The Symptoms and Histopathology of Poisoning by Maneb in Oncopeltus fasciatus (Dallas),

1965 ◽  
Vol 97 (11) ◽  
pp. 1200-1208 ◽  
Author(s):  
R. D. McMullen
Keyword(s):  
Oxygen Consumption ◽  
Malpighian Tubules ◽  
Oncopeltus Fasciatus ◽  
Secretory Cells ◽  
Cell Nuclei ◽  
Gut Epithelium

AbstractManeb (manganous ethylene bisdithiocarhamate) applied topically to Oncopeltus fasciatus nymphs causes death after 7 to 10 days. The gross symptoms of intoxication, histopathology and effect on oxygen consumption are described. Activities such as feeding and walking are slightly reduced after 24 hours and completely inhibited after 3 to 4 days. The tissues most severely affected by the treatment are the secretory cells of the mid-gut epithelium and the cells of the Malpighian tubules. These at first show extreme vacuolization, reduction of the size of cell nuclei and finally cytolysis. Oxygen consumption in vivo is reduced by the treatment.

scholarly journals Necrostatin-1 Supplementation to Islet Tissue Culture Enhances the In-Vitro Development and Graft Function of Young Porcine Islets

2021 ◽  
Vol 22 (16) ◽  
pp. 8367
Author(s):  
Hien Lau ◽  
Shiri Li ◽  
Nicole Corrales ◽  
Samuel Rodriguez ◽  
Mohammadreza Mohammadi ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Oxygen Consumption ◽  
Insulin Secretion ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
In Vitro Development ◽  
Porcine Islets ◽  
Vitro Development

Pre-weaned porcine islets (PPIs) represent an unlimited source for islet transplantation but are functionally immature. We previously showed that necrostatin-1 (Nec-1) immediately after islet isolation enhanced the in vitro development of PPIs. Here, we examined the impact of Nec-1 on the in vivo function of PPIs after transplantation in diabetic mice. PPIs were isolated from pancreata of 8–15-day-old, pre-weaned pigs and cultured in media alone, or supplemented with Nec-1 (100 µM) on day 0 or on day 3 of culture (n = 5 for each group). On day 7, islet recovery, viability, oxygen consumption rate, insulin content, cellular composition, insulin secretion capacity, and transplant outcomes were evaluated. While islet viability and oxygen consumption rate remained high throughout 7-day tissue culture, Nec-1 supplementation on day 3 significantly improved islet recovery, insulin content, endocrine composition, GLUT2 expression, differentiation potential, proliferation capacity of endocrine cells, and insulin secretion. Adding Nec-1 on day 3 of tissue culture enhanced the islet recovery, proportion of delta cells, beta-cell differentiation and proliferation, and stimulation index. In vivo, this leads to shorter times to normoglycemia, better glycemic control, and higher circulating insulin. Our findings identify the novel time-dependent effects of Nec-1 supplementation on porcine islet quantity and quality prior to transplantation.

scholarly journals Cellular correlates of gray matter volume changes in magnetic resonance morphometry identified by two-photon microscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Livia Asan ◽  
Claudia Falfán-Melgoza ◽  
Carlo A. Beretta ◽  
Markus Sack ◽  
Lei Zheng ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Cell Density ◽  
Gray Matter ◽  
Gray Matter Volume ◽  
Cell Nuclei ◽  
Cellular Mechanisms ◽  
Tissue Volume ◽  
Two Photon ◽  
Matter Volume

AbstractMagnetic resonance imaging (MRI) of the brain combined with voxel-based morphometry (VBM) revealed changes in gray matter volume (GMV) in various disorders. However, the cellular basis of GMV changes has remained largely unclear. We correlated changes in GMV with cellular metrics by imaging mice with MRI and two-photon in vivo microscopy at three time points within 12 weeks, taking advantage of age-dependent changes in brain structure. Imaging fluorescent cell nuclei allowed inferences on (i) physical tissue volume as determined from reference spaces outlined by nuclei, (ii) cell density, (iii) the extent of cell clustering, and (iv) the volume of cell nuclei. Our data indicate that physical tissue volume alterations only account for 13.0% of the variance in GMV change. However, when including comprehensive measurements of nucleus volume and cell density, 35.6% of the GMV variance could be explained, highlighting the influence of distinct cellular mechanisms on VBM results.

