Spectropolarimetric fluctuations in a sunspot chromosphere

The instrumental advances made in this new era of 4 m class solar telescopes with unmatched spectropolarimetric accuracy and sensitivity will enable the study of chromospheric magnetic fields and their dynamics with unprecedented detail. In this regard, spectropolarimetric diagnostics can provide invaluable insight into magneto-hydrodynamic (MHD) wave processes. MHD waves and, in particular, Alfvénic fluctuations associated with particular wave modes were recently recognized as important mechanisms not only for the heating of the outer layers of the Sun's atmosphere and the acceleration of the solar wind, but also for the elemental abundance anomaly observed in the corona of the Sun and other Sun-like stars (also known as first ionization potential) effect. Here, we take advantage of state-of-the-art and unique spectropolarimetric Interferometric BIdimensional Spectrometer observations to investigate the relation between intensity and circular polarization (CP) fluctuations in a sunspot chromosphere. Our results show a clear link between the intensity and CP fluctuations in a patch which corresponds to a narrow range of magnetic field inclinations. This suggests the presence of Alfvénic perturbations in the sunspot. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.

Vascular Function Is Improved After an Environmental Enrichment Program

Environmental enrichment may slow cognitive decay possibly acting through an improvement in vascular function. Aim of the study was to assess the effects of a 7-month cognitive, social, and physical training program on cognitive and vascular function in patients with mild cognitive impairment. In a single-center, randomized, parallel-group study, 113 patients (age, 65–89 years) were randomized to multidomain training (n=55) or usual care (n=58). All participants underwent neuropsychological tests and vascular evaluation, including brachial artery flow-mediated dilation, carotid–femoral pulse wave velocity, carotid distensibility, and assessment of circulating hematopoietic CD34+ and endothelial progenitor cells. At study entry, an age-matched control group (n=45) was also studied. Compared with controls, patients had at study entry a reduced flow-mediated dilation (2.97±2.14% versus 3.73±2.06%; P =0.03) and hyperemic stimulus (shear rate area under the curve, 19.1±15.7 versus 25.7±15.1×10 −3 ; P =0.009); only the latter remained significant after adjustment for confounders ( P =0.03). Training improved Alzheimer disease assessment scale cognitive (training, 14.0±4.8 to 13.1±5.5; nontraining, 12.1±3.9 to 13.2±4.8; P for interaction visit×training=0.02), flow-mediated dilation (2.82±2.19% to 3.40±1.81%, 3.05±2.08% to 2.24±1.59%; P =0.006; P =0.023 after adjustment for diameter and shear rate area under the curve), and circulating hematopoietic CD34 + cells and prevented the decline in carotid distensibility (18.4±5.3 to 20.0±6.6, 23.9±11.0 to 19.5±7.1 Pa −1 ; P =0.005). The only clinical predictor of improvement of cognitive function after training was established hypertension. There was no correlation between changes in measures of cognitive and vascular function. In conclusion, a multidomain training program slows cognitive decline, especially in hypertensive individuals. This effect is accompanied by improved systemic endothelial function, mobilization of progenitor CD34 + cells, and preserved carotid distensibility.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01725178.

Sucralfate Prophylaxis of Fluorouracil-Induced Stomatitis

Aims and Background

Various attempts have been made to prevent 5-fluorouracil-induced stomatitis, with unsatisfactory results. Sucralfate is an aluminum hydroxide, complex of sulfated sucrose commonly used in the treatment of gastroduodenal ulcers. We used the compound in a phase II study to reduce and minimize the stomatotoxicity of 5-fluorouracil chemotherapy administered in a multiple-day schedule.

Methods

Fifty-two patients entered the study, and 129 cycles of chemotherapy were evaluated. Seven patients refused sucralfate rinses for taste intolerance.

Results

A low level of stomatotoxicity was recorded: grade 2 stomatitis was observed after 14 cycles (10.8%) and grade 3 after 3 cycles (2.3%).

Conclusions

Sucralfate administration could have a role in the prevention of 5-fluorouracil-induced stomatitis.

