Latent TGFβ-binding proteins regulate UCP1 expression and function via TGFβ2

Objective

Activation of brown adipose tissue (BAT) in humans has been proposed as a new treatment approach for combating obesity and its associated diseases, as BAT participates in the regulation of energy homeostasis as well as glucose and lipid metabolism. Genetic contributors driving brown adipogenesis in humans have not been fully understood.

Methods

Profiling the gene expression of progenitor cells from subcutaneous and deep neck adipose tissue, we discovered new secreted factors with potential regulatory roles in white and brown adipogenesis. Among these, members of the latent transforming growth factor beta-binding protein (LTBP) family were highly expressed in brown compared to white adipocyte progenitor cells, suggesting that these proteins are capable of promoting brown adipogenesis. To investigate this potential, we used CRISPR/Cas9 to generate LTBP-deficient human preadipocytes.

Results

We demonstrate that LTBP2 and LTBP3 deficiency does not affect adipogenic differentiation, but diminishes UCP1 expression and function in the obtained mature adipocytes. We further show that these effects are dependent on TGFβ2 but not TGFβ1 signaling: TGFβ2 deficiency decreases adipocyte UCP1 expression, whereas TGFβ2 treatment increases it. The activity of the LTBP3–TGFβ2 axis that we delineate herein also significantly correlates with UCP1 expression in human white adipose tissue (WAT), suggesting an important role in regulating WAT browning as well.

Conclusions

These results provide evidence that LTBP3, via TGFβ2, plays an important role in promoting brown adipogenesis by modulating UCP1 expression and mitochondrial oxygen consumption.

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Inhibition of LTBP2 and LTBP3 reduces secretion of TGFβ2.

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Both knockout of LTBP2/3 or TGFβ2 inhibit UCP1 expression and mitochondrial respiration in human adipocytes.

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Expression of TGFβ2 correlates with UCP1 expression in human adipose tissue.

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Treatment with TGFβ2 rescues inhibition of UCP1 by LTBP knockout during adipogenesis.

Coil embolization of a thoracic aorta hematoma with branch artery pseudoaneurysm - case report

Background

A thoracic aorta hematoma with branch artery pseudonaneurysm is a very rare complication of thoraric blunt trauma. The standard treatment of this type of injury is aortic endograft placement.

Case presentation

We present a case in which a thoracic aorta hematoma with branch artery pseudoaneurysm was treated with coil embolization instead of endografting.

Conclusions

Coil embolization of aortic injuries may be a safe and definitive treatment alternative in selected cases. This technique has the potential to reduce the risk of procedure-related complications.

Triplex doppler ultrasonography to describe the uterine arteries during diestrus and progesterone profile in pregnant and non-pregnant bitches of different sizes

Hemodynamics of uterine vascularization is modified throughout pregnancy to meet the increasing demand of the growing fetuses and triplex doppler ultrasonography is widely used in human medicine to study the uterine arteries and assess the fetal and placental conditions. The aim of our study was to confirm this observation in the bitch, to evaluate differences between bitches of different sizes and to study abnormal pregnancies. Forty-four bitches were monitored during the estrous period to determine ovulation and every 10 days from ovulation to 50 days post-ovulation: the resistivity (RI) and pulsatility (PI) indexes of the right uterine artery were measured as well as usual assessment of fetal development and follow up of the luteal function. Thirty-three out of forty-four bitches were pregnant, including 6 abnormal pregnancies (resorption of more than 10% of the embryos). We also divided them in four weight categories: 8 were small (<10 kg), 13 medium (10-25 kg), 13 large (>25-40 kg) and 10 were giant breeds (>40 kg). We observed that RI and PI decreased over time and were significantly lower for pregnant bitches compared to non-pregnant ones from 30 days post-ovulation. In contrast, RI and PI did not significantly vary with the size of the bitches and we could not determine a significant impact of abnormal pregnancies either. In conclusion, we found no significant difference related to the size of bitches in the RI and PI. The only significant difference between pregnant and non-pregnant bitches was observed from 30 days post-ovulation.

Improvement after two sessions of electroconvulsive therapy predicts final remission in in-patients with major depression

OBJECTIVE

To investigate whether early improvement, measured after two electroconvulsive therapy (ECT) sessions, is a good predictor of eventual remission in severely depressed in-patients receiving ECT.

