A quantitative study of the growth and development of the ventral root in normal and experimental conditions

Development ◽  
1974 ◽  
Vol 32 (3) ◽  
pp. 819-833
Author(s):  
M. C. Prestige ◽  
Margaret A. Wilson
Keyword(s):  
Normal Development ◽  
Cell Number ◽  
Ventral Horn ◽  
Ventral Root ◽  
Limb Bud ◽  
Experimental Conditions ◽  
Collateral Sprouting ◽  
Cell Counts ◽  
Ventral Roots ◽  
Fibre Loss

1. The development of the ventral root (VR) in Xenopus has been studied by electron microscopy. Total fibre counts, and counts of classes of fibres were made from large photomontages of the whole of VR 9 at × 15000. 2. The total number of fibres in the root shows the same pattern of initial rise, peak, and subsequent decline that previous ventral horn (VH) cell counts had shown, The two curves overlay each other initially, but after the decline, there were apparently more cells than fibres. 3. Promyelin and myelin formation was seen at the time of the decline. There was no evidence that dying axons had started to myelinate. 4. In some animals the limb-bud was removed at the time of its first penetration by nerve fibres. The ventral roots developed normally for a week, but thereafter fibre loss was accentuated, advanced and more profound, so that after another week, no fibres were left. In these roots, no promyelin or myelin was formed. 5. In other animals, it was shown that there is no evidence for collateral sprouting in the ventral roots during normal development. 6. It is argued that the axons which die in normal development have already reached the limb-bud. 7. The correspondence between axon and cell number is discussed.

The response of the brachial ventral horn of Xenopus laevis to forelimb amputation during development

Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 453-468
Author(s):  
Joanne E. Fortune ◽  
Antonie W. Blackler
Keyword(s):  
Xenopus Laevis ◽  
Normal Development ◽  
Developmental Stages ◽  
Neuronal Degeneration ◽  
Neuronal Loss ◽  
Cell Loss ◽  
Cell Number ◽  
Ventral Horn ◽  
Cell Degeneration ◽  
Cell Numbers

The normal development of the brachial ventral horn of the frog Xenopus laevis and the response of the brachial ventral horn to complete forelimb extirpation at five developmental stages were assessed histologically. Differentiation of brachial ventral horn neurons occurred in pre-metamorphic tadpoles between stages 52/53 and 57. Mean cell number in the brachial ventral horn reached a peak of 2576 (S.E.M. = ±269, n = 2) per side of the spinal cord at stage 55 and decreased to 1070 (S.E.M. = ± 35, n =7) by the end of metamorphosis. Cell degeneration was presumed to be the mode of cell loss since it was most prevalent during the period of rapid decrease in cell numbers. The response of the ventral horn to forelimb removal varied with the stage of the animal at amputation. Following amputation at stage 52/53 or 54 the ipsilateral ventral horn neurons appeared less differentiated than those on the controlside and a rapid cell loss of about 80 % occurred on the operated side. These effects occurred more rapidly after ablation at stage 54 than at stage 52/53. Amputation at stage 58, 61, or 66 caused chromatolysis in the ventral horn, a period of relative cell excess on the operated side, and a delayed neuronal loss of 32–66%. It was concluded that excess cell degeneration accounted for cell loss and that suppression of normal neuronal degeneration caused the relative cell excess on the operated side. The data indicate that the brachial ventral horn was indifferent to the periphery before stage 54, was quickly affected by limb removal between stages 54 and 58, and by stage 58 had entered a phase in which a delay preceded cell death. No forelimb regeneration occurred.

241 STRATEGIES TO IMPROVE GLUTATHIONE CONTENT OF IN VITRO-MATURED BOVINE OOCYTES

2008 ◽  
Vol 20 (1) ◽  
pp. 200 ◽  
Author(s):  
E. C. Curnow ◽  
J. Ryan ◽  
D. Saunders ◽  
E. S. Hayes
Keyword(s):  
Oocyte Maturation ◽  
Colorimetric Assay ◽  
Calf Serum ◽  
Cumulus Cells ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Blastocyst Development ◽  
Experimental Conditions ◽  
Cell Counts

