Biomechanics of the movable pretarsal adhesive organ in ants and bees

Hymenoptera attach to smooth surfaces with a flexible pad, the arolium, between the claws. Here we investigate its movement in Asian weaver ants (Oecophylla smaragdina) and honeybees (Apis mellifera).  When ants run upside down on a smooth surface, the arolium is unfolded and folded back with each step. Its extension is strictly coupled with the retraction of the claws. Experimental pull on the claw-flexor tendon revealed that the claw-flexor muscle not only retracts the claws, but also moves the arolium. The elicited arolium movement comprises (i) about a 90° rotation (extension) mediated by the interaction of the two rigid pretarsal sclerites arcus and manubrium and (ii) a lateral expansion and increase in volume. In severed legs of O. smaragdina ants, an increase in hemolymph pressure of 15 kPa was sufficient to inflate the arolium to its full size. Apart from being actively extended, an arolium in contact also can unfold passively when the leg is subject to a pull toward the body.  We propose a combined mechanical–hydraulic model for arolium movement: (i) the arolium is engaged by the action of the unguitractor, which mechanically extends the arolium; (ii) compression of the arolium gland reservoir pumps liquid into the arolium; (iii) arolia partly in contact with the surface are unfolded passively when the legs are pulled toward the body; and (iv) the arolium deflates and moves back to its default position by elastic recoil of the cuticle.

Leptin induces vascular permeability and synergistically stimulates angiogenesis with FGF-2 and VEGF

Most endocrine hormones are produced in tissues and organs with permeable microvessels that may provide an excess of hormones to be transported by the blood circulation to the distal target organ. Here, we investigate whether leptin, an endocrine hormone, induces the formation of vascular fenestrations and permeability, and we characterize its angiogenic property in the presence of other angiogenic factors. We provide evidence that leptin-induced new blood vessels are fenestrated. Under physiological conditions, capillary fenestrations are found in the leptin-producing adipose tissue in lean mice. In contrast, no vascular fenestrations were detected in the adipose tissue of leptin-deficient ob/ob mice. Thus, leptin plays a critical role in the maintenance and regulation of vascular fenestrations in the adipose tissue. Leptin induces a rapid vascular permeability response when administrated intradermally. Further, leptin synergistically stimulates angiogenesis with fibroblast growth factor (FGF)-2 and vascular endothelial growth factor (VEGF), the two most potent and commonly expressed angiogenic factors. These findings demonstrate that leptin has another new function—the increase of vascular permeability.

Tomato Flower Abnormalities Induced by Low Temperatures Are Associated with Changes of Expression of MADS-Box Genes1

Flower and fruit development in tomato (Lycopersicon esculentum Mill.) were severely affected when plants were grown at low temperatures, displaying homeotic and meristic transformations and alterations in the fusion pattern of the organs. Most of these homeotic transformations modified the identity of stamens and carpels, giving rise to intermediate organs. Complete homeotic transformations were rarely found and always affected organs of the reproductive whorls. Meristic transformations were also commonly observed in the reproductive whorls, which developed with an excessive number of organs. Scanning electron microscopy revealed that meristic transformations take place very early in the development of the flower and are related to a significant increase in the floral meristem size. However, homeotic transformations should occur later during the development of the organ primordia. Steady-state levels of transcripts corresponding to tomato MADS-box genes TM4, TM5, TM6, and TAG1 were greatly increased by low temperatures and could be related to these flower abnormalities. Moreover, in situ hybridization analyses showed that low temperatures also altered the stage-specific expression of TM4.

Expression of a Soybean Hydroxyproline-Rich Glycoprotein Gene Is Correlated with Maturation of Roots1

A novel extensin gene has been identified in soybean (Glycine max L.) that encodes a hydroxyproline-rich glycoprotein (SbHRGP3) with two different domains. In this study expression of SbHRGP3 was investigated during soybean root development. SbHRGP was expressed in roots of mature plants, as well as seedlings, and showed a distinct pattern of expression during root development. The expression of SbHRGP3 increased gradually during root development of seedlings and reached a maximum while the secondary roots were maturing. The maximum expression level was contributed mainly by the secondary roots rather than by the primary root. Furthermore, expression of SbHRGP3 was preferentially detected in the regions undergoing maturation of the primary and secondary roots. These results imply that the expression of SbHRGP3 is regulated in an organ- and development-specific manner and that in soybean SbHRGP3 expression may be required for root maturation, presumably for the cessation of root elongation. Wounding and sucrose in combination enhanced expression of SbHRGP3 in roots, whereas both wounding and sucrose were required for the expression of SbHRGP3 in leaves.

The Drosophila Numb protein inhibits signaling of the Notch receptor during cell-cell interaction in sensory organ lineage.