METHOD

A prospective cohort study was performed that included 89 major depressive disorder in-patients treated with bilateral ECT. Sensitivity, specificity, and predictive values were computed for various definitions of early improvement (15%, 20%, 25%, and 30% reduction on the Montgomery Asberg depression rating scale (MADRS) score) after 1 week (i.e. two sessions) of ECT regarding prediction of remission (final MADRS score ≤ 9).

RESULTS

A 15% reduction in MADRS score appeared to be the best definition of early improvement, with modest sensitivity (51%) and relatively good specificity (79%). Kaplan-Meier analysis showed a more than 2-week shorter time to remission in patients with early improvement compared with patients lacking early improvement.

CONCLUSION

Early improvement during an ECT course may be assessed after two ECT sessions. Such improvement, defined as a 15% reduction in the MADRS score, is a moderately sensitive predictor for eventual remission in an in-patient population with severe major depression.

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

BACKGROUND

The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications.

METHODS

ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery.

RESULTS

The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784.

CONCLUSIONS

This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance.

CLINICAL TRIAL REGISTRATION

NCT03044899.

Interlaboratory Oral Anticoagulant Quality Assessment by the Netherlands Federation of Thrombosis Services

The 50 laboratories of the Netherlands Federation of Thrombosis Services, covering a population of 9 million and responsible for the laboratory control of approximately 150,000 patients under oral anticoagulation, have participated since 1974 in a voluntary external and internal quality control program. The external program comprises a monthly distribution to the member laboratories of a series of artificially prepared control blood samples, two of which are identical. The overall variation of the coagulation times found were 10% (CV) in 1974 and 8% (CV) in 1975. Performance improved rather abruptly at the beginning of 1975, after the application of a tight methodological standardization and improvement by the manufacturer of the thromboplastin preparation (Thrombotest) used by the great majority of the laboratories involved. The main source of variation was found to be random error in the Thrombotest determination, approximating 6%. Interbatch variation of Thrombotest and inter-aliquot variation of control blood samples both do amount to approximately 3% (CV). In terms of rabbit tissue thromboplastins, which have a lower sensitivity than Thrombotest (i. e., a flatter slope of the correlation between the PT and the anticoagulant effect), the total variation in the performance of the Dutch laboratories is 2.2-5.6% (CV), which is unusually low. The main reason for this is the fact that the laboratories can rely not only on the services of the manufacturer but also on a central information office and a reference laboratory responsible for the preparation of the control blood as well as the standardization (calibration) of thromboplastin.

Progressive Antithrombin and Fibrinogen The Antithrombin Time According to Innerfield and its Relation to Acute Pancreatitis

Innerfield’s method of determining antithrombin III using plasma “defibrinated” by thrombin is submitted to criticsm. This method proves to involve insufficient defibrination: the higher the fibrinogen concentration of the plasma to be tested, the larger the fibrinogen remnant after “defibrination”. The residual fibrinogen interferes in the determinations of antithrombin III, as fibrin (antithrombin I) adsorbes thrombin; an increase in antithrombin III activity is suggested. This becomes manifest in all conditions associated with hyperfibrinogenaemia, including acute pancreatitis.

A “New” Family with Stuart-Prower Deficiency

A description is given of the coagulation disturbances in six patients with a haemorrhagic diathesis due to Stuart-Prower deficiency. Relatives of these patients, if heterozygous for this deficiency, showed no significant haemorrhagic diathesis; in the laboratory, their one-stage “prothrombin” times showed only a slight prolongation. Thromboplastin formation in these relatives was sufficient, but determination of the Stuart-Prower factor revealed lower values. The relatives in question were incapable of giving the same correction of the thromboplastin generation test in their bleeder relatives as normal serum does.

The relation between Stuart-Prower deficiency and Christmas factor is discussed.

One patient is described who combined heterozygotism for Stuart-Prower deficiency with alcaptonuria.

The mode of inheritance of the Stuart-Prower deficiency is discussed.

Blood Coagulation as a Continuous Process

In order to study the phenomenon of spontaneous hemorrhages in cases of diminished clotting power, we performed an investigation with the aid of the electron-microscope by means of a replica technique, on the aspect of aorta endothelium in two groups of rabbits, the first with a normal clotting power, the second with a hypocoagulability. Comparison of these two groups revealed two points of discrepancy. In the first place, in all the preparations of normal rabbits we saw fibres lying perpendicular to the borderlines of endothelial cells. These fibres were hardly seen under conditions of hypocoagulability, which is one of the arguments for equating these filaments with fibrin. In the second place, the nuclei of endothelial cells were less prominent into the vascular lumen in hypocoagulability than in cases of normal clotting power. From these observations and from some theoretical arguments we came to the hypothesis that blood coagulation is a continuous process which lays down fibrin fibres on the endothelium and which influences the swelling of the cytoplasm of endothelial cells. We could not get more information concerning the problem of how erythrocytes can penetrate endothelium in cases of hypocoagulability by studying the aspect of the blood-urine barrier in the glomeruli in the same two groups of rabbits.