The cell biology of the thyroid-disrupting mechanism of dichlorodiphenyltrichloroethane (DDT)

OBJECTIVE

Dichlorodiphenyltrichloroethane (DDT) is an organochlorine known for its pesticide properties and for its negative effects on human health. It was banned in most countries for its toxicity to the endocrine system, but due to its persistence at clinically relevant concentrations in both soil and animal tissues, DDT is still linked to several health and social problems.

METHODS

We have previously shown that DDT exposure is causally related to the extracellular release of vesicular organelles such as microvesicles and/or exosomes by using immunocytochemistry with gold-tagged antibodies and various fluorescent membrane markers.

RESULTS

It is now well recognized that microvesicles and/or exosomes organelles are implicated in cell-to-cell communication, and that they are fundamental elements for transferring proteins, RNA, DNA, lipids and transcriptional factors among cells. In this short review, we discussed the role of extracellular vesicle formation in the thyroid-disrupting mechanism of DDT. In particular, we described how DDT, by dislodging the thyrotropin hormone (TSH) receptor from the raft containing compartments of the cells, prevents its activation and internalization.

CONCLUSION

Based on our earlier finding and on the large body of evidence here reviewed, we propose that DDT-induced formation of extracellular vesicles containing the TSH receptor could be directly involved in the development of autoimmune responses against the TSH receptor and that, therefore, their release could lead to the development of the Graves' disease.

Laparoscopic ventral rectopexy using biologic mesh for the treatment of obstructed defaecation syndrome and/or faecal incontinence in patients with internal rectal prolapse: a critical appraisal of the first 100 cases

BACKGROUND

Laparoscopic ventral mesh rectopexy (LVR) is gaining wider acceptance as the preferred procedure to correct internal as well as external rectal prolapse associated with obstructed defaecation syndrome and/or faecal incontinence. Very few reports exist on the use of biologic mesh for LVR. The aim of our study was to report the complication and recurrence rate of our first 100 cases of LVR for symptomatic internal rectal prolapse and/or rectocele using a porcine dermal collagen mesh.

METHODS

Prospectively collected data on LVR for internal rectal prolapse were analysed. Surgical complications and functional results in terms of faecal incontinence (measured with the Faecal Incontinence Severity Index = FISI) and constipation (measured with the Wexner Constipation Score = WCS) at 3, 6 and 12 months were analysed. It was considered an improvement if FISI or WCS scores were reduced by at least 25 % and a cure if the FISI score decreased to <10 and the WCS decreased to <5.

RESULTS

Between April 2009 and April 2013, 100 consecutive female patients (mean age 63 years, range 24-88 years) underwent LVR. All patients had internal rectal prolapse (grade III [n = 25] and grade IV [n = 75] according to the Oxford classification) and rectocele. Mean operative time was 85 ± 40 min. Conversion rate to open technique was 1 %. There was no post-operative mortality. Overall 16 patients (16 %) experienced 18 complications, including rectal perforation (n = 1), small bowel obstruction (n = 2), urinary tract infection (n = 8), subcutaneous emphysema (n = 3), wound haematoma (n = 2), long lasting sacral pain (n = 1) and incisional hernia (1). Median post-operative length of stay was 2 days. Ninety-eight out of 100 patients completed follow-up. At the end of follow-up, the mean FISI score improved from 8.4 (±4.0 standard deviation (SD) p = 0.003) to 3.3 ± 2.3 SD (p = 0.04). Incontinence improved in 37 out of 43 patients (86 %), and 31 patients (72 %) were cured. Similarly, the mean WCS score improved from 18.4 ± 11.6 SD to 5.4 ± 4.1 SD (p = 0.04). Constipation improved in 82 out of 89 patients (92 %), and 70 patients (79 %) were cured. No worsening of continence status, constipation or sexual function was observed. Fourteen patients (14 %) experienced persistence or recurrence of prolapse.

CONCLUSIONS

LVR using biologic mesh is a safe and effective procedure for improving symptoms of obstructed defaecation and faecal incontinence in patients with internal rectal prolapse associated with rectocele.