Specification of unequal daughter cell fates in the Drosophila external sense organ lineage requires asymmetric localization of the intrinsic determinant Numb as well as cell-cell interactions mediated by the Delta ligand and Notch receptor. Previous genetic studies indicated that numb acts upstream of Notch, and biochemical studies revealed that Numb can bind Notch. For a functional assay of the action of Numb on Notch signaling, we expressed these proteins in cultured Drosophila cells and used nuclear translocation of Suppressor of Hairless [Su(H)] as a reporter for Notch activity. We found that Numb interfered with the ability of Notch to cause nuclear translocation of Su(H); both the C-terminal half of the phosphotyrosine binding domain and the C terminus of Numb are required to inhibit Notch. Overexpression of Numb during wing development, which is sensitive to Notch dosage, revealed that Numb is also able to inhibit the Notch receptor in vivo. In the external sense organ lineage, the phosphotyrosine binding domain of Numb was found to be essential for the function but not for asymmetric localization of Numb. Our results suggest that Numb determines daughter cell fates in the external sense organ lineage by inhibiting Notch signaling.

Organ-specific and Agamous-regulated expression and glycosylation of a pollen tube growth-promoting protein.

Transmitting tissue-specific (TTS) protein is a pollen tube growth-promoting and attracting glycoprotein located in the stylar transmitting tissue extracellular matrix of the pistil of tobacco. The TTS protein backbones have a deduced molecular mass of about 28 kDa, whereas the glycosylated stylar TTS proteins have apparent molecular masses ranging between 50 and 100 kDa. TTS mRNAs and proteins are ectopically produced in transgenic tobacco plants that express either a cauliflower mosaic virus (CaMV) 35S promoter-TTS2 transgene or a CaMV 35S-promoter-NAG1 (NAG1 = Nicotiana tabacum Agamous gene) transgene. However, the patterns of TTS mRNA and protein accumulation and the quality of the TTS proteins produced are different in these two types of transgenic plants. In 35S-TTS transgenic plants, TTS mRNAs and proteins accumulate constitutively in vegetative and floral tissues. However, the ectopically expressed TTS proteins in these transgenic plants accumulate as underglycosylated protein species with apparent molecular masses between 30 and 50 kDa. This indicates that the capacity to produce highly glycosylated TTS proteins is restricted to the stylar transmitting tissue. In 35S-NAG transgenic plants, NAG1 mRNAs accumulate constitutively in vegetative and floral tissues, and TTS mRNAs are induced in the sepals of these plants. Moreover, highly glycosylated TTS proteins in the 50- to 100-kDa molecular mass range accumulate in the sepals of these transgenic, 35S-NAG plants. These results show that the tobacco NAGI gene, together with other yet unidentified regulatory factors, control the expression of TTS genes and the cellular capacity to glycosylate TTS proteins, which are normally expressed very late in the pistil developmental pathway and function in the final stage of floral development. The sepals in the transgenic 35S-NAG plants also support efficient pollen germination and tube growth, similar to what normally occurs in the pistil, and this ability correlates with the accumulation of the highest levels of the 50- to 100-kDa glycosylated TTS proteins.

A large-capacity memory system that recognizes the calls and songs of individual birds.

Auditory responses in the caudomedial neostriatum (NCM) of the zebra finch (Taeniopygia guttata) forebrain habituate to repeated presentations of a novel conspecific song. This habituation is long lasting and specific to individual stimuli. We here test the acoustic and ethological basis of this stimulus-specific habituation by recording extracellular multiunit activity in the NCM of awake male and female zebra finches presented with a variety of conspecific and heterospecific vocalizations, white noise, and tones. Initial responses to conspecific song and calls and to human speech were higher than responses to the other stimuli. Immediate habituation rates were high for all novel stimuli except tones, which habituated at a lower rate. Habituation to conspecific calls and songs outlasted habituation to other stimuli. The extent of immediate habituation induced by a particular novel song was not diminished when other conspecific songs were presented in alternation. In addition, the persistence of habituation was not diminished by exposure to other songs before testing, nor was it influenced by gender or laterality. Our results suggest that the NCM is specialized for remembering the calls and songs of many individual conspecifics.

The cell wall components peptidoglycan and lipoteichoic acid from Staphylococcus aureus act in synergy to cause shock and multiple organ failure.

