Expanded applications of rotational atherectomy in contemporary coronary and peripheral interventional practice

Percutaneous rotational atherectomy is mainly utilized in contemporary interventional practice to alter lesion compliance, facilitating stent delivery and antirestenotic drug delivery at the site of the underlying lesion. This enables a percutaneous revascularization strategy in a group of patients who would otherwise require a surgical revascularization. We identify and present three novel uses for this device in percutaneous coronary and peripheral interventional procedures, which further expands the applications of rotational atherectomy.     

Eustachian valve endocarditis: Detection with multiplane transesophageal echocardiography

Right-sided involvement is fairly common in infective endocarditis, but involvement of the eustachian valve is distinctly rare. We present the case of a 36-year-old intravenous drug user with staphylococcal bacteremia and septic pulmonary emboli. Transthoracic echocardiography was normal, but transesophageal echocardiography revealed a large eustachian valve vegetation. This case illustrates the utility of multiplane transesophageal echocardiography in the evaluation of eustachian valve pathology.     

Immunogenicity and protective efficacy of Escherichia coli expressed Plasmodium falciparum merozoite surface protein-1(42) using human compatible adjuvants

The C-terminal 42-kDa fragment of the merozoite surface protein-1 of Plasmodium falciparum (PfMSP-1(42)) was expressed as a recombinant protein in Escherichia coli and purified to near homogeneity. We tested the immunogenicity of recombinant PfMSP-1(42) in three clinically acceptable adjuvants (Montanide ISA 720, alum and MF59) in mice and in rabbits. High antibody responses were obtained with two adjuvant formulations with IgGl being the predominant immunoglobulin isotype. Significant T-cell proliferation responses were also observed. Competitive enzyme linked immunosorbant assay (ELISA) showed the presence of both invasion and processing inhibitory antibodies in sera obtained from the immunized rabbits. Passive immunizations of mice with anti-PfMSP-1(42) IgG purified from the rabbit-sera were found to be protective against a parasite challenge with P. berghei/P. falciparum chimeric line (Pb-PfM19) that expresses Plasmodium falciparum MSP-1(19). These findings may be useful for the development of a malaria vaccine based on Plasmodium falciparum MSP-1(42).     

From the Cover: Discovery of a body-wide photosensory array that matures in an adult-like animal and mediates eye–brain-independent movement and arousal

The ability to respond to light has profoundly shaped life. Animals with eyes overwhelmingly rely on their visual circuits for mediating light-induced coordinated movements. Building on previously reported behaviors, we report the discovery of an organized, eye-independent (extraocular), body-wide photosensory framework that allows even a head-removed animal to move like an intact animal. Despite possessing sensitive cerebral eyes and a centralized brain that controls most behaviors, head-removed planarians show acute, coordinated ultraviolet-A (UV-A) aversive phototaxis. We find this eye–brain-independent phototaxis is mediated by two noncanonical rhabdomeric opsins, the first known function for this newly classified opsin-clade. We uncover a unique array of dual-opsin–expressing photoreceptor cells that line the periphery of animal body, are proximal to a body-wide nerve net, and mediate UV-A phototaxis by engaging multiple modes of locomotion. Unlike embryonically developing cerebral eyes that are functional when animals hatch, the body-wide photosensory array matures postembryonically in “adult-like animals.” Notably, apart from head-removed phototaxis, the body-wide, extraocular sensory organization also impacts physiology of intact animals. Low-dose UV-A, but not visible light (ocular-stimulus), is able to arouse intact worms that have naturally cycled to an inactive/rest-like state. This wavelength selective, low-light arousal of resting animals is noncanonical-opsin dependent but eye independent. Our discovery of an autonomous, multifunctional, late-maturing, organized body-wide photosensory system establishes a paradigm in sensory biology and evolution of light sensing.