Two years' experience with inspiration breath-hold in liver SBRT

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The workflow of inspiration breath-hold SBRT for liver metastases is described.

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Inspiration breath-hold in liver SBRT is feasible for 95% of the patients.

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An individual margin recipe for inspiration breath-hold liver SBRT is explained.

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Margin reduction of 10 mm using inspiration breath-hold compared to free breathing.

Circulating levels of miR-122 and nonalcoholic fatty liver disease in pre-pubertal obese children

OBJECTIVES

The liver-specific miR-122 was proposed as biomarker for NAFLD in adults. Here, we investigated the relationship between miR-122 levels, parameters of liver metabolism and NAFLD in pre-pubertal obese children.

METHODS

Parameters of liver metabolism (ALT, AST and GGT) of three European cohorts were included (German cohort [n = 71; age: 11.53 ± 1.29 years; BMI z-score: 2.96 ± 0.64], Italian cohort [n = 45; age: 9.60 ± 2.11 years; BMI z-score: 3.57 ± 1.16], Slovenian cohort [n = 31; age: 7.53 ± 1.47 years; BMI z-score: 3.66 ± 0.88]). MiR-122 levels and CK18 concentrations were measured in fasting blood samples. In the German and Italian cohort, the diagnosis of NAFLD and grading of NAFLD was assessed by ultrasound.

RESULTS

NAFLD was diagnosed in n = 50 patients of the German cohort (29.6%) and in n = 29 patients (72.5%) of the Italian cohort. In all three cohorts, miR-122 was positively correlated with ALT and AST as well as with CK18 concentrations. MiR-122 levels were higher in children with NAFLD compared with healthy controls.

CONCLUSIONS

MiR-122 levels in pre-pubertal obese children could be a potential biomarker for paediatric NAFLD.

A case of small-bowel obstruction after insertion of a percutaneous endoscopic gastrostomy tube due to mesenteric penetration

A case of small-bowel obstruction after insertion of a percutaneous endoscopic gastrostomy (PEG) tube is described. At laparotomy, the PEG tube was found to have penetrated the jejunal mesentery at two points, thereby acting as a focus for a volvulus. Direct injury and obstruction to the small bowel have been described but volvulus due to mesenteric penetration has not.

Absence of orbital currents in superconducting YBa2Cu4O8 using a zeeman-perturbed nuclear-quadrupole-resonance technique

Zeeman perturbed nuclear quadrupole resonance was applied to evaluate weak magnetic fields in the context of orbital currents in cuprate superconductors. The magnetic environment of the barium atom in c-axis oriented powder samples of YBa(2)Cu(4)O(8) was investigated in the pseudogap phase at 90 K. No evidence for orbital currents was found: any static and dynamic field must be less than 0.07 and 0.7 mT, respectively.

Lack of evidence for orbital-current effects in the high-temperature Y2Ba4Cu7O15-delta superconductor using 89Y nuclear magnetic resonance

We have performed NMR measurements at the Y site on a c-axis-oriented powder sample of the cuprate superconductor Y2Ba4Cu7O15-delta to search for the possible orbital-current phase. The temperature dependence of the Y linewidth and relaxation behavior in the normal-conducting phase were studied down to 100 K. These measurements give upper limits for a static magnetic field and the amplitude of a fluctuating magnetic field at the Y site of < or approximately 0.15 and < or approximately 0.7 mT, respectively. These values provide significant constraints on possible static or quasistatic orbital currents.

Mechanical thrombo-embolectomy in acute ischaemic stroke: a local experience

Large-vessel ischaemic strokes have a very poor natural history. Thombolysis is indicated for the treatment of ischaemic stroke but in practice is given to less than 10% of stroke sufferers, and its efficacy in large-vessel occlusion is poor. Mechanical embolectomy is a new therapy that allows attempted revascularisation up to eight hours after stroke onset. With its improved efficacy, it therefore offers some hope to patients admitted with this devastating condition.

