns of facial injuries and the use of restraining devices in the pediatric population. A retrospective analysis was performed on motor vehicle collision data submitted to the Pennsylvania Trauma Outcome Study database from 1990 through 1995. Criteria for submission included trauma patients who were admitted to the Intensive Care Unit, those who died during hospitalization, those who were hospitalized for more than 72 hours, or those who were transferred in or out of the receiving hospital. A subset of 412 pediatric patients, 15 years of age or younger, was analyzed for patterns of facial injury and the presence or absence of restraining devices. Restraining devices were categorized as a car seat or a seatbelt. Statistical analysis was performed using chi-square and Fisher's exact tests. Of the 412 pediatric patients, only 17 children were restrained with a car seat and 121 were wearing a seatbelt. A total of 30 children sustained facial fractures, and 50 children suffered facial lacerations. There was a statistically significant increase in the incidence of facial fractures with increasing age of the child (p < 0.001). Of children with facial fractures, 70 percent of those 5 to 12 years old and 90 percent of those 13 to 15 years old were unrestrained (p = 0.166). In conclusion, despite legislation mandating the use of restraints, a large proportion of children involved in motor vehicle collisions were unrestrained. Furthermore, there seems to be a direct relationship between the age of a child and the incidence of facial fractures sustained in motor vehicle collisions.     

Patterns of molecular genetic variation among African elephant populations

The highly threatened African elephants have recently been subdivided into two species, Loxodonta africana (savannah or bush elephant) and L. cyclotis (forest elephant) based on morphological and molecular studies. A molecular genetic assessment of 16 microsatellite loci across 20 populations (189 individuals) affirms species level genetic differentiation and provides robust genotypic assessment of species affiliation. Savannah elephant populations show modest levels of phylogeographic subdivision based on composite microsatellite genotype, an indication of recent population isolation and restricted gene flow between locales. The savannah elephants show significantly lower genetic diversity than forest elephants, probably reflecting a founder effect in the recent history of the savannah species.     

Fungal life in the extremely hypersaline water of the Dead Sea: first records.

The first report, to our knowledge, on the occurrence of filamentous fungi in the hypersaline (340 g salt l-1) Dead Sea is presented. Three species of filamentous fungi from surface water samples of the Dead Sea were isolated: Gymnascella marismortui (Ascomycota), which is described as a new species, Ulocladium chlamydosporum and Penicillium westlingii (Deuteromycota). G. marismortui and U. chlamydosporum grew on media containing up to 50% Dead Sea water. G. marismortui was found to be an obligate halophile growing optimally in the presence of 0.5-2 M NaCl or 10 30% (by volume) of Dead Sea water. Isolated cultures did not grow on agar media without salt, but grew on agar prepared with up to 50% Dead Sea water. This suggests that they may be adapted to life in the extremely stressful hypersaline Dead Sea.     

New evidence for hybrid zones of forest and savanna elephants in Central and West Africa

The African elephant consists of forest and savanna subspecies. Both subspecies are highly endangered due to severe poaching and habitat loss, and knowledge of their population structure is vital to their conservation. Previous studies have demonstrated marked genetic and morphological differences between forest and savanna elephants, and despite extensive sampling, genetic evidence of hybridization between them has been restricted largely to a few hybrids in the Garamba region of northeastern Democratic Republic of Congo (DRC). Here, we present new genetic data on hybridization from previously unsampled areas of Africa. Novel statistical methods applied to these data identify 46 hybrid samples – many more than have been previously identified – only two of which are from the Garamba region. The remaining 44 are from three other geographically distinct locations: a major hybrid zone along the border of the DRC and Uganda, a second potential hybrid zone in Central African Republic and a smaller fraction of hybrids in the Pendjari–Arli complex of West Africa. Most of the hybrids show evidence of interbreeding over more than one generation, demonstrating that hybrids are fertile. Mitochondrial and Y chromosome data demonstrate that the hybridization is bidirectional, involving males and females from both subspecies. We hypothesize that the hybrid zones may have been facilitated by poaching and habitat modification. The localized geography and rarity of hybrid zones, their possible facilitation from human pressures, and the high divergence and genetic distinctness of forest and savanna elephants throughout their ranges, are consistent with calls for separate species classification.     

Medicinal mushroom modulators of molecular targets as cancer therapeutics

Empirical approaches to discover anticancer drugs and cancer treatments have made limited progress in the past several decades in finding a cure for cancer. The expanded knowledge of the molecular basis of tumorigenesis and metastasis, together with the inherently vast structural diversity of natural compounds found in mushrooms, provided unique opportunities for discovering new drugs that rationally target the abnormal molecular and biochemical signals leading to cancer. This review focuses on mushroom low-molecular-weight secondary metabolites targeting processes such as apoptosis, angiogenesis, metastasis, cell cycle regulation, and signal transduction cascades. Also discussed in this review are high-molecular-weight polysaccharides or polysaccharide–protein complexes from mushrooms that appear to enhance innate and cell-mediated immune responses, exhibit antitumor activities in animals and humans, and demonstrate the anticancer properties of selenium compounds accumulated in mushrooms.     

Carbon and nitrogen sources influence the ligninolytic enzyme activity of <Emphasis Type="Italic">Trametes versicolor</Emphasis>

Among carbon sources studied, cellobiose and mannitol provided the highest laccase (Lac) activity (648 and 742 U1^-1, respectively) of Trametes versicolor 775 while glucose gave maximum manganese peroxidase (MnP) and peroxidase activities (44 and 114U1^-1, respectively). Citrus fruit peel as growth substrate enhanced Lac activity 7-fold when compared to the medium with cellobiose, whereas grape vine sawdust increased MnP and peroxidase activity up to 148 and 677U1^-1, respectively.