Histone deacetylase inhibitor treatment restores memory-related gene expression and learning ability in neonicotinoid-treated Apis mellifera.

Apis mellifera plays crucial roles in maintaining the balance of global ecosystems and stability of agricultural systems by helping pollination of flowering plants, including many crops. In recent years, this balance has been disrupted greatly by some pesticides, which results in great losses of honeybees worldwide. Previous studies have found that pesticide-caused memory loss might be one of the major reasons for colony loss. Histone deacetylase inhibitors (HDACis) are chemical compounds that inhibit the activity of histone deacetylases and are known to cause hyperacetylation of histone cores and influence gene expression. In our study, the HDACi sodium butyrate was applied to honeybees as a dietary supplement. The effect of sodium butyrate on the expression profiles of memory-related genes was analysed by quantitative reverse transcription PCR. The results revealed that this HDACi had up-regulation effects on most of the memory-related genes in bees, even in bees treated with imidacloprid. In addition, using the proboscis extension reflex to evaluate olfactory learning in bees, we found that this HDACi boosted the memory formation of bees after impairment owing to imidacloprid exposure. This study investigated the association between gene expression and memory formation from an epigenetic perspective. Additionally, we further demonstrate the possibility of enhancing bee learning using HDACis and provide initial data for future research.

A microwave applicator for uniform irradiation by circularly polarized waves in an anechoic chamber.

Microwave applicators are widely employed for materials heating in scientific research and industrial applications, such as food processing, wood drying, ceramic sintering, chemical synthesis, waste treatment, and insect control. For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, but often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and a preliminary heating test of the overall system.

Signal-dependent fra-2 regulation in skeletal muscle reserve and satellite cells.

Activator protein-1 (AP-1) is a ubiquitous transcription factor that paradoxically also has some tissue-specific functions. In skeletal muscle cells, we document that the AP-1 subunit, Fra-2, is expressed in the resident stem cells (Pax7-positive satellite cells) and also in the analogous undifferentiated 'reserve' cell population in myogenic cultures, but not in differentiated myofiber nuclei. Silencing of Fra-2 expression enhances the expression of differentiation markers such as muscle creatine kinase and myosin heavy chain, indicating a possible role of Fra-2 in undifferentiated myogenic progenitor cells. We observed that Fra-2 is a target of cytokine-mediated extracellular signal-regulated kinase-1/2 signaling in cultured muscle cells, and extensive mass spectrometry and mutational analysis identified S320 and T322 as regulators of Fra-2 protein stability. Interestingly, Fra-2 S320 phosphorylation occurs transiently in activated satellite cells and is extinguished in myogenin-positive differentiating cells. Thus, cytokine-mediated Fra-2 expression and stabilization is linked to regulation of myogenic progenitor cells having implications for the molecular regulation of adult muscle stem cells and skeletal muscle regeneration.

Insect form vision as one potential shaping force of spider web decoration design.

Properties of prey sensory systems are important factors shaping the design of signals generated by organisms exploiting them. In this study we assessed how prey sensory preference affected the exploiter signal design by investigating the evolutionary relationship and relative attractiveness of linear and cruciate form web decorations built by Argiope spiders. Because insects have an innate preference for bilaterally symmetrical patterns, we hypothesized that cruciate form decorations were evolved from linear form due to their higher visual attractiveness to insects. We first reconstructed a molecular phylogeny of the Asian members of the genus Argiope using mitochondrial markers to infer the evolutionary relationship of two decoration forms. Results of ancestral character state reconstruction showed that the linear form was ancestral and the cruciate form derived. To evaluate the luring effectiveness of two decoration forms, we performed field experiments in which the number and orientation of decoration bands were manipulated. Decoration bands arranged in a cruciate form were significantly more attractive to insects than those arranged in a linear form, no matter whether they were composed of silks or dummies. Moreover, dummy decoration bands arranged in a cruciate form attracted significantly more insects than those arranged in a vertical/horizontal form. Such results suggest that pollinator insects' innate preference for certain bilateral or radial symmetrical patterns might be one of the driving forces shaping the arrangement pattern of spider web decorations.

Magnetic quantum tunneling: key insights from multi-dimensional high-field EPR.