Should human chondrocytes fly? The impact of electromagnetic irradiation on chondrocyte viability and implications for their use in tissue engineering

A significant logistic factor as to the successful clinical application of the autologous tissue engineering concept is efficient transportation: the donor cells need to be delivered to tissue processing facilities which in most cases requires air transportation. This study was designed to evaluate how human chondrocytes react to X-ray exposure. Primary cell cultures were established, cultured, incubated and exposed to different doses and time periods of radiation. Subsequently, quantitative cell proliferation assays were done and qualitative evaluation of cellular protein production were performed. Our results show that after irradiation of chondrocytes with different doses, no significant differences in terms of cellular viability occurred compared with the control group. These results were obtained when chondrocytes were exposed to luggage transillumination doses as well as exposure to clinically used radiation doses. Any damage affecting cell growth or quality was not observed in our study. However, information about damage of cellular DNA remains incomplete.

[Osteofluorosis caused by excess use of toothpaste]

BACKGROUND

Osteofluorosis is caused by chronic fluoride intoxication. Fluoride is used in toothpaste for the prevention of dental caries, and dental fluorosis has often been reported among children and attributed to ingestion of fluoride toothpaste. We report a case of chronic fluoride intoxication caused by excess use of toothpaste in an adult.

CASE

A 45-year-old woman consulted a rheumatologist for painful swelling of the fingers, phalangeal rather than articular. She also had brown staining on her teeth. Radiography of the hands showed periosteal apposition on the phalanges. Further work-up ruled out tumoral or thyroid causes. Laboratory tests showed elevated fluoride levels in the blood (50.9 micromol/L, normal<1.5 micromol/L) and in the urine (721 micromol/L, normal<46 micromol/L). On questioning, we found only one cause for chronic fluoride intoxication: excess and unusual use of toothpaste. The patient brushed her teeth 18 times a day and swallowed the toothpaste, because she liked the taste. She consumed a tube of toothpaste every 2 days, thereby swallowing 68.5 mg of fluoride every day. Suspecting fluorosis from toothpaste, we asked the patient to use a toothpaste without fluoride. Sixteen weeks later, the pain had ceased, and laboratory tests showed massively reduced but still elevated fluoride levels in the blood (6.9 micromol/L) and urine (92.7 micromol/L).

CONCLUSION

In this rare case of fluoride intoxication, misuse of a normally innocuous product caused osteofluorosis.

[Application of multislice spiral CT (MSCT) in multiple injured patients and its effect on diagnostic and therapeutic algorithms]

The initial diagnostic work-up of trauma victims with multiple injuries is currently a combination of conventional radiography (CR), ultrasound (US), and computed tomography (CT). This article reviews the diagnostic quality of the different imaging modalities regarding detection and classification of injuries. CT performs better than US in detecting traumatic lesions of abdominal parenchymal organs. Furthermore, CT is better than CR in detecting therapeutically relevant chest and bone injuries. MSCT may replace CR and US under the condition that it is faster than or at least as fast as the conventional approach to diagnose life threatening injuries. This can be achieved only by changing the work-flow for the entire trauma team including radiologist. Furthermore, certain prerequisites must be fulfilled including integration of a MSCT scanner into the emergency room. An optimized whole body CT protocol for the assessment of trauma victims using MSCT as well as a two-step algorithm for reporting the imaging findings depending on their clinical significance is presented.

Direct observation of the oxygen isotope effect on the in-plane magnetic field penetration depth in optimally doped YBa2Cu3O7-delta

We report the first direct observation of the oxygen-isotope ((16)O/(18)O) effect on the in-plane penetration depth lambda(ab) in a nearly optimally doped YBa(2)Cu(3)O(7-delta) film using the novel low-energy muon-spin rotation technique. Spin-polarized low-energy muons are implanted in the film at a known depth z beneath the surface and process in the local magnetic field B(z). This feature allows us to measure directly the profile B(z) of the magnetic field inside the superconducting film in the Meissner state and to make a straightforward determination of lambda(ab). A substantial isotope shift Delta lambda(ab)/lambda(ab)=2.8(1.0)% at 4 K is observed, implying that the in-plane effective supercarrier mass m*(ab) is oxygen-isotope dependent with Delta m*(ab)/m*(ab)=5.5(2.0)%. These results are in good agreement with magnetization measurements on powder samples.

[Initial examination for school attendance in Mannheim: language development at initial school entry level]

INTRODUCTION

In autumn 2001 the initial examination for school attendance in Mannheim has been fundamentally reorganised. The individual examination elements had been widely standardized, the results can be evaluated by regions and a diagnosis for the early detection of legasthenia has been developed.