Glutathione is the main non-enzymatic defense against oxidative stress and a critical part of oocyte maturation and normal fertilization. Our aim was to test different strategies to manipulate cellular glutathione (GSH) content of bovine in-vitro-matured (IVM) oocytes and study the development of embryos produced from such oocytes. The reducing agents lipoic acid (LA, intracellular) and dihydrolipoic acid (DHLA, extracellular) were compared to the cell-permeable reduced glutathione (GSH) donor glutathione ethyl ester (OET) for their effect on oocyte GSH content, oocyte maturation, and blastocyst development (OET only). Reagents were purchased from Sigma (St. Louis, MO, USA) unless stated otherwise. Cumulus–oocyte complexes (COCs) were aspirated from abattoir-derived ovaries and matured for 24 h in a humidified atmosphere of 6% CO2 at 38.5�C in modified tissue culture medium (mTCM199) supplemented with 2% (LA, DHLA) or 10% (OET) fetal calf serum (FCS; Gibco, Grand Island, NY, USA), 0.1 IU bLH and 0.1 IU bFSH (Sioux Biochemicals, Sioux City, IA, USA). COCs were matured in the presence of either LA (100 µm) or DHLA (100 µm) alone or in combination with L-cystine (CYS; 0.6 mm), CYS alone, or OET at 1, 3, and 5 mm. COCs matured under control and experimental conditions were denuded of cumulus cells (40 IU hyaluronidase) and scored for maturity. GSH content of MII oocytes was determined by colorimetric assay (Northwest Life Science Specialties, LLC, Vancouver, WA, USA). Oocytes matured in OET were inseminated with frozen/thawed bull sperm (2 � 106 mL-1), cultured to the blastocyst stage (COOK bovine medium, COOK Australia, Brisbane, Queensland, Australia), and subjected to differential cell count (propidium iodide/Hoechst). GSH levels (mean � SEM) and developmental data (percentage) are expressed for n = 18–73 oocytes or embryos and were analyzed by ANOVA or chi-square test (significance, P ≤ 0.05). LA alone failed to increase oocyte GSH content over 2% FCS control levels (6.98 � 0.22 pmol/oocyte v. 5.26 � 0.4 pmol/oocyte). DHLA alone significantly increased oocyte GSH content (9.64 � 0.8 pmol/oocyte) compared to both LA and controls (10% FCS; 4.78 � 0.36 pmol/oocyte). CYS alone (10.18 � 0.58 pmol/oocyte) or in combination with LA (10.84 � 0.37 pmol/oocyte) or DHLA (9.75 � 0.66 pmol/oocyte) significantly increased GSH compared to controls. GSH content of MII oocytes matured in 5 mm OET (8.35 � 0.35 pmol/oocyte) was significantly higher compared to control (5.07 � 0.32 pmol/oocyte), 1 mm (4.21 � 0.18 pmol/oocyte), and 3 mm (7.12 � 0.35 pmol/oocyte) OET treatments. Maturation rates of oocytes were significantly reduced in 2% FCS (51.1–72%) compared to 10% FCS (90.5%). OET treatment (1–5 mm) did not significantly alter maturation rate compared to control (75–89.8%). Blastocyst development of IVM oocytes treated with 1 mm OET (22.5%) was significantly lower compared to 3 mm (42.3%) and 5 mm (41.1%) OET but not to control (33.6%). Blastocysts from IVM oocytes treated with 5 mm OET had significantly higher cell counts compared to controls (126 � 6.4 cells v. 100.8 � 5.2 cells). Bovine IVM is a valuable model for testing the efficacy of various strategies to increase oocyte cellular GSH. Both strategies improve oocyte GSH levels, and an increase in blastocyst cell number occurred with GSH donor treatment (5 mm OET).

An analysis of the condensation process during chondrogenesis in the embryonic chick hind limb

Development ◽  
1975 ◽  
Vol 33 (3) ◽  
pp. 581-606
Author(s):  
P. V. Thorogood ◽  
J. R. Hinchliffe
Keyword(s):  
Hind Limb ◽  
Mesenchymal Cell ◽  
Cell Number ◽  
Limb Bud ◽  
Condensation Process ◽  
Embryonic Chick ◽  
Cellular Events ◽  
Cell Counts

