scholarly journals Lactate dehydrogenase in developing rat oral epithelium.

1984 ◽  
Vol 32 (1) ◽  
pp. 1-6 ◽  
Author(s):  
S Sjögren

Freeze-dried sagittal, whole-body sections of 10-day-old rats were incubated for lactic dehydrogenase (LDH) using different media in the presence of the inhibitors urea and fluoropyruvate. Phenazine methosulfate (PMS) and menadione, which are regularly used in current histochemical media and are believed to promote the demonstration of LDH activity, were also added and shown to be insufficient for the demonstration of total LDH activity, and PMS even seemed to have an inhibitory effect on LDH activity in oral epithelium. However, cumulated data from the different incubations show that the oral epithelium of developing rats may contain two different types of LDH, one in the basal cells with possibly aerobic characteristics, and another in the spinosum/granulosum cells with anaerobic characteristics.

1984 ◽  
Vol 32 (9) ◽  
pp. 958-964 ◽  
Author(s):  
S Sjögren

Histochemical lactic acid dehydrogenase (LDH) staining methods seem unable to demonstrate the total LDH activity in tissue sections. An analysis was made of LDH tissue staining methods applied on LDH zymograms. The menadione-mediated LDH staining of tissue sections can not possibly reflect true LDH activity. The addition of cyanide also slightly inhibited LDH activity. The cyanide inhibition was confirmed via LDH assay and found to be competitive in character. It is concluded that cyanide and menadione should be replaced by agents suitable from both a histochemical and a biochemical point of view. Based on the findings of this study the presence of LDH in oral epithelium was analyzed. Evidently LDH of the oral epithelium is basically anaerobic in character and located primarily in spinosum/granulosum layers and only sparsely in the basal layer.


2021 ◽  
Vol 35 (3) ◽  
pp. 406-414
Author(s):  
Yoko Satoh ◽  
Masami Kawamoto ◽  
Kazunori Kubota ◽  
Koji Murakami ◽  
Makoto Hosono ◽  
...  

AbstractBreast positron emission tomography (PET) has had insurance coverage when performed with conventional whole-body PET in Japan since 2013. Together with whole-body PET, accurate examination of breast cancer and diagnosis of metastatic disease are possible, and are expected to contribute significantly to its treatment planning. To facilitate a safer, smoother, and more appropriate examination, the Japanese Society of Nuclear Medicine published the first edition of practice guidelines for high-resolution breast PET in 2013. Subsequently, new types of breast PET have been developed and their clinical usefulness clarified. Therefore, the guidelines for breast PET were revised in 2019. This article updates readers as to what is new in the second edition. This edition supports two different types of breast PET depending on the placement of the detector: the opposite-type (positron emission mammography; PEM) and the ring-shaped type (dedicated breast PET; dbPET), providing an overview of these scanners and appropriate imaging methods, their clinical applications, and future prospects. The name “dedicated breast PET” from the first edition is widely used to refer to ring-shaped type breast PET. In this edition, “breast PET” has been defined as a term that refers to both opposite- and ring-shaped devices. Up-to-date breast PET practice guidelines would help provide useful information for evidence-based breast imaging.


Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 506
Author(s):  
Alexander Ereskovsky ◽  
Ilya E. Borisenko ◽  
Fyodor V. Bolshakov ◽  
Andrey I. Lavrov

While virtually all animals show certain abilities for regeneration after an injury, these abilities vary greatly among metazoans. Porifera (Sponges) is basal metazoans characterized by a wide variety of different regenerative processes, including whole-body regeneration (WBR). Considering phylogenetic position and unique body organization, sponges are highly promising models, as they can shed light on the origin and early evolution of regeneration in general and WBR in particular. The present review summarizes available data on the morphogenetic and cellular mechanisms accompanying different types of WBR in sponges. Sponges show a high diversity of WBR, which principally could be divided into (1) WBR from a body fragment and (2) WBR by aggregation of dissociated cells. Sponges belonging to different phylogenetic clades and even to different species and/or differing in the anatomical structure undergo different morphogeneses after similar operations. A common characteristic feature of WBR in sponges is the instability of the main body axis: a change of the organism polarity is described during all types of WBR. The cellular mechanisms of WBR are different across sponge classes, while cell dedifferentiations and transdifferentiations are involved in regeneration processes in all sponges. Data considering molecular regulation of WBR in sponges are extremely scarce. However, the possibility to achieve various types of WBR ensured by common morphogenetic and cellular basis in a single species makes sponges highly accessible for future comprehensive physiological, biochemical, and molecular studies of regeneration processes.


1988 ◽  
Vol 254 (6) ◽  
pp. R891-R896 ◽  
Author(s):  
F. P. Lafeber ◽  
G. Flik ◽  
S. E. Wendelaar Bonga ◽  
S. F. Perry

Bidirectional whole body flux and branchial Ca2+ influx were measured in freshwater rainbow trout. Intra-arterial injections of homogenates of Stannius corpuscles (CS) as well as of a 54-kDa isolated product (hypocalcin) exerted an inhibitory effect on whole body Ca2+ influx, but did not effect Ca2+ efflux. Hypocalcin was more effective in reducing Ca2+ influx in trout acclimated to low-calcium freshwater than in fish from normal-calcium water. We conclude that the isolated product (hypocalcin) represents the hypocalcemic principle of the CS. Similar doses of hypocalcin caused quantitatively similar decreases in Ca2+ influx in vivo and in the isolated perfused head preparation. This indicates that the gills form the principle target for hypocalcin in trout. The branchial transepithelial potential did not change during hormone treatments. Possible mechanisms of hypocalcin action are suggested.