Thermodynamic and kinetic investigation of monoketo-aldehyde-peroxyhemiacetal (MKA), a stereolabile degradation product of dihydroartemisinin

Theβ⇆αepimerization process ofMKAhas been studied under a thermodynamic and kinetic point of view in several solvents. LSER analyses and molecular modeling calculations allowed an effective rationalization of the findings.

Modified laparoscopic ventral mesh rectopexy

We present a modified laparoscopic ventral mesh rectopexy procedure using biological mesh and bilateral anterior mesh fixation. The rectopexy is anterior with a minimal posterior mobilization. The rectum is symmetrically suspended to the sacral promontory through a mesorectal window.

Collagen matrix injection combined with flap repair for complex anal fistula

Several biomaterials have been proposed to treat anal fistula alone or in combination with other surgical procedures aiming to reduce recurrence rates while minimizing continence impairment. More recently a porcine dermal matrix injection has been proposed as infill biomaterial to treat fistulae. We propose an approach consisting of non-cutting seton positioning followed several weeks later by flap repair associated with dermal matrix injection into the fistula tracts. We report our experience with this two-staged procedure on 24 consecutive patients with complex anal fistulae with a median follow up of > 12 months. In our experience this two-stage approach seems to be safe and effective.

Binding, uptake, and degradation of internalized thyroglobulin in cultured thyroid and non-thyroid cells

Thyroid hormone release requires degradation of thyroglobulin (Tg) by thyroid epithelial cells, which occurs mainly in the lysosomal pathway following Tg endocytosis. Non-specific fluid-phase endocytosis is thought to be the main route of Tg uptake leading to degradation, whereas receptor- mediated endocytosis is believed to lead to post-endocytic pathways other than degradation. To gain more insights into these issues, we investigated handling of Tg by various cell types. Tg bound similarly to thyroid (FRTL-5, FRT) and non-thyroid (COS-7, IRPT) cells, indicating the presence of membrane-binding sites, presumably receptors, in both cell types. Tg was internalized and degraded by all cells and degradation paralleled uptake, with the exception of FRTL- 5 cells, in which a lower proportion of Tg was degraded, suggesting that in FRTL-5 cells mechanisms that target Tg to the various post-endocytic pathways (either receptors or postreceptorial factors) are differently represented. Immunoelectronmicroscopy showed a common path of endocytosis in FRTL-5, COS-7, and IRPT cells, namely the formation of pseudopods engulfing Tg, followed by internalization and accumulation of Tg in cytoplasmic vesicles and lysosomes. The fastest rate was observed in COS-7 cells, probably reflecting a lower impact of endocytic receptors. Our findings suggest that Tg uptake and degradation are not thyroid-specific, that Tg binding sites exist in different cell types, and that uptake and/or degradation are differently regulated in differentiated thyroid cells, presumably because of a different impact of endocytic receptors or post-endocytic mechanisms, which are probably responsible for the regulation of hormone release.

MEGAPOLI: concept of multi-scale modelling of megacity impact on air quality and climate

Abstract. The EU FP7 Project MEGAPOLI: "Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation" (http://megapoli.info) brings together leading European research groups, state-of-the-art scientific tools and key players from non-European countries to investigate the interactions among megacities, air quality and climate. MEGAPOLI bridges the spatial and temporal scales that connect local emissions, air quality and weather with global atmospheric chemistry and climate. The suggested concept of multi-scale integrated modelling of megacity impact on air quality and climate and vice versa is discussed in the paper. It requires considering different spatial and temporal dimensions: time scales from seconds and hours (to understand the interaction mechanisms) up to years and decades (to consider the climate effects); spatial resolutions: with model down- and up-scaling from street- to global-scale; and two-way interactions between meteorological and chemical processes.