The anterior and posterior ‘stomach’ regions of larval Aedes aegypti midgut: regional specialization of ion transport and stimulation by 5-hydroxytryptamine

1999 ◽  
Vol 202 (3) ◽  
pp. 247-252 ◽  
Author(s):  
T.M. Clark ◽  
A. Koch ◽  
D.F. Moffett
Keyword(s):  
Steady State ◽  
Aedes Aegypti ◽  
Ion Transport ◽  
Malpighian Tubules ◽  
Transport Mechanisms ◽  
Regional Specialization ◽  
Negative Deflection ◽  
Electrical Polarity

The ‘stomach’ region of the larval mosquito midgut is divided into histologically distinct anterior and posterior regions. Anterior stomach perfused symmetrically with saline in vitro had an initial transepithelial potential (TEP) of −66 mV (lumen negative) that decayed within 10–15 min to a steady-state TEP near −10 mV that was maintained for at least 1 h. Lumen-positive TEPs were never observed in the anterior stomach. The initial TEP of the perfused posterior stomach was opposite in polarity, but similar in magnitude, to that of the anterior stomach, measuring +75 mV (lumen positive). This initial TEP of the posterior stomach decayed rapidly at first, then more slowly, eventually reversing the electrical polarity of the epithelium as lumen-negative TEPs were recorded in all preparations within 70 min. Nanomolar concentrations of the biogenic amine 5-hydroxytryptamine (5-HT, serotonin) stimulated both regions, causing a negative deflection of the TEP of the anterior stomach and a positive deflection of the TEP of the posterior stomach. Phorbol 12,13-diacetate also caused a negative deflection of the TEP of the anterior stomach, but had no effect on the TEP of the posterior stomach. These data demonstrate that 5-HT stimulates region-specific ion-transport mechanisms in the stomach of Aedes aegypti and suggest that 5-HT coordinates the actions of the Malpighian tubules and midgut in the maintenance of an appropriate hemolymph composition in vivo.

Abstract 121: Development of Enzyme Replacement Therapy in Mammalian Models of Barth Syndrome

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Ana Dinca ◽  
Wei-Ming Chien ◽  
Michael Chin
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Cell Line ◽  
Single Gene ◽  
Barth Syndrome ◽  
Protein Therapy ◽  
Knock Out ◽  
Enzyme Replacement ◽  
C Terminus

Barth Syndrome (BTHS) is caused by a single gene mutation in the mitochondrial transacylase, tafazzin (TAZ), which results in impaired lipid metabolism leading to dysfunction in highly energetic tissues such as the heart and skeletal muscle. TAZ remodels the signature mitochondrial phospholipid, cardiolipin (CL), which is responsible for providing support to the electron transport chain. BTHS patients suffer from growth deficiencies, cardiomyopathy, hypotonia and neutropenia. Currently, treatment for patients with BTHS is supportive, seeking to ameliorate rather than prevent heart problems, skeletal muscle problems and recurring infections. Protein therapy, on the other hand, might treat and even prevent cardiac, skeletal muscle as well as infection-related morbidities. We designed a recombinant TAZ protein containing a cell penetrating peptide in its C-terminus, which enables the recombinant TAZ to penetrate cells and then treated TAZ-deficient cells with it. We tested the permeability of the recombinant protein by direct delivery to H9C2 cardiomyoblasts and found that the protein is successfully taken up by the cells. We have generated a CRISPR-mediated TAZ knock out cardiomyoblast cell line and we found that TAZ knock out cells show a decrease in oxygen consumption as compared to the wild type cells; this is consistent with data from BTHS patient-derived cells. We are using this cell line to assess the enzymatic activity of the delivered protein by conducting mitochondrial respiration measurements. We have also acquired a mouse model of BTHS and are testing the recombinant TAZ in vivo. Preliminary data shows an augmentation in oxygen consumption following treatment with TAZ. These results indicate that the protein is able to reach the mitochondria, where it is enzymatically active and able to enhance respiration. As the protein is able to rescue respiration in cells in which tafazzin was absent, this suggests that our approach should not only be able to prevent onset of symptoms, but also rescue the phenotype in already affected tissues.

Anti-diuresis in the blood-feeding insect Rhodnius prolixus Stål: the peptide CAP2b and cyclic GMP inhibit Malpighian tubule fluid secretion.

1997 ◽  
Vol 200 (17) ◽  
pp. 2363-2367 ◽  
Author(s):  
M C Quinlan ◽  
N J Tublitz ◽  
M J O'Donnell
Keyword(s):  
Cyclic Gmp ◽  
Physiological Role ◽  
Malpighian Tubule ◽  
Fluid Secretion ◽  
Blood Feeding ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Tubule Fluid ◽  
Secretion Rates

Rhodnius prolixus eliminates NaCl-rich urine at high rates following its infrequent but massive blood meals. This diuresis involves stimulation of Malpighian tubule fluid secretion by diuretic hormones released in response to distention of the abdomen during feeding. The precipitous decline in urine flow that occurs several hours after feeding has been thought until now to result from a decline in diuretic hormone release. We suggest here that insect cardioacceleratory peptide 2b (CAP2b) and cyclic GMP are part of a novel mechanism of anti-diuresis. Secretion rates of 5-hydroxytryptamine-stimulated Malpighian tubules are reduced by low doses of CAP2b or cyclic GMP. Maximal secretion rates are restored by exposing tubules to 1 mmol l-1 cyclic AMP. Levels of cyclic GMP in isolated tubules increase in response to CAP2b, consistent with a role for cyclic GMP as an intracellular second messenger. Levels of cyclic GMP in tubules also increase as urine output rates decline in vivo, suggesting a physiological role for this nucleotide in the termination of diuresis.

