Commentary: Cellular Destruction vs Cellular Promotion

2014 ◽  
Vol 29 (1) ◽  
pp. e58
Author(s):  
Robert E. Marx
Keyword(s):  
1968 ◽  
Vol 17 (1) ◽  
pp. 182-184
Author(s):  
Pierre Dustin

Recently discovered substances with antimitotic action fall in the two categories which have been defined since many years, i. e. spindle poisons and chromatin (or “radiomimetic”) poisons. The most recently studied are hydroxyurea — a powerful inhibitor of DNA synthesis — and the Vinca alcaloids — which destroy the tubular components of the spindle, bringing a prolonged arrest in metaphase.The mechanisms of action of many of these drugs remain most obscure. In the field of spindle-poisons, there has been no explanation sofar of the relationship between their chemical structure and cytological action. While it is known that minor changes in the chemical structure of colchicine can prevent its specific action on the spindle, the precise relation which appears to exist between this complex molecule and the spindle structures remains obscure. The same remark applies to the Vinca alcaloids. Progress is being made however in this field. The ultrastructural aspects of the spindle have been analysed by electron microscopy, and a precise definition in chemical terms of the spindle may be close. These observations have shown the similarity between the tubules of the spindle and other tubular structures of identifical size: the neurotubules. Some recent observations indicate that these may also be destroyed by colchicine, a fact which may be related to the well-known and severe neurotoxicity of this alcaloid. What remains to be explained is the fact that the most effective spindle poisons are molecules of the size and complexity of those of vinblastine, while simple inorganic substances (arsenicals, heavy metals) may exert identical if not so powerful effects on the spindle structures. Another point which needs further research is the cause of the extensive cellular destruction which follows, in animal cells, any prolonged inhibition of the spindle function. The chemotherapic actions of spindle poisons are most probably related, not only to the growth inhibiting effects of these drugs, but most of all to the cellular breakdown which is observed in cells when they have been kept for several hours in metaphase.


1957 ◽  
Vol 26 (2) ◽  
pp. 421-424 ◽  
Author(s):  
K. Lauenstein ◽  
G.L. Haberland ◽  
L.H. Hempelman ◽  
K.I. Altman

1979 ◽  
Vol 25 (6) ◽  
pp. 680-685 ◽  
Author(s):  
C. K. Ho ◽  
L. A. Babiuk

A Vero cell adapted Green strain of canine distemper virus (CDV) was tested for its plaque-forming capacity in different cell lines. Plaque formation was observed in HEp-2, BS-C-I, and HeLa cells but not in Vero or dog kidney cells even though replication and cytopathology were observed in the latter cell types. In the cells in which the virus was capable of producing plaques, the plaques were observed within 24 h post infection and continued to increase in size with subsequent cellular destruction such that by 72 h postinfection the size of the plaques approached 0.5 mm. With the use of the plaquing technique, it was possible to demonstrate the thermal lability of the virus as well as the kinetics of adsorption. Thus, it was shown that the half-life of the virus was 125 min at 25 °C, 75 min at 35 °C, and 65 min at 37 °C. The rate of adsorption of CDV to HEp-2 cells was 17.2% in 30 min at 37 °C and continued slowly for 4 h before completion. Application of this rapid plaque-forming assay to plaque-reduction tests for CDV antibody and for CDV-infected cells by the infectious center assay are described.


1955 ◽  
Vol 101 (2) ◽  
pp. 197-204
Author(s):  
George P. Vennart ◽  
Frank W. McKee

In dogs maintained on low protein diets and subjected to phlebotomy over a long period of time, the inhalation of chloroform, for 30 minutes, produced uniform fatality within 48 hours. The histological changes of massive hepato-cellular destruction were observed at autopsy. Homocystine, in the amount of 2.0 gm., given orally 2 hours after or 2 hours prior to the administration of chloroform, protected dogs against the lethal action of the toxin. Inconstant changes in fibrinogen and icteric indices were observed in the protected animals, indicating some mild liver damage, but this was not correlated with the length of the previous depletion period, the phase of the experiment, or any other factor. No evidence was obtained that methyl groups are necessary for the protection of the liver by homocystine.


2016 ◽  
Author(s):  
Maríacruz López-Díaz ◽  
Julia Buján-Varela ◽  
Carlos Cadórniga-Valiño

ABSTRACTIn birds the construction of germline chimeras by grafting exogenous primordial germ cells (PGCs) during embryonic development is feasible since they migrate to the gonads through the blood. Up to date, the efficiencies are highly variable, in part dependent on the destruction of endogenous PGCs in the recipient embryo. We show an almost complete ablation of the endogenous PGCs in stage X embryos using a baby rabbit serum (BRS), with previous cellular signaling by specific antibodies (SSEA1). The application of the treatments, either on epiblast or subgerminaly, produced the reduction of the PGCs in the embryos in a dose dependent manner. No malformations or damages were detected in the treated embryos. However, subgerminal injection of this cocktail produced a massive cellular destruction in all embryos. Therefore, sequential application is a selective and effective method to produce receptor embryos. Nevertheless, it can also be highly destructive if the mixture is applied locally, this could be useful in the treatment of malignancies.SUMMARY STATEMENTAn immunosurgery procedure is described that yields an almost complete ablation of primordial germ cells in early developing chick embryos, thus increasing the expected rates of chimerism when foreign PGCs are grafted onto these embryos