METHODS

The testing involved repeating sentences, numbers and artificial words. This has been developed by the Pedagogical University Heidelberg. In pre-examinations in Heidelberg the results relate significantly to the subsequent results in reading and writing.

PROBANDS

A total of 2,744 children (46.1% girls, 53.9% boys) aged of 5 to 7 years was seen. 71.5% of the children were German nationality. Most non-German nationalities were Turkish (15.4%) and Italian (3.6%) children. Besides the nationality the mother tongue has been also recorded. More than 96% of the children had been attending a kindergarten. For judgement of the social strata the frequency of social welfare receivers has been recorded.

RESULTS

The testing results are significantly influenced by the native language and the social strata of the children. The results of children with German as native language are above those of non-Germans. Within the migrant children there are significant differences between the several nationalities. Children from a lower social strata achieved lower results. A positive effect to the language development is attributed to the attendance of a kindergarten.

CONCLUSION

These results are the basis for language- and general health supporting projects in Mannheim. For the examination for school attendance in the current year the diagnostic for language development has been extended by some more aspects.

Temperature and field dependence of the anisotropy of MgB2

The anisotropy gamma of the superconducting state of high quality single crystals of MgB2 was determined, using torque magnetometry with two different methods. The anisotropy of the upper critical field was found to be temperature dependent, decreasing from gamma approximately 6 at 15 K to 2.8 at 35 K. Reversible torque data near T(c) reveal a field dependent anisotropy, increasing nearly linearly from gamma approximately equal to 2 in zero field to 3.7 in 10 kOe. The unusual temperature dependence is a true bulk property and can be explained by nonlocal effects of anisotropic pairing and/or the k--> dependence of the effective mass tensor.

Expression of TCL1 in hematologic disorders

OBJECTIVE

TCL1, MTCP1 and TCL1b are three members of a new family of oncogenes that are expressed in T cell leukemias of ataxia telangiectasia patients (T-PLL, T-CLL). TCL1 is located at 14q32.1 and activated by juxtaposition to the alpha/delta-locus at 14q11 or beta-locus at 7q35 of the T cell receptor during the reciprocal translocations t(14;14)(q11;q32), t(7;14)(q35;q32), or inversion inv(14)(q11;q32). TCL1 encodes a predominantly cytoplasmic protein of 114 aa (14 kD) of unknown function. Recent studies suggest that TCL1 promotes cell survival rather than stimulating cell proliferation, as previously proposed.

METHODS

In an attempt to clarify the contexts in which TCL1 is expressed, we investigated TCL1 expression in 114 lymphoma and leukemia patients by Northern blot, RT-PCR and immunohistochemistry.

RESULTS

TCL1 expression is restricted to lymphoid cells, and is found in neoplastic (T and B cell neoplasms, and Hodgkin's disease) and nonneoplastic proliferations (reactive lesions). Out of 114 cases, 18 neoplasms of myeloid and 4 cases of epithelial origin were TCL1-negative. In lesions of the lymphoid system, both low- and high-grade lymphomas were found to express TCL1.

CONCLUSIONS

We propose that TCL1 expression especially in high-grade B cell non-Hodgkin's lymphomas might interfere with B cell differentiation and promote the transition from low- to high-grade lymphoma.

Maxillary implants loaded at 3 months after insertion: results with Astra Tech implants after up to 5 years

BACKGROUND

To date, clinical studies have mainly focused on early loading of mandibular implants. Recently, there has also been considerable interest in early loading of maxillary implants.

PURPOSE

The purpose of this article is to report the outcome of maxillary implants loaded after a 3-month healing period and followed up to 5 years.

MATERIALS AND METHODS

Seventeen patients (11 males and 6 females) received 44 Astra Tech implants (Mölndal, Sweden) for treatment of single-tooth (13 cases) and partial edentulism (9 cases). The patients were followed up to 5 years after implant placement: 50% of the implants were followed for 3 years and 16% have been followed throughout the observation period. Preoperatively, bone height and width were assessed on radiographs. Marginal bone loss was recorded on intraoral radiographs annually.

RESULTS

No implant was lost during the observation period. The average marginal bone loss was 0.5 +/- 0.7 mm after 1 year, 0.6 +/- 0.7 mm after 3 years, and 0.9 +/- 1.6 mm after 5 years. There were no soft-tissue or prosthetic failures recorded during the observation period.

CONCLUSION

Early loading of Astra Tech implants was highly successful in maxillary partial and single-tooth cases followed up to 5 years in function.