Multi-dimensional high-field/frequency electron paramagnetic resonance (HFEPR) spectroscopy is performed on single-crystals of the high-symmetry spin S = 4 tetranuclear single-molecule magnet (SMM) [Ni(hmp)(dmb)Cl](4), where hmp(-) is the anion of 2-hydroxymethylpyridine and dmb is 3,3-dimethyl-1-butanol. Measurements performed as a function of the applied magnetic field strength and its orientation within the hard-plane reveal the four-fold behavior associated with the fourth order transverse zero-field splitting (ZFS) interaction, (1/2)B(S + S), within the framework of a rigid spin approximation (with S = 4). This ZFS interaction mixes the m(s) = +/-4 ground states in second order of perturbation, generating a sizeable (12 MHz) tunnel splitting, which explains the fast magnetic quantum tunneling in this SMM. Meanwhile, multi-frequency measurements performed with the field parallel to the easy-axis reveal HFEPR transitions associated with excited spin multiplets (S < 4). Analysis of the temperature dependence of the intensities of these transitions enables determination of the isotropic Heisenberg exchange constant, J = -6.0 cm(-1), which couples the four spin s = 1 Ni(II) ions within the cluster, as well as a characterization of the ZFS within excited states. The combined experimental studies support recent work indicating that the fourth order anisotropy associated with the S = 4 state originates from second order ZFS interactions associated with the individual Ni(II) centers, but only as a result of higher-order processes that occur via S-mixing between the ground state and higher-lying (S < 4) spin multiplets. We argue that this S-mixing plays an important role in the low-temperature quantum dynamics associated with many other well known SMMs.

Abnormal foraging behavior induced by sublethal dosage of imidacloprid in the honey bee (Hymenoptera: Apidae).

Although sublethal dosages of insecticide to nontarget insects have never been an important issue, they are attracting more and more attention lately. It has been demonstrated that low dosages of the neonicotinoid insecticide imidacloprid may affect honey bee, Apis mellifera L., behavior. In this article, the foraging behavior of the honey bee workers was investigated to show the effects of imidacloprid. By measuring the time interval between two visits at the same feeding site, we found that the normal foraging interval of honey bee workers was within 300 s. However, these honey bee workers delayed their return visit for > 300 s when they were treated orally with sugar water containing imidacloprid. This time delay in their return visit is concentration-dependent, and the lowest effective concentration was found to be 50 microg/liter. When bees were treated with an imidacloprid concentration higher than 1,200 microg/liter, they showed abnormalities in revisiting the feeding site. Some of them went missing, and some were present again at the feeding site the next day. Returning bees also showed delay in their return trips. Our results demonstrated that sublethal dosages of imidacloprid were able to affect foraging behavior of honey bees.

Quantum superposition of high spin states in the single molecule magnet Ni4.

Quantum tunneling of the magnetization in a single molecule magnet has been studied in experiments that combine microwave spectroscopy with high sensitivity magnetic measurements. By monitoring spin-state populations in the presence of microwave radiation, the energy splittings between low lying superpositions of high-spin states of single molecule magnet Ni4 (S=4) have been measured. Absorption linewidths give an upper bound on the rate of decoherence. Pulsed microwave experiments provide a measure of energy relaxation time, which is found to increase with frequency.

Retinal regionalization and heterogeneity of butterfly eyes.

The regional characteristics of the eyes of butterflies from different families have been surveyed using epi-illumination microscopy, utilizing the eyeshine visible due to the tapetum situated proximally to the rhabdom. All butterflies studied have a high spatial acuity in the frontal region. The facet diameter varies slightly across the eye, and the interommatidial angle and the eye parameter p are especially large dorsally. Whereas the ommatidial lattice is generally highly regular, the eyeshine colours distinctly depend on the species. Sometimes the eyeshine is locally uniform, but often it is heterogeneous. It is hypothesized that the regional characteristics as well as the local heterogeneity are adaptations that optimize spectral discrimination.

Initial treatment of traumatic hip dislocations in the adult.

The initial treatment of traumatic hip dislocations is critical to successful treatment of this injury. It generally is agreed that prompt reduction with the patient under anesthesia or sedation is required. Delay in reduction of posterior hip dislocations is associated with avascular necrosis of the hip. Occasionally the hip dislocation will be irreducible. Various methods to reduce hip dislocations have been described in the literature. The superiority of one particular technique has not been shown and the choice of reduction maneuver must be tailored to the condition of the patient. Traumatic hip dislocations often are associated with multiple injuries that may limit the options available for initial treatment of the hip dislocation. Adherence to general principles of skeletal reduction will increase the ease of reduction and decrease the risk of iatrogenic injury during reduction. Additional clinical and radiographic evaluation of the hip that was reduced often is necessary to determine whether subsequent open treatment is required.

Glycosylation of fluoroquinolones through direct and oxygenated polymethylene linkages as a sugar-mediated active transport system for antimicrobials.