Chemotherapy in very elderly cancer patients (85 years and over): A retrospective study

e20632

Background: Elderly cancer patients (pts) population is expanding due to demographic changes. Currently 2.4 % of Italian population is older than 85, with this group accounting ∼8 % of all cancer pts in our geographic area. Since very elderly (85 years and over) cancer pts are generally excluded from clinical trials, few data are available about tolerability of chemotherapy in this population. Methods: We conducted a retrospective analysis of cancer pts aged 85 years and over receiving chemotherapy for advanced disease in the years 2005–2007 in three Oncology Unit of the Regione Marche, Italy. Results: We identified 50 patients (26 males, 24 females) with a mean age of 86.4 (range 85–95), ECOG PS 0 (4 pts) 1 (25 pts) 2 (13 pts) 3 (8 pts). Type of cancer (pts): NSCLC (13), colorectal (11), breast (5), prostate (4), gastric (3), NHL (3), bladder (2), head-neck (2), ovarian (2), vulvar (1), skin (1), pancreas (1), GIST (1), UPT (1). Main co-morbidities included hypertension (18 pts), COPD (8 pts) and heart disease (6 pts). The median number of cycles in first line chemotherapy were 6 (1–44); 20 pts received 2 or more lines of chemotherapy (range 2–5). Dose reductions were planned in all pts: in 26 dose reduction was 30 %, in 22 was 50%, in 2 > 50 %. Most used drugs were: vinorelbine os or iv (14 pts), capecitabine (9 pts), gemcitabine (7 pts). Target agents were used in 7 pts (5 erlotinib, 2 gefitinib, 2 rituximab, 1 sunitinib). Ten partial responses were observed; main toxicities were: grade 3–4 neutropenia (10 %), grade 3 diarrhea (5 %), and 1 pts had grade 3 hand-foot syndrome. No treatment related deaths were observed. Conclusions: Very elderly cancer pts (85 years and over) in good PS and few co-morbid conditions receiving dose reduced chemotherapy experienced acceptable toxic effects; a partial response was documented in 10 out of 50 pts. The expanding use of chemotherapy and target therapy in this clinical setting has profound influence on health care management and costs. Prospective studies specifically designed for this pts population could clarify the benefit, in terms of quality of life and survival, of an interventionist instead of a supportive care only approach.

No significant financial relationships to disclose.

Identification of an isomer impurity in piperaquine drug substance

A significant contaminant of the antimalarial drug piperaquine (1,3-bis-[4-(7-chloroquinolyl-4)-piperazinyl-1]propane) has been identified using liquid chromatography-mass spectrometry (LC-MS) and 2D NMR spectroscopy (1H-1H COSY, 1H-13C HSQC, 1H-13C HMBC). The impurity was identified as the positional isomer 1-[(5-chloroquinolin-4)-piperazinyl]-3-[(7-chloroquinolin-4)-piperazinyl]propane. The impurity is formed because of contamination of batches of 4,7-dichloroquinoline (a precursor in the synthesis of piperaquine) with 4,5-dichloroquinoline. The amount of impurity (peak area impurity/peak area piperaquine using LC-UV at 347 nm) in old batches of piperaquine and in Artekin (the combination of dihydroartemisinin-piperaquine) ranged from 1.5 to 5%.

Extreme heat reduces and shifts United States premium wine production in the 21st century

Premium wine production is limited to regions climatically conducive to growing grapes with balanced composition and varietal typicity. Three central climatic conditions are required: (i) adequate heat accumulation; (ii) low risk of severe frost damage; and (iii) the absence of extreme heat. Although wine production is possible in an extensive climatic range, the highest-quality wines require a delicate balance among these three conditions. Although historical and projected average temperature changes are known to influence global wine quality, the potential future response of wine-producing regions to spatially heterogeneous changes in extreme events is largely unknown. Here, by using a high-resolution regional climate model forced by the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios A2 greenhouse gas emission scenario, we estimate that potential premium winegrape production area in the conterminous United States could decline by up to 81% by the late 21st century. While increases in heat accumulation will shift wine production to warmer climate varieties and/or lower-quality wines, and frost constraints will be reduced, increases in the frequency of extreme hot days (>35 degrees C) in the growing season are projected to eliminate winegrape production in many areas of the United States. Furthermore, grape and wine production will likely be restricted to a narrow West Coast region and the Northwest and Northeast, areas currently facing challenges related to excess moisture. Our results not only imply large changes for the premium wine industry, but also highlight the importance of incorporating fine-scale processes and extreme events in climate-change impact studies.