An analysis has been made of the pre-cartilaginous condensation stage in the development of the femur and tibia/fibula skeletal blastemata of the embryonic chick hind limb. Light microscopy serial sections were used to ‘map’ the mesenchymal cell condensations of both myogenic and chondrogenic anlagen in the limb-bud from stages 22 to 26 (Hamburger & Hamilton, 1951). Cell counts reveal that an increase in mesenchymal cell number per unit area occurs in the central chondrogenic locus at stage 24 (4½ days) prior to matrix formation. Electron microscopy, using a simultaneous double fixation with osmium and glutaraldehyde, reveals that the pre-chondrogenic cells are characterized by large areas of close surface contact between adjacent cells, as compared with the extensive intercellular spaces associated with undifferentiated mesenchymal cells. The results are discussed and related to other investigations of in vivo chondrogenesis and to analyses of cellular events during in vitro chondrogenesis. These observations are consistent with the theory that condensations are formed by a process of aggregation rather than by localized increased mitosis.

scholarly journals Development of Injectable Polydactyly-Derived Chondrocyte Sheets

2021 ◽  
Vol 22 (6) ◽  
pp. 3198
Author(s):  
Shiho Wasai ◽  
Eriko Toyoda ◽  
Takumi Takahashi ◽  
Miki Maehara ◽  
Eri Okada ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cartilage Damage ◽  
Enzyme Linked Immunosorbent Assay ◽  
Invasive Treatment ◽  
Experimental Conditions ◽  
Humoral Factors ◽  
Less Invasive ◽  
Cell Counts ◽  
Invasive Method ◽  
Injection Control

We are conducting a clinical study of the use of allogeneic polydactyly-derived chondrocyte sheets (PD sheets) for the repair of articular cartilage damage caused by osteoarthritis. However, the transplantation of PD sheets requires highly invasive surgery. To establish a less invasive treatment, we are currently developing injectable fragments of PD sheets (PD sheets-mini). Polydactyly-derived chondrocytes were seeded in RepCell™ or conventional temperature-responsive inserts and cultured. Cell counts and viability, histology, enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qPCR), and flow cytometry were used to characterize PD sheets-mini and PD sheets collected from each culture. To examine the effects of injection on cell viability, PD sheets-mini were tested in four experimental conditions: non-injection control, 18 gauge (G) needle, 23G needle, and syringe only. PD sheets-mini produced similar amounts of humoral factors as PD sheets. No histological differences were observed between PD sheets and PD sheets-mini. Except for COL2A1, expression of cartilage-related genes did not differ between the two types of PD sheet. No significant differences were observed between injection conditions. PD sheets-mini have characteristics that resemble PD sheets. The cell viability of PD sheets-mini was not significantly affected by needle gauge size. Intra-articular injection may be a feasible, less invasive method to transplant PD sheets-mini.

ATP concentrations and muscle tension increase linearly with muscle contraction

2003 ◽  
Vol 95 (2) ◽  
pp. 577-583 ◽  
Author(s):  
Jianhua Li ◽  
Nicholas C. King ◽  
Lawrence I. Sinoway
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Motor Nerve ◽  
Muscle Tension ◽  
Nerve Fibers ◽  
Ventral Root ◽  
Ventral Roots ◽  
Root Stimulation ◽  
Stimulation Of

Previous studies have suggested that activation of ATP-sensitive P2X receptors in skeletal muscle play a role in mediating the exercise pressor reflex (Li J and Sinoway LI. Am J Physiol Heart Circ Physiol 283: H2636–H2643, 2002). To determine the role ATP plays in this reflex, it is necessary to examine whether muscle interstitial ATP (ATPi) concentrations rise with muscle contraction. Accordingly, in this study, muscle contraction was evoked by electrical stimulation of the L7 and S1 ventral roots of the spinal cord in 12 decerebrate cats. Muscle ATPi was collected from microdialysis probes inserted in the muscle. ATP concentrations were determined by the HPLC method. Electrical stimulation of the ventral roots at 3 and 5 Hz increased mean arterial pressure by 13 ± 2 and 16 ± 3 mmHg ( P < 0.05), respectively, and it increased ATP concentration in contracting muscle by 150% ( P < 0.05) and 200% ( P < 0.05), respectively. ATP measured in the opposite control limb did not rise with ventral root stimulation. Section of the L7 and S1 dorsal roots did not affect the ATPi seen with 5-Hz ventral root stimulation. Finally, ventral roots stimulation sufficient to drive motor nerve fibers did not increase ATP in previously paralyzed cats. Thus ATPi is not largely released from sympathetic or motor nerves and does not require an intact afferent reflex pathway. We conclude that ATPi is due to the release of ATP from contracting skeletal muscle cells.