Diabetes increases stiffness of live cardiomyocytes measured by atomic force microscopy nanoindentation

2014 ◽  
Vol 307 (10) ◽  
pp. C910-C919 ◽  
Author(s):  
Juan C. Benech ◽  
Nicolás Benech ◽  
Ana I. Zambrana ◽  
Inés Rauschert ◽  
Verónica Bervejillo ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Physiological Condition ◽  
Diabetic Mice ◽  
Cell Nuclei ◽  
Buffer Solution ◽  
Isolated Cardiomyocytes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Myocardial Fibers

Stiffness of live cardiomyocytes isolated from control and diabetic mice was measured using the atomic force microscopy nanoindentation method. Type 1 diabetes was induced in mice by streptozotocin administration. Histological images of myocardium from mice that were diabetic for 3 mo showed disorderly lineup of myocardial cells, irregularly sized cell nuclei, and fragmented and disordered myocardial fibers with interstitial collagen accumulation. Phalloidin-stained cardiomyocytes isolated from diabetic mice showed altered (i.e., more irregular and diffuse) actin filament organization compared with cardiomyocytes from control mice. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) pump expression was reduced in homogenates obtained from the left ventricle of diabetic animals compared with age-matched controls. The apparent elastic modulus (AEM) for live control or diabetic isolated cardiomyocytes was measured using the atomic force microscopy nanoindentation method in Tyrode buffer solution containing 1.8 mM Ca2+ and 5.4 mM KCl (physiological condition), 100 nM Ca2+ and 5.4 mM KCl (low extracellular Ca2+ condition), or 1.8 mM Ca2+ and 140 mM KCl (contraction condition). In the physiological condition, the mean AEM was 112% higher for live diabetic than control isolated cardiomyocytes (91 ± 14 vs. 43 ± 7 kPa). The AEM was also significantly higher in diabetic than control cardiomyocytes in the low extracellular Ca2+ and contraction conditions. These findings suggest that the material properties of live cardiomyocytes were affected by diabetes, resulting in stiffer cells, which very likely contribute to high diastolic LV stiffness, which has been observed in vivo in some diabetes mellitus patients.

scholarly journals Active Microrheology of Intestinal Mucus in the Larval Zebrafish

2016 ◽  
Author(s):  
Michael J. Taormina ◽  
Raghuveer Parthasarathy
Keyword(s):  
Biological Fluid ◽  
Measurement Techniques ◽  
Model Organisms ◽  
Secretory Cells ◽  
Fluid Viscosity ◽  
Intestinal Microbes ◽  
Germ Free ◽  
Larval Zebrafish ◽  
Intestinal Mucus

Mucus is a complex biological fluid that plays a variety of functional roles in many physiological systems. Intestinal mucus in particular serves as a physical barrier to pathogens, a medium for the diffusion of nutrients and metabolites, and an environmental home for colonizing microbes. Its rheological properties have therefore been the subject of many investigations, thus far limited, however, to in vitro studies due to the difficulty of measurement in the natural context of the gut. This limitation especially hinders our understanding of how the gut microbiota interact with the intestinal environment, since examination of this calls not only for in vivo measurement techniques, but for techniques that can be applied to model organisms in which the microbial state of the gut can be controlled. We address this challenge by developing a method that combines magnetic microrheology, light sheet fluorescence microscopy, and microgavage of particles, applying this to the larval zebrafish, a model vertebrate. We present measurements of the viscosity of mucus within the intestinal bulb of both germ-free (devoid of intestinal microbes) and conventionally reared larval zebrafish. At the length scale probed (≈ 10 μ m), we find that mucus behaves as a Newtonian fluid, with no discernable elastic component. Surprisingly, despite known differences in the the number of secretory cells in germ-free zebrafish and their conventional counterparts, the fluid viscosity for these two groups was very similar. Our measurements provide the first in vivo measurements of intestinal mucus rheology at micron length scales in living animals, quantifying of an important biomaterial environment and highlighting the utility of active magnetic microrheology for biophysical studies.

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