Differential tissue expression of a calpastatin isoform in Xenopus embryos

This study is aimed at demonstrating the role played by a calpastatin isoform (Xcalp3) in Xenopus embryos. A specific monoclonal antibody (mAb) was raised against a glutathione S-transferase (GST)-Xcalp3 fusion protein and characterized by immunoblotting and confocal fluorescence microscopy on stage 20-36 embryos. Under these conditions, calpastatin reactivity is associated with a major 110kDa protein fraction and preferentially expressed by notochord and somitic cells. In notochord cells, anti-calpastatin reactive sites were initially restricted to the luminal space of the vacuoles and later became diffused throughout the cytoplasm. In contrast, anti-calpastatin reactive sites in somitic cells were initially diffused throughout the cytoplasm and became restricted to a few intracellular granules in the later developmental stages. At the ultrastructural level, notochord cells appeared as flattened discs containing several vacuoles and numerous electron-dense granules. During transition from stages 26 to 32, electron-dense granules were gradually reduced in number as vacuoles enlarged in size and losed their calpastatin reactivity. Electron-dense granules were also present in myoblast cells and their number gradually reduced during development. To determine whether these observations bear any causal relationship to the calpain/calpastatin system, a number of Xenopus embryos were examined both ultrastructurally and histochemically following exposure to a specific calpain inhibitor (CI3). Under these conditions, Xenopus embryos exhibited an altered right-left symmetry and an abnormal axial shortening. In CI3-treated stage 32 embryos, notochord cells had a reduced vacuolar extension and exhibited at the same time an increase in granular content. The overall morphology of the somites was also distorted and myoblasts were altered both in shape and granular content. Based on these findings, it is concluded that the calpain/calpastatin may play an important role in the control of notochord elongation and somite differentiation during Xenopus embryogenesis.

Viral particles of the endogenous retrovirus ZAM from Drosophila melanogaster use a pre-existing endosome/exosome pathway for transfer to the oocyte

Background

Retroviruses have evolved various mechanisms to optimize their transfer to new target cells via late endosomes. Here, we analyzed the transfer of ZAM, a retroelement from Drosophila melanogaster, from ovarian follicle cells to the oocyte at stage 9–10 of oogenesis, when an active yolk transfer is occurring between these two cell types.

Results

Combining genetic and microscopic approaches, we show that a functional secretory apparatus is required to tether ZAM to endosomal vesicles and to direct its transport to the apical side of follicle cells. There, ZAM egress requires an intact follicular epithelium communicating with the oocyte. When gap junctions are inhibited or yolk receptors mutated, ZAM particles fail to sort out the follicle cells.

Conclusion

Overall, our results indicate that retrotransposons do not exclusively perform intracellular replication cycles but may usurp exosomal/endosomal traffic to be routed from one cell to another.

P300-based brain computer interface: Reliability and performance in healthy and paralysed participants

OBJECTIVE

This study aimed to describe the use of the P300 event-related potential as a control signal in a brain computer interface (BCI) for healthy and paralysed participants.

METHODS

The experimental device used the P300 wave to control the movement of an object on a graphical interface. Visual stimuli, consisting of four arrows (up, right, down, left) were randomly presented in peripheral positions on the screen. Participants were instructed to recognize only the arrow indicating a specific direction for an object to move. P300 epochs, synchronized with the stimulus, were analyzed on-line via Independent Component Analysis (ICA) with subsequent feature extraction and classification by using a neural network.

RESULTS

We tested the reliability and the performance of the system in real-time. The system needed a short training period to allow task completion and reached good performance. Nonetheless, severely impaired patients had lower performance than healthy participants.

CONCLUSIONS

The proposed system is effective for use with healthy participants, whereas further research is needed before it can be used with locked-in syndrome patients.