5-HT Prolongs Ventral Root Bursting Via Presynaptic Inhibition of Synaptic Activity During Fictive Locomotion in Lamprey

2005 ◽  
Vol 93 (2) ◽  
pp. 980-988 ◽  
Author(s):  
Eric J. Schwartz ◽  
Tatyana Gerachshenko ◽  
Simon Alford
Keyword(s):  
Synaptic Transmission ◽  
Presynaptic Inhibition ◽  
Cellular Level ◽  
Ventral Horn ◽  
Pattern Generation ◽  
Ventral Root ◽  
Synaptic Activity ◽  
Fictive Locomotion ◽  
Cellular Mechanisms ◽  
Bath Application

Locomotor pattern generation is maintained by integration of the intrinsic properties of spinal central pattern generator (CPG) neurons in conjunction with synaptic activity of the neural network. In the lamprey, the spinal locomotor CPG is modulated by 5-HT. On a cellular level, 5-HT presynaptically inhibits synaptic transmission and postsynaptically inhibits a Ca2+-activated K+ current responsible for the slow afterhyperpolarization (sAHP) that follows action potentials in ventral horn neurons. To understand the contribution of these cellular mechanisms to the modulation of the spinal CPG, we have tested the effect of selective 5-HT analogues against fictive locomotion initiated by bath application of N-methyl-d-aspartate (NMDA). We found that the 5-HT1D agonist, L694-247, dramatically prolongs the frequency of ventral root bursting. Furthermore, we show that L694-247 presynaptically inhibits synaptic transmission without altering postsynaptic Ca2+ -activated K+ currents. We also confirm that 5-HT inhibits synaptic transmission at concentrations that modulate locomotion. To examine the mechanism by which selective presynaptic inhibition modulates the frequency of fictive locomotion, we performed voltage- and current-clamp recordings of CPG neurons during locomotion. Our results show that 5-HT decreases glutamatergic synaptic drive within the locomotor CPG during fictive locomotion. Thus we conclude that presynaptic inhibition of neurotransmitter release contributes to 5-HT–mediated modulation of locomotor activity.

scholarly journals Human Physiological Responses to a Single Deep Helium-Oxygen Diving

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao-Chen Bao ◽  
Quan Shen ◽  
Yi-Qun Fang ◽  
Jian-guo Wu
Keyword(s):  
Oxidative Stress ◽  
Creatine Kinase ◽  
Blood Cell ◽  
Stress Responses ◽  
Physiological Stress ◽  
Open Water ◽  
Endothelial Activation ◽  
Cell Number ◽  
Cardiac Damage ◽  
Cell Counts

Objective: The objective of this study was to explore whether a single deep helium-oxygen (heliox) dive affects physiological function.Methods: A total of 40 male divers performed an open-water heliox dive to 80 m of seawater (msw). The total diving time was 280 min, and the breathing helium-oxygen time was 20 min. Before and after the dive, blood and saliva samples were collected, and blood cell counts, cardiac damage, oxidative stress, vascular endothelial activation, and hormonal biomarkers were assayed.Results: An 80 msw heliox dive induced a significant increase in the percentage of granulocytes (GR %), whereas the percentage of lymphocytes (LYM %), percentage of intermediate cells (MID %), red blood cell number (RBC), hematocrit (hCT), and platelets (PLT) decreased. During the dive, concentrations of creatine kinase (CK), a myocardial-specific isoenzyme of creatine kinase (CK-MB) in serum and amylase alpha 1 (AMY1), and testosterone levels in saliva increased, in contrast, IgA levels in saliva decreased. Diving caused a significant increase in serum glutathione (GSH) levels and reduced vascular cell adhesion molecule-1 (VCAM-1) levels but had no effect on malondialdehyde (MDA) and endothelin-1 (ET-1) levels.Conclusion: A single 80 msw heliox dive activates the endothelium, causes skeletal-muscle damage, and induces oxidative stress and physiological stress responses, as reflected in changes in biomarker concentrations.