Although the incidence of Gram-positive sepsis has risen strongly, it is unclear how Gram-positive organisms (without endotoxin) initiate septic shock. We investigated whether two cell wall components from Staphylococcus aureus, peptidoglycan (PepG) and lipoteichoic acid (LTA), can induce the inflammatory response and multiple organ dysfunction syndrome (MODS) associated with septic shock caused by Gram-positive organisms. In cultured macrophages, LTA (10 micrograms/ml), but not PepG (100 micrograms/ml), induces the release of nitric oxide measured as nitrite. PepG, however, caused a 4-fold increase in the production of nitrite elicited by LTA. Furthermore, PepG antibodies inhibited the release of nitrite elicited by killed S. aureus. Administration of both PepG (10 mg/kg; i.v.) and LTA (3 mg/kg; i.v.) in anesthetized rats resulted in the release of tumor necrosis factor alpha and interferon gamma and MODS, as indicated by a decrease in arterial oxygen pressure (lung) and an increase in plasma concentrations of bilirubin and alanine aminotransferase (liver), creatinine and urea (kidney), lipase (pancreas), and creatine kinase (heart or skeletal muscle). There was also the expression of inducible nitric oxide synthase in these organs, circulatory failure, and 50% mortality. These effects were not observed after administration of PepG or LTA alone. Even a high dose of LTA (10 mg/kg) causes only circulatory failure but no MODS. Thus, our results demonstrate that the two bacterial wall components, PepG and LTA, work together to cause systemic inflammation and multiple systems failure associated with Gram-positive organisms.

Incorporation of acetylcholine receptors and Cl- channels in Xenopus oocytes injected with Torpedo electroplaque membranes.

A method was developed to transplant assembled nicotinic acetylcholine receptors (AcChoRs) and Cl- channels from the electric organ of Torpedo to the membrane of Xenopus oocytes. Membrane vesicles from Torpedo electroplaques were injected into the oocytes and, within a few hours, the oocyte membrane acquired AcChoRs and Cl- channels. The mechanism of expression of these receptors and channels is very different from that which follows the injection of mRNA, since the appearance of receptors after membrane injection does not require de novo protein synthesis or N-glycosylation. This, and other controls, indicate that the foreign receptor-bearing membranes fuse with the oocyte membrane and cause the appearance of functional receptors and channels. All this makes the Xenopus oocyte an even more powerful tool for studies of the structure and function of membrane proteins.

Short nomenclator or vocabular in English and Hebrew: composed alphabetically for the use and benefit of my pupils in particular and for the advantage of those who are desirous to obtain the knowledge of the Hebrew tongue in general, which may be that great help to understand not only ye sacred oracles in their original, but even any Jewish author (so far as concern owns) as also it may give great insight in ye tongue to those, as to compose it, a work altogether new, [ca. 1735]

Headed on the first page with the words "Nomenclatura hebraica," this handwritten volume is a vocabulary with the Hebrew word in the left column, and the English translation on the right. While the book is arranged in sections by letter, individual entries do not appear in strict alphabetical order. The small vocabulary varies greatly and includes entries like enigma, excommunication, and martyr, as well as cucumber and maggot. There are translations of the astrological signs at the end of the volume. Poem written at the bottom of the last page in different hand: "Women when good the best of saints/ that bright seraphick lovely/ she, who nothing of an angel/ wants but truth & immortality./ Verse 2: Who silken limbs & charming/ face. Keeps nature warm."

Compression Loading Induced Cellular Stress Response of Intervertebral Disc Cells in Organ Culture

Introduction: Mechanical stress is often associated to interverterbal disc (IVD) degeneration and the effect of mechanical loading on IVD has been studied and reviewed.1,2 Previously, expression of heat shock proteins, HSP70 and HSP27 has been found in pathological discs.3 However, there is no direct evidence on whether IVD cells respond to the mechanical loading by expression of HSPs. The objective of this study is to investigate the stress response of IVD cells during compressive loading in an organ culture. Materials and Methods: Fresh adult bovine caudal discs were cultured with compressive loading applied at physiological range. Effect of loading type (static and dynamic) and repeated loading (2 hours per day for 2 days) were studied. Nucleus pulposus (NP) and annulus fibrosus (AF) of the IVD were retrieved at different time points: right after loading and right after resting. Positive control discs were heat shocked (43°C). Cell activity was assessed and expression of stress response genes (HSP70 and HSF1) and matrix remodeling genes (ACAN, COL2, COL1, ADAMTS4, MMP3 and MMP13) were studied. Results: Cell activity was maintained in all groups. Both NP and AF expressed high level of HSP70 in heat shock groups, confirming their expression in response to stress. In NP, expression of HSP70 was up-regulated after static loading and dynamic loading with higher fold change was observed after static loading. During repeated loading, HSP70 appeared to be upregulated right after loading and decreased after resting. Such trend was not observed in AF and HSF1 levels. Expressions of matrix remodeling genes did not change significantly with loading except ADAMTS4 decreased in AF during static loading. Conclusion: This study demonstrated that NP cells upregulate expression of HSP70 in response to loading induced stress without changing cell activity and matrix remodeling significantly. Acknowledgments: This project was funded by AO Spine (AOSPN) (grant number: SRN_2011_14) and a fellowship exchange award by AO Spine Scientific Research Network (SRN).