SIGNIFICANCE

The P300-based BCI described can reliably control, in 'real time', the motion of a cursor on a graphical interface, and no time-consuming training is needed in order to test possible applications for motor-impaired patients.

Carboplatin, doxorubicin and etoposide in the treatment of tumours of unknown primary site

The aim of this study was to assess the activity and toxicity of a platinum-based treatment on a group of patients with unknown primary tumours (UPTs). Patients with a diagnosis of UPT underwent a standard diagnostic procedure. Treatment was started within 2 weeks from diagnosis and consisted of carboplatin 400 mg m(-2) day 1, doxorubicin 50 mg m(-2) day 1, etoposide 100 mg m(-2) days 1-3, every 21 days. Response was evaluated after three courses and treatment continued in case of objective response (OR) or symptom control. A total of 102 patients were eligible. The median age was 59 years, sex male/female 54/48, histology was mainly adenocarcinoma or poorly differentiated carcinoma. Nodes, bone, liver and lung were the most frequently involved sites. In all, 79 patients received at least three courses of treatment; 26 patients received six courses or more. Six complete responses and 21 partial responses were observed, for a total of 27 of 102 ORs or 26.5% (95% confidence interval 18.2-36.1%). The median survival was 9 months and median progression-free survival was 4 months. Toxicity was moderate to severe, with 57.8% of patients experiencing grade III-IV haematological toxicity, mainly leucopenia. The regimen employed has shown activity in tumours of unknown primary site, but was associated with significant toxicity. Such toxicity may be considered unjustified, given the large proportion of patients with tumours not likely to respond. Efforts should therefore be addressed to identify predictors of response to chemotherapy, thus limiting aggressive treatment to those patients who could benefit from it.

Vitellin polypeptide pathways in late insect yolk sacs

A panel of monoclonal antibodies was raised against late yolk sacs of the stick insect Carausius morosus and tested by immunoblotting to establish the extent vitellin polypeptides are processed proteolytically during embryonic development. Cryosections of late yolk sacs were also examined by confocal laser microscopy to determine how vitellin cleavage products become spatially distributed amongst yolk granules during the same developmental period. Distinct labelling patterns were obtained on yolk granules depending on: (1) the nature of the proteolytic processing; (2) the origin of vitellin cleavage products; and ultimately (3) their molecular sizes. Monoclonal antibodies raised against vitellin cleavage products resulting from proteolytic processing appeared to label: (1) the entire volume of many yolk granules; (2) their limiting membrane; or (3) a number of small vesicles interposed between larger yolk granules. On the other hand, monoclonal antibodies against vitellin cleavage products that remain invariant throughout development appeared to label either the serosa membrane or the cytosolic space comprised between adjacent yolk granules. Data are interpreted as indicating that vitellin cleavage products may leak out from the yolk granules, gain access to the cytosolic space of the vitellophages and eventually percolate through the serosa membrane enclosing the yolk sac.

Serosa membrane plays a key role in transferring vitellin polypeptides to the perivitelline fluid in insect embryos

In mid-embryogenesis, the stick insect Carausius morosus comes to be comprised of three distinct districts: the embryo proper, the yolk sac and the perivitelline fluid. A monolayered epithelium, the so-called serosa membrane, encloses the yolk sac and its content of vitellophages and large yolk granules. During embryonic development, the yolk sac declines gradually in protein concentration due to Vt polypeptides undergoing limited proteolysis to yield a number of Vt cleavage products of lower molecular weights. mAbs 1D1 and 5H11 are monoclonal antibodies raised against some of the Vt cleavage products generated by this process in the yolk sac. At the confocal microscope, antibody fluorescence is initially associated with a few yolk granules, while it is gradually displaced in the cytosolic spaces of the vitellophages. With the proceeding of embryonic development, label appears also in the serosa membrane in the form of clustered dots. At the ultrastructural level, gold particles are initially associated with the vitellophages that are labeled on a few yolk granules and in the cytosolic space flanking the yolk granules. Subsequently, the serosa cells become labeled on vesicles close to the yolk granules or just underneath the plasma membrane. Inside the serosa cells, label is also associated with granules budding from the Golgi apparatus, but never with the intercellular channels percolating the serosa membrane. These observations are interpreted as indicating that Vt cleavage products leak out from the yolk granules into the cytosolic spaces of the vitellophages and are eventually transferred to the perivitelline fluid via transcytosis through the serosa cells.