Bile salt exposure increases proliferation through p38 and ERK MAPK pathways in a non-neoplastic Barrett’s cell line

2006 ◽  
Vol 290 (2) ◽  
pp. G335-G342 ◽  
Author(s):  
Kshama Jaiswal ◽  
Christie Lopez-Guzman ◽  
Rhonda F. Souza ◽  
Stuart J. Spechler ◽  
George A. Sarosi
Keyword(s):  
Bile Salt ◽  
Cell Line ◽  
P38 Mapk ◽  
Bile Salts ◽  
Bile Reflux ◽  
Cell Number ◽  
Brdu Incorporation ◽  
Neoplastic Progression ◽  
Mapk Pathways ◽  
Cell Counts

Bile reflux has been implicated in the neoplastic progression of Barrett’s esophagus (BE). Bile salts increase proliferation in a Barrett’s-associated adenocarcinoma cell line (SEG-1 cells) by activating ERK and p38 MAPK pathways. However, it is not clear that these findings in cancer cells are applicable to non-neoplastic cells of benign BE. We examined the effect of bile salts on three human cell lines: normal esophageal squamous (NES) cells, non-neoplastic Barrett’s cells (BAR cells), and SEG-1 cells. We hypothesized that bile salt exposure activates proproliferative and antiapoptotic pathways to promote increased growth in BE. NES, BAR, and SEG-1 cells were exposed to glycochenodeoxycholic acid (GCDA) at a neutral pH for 5 min. Proliferation was measured by Coulter counter cell counts and a 5-bromo-2′-deoxyuridine (BrdU) incorporation assay. GCDA-induced MAPK activation was examined by Western blot analysis for phosphorylated ERK and p38. Apoptosis was measured by TdT-mediated dUTP nick-end labeling and annexin V staining after GCDA and UV-B exposure. Statistical significance was determined by ANOVA. NES cells exposed to 5 min of GCDA did not increase cell number. In BAR cells, GCDA exposure increased cell number by 31%, increased phosphorylated p38 and ERK levels by two- to three-fold, increased BrdU incorporation by 30%, and decreased UV-induced apoptosis by 15–20%. In conclusion, in a non-neoplastic Barrett’s cell line, GCDA exposure induces proliferation by activation of both ERK and p38 MAPK pathways. These findings suggest a potential mechanism whereby bile reflux may facilitate the neoplastic progression of BE.

Rapid increase in mast cell numbers in canine central and peripheral airways

1988 ◽  
Vol 65 (1) ◽  
pp. 445-451 ◽  
Author(s):  
C. R. Turner ◽  
J. Kolbe ◽  
E. W. Spannhake
Keyword(s):  
Mast Cell ◽  
Airway Epithelium ◽  
Time Course ◽  
Isotonic Saline ◽  
Cell Movement ◽  
Cell Number ◽  
Small Airways ◽  
Cell Numbers ◽  
Peripheral Airways ◽  
Cell Counts

In preliminary studies of antigen-induced airway inflammation, we noted an apparent increase in peribronchiolar mast cell number. Experiments were thus undertaken to investigate the nature of this migration of mast cells into the central and peripheral airway epithelium and to determine its time course. The tracheae and small airways of 10 anesthetized mongrel dogs were exposed via a bronchoscope to Ascaris suum antigen (Ag), fMet-Leu-Phe (fMLP), ovalbumin (OVA), and isotonic saline (SAL). In the central airways, all stimuli provoked a significant increase (P less than 0.05) in mast cell numbers at the base of the airway epithelium within 3 h. In the peripheral airways, only Ag aerosol stimulated a significant mast cell increase compared with unexposed tissue. In a second series of experiments, the trachea of seven dogs were exposed to 0.026, 0.26, and 2.6 micrograms of Ag. The tissue was collected at 1, 3, 6, and 10 h after exposure. In these experiments, there was a significant mast cell increase seen within 1 h but it was not dose dependent. By 6-10 h after exposure, mast cell counts were not significantly different from the unexposed condition, which is consistent with the idea that some of the cells either degranulated or migrated into the airway lumen. We conclude that mast cell migration is an acute response that can be demonstrated within 1 h of stimulation with Ag. The observation that nonimmunological stimuli may, in some cases, also stimulate mast cell movement affords the possibility that this process represents a generalized response to airway irritation.

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