We report herein the synthesis and biological testing of several glycosylated derivatives of some fluoroquinolone antibiotics. In particular, we have prepared several glycosylated derivatives of ciprofloxacin (2) in which the carbohydrate units are linked to the free secondary amine of the piperazine unit by: (a) no linker (e.g., a glycosylamine), (b) a beta-oxyethyl linker, and (c) a gamma-oxypropyl linker. Both glucose and galactose were used as carbohydrates so that six compounds of this type were prepared, e.g., no linker 4a,b, oxyethyl linker 5a,b, and oxypropyl linker 6a,b. In addition the aryl glycosides of glucose and galactose (7a,b) were prepared from the active 1-(4-hydroxyphenyl)fluoroquinolone (3.) The syntheses of the glycosylamines 4a,b involved the direct condensation of glucose and galactose with the hydrochloride salt of ciprofloxacin (2). For the oxyalkyl-linked compounds, we first prepared the peracetylated omega-bromoalkyl glycopyranosides 14a,b and 15a,b and then coupled them to the allyl ester of ciprofloxacin (11) to give, after saponification to remove all of the esters, the desired fluoroquinolone carbohydrates 5a,b and 6a,b. The final series was prepared from 2,4,5-trifluorobenzoyl chloride (22) which gave 3 in four precedented steps. Coupling of 3 with the peracetylated glucosyl and galactosyl halides 12a,b and 26 afforded, after saponification, the desired aryl glycosides 7a,b. Six of these derivatives of ciprofloxacin-4a,b, 5a,b, and 6a,b-were subjected to microbiological screening. Of the six, compound 6a showed the highest activity. Since 6a would give the hydroxypropyl-substituted ciprofloxacin on hydrolysis and its activity is approximately 4-8 times less than that of ciprofloxacin (2), this implies that compound 6a is probably being actively transported. Thus preliminary results suggest that some of the compounds are stable in culture conditions and may be differentially transported by multiple resistant organisms. In some cases, the addition of a linker and a carbohydrate to ciprofloxacin lessens, but does not eliminate, antimicrobial activity.

Treatment of type II and type III open tibia fractures in children.

OBJECTIVES: To determine whether severe open tibial fractures in children behave like similar fractures in adults. DESIGN AND SETTING: A combined retrospective and prospective review evaluated treatment protocol for type II and type III open tibial fractures in children over a ten-year period from 1984 to 1993. PATIENTS: Twenty-three fractures were studied in children aged 3.5 to 14.5 (18 boys and 5 girls). There were six type II, eight type IIIA, and nine type IIIB fractures. Type I fractures were not included. Seven fractures were comminuted with significant butterfly fragments or segmental patterns. INTERVENTION: Treatment consisted of adequate debridement of soft tissues, closure of dead space, and stabilization with external fixation. Bone debridement only included contaminated devitalized bone or devitalized bone without soft tissue coverage. Bone that could be covered despite periosteal stripping was preserved. MAIN OUTCOME MEASUREMENTS: Clinical and roentgenographic examinations were used to determine time to union. RESULTS: All fractures in this series healed between eight and twenty-six weeks. Wound coverage included two flaps, three skin grafts, and two delayed primary closures. No bone grafts were required. There were no deep infections, growth arrests, or malunions. Follow-up has ranged from six months to four years. CONCLUSIONS: Open tibia fractures in children differ from similar fractures in adults in the following ways: soft tissues have excellent healing capacity, devitalized bone that is not contaminated or exposed can be saved and will become incorporated, and external fixation can be maintained until the fracture has healed. Periosteum in young children can form bone even in the face of bone loss.

Orientation-sensitive Neurons in the Brain of the Honey Bee (Apis mellifera).

Recent behavioural experiments have shown that bees are able to distinguish vertically presented patterns with orientation cues, although the locations of areas of black are randomized. To discriminate between two orientations, the bees must possess more than one orientation-sensitive neuron type. Therefore, the aim is to search for different types of orientation-sensitive cells of the honey bee, and measure their receptive field, velocity sensitivity and contrast sensitivity. Orientation-sensitive cells with two different types of orientation tuning-curves were recorded intracellularly in the mid-brain of the honey bee when the stimulus was a narrow bar (bar width = 5 degrees ). These cells are sensitive to bar movement within their large receptive field, which covers the visual field of one eye. They are quite distinct from the well-known directional motion detectors. The contrast sensitivity of the orientation-sensitive cells recorded in this study corresponds to results from behavioural experiments. The velocity-sensitivity curves of the orientation-sensitive cells differ from those of the direction-sensitive cells. Measurements of orientation sensitivity and contrast sensitivity when the stimulus is a wide bar (bar width = 10 degrees ), done in different eye regions, suggest that each orientation-sensitive cell receives visual signals from an array of orientational subunits within its receptive field. The correspondence between these physiological results and the results of recent behavioural experiments are discussed. Copyright 1997 Elsevier Science Ltd. All rights reserved

The use of an anterior incision of the meniscus for exposure of tibial plateau fractures requiring open reduction and internal fixation.