Charge degree of freedom and the single-spin fluid model in YBa2Cu4O8

We present a 17O nuclear magnetic resonance study in the stoichiometric superconductor YBa2Cu4O8. A double irradiation method enables us to show that, below around 200 K, the spin-lattice relaxation rate of plane oxygen is not only driven by magnetic fluctuations, but also significantly by quadrupolar fluctuations, i. e., low-frequency charge fluctuations. In the superconducting state, on lowering the temperature, the quadrupolar relaxation diminishes faster than the magnetic one. These findings show that, with the opening of the spin pseudogap, a charge degree of freedom of mainly oxygen character is present in the electronic low-energy excitation spectrum.

Drosophila Futsch regulates synaptic microtubule organization and is necessary for synaptic growth

We present evidence that Futsch, a novel protein with MAP1B homology, controls synaptic growth at the Drosophila neuromuscularjunction through the regulation of the synaptic microtubule cytoskeleton. Futsch colocalizes with microtubules and identifies cytoskeletal loops that traverse the lateral margin of select synaptic boutons. An apparent rearrangement of microtubule loop architecture occurs during bouton division, and a genetic analysis indicates that Futsch is necessary for this process. futsch mutations disrupt synaptic microtubule organization, reduce bouton number, and increase bouton size. These deficits can be partially rescued by neuronal overexpression of a futsch MAP1B homology domain. Finally, genetic manipulations that increase nerve-terminal branching correlate with increased synaptic microtubule loop formation, and both processes require normal Futsch function. These data suggest a common microtubule-based growth mechanism at the synapse and growth cone.

Drosophila Futsch/22C10 is a MAP1B-like protein required for dendritic and axonal development

Here we report the description of the Drosophila gene futsch, which encodes a protein recognized by the monoclonal antibody 22C10 that has been widely used to visualize neuronal morphology and axonal projections. The Futsch protein is 5327 amino acids in length. It localizes to the microtubule compartment of the cell and associates with microtubules in vitro. The N- and C-terminal domains of Futsch are homologous to the vertebrate MAP1B microtubule-associated protein. The central domain of the Futsch protein is highly repetitive and shows sequence similarity to neurofilament proteins of which no Drosophila homologs have been reported. Loss-of-function analyses demonstrate that during embryogenesis Futsch is necessary for dendritic and axonal growth. Gain-of-function analyses demonstrate a functional interaction of Futsch with other MAPs. In addition, we show that during development, futsch expression is negatively regulated in nonneuronal tissues.

Separation of quadrupolar and magnetic contributions to spin-lattice relaxation in the case of a single isotope

We present a NMR pulse double-irradiation method which allows one to separate magnetic from quadrupolar contributions in the spin-lattice relaxation. The pulse sequence fully saturates one transition while another is observed. In the presence of a ||Deltam || = 2 quadrupolar contribution, the intensity of the observed line is altered compared to a standard spin-echo experiment. We calculated analytically this intensity change for spins I = 1, 32, 52, thus providing a quantitative analysis of the experimental results. Since the pulse sequence we used takes care of the absorbed radiofrequency power, no problems due to heating arise. The method is especially suited when only one NMR sensitive isotope is available. Different cross-checks were performed to prove the reliability of the results obtained. The applicability of this method is demonstrated by a study of the plane oxygen (17)O (I = 52) in the high-temperature superconductor YBa(2)Cu(4)O(8): the (17)O spin-lattice relaxation rate consists of magnetic as well as quadrupolar contributions. Copyright 2000 Academic Press.

The endocytic machinery in nerve terminals surrounds sites of exocytosis

In most models of endocytosis, the endocytic machinery is recruited from the cytoplasm by cytoplasmic tails of the plasma membrane proteins that are to be internalized. This does not appear to be true at synapses where the endocytic machinery required for synaptic vesicle recycling is localized to membrane-associated 'hot spots' [1] [2]. In Drosophila neuromuscular junctions, the multi-domain protein Dap160 is also localized to hot spots [3] and has some characteristics expected of an anchoring protein. Anchoring the endocytic machinery to the plasma membrane might help contribute to the remarkable speed of synaptic vesicle recycling [4]. Here, we report that the endocytic machinery surrounds sites that are believed to be sites of exocytosis. We propose that the radial distribution of the synaptic vesicle recycling machinery already present on the plasma membrane in unstimulated nerve terminals is a fundamental unit of pre-synaptic organization and allows the nerve terminal to extract maximum recycling efficiency out of conventional endocytic machinery.