Light sensing has independently evolved multiple times and has profoundly shaped life. The ability to process light information in distinct ways and respond to a changing light environment can dramatically shape physiology and fitness of life forms. Movement, triggered by light, is one of the most fundamental responses in nature (1). Among metazoans, a wide variety of animals are known to show coordinated motion in response to light stimuli. So far, this is overwhelmingly known to be mediated through the animal eyes. In fact, eye-driven light sensing and taxis has been extensively studied across phyla. Interestingly, motion in metazoans can also be mediated through eye-independent or extraocular (EO) photoreception (2–5). However, our conceptual and mechanistic grasp on how coordinated movement can be triggered and controlled through EO light-sensing systems is extremely limited. Moreover, the few prominent examples of EO phototaxis have all been reported in life forms/developmental stages completely lacking eyes or possessing only rudimentary eyes (2, 5). Almost nothing is known about sensitive EO light-sensing systems capable of triggering coordinated motion that may coexist with sensitive eyes in a single organism.There are intriguing reports of photoreceptor molecules that are expressed in locations other than conventional eyes, including in unusual structures seen in polyclad flatworms, clitellate segmented worms, crustaceans, cephalopods, and fishes. However, the functions of such structures remain elusive (6–13). A single organism may indeed possess multiple, independent light-responsive systems, both eye based as well as eye independent (13–17), but the functions rarely overlap. “Nonvisual”/EO sensory systems like pineal glands and deep-brain photoreceptors across vertebrates and retinal ganglion cells in mammals (18–21) have been reported. However, these sensory systems are generally known to perform “nonvisual” functions like maintaining circadian rhythms and modulating behavior (22–25). Here, we report an EO phototactic network that can independently trigger coordinated movement just like what the eye-based (ocular) system can, while also having its own distinctive role even when the eyes are present.Do highly sensitive EO phototactic systems coexist and function in life forms that have prominent eye-based networks as well? How would such a system operate? What would be the mechanistic framework and the functional consequence of such an eye-independent light-sensory system? Planarian flatworms offer a fascinating opportunity to explore such a paradigm. Planarians are highly light aversive and have well-developed ocular cerebral eyes (eyes connected to a centralized ganglion) that process light stimuli and guide behavior like feeding, escape, and predation (26–30). In fact, the planarian ocular network is highly sensitive and capable of surprisingly complex processing (17). These eye-mediated behaviors are reliant on an organized, cephalized bilobed brain, a prominent example of a “primitive” brain in evolution (17, 31, 32). Indeed, the brain is required for most locomotive behaviors including thermotaxis, chemotaxis, and eye-mediated phototaxis including the ability to discriminate closely related light stimuli, shown by these animals (17, 32–34). However, planarians also show dramatic, eye–brain-independent light-induced movements (17, 35). Even after sudden decapitation (removal of both eyes and brain), worms are able to acutely respond to ultraviolet-A (UV-A) light and show seemingly coordinated movement away from light (17, 35). While such eye–brain-independent behavior has long fascinated biologists, almost nothing is known about how this dramatic behavior is mediated (17, 35–39). It is also not clear what would be the physiological role of such an acutely sensitive EO sensory network capable of triggering coordinated movement, especially since planarians do have a well-developed ocular network.Here, we show how such an acute response to light is mediated by an organism removed of its “primary” light-sensory organ and brain. We report the discovery of photoreceptor molecules as well as a widespread but organized network of photoreceptor cells that are required for this acute eye-independent UV-A light response. Intriguingly, this entire multiscale sensory system from photoreceptors to the network of cells arises and matures postembryonically, in an “adult-like” organism. This developmental trajectory is distinct from that of the cerebral eyes, which develop embryonically. We also demonstrate that while both the eyes as well the EO network led to coordinated movements relying on the same locomotion machinery, the physiological consequences of the ocular and EO sensory responses can be divergent. Intact planarians periodically go into “sleep-like” resting phases, in which their activity diminishes and sensory perception reduces (40). Strikingly, we find that the EO sensory system in these intact animals can override the natural “rest”-activity cycles and is able to acutely photoactivate and arouse even resting worms. This is distinct from the ocular network that becomes dormant during the “rest phase.” Our work illustrates an unprecedented level of organization and complexity in form and function of an acutely sensitive EO light-sensory system that matures and functions in parallel to the ocular network.     

Identification of karyopherin beta as an immunogenic antigen of the malaria parasite using immune mice and human sera

A differential immunoscreening of the lambdagt11 Plasmodium falciparum genomic expression library was carried out using anti-P. yoelii sera (convalescent-phase mouse sera) and immune sera collected from healthy adults, to identify novel cross-reactive and possibly protective antigens of the parasite. One clone, with an insert size of 1132 bp that reacted strongly with both the sera was selected. The insert was found to be a part of the P. falciparum karyopherin beta (PfKbeta) homologue. RT-PCR and Northern blot analysis confirmed the expression of PfKbeta in the blood stages of the parasite. The approximately 110 kDa protein was localized in the cytoplasm at the ring and trophozoite, and in the parasitophorous vacuole at the schizont stage. Two large fragments of PfKbeta representing the N- and C-terminal halves were expressed in E. coli. The recombinant proteins were highly immunogenic in mice, and also found to be the target for immune response in natural infections of Plasmodium spp. Anti-sera against the protein showed a low level of anti-parasitic activity. Immunization with recombinant PfKbeta fragments was only partially protective against a heterologous challenge infection in mice. Our results show that the parasite releases a highly immunogenic, cytoplasmic protein into the host which may not contribute to the development of protective immunity.     

The role of late/slow replication of the FRA16D in common fragile site induction

The FRA16D, at 16q23, spans the WWOX gene and is one of the most highly expressed common fragile sites observed when DNA replication is perturbed by aphidicolin. Several lines of evidence suggest that fragile sites are regions of DNA that are unusually sensitive to interference during replication. We have determined that the FRA16D alleles replicate in a synchronous fashion and that replication of these sequences occurs primarily in late S phase extending into G2 phase. Exposure to aphidicolin, an inhibitor of DNA polymerase alpha, results in a modest increase in cells with replication of FRA16D sequences in early S phase. This may represent initiation of replication in early S phase coupled with slow replication progression, or, alternatively, these cells may have passed through mitosis, entered the G1-S phase of the next cell cycle, and initiated replication/repair. Our results support a model in which common fragile sites are sequences that may initiate replication in early-mid S phase but are slow to complete replication, and the chromosomal breaks and gaps observed in metaphase cells result from unreplicated DNA.