2013 ◽  
Vol 57 (8) ◽  
pp. 659-662 ◽  
Author(s):  
Zhe Zhang ◽  
Chengjiang Li

Thyroidal 99mTc uptake in the acute thyrotoxic phase of subacute thyroiditis (SAT) is always inhibited. However, a patient with SAT had signs in the right-side thyroid gland with transient thyrotoxicosis and slightly high 99mTc uptake levels in the right lobe, low 99mTc uptake in the left lobe, and normal overall uptake. Histological examination showed cellular destruction and granulomatous inflammatory changes in the right lobe, with marked interstitial fibrosis in the left lobe. The patient was thyrotrophin-receptor antibody (TRAb) positive. After a short course of prednisolone, SAT-like symptoms and signs improved. TRAb-positivity resolved spontaneously after 22 months, and TSH levels were slightly low for 22 months. Levels then kept normal in the following four years. In conclusion, high 99mTc uptake by the right lobe was due to the combined effects of TRAb and left thyroid gland fibrosis.


2001 ◽  
Vol 123 (4) ◽  
pp. 310-316 ◽  
Author(s):  
Nathan E. Hoffmann ◽  
John C. Bischof

It has been hypothesized that vascular injury may be an important mechanism of cryosurgical destruction in addition to direct cellular destruction. In this study, we report correlation of tissue and vascular injury after cryosurgery to the temperature history during cryosurgery in an in vivo microvascular preparation. The dorsal skin flap chamber, implanted in the Copenhagen rat, was chosen as the cryosurgical model. Cryosurgery was performed in the chamber on either normal skin or tumor tissue propagated from an AT-1 Dunning rat prostate tumor, as described in a companion paper (Hoffmann and Bischof, 2001). The vasculature was then viewed at 3 and 7 days after cryoinjury under brightfield and FITC-labeled dextran contrast enhancement to assess the vascular injury. The results showed that there was complete destruction of the vasculature in the center of the lesion and a gradual return to normal patency moving radially outward. Histologic examination showed a band of inflammation near the edge of a large necrotic region at both 3 and 7 days after cryosurgery. The area of vascular injury observed with FITC-labeled dextran quantitatively corresponded to the area of necrosis observed in histologic section, and the size of the lesion for tumor and normal tissue was similar at 3 days post cryosurgery. At 7 days after cryosurgery, the lesion was smaller for both tissues, with the normal tissue lesion being much smaller than the tumor tissue lesion. A comparison of experimental injury data to the thermal model validated in a companion paper (Hoffmann and Bischof, 2001) suggested that the minimum temperature required for causing necrosis was −15.6±4.3°C in tumor tissue and −19.0±4.4°C in normal tissue. The other thermal parameters manifested at the edge of the lesion included a cooling rate of ∼28°C/min, 0 hold time, and a ∼9°C/min thawing rate. The conditions at the edge of the lesion are much less severe than the thermal conditions required for direct cellular destruction of AT-1 cells and tissues in vitro. These results are consistent with the hypothesis that vascular-mediated injury is responsible for the majority of injury at the edge of the frozen region in microvascular perfused tissue.


2003 ◽  
Vol 2 (2) ◽  
pp. 38-43
Author(s):  
I. I. Ivanchuk ◽  
A. E. Sazonov ◽  
F. I. Petrovsky ◽  
I. S. Lescheva ◽  
A. P. Kopieva ◽  
...  

Investigations of the mRNA expression of apoptosis intracellular regulators, bcl-2 and bcl-xL antagonists and bax, bcl-xL agonists of cellular destruction as well as mRNA expression of IL-5 were carried out. As a result of investigation of potential role of IL-5 in the regulation of programmable bcl-2-dependent destruction we found the increase of vitality and mRNA expression stimulation of bcl-2 peripheral blood eosinophils in patients with bronchial asthma (BA). It was found that fresh-isolated peripheral blood eosinophils in all investigated groups expressed bax and bcl-xL mRNA, bcl-xS had the less activity. In peripheric blood eosinophils of healthy donors the bcl-2 expression was not found, however, the increase of mRNA expression by IL-5 was shown in group of patients with bronchial asthma and, possibly connected with this, the appearance of bcl-2 activity. Thus, the decrease of apoptotic activity in peripheral blood eosinophils in patients with bronchial asthma may lead to the increase of eosinophil portion that is subjected to necrotic destruction and this may significantly contribute into bronchial asthma pathogenesis.


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