Yolk granules are differentially acidified during embryo development in the stick insect Carausius morosus

Newly laid eggs of stick insects comprise a unique fluid ooplasm that is gradually partitioned into a number of yolk granules by invasion of secondary vitellophages. This study aimed at establishing how yolk granules become acidified in the course of embryonic development. Data show that acidified yolk granules are rather scarce and randomly distributed in vitellophages of early embryos, while they tend to increase gradually in number as development proceeds to completion. Yolk granule acidification is progressively more inhibited in the presence of increasing concentrations of chloroquine, monensin and bafilomycin. A pro-protease was identified cytochemically and by immunoblotting in yolk extracts of progressively more advanced embryos. A specific monoclonal antibody raised against this pro-protease helped to demonstrate that it is gradually processed to yield a lower molecular weight polypeptide as development proceeds to completion. This latter polypeptide was identified as a protease using electrophoresis in polyacrylamide gels containing yolk extracts. Simultaneous administration of a fluorescent substrate for cysteine protease and an acidotropic probe produced superimposable labelling patterns, suggesting that only acidified yolk granules possess a proteolytic activity. On the other hand, yolk granules probed simultaneously for acidification and latent pro-protease yielded labelling patterns partially superimposed. Pro-protease labelling is gradually lost as yolk granules are progressively more acidified during development. Distinct labelling patterns were also obtained in vitellophages processed for the simultaneous detection of pro-protease and protease, suggesting that the two activities are expressed by different yolk granule populations, and that one is gradually converted into the other as time goes by.

Reversible carnitine palmitoyltransferase inhibitors with broad chemical diversity as potential antidiabetic agents

A series of carnitine related compounds of general formula XCH(2)CHZRCH(2)Y were evaluated as CPT I inhibitors in intact rat liver (L-CPT I) and heart mitochondria (M-CPT I). Derivative 27 (ZR = -HNSO(2)R, R = C(12), X = trimethylammonium, Y = carboxylate, (R) form) showed the highest activity (IC(50) = 0.7 microM) along with a good selectivity (M-CPT I/L-CPTI IC(50) ratio = 4.86). Diabetic db/db mice treated orally with 27 showed a significant reduction of serum glucose levels.

Yolk utilization in stick insects entails the release of vitellin polypeptides into the perivitelline fluid

This study investigates the developmental fate of vitellin (Vt) polypeptides generated by limited proteolysis in an insect embryo. To this end, a number of polyclonal (pAb) and monoclonal antibodies (mAb) were raised against the yolk sac and the perivitelline fluid of late embryos of the stick insect Carausius morosus. Two dimensional immuno gel electrophoresis and Western blotting demonstrate that polypeptides resulting from Vt processing are present both in the yolk sac and the perivitelline fluid. At the confocal microscope, different labelling patterns were detected in the ooplasm depending on the stage of development attained by the embryo. At early developmental stages, label is associated with large unsegmented portions of the fluid ooplasm. During embryonic development, the fluid ooplasm is gradually transformed into yolk granules by intervention of vitellophages. Prior to dorsal closure, the yolk sac is separated from the perivitelline fluid by interposition of serosa cells (the so called serosa membrane). Several mAbs raised against the perivitelline fluid react specifically with this membrane suggesting that the release of Vt polypeptides from the yolk sac occurs by intracellular transit through the serosa cells. By immunocytochemistry, gold label appears associated with the cell surface and a number of vacuoles of the serosa membrane. These data are interpreted as suggesting that Vt polypeptides resulting from limited proteolysis in stick insect embryos are not exhaustively degraded within the yolk sac, but are instead transferred transcytotically to the perivitelline fluid through the serosa membrane.