Nocardia infection in solid organ transplant recipients: a multicenter European case-control study.

BACKGROUND  Nocardiosis is a rare, life-threatening opportunistic infection, affecting 0.04% to 3.5% of patients after solid organ transplantation (SOT). The aim of this study was to identify risk factors for Nocardia infection after SOT and to describe the presentation of nocardiosis in these patients. METHODS  We performed a retrospective case-control study of adult patients diagnosed with nocardiosis after SOT between 2000 and 2014 in 36 European (France, Belgium, Switzerland, Netherlands, Spain) centers. Two control subjects per case were matched by institution, transplant date and transplanted organ. A multivariable analysis was performed using conditional logistic regression to identify risk factors for nocardiosis. RESULTS  One hundred and seventeen cases of nocardiosis and 234 control patients were included. Nocardiosis occurred at a median of 17.5 [range 2-244] months after transplantation. In multivariable analysis, high calcineurin inhibitor trough levels in the month before diagnosis (OR=6.11 [2.58-14.51]), use of tacrolimus (OR=2.65 [1.17-6.00]) and corticosteroid dose (OR=1.12 [1.03-1.22]) at the time of diagnosis, patient age (OR=1.04 [1.02-1.07]) and length of stay in intensive care unit after SOT (OR=1.04 [1.00-1.09]) were independently associated with development of nocardiosis; low-dose cotrimoxazole prophylaxis was not found to prevent nocardiosis. Nocardia farcinica was more frequently associated with brain, skin and subcutaneous tissue infections than were other Nocardia species. Among the 30 cases with central nervous system nocardiosis, 13 (43.3%) had no neurological symptoms. CONCLUSIONS  We identified five risk factors for nocardiosis after SOT. Low-dose cotrimoxazole was not found to prevent Nocardia infection. These findings may help improve management of transplant recipients.

Prognostic Value of Secretoneurin in Critically Ill Patients With Infections.

OBJECTIVES Secretoneurin is produced in neuroendocrine cells, and the myocardium and circulating secretoneurin levels provide incremental prognostic information to established risk indices in cardiovascular disease. As myocardial dysfunction contributes to poor outcome in critically ill patients, we wanted to assess the prognostic value of secretoneurin in two cohorts of critically ill patients with infections. DESIGN Two prospective, observational studies. SETTING Twenty-four and twenty-five ICUs in Finland. PATIENTS A total of 232 patients with severe sepsis (cohort #1) and 94 patients with infections and respiratory failure (cohort #2). INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS We measured secretoneurin levels by radioimmunoassay in samples obtained early after ICU admission and compared secretoneurin with other risk indices. In patients with severe sepsis, admission secretoneurin levels (logarithmically transformed) were associated with hospital mortality (odds ratio, 3.17 [95% CI, 1.12-9.00]; p = 0.030) and shock during the hospitalization (odds ratio, 2.17 [1.06-4.46]; p = 0.034) in analyses that adjusted for other risk factors available on ICU admission. Adding secretoneurin levels to age, which was also associated with hospital mortality in the multivariate model, improved the risk prediction as assessed by the category-free net reclassification index: 0.35 (95% CI, 0.06-0.64) (p = 0.02). In contrast, N-terminal pro-B-type natriuretic peptide levels were not associated with mortality in the multivariate model that included secretoneurin measurements, and N-terminal pro-B-type natriuretic peptide did not improve patient classification on top of age. Secretoneurin levels were also associated with hospital mortality after adjusting for other risk factors and improved patient classification in cohort #2. In both cohorts, the optimal cutoff for secretoneurin levels at ICU admission to predict hospital mortality was ≈ 175 pmol/L, and higher levels were associated with mortality also when adjusting for Simplified Acute Physiology Score II and Sequential Organ Failure Assessment scores. CONCLUSIONS Secretoneurin levels provide incremental information to established risk indices for the prediction of mortality and shock in critically ill patients with severe infections.

Sixty Irish songs : for high voice /

For high voice and piano.

My scrapbook of medicine : a series of squibs in prose and verse, presented in popular medicine style, that are calculated to throw a few highlights on some of the personages and some of the events that have made medical history : with bibliography and index /

"Some of these squibs have appeared in the monthly 'Bulletin' which is the official organ of the Academy of medicine of Toledo and Lucas county. They ran under the caption 'Medical phflugg'." - Pref.