The purpose of this study was to examine the use of an anterior incision of the meniscus for exposure of tibial plateau fractures. We studied 27 fractures of the proximal tibia treated with open reduction and internal fixation (ORIF). There were nine unicondylar fractures (five A-O B2; four A-O B3) fixed with plates and screws and 18 bicondylar fractures (seven A-O C1; five A-O C2; six A-O C3) fixed with combination internal and external fixation. Length of follow-up averaged 26 months. All patients were treated with an anterior incision of the meniscus and retraction with the condyle. Of the 18 bicondylar fractures, nine severely displaced fractures were found to have peripherally detached menisci. Unicondylar fractures did not display this finding. After fixation, menisci were repaired at the periphery and sewn to the original anterior insertion. The repair begins posteriorly and advances the cartilage to ensure anatomic placement. There were four medial and 23 lateral menisci in this series. Ten patients underwent knee arthroscopy 6 months to 2 years post-ORIF as a routine procedure during hardware removal. All menisci were found to be healed to the periphery and were stable. There were no gross tears. In one patient, the anterior meniscal incision could be visualized. No patients developed mechanical symptoms either in postoperative rehabilitation or postoperative follow-up at a maximum of 6 years. All patients had > 125 degrees of motion. Less motion when compared with the normal knee was felt to be related to more complex fracture patterns. In conclusion, the anterior meniscal incision allows for excellent exposure of severe proximal tibia fractures. This technique allows for anatomic meniscal repair and early rehabilitation. Arthroscopic examination confirms peripheral meniscal healing. No patient experienced clinical symptoms of meniscal pathology.

Metaphyseal dissociation fractures of the proximal tibia. An analysis of treatment and complications.

A study was done of 44 metaphyseal dissociation fractures of the proximal tibia in 42 patients (27 men and 15 women, aged 22 to 77 years; mean, 42 years). Follow-up ranged from 6 months to 4 years. There were 2 study groups: a retrospective group (group 1, 22 fractures) given a variety of treatments ranging from casts to dual plates, and a prospective group (group 2, 22 fractures) treated by combining external fixation and optional minimal internal fixation. There were 12 comminuted fractures in group 1 and 20 in group 2 (P < 0.01). All fractures eventually healed, with an average healing time in group 1 of 3.8 months, and 5.3 months in group 2. There was one delayed union in group 2. Results were graded from poor to excellent, based on pain, range-of-motion, and malunion. There were 6 poor and 4 fair results in group 1, and no poor and 3 fair results in group 2. Complications included 6 deep infections, 5 in group 1 (1 requiring a free-flap procedure); and 1 pin-tract infection resulting in septic arthritis in group 2. There were 7 gastrocnemius flaps required in group 1, and 1 in group 2. The results of this study suggest that patients treated with external fixation had better results with less infection and soft-tissue complications than those treated with conventional internal fixation.

Gunshot wounds to the forearm.

The rising incidence of civilian gunshot wounds has been well documented. Approximately 4% to 20% of these wounds consist of injuries to the forearm. An organized approach to the treatment of these injuries should be used to obtain an optimal result. Factors to be considered in treatment include the type of weapon and bullet involved, the neurovascular status of the patient, the possibility of compartment syndrome, the presence and type of fracture, and soft-tissue injury.

Timing of internal fixation in low-velocity extremity gunshot fractures.

A ten-year retrospective review of extremity long bone gunshot fractures treated operatively at the Elmhurst City Hospital Center, New York, was performed to examine the operative outcomes with regard to immediate, intermediate, and delayed fixation. A total of 121 low-velocity gunshot fractures were evaluated in 107 patients. Cases were separated into three groups according to the actual timing of the internal fixation procedure. The results revealed a total deep infection rate of 2.6% (3/121) and a nonunion rate of 3.3% (4/121), with no significant differences among the three groups. Early internal fixation reduced comparative hospital stay length and overall costs for operative patients.

Inserting distal screws into interlocking IM nails.

The use of interlocking IM nails is commonplace in major trauma centers. Currently, an accurate guide for inserting the distal screws is not available. Most centers use the "free-hand" technique. Every surgeon must be familiar with this method to insert the screws. We describe our protocol for inserting the distal screws into interlocking IM nails.

The Thurstan-Holland fragment.

The Thurstan-Holland fragment, a small triangular piece of metaphyseal bone, may provide the only roentgenographic evidence of a prior epiphyseal separation that subsequently resolved.

Pseudomonas aeruginosa as a causative agent of cervical osteomyelitis. Case report and review of the literature.

Pseudomonas aeruginosa osteomyelitis and epidural abscess of the cervical spine developed in a previously healthy, 73-year-old man who was not an intravenous drug abuser. In the recent literature, Pseudomonas cervical osteomyelitis has been reported only in intravenous drug abusers or in otherwise healthy individuals after a tooth extraction. In the literature of the past 30 years, isolated cases of cervical osteomyelitis were associated with urinary tract infections. The majority of these cases involved urinary tract instrumentation. The pathogenesis remains controversial. It appears that spontaneous cervical osteomyelitis in a non-intravenous drug abuser has not been previously reported.