1991 ◽  
Vol 37 (5) ◽  
pp. 397-403 ◽  
Author(s):  
Hiroshi Kuriyama ◽  
Itaru Umeda ◽  
Harumi Kobayashi

Asexual yeast flocculation was studied using strong flocculents of Saccharomyces cerevisiae. The inhibitory effect of cations on flocculation is considered to be caused by competition between those cations and Ca2+ at the binding site of the Ca2+-requiring protein that is involved in flocculation. Inhibition of flocculation by various cations occurred in the following order: La3+, Sr2+, Ba2+, Mn2+, Al3+, and Na+. Cations such as Mg2+, Co2+, and K+ promoted flocculation. This promoting effect may be based on the reduction of electrostatic repulsive force between cells caused by binding of these cations anionic groups present on the cell surface. In flocculation induced by these cations, trace amounts of Ca2+ excreted on the cell surface may activate the corresponding protein. The ratio of Sr2+/Ca2+ below which cells flocculated varied among strains: for strains having the FLO5 gene, it was 400 to 500; for strains having the FLO1 gene, about 150; and for two alcohol yeast strains, 40 to 50. This suggests that there are several different types of cell surface proteins involved in flocculation in different yeast strains. Key words: yeast, flocculation, protein, cation, calcium.


2002 ◽  
Vol 13 (3) ◽  
pp. 162-165 ◽  
Author(s):  
Rodrigo de Castro Albuquerque ◽  
Ricardo Santiago Gomez ◽  
Rodrigo Aliprandi Dutra ◽  
Wallison Arthuso Vasconcellos ◽  
Renato Santiago Gomez ◽  
...  

The purpose of the present study was to evaluate the influence of short course topical application of carbamide peroxide on proliferating cell nuclear antigen (PCNA) immunohistochemical expression in the oral tongue mucosa of rats. Twelve male Wistar rats were submitted to topical application of 10% carbamide peroxide on one side of the dorsal tongue once a week for three consecutive weeks. Only distilled water was applied on the control side. The animals were killed on days 0, 10, and 20 after the last application. The tongue was fixed in buffered formalin for 24 h and embedded in paraffin. Tissue blocks (3 µm) were subjected to the biotin-streptavidin amplified system for identification of PCNA. The percentage of epithelial-positive basal cells in each side of the tongue mucosa was calculated. The results demonstrated that topical application of 10% carbamide peroxide increases PCNA immunohistochemical expression on the basal layer of the oral mucosa epithelium of rats on day 0 after treatment. In conclusion, short-course use of carbamide peroxide induces transient epithelial cell proliferation of the oral mucosa of rats.


2012 ◽  
Vol 47 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Nasima Akhtar ◽  
Monzur Morshed Ahmeda ◽  
Nishat Sarker ◽  
Khandaker Rayhan Mahbuba ◽  
Abdul Matin Sarker

Growth response of Spirulina platensis in papaya skin extract media and their antimicrobial activity were studied. Five different concentrations  e.g. 10gm/L, 8gm/L, 6 gm/L, 4 gm/L and 2gm/L of Papaya (Carica papaya) skin extract media and BD1 (control) medium were used  in this study. After 8 days of cultivation, the optical density (0.33) was recorded in BD1 medium and among the five different concentrations  of papaya skin extract media the maximum was found (0.31) in 6gm/L. Antimicrobial activity of Spirulina platensis grown in three  media namely Zarrouk, BD1 media and media made from papaya skin extract was also studied. Only freeze dried Spirulina platensis powder  extract showed inhibitory effect against bacteria and no antifungal activity was observed. DOI: http://dx.doi.org/10.3329/bjsir.v47i2.11445 Bangladesh J. Sci. Ind. Res. 47(2), 147-152, 2012  


1989 ◽  
Vol 262 (1) ◽  
pp. 313-319 ◽  
Author(s):  
J M Duerden ◽  
S M Bartlett ◽  
G F Gibbons

Hepatocytes were derived from 2-3-day streptozotocin-diabetic rats and maintained in culture for up to 3 days. Compared with similar cultures from normal animals, these hepatocytes secreted less very-low-density-lipoprotein (VLDL) triacylglycerol, but the decrease in the secretion of VLDL non-esterified and esterified cholesterol was not so pronounced. This resulted in the secretion of relatively cholesterol-rich VLDL particles by the diabetic hepatocytes. Addition of insulin for a relatively short period (24 h) further decreased the low rates of VLDL triacylglycerol secretion from the diabetic hepatocytes. The secretion of VLDL esterified and non-esterified cholesterol also declined. These changes occurred irrespective of whether or not exogenous fatty acids were present in the culture medium. Little or no inhibitory effect of insulin was observed after longer-term (24-48 h) exposure to the hormone. Both dexamethasone and a mixture of lipogenic precursors (lactate plus pyruvate) stimulated VLDL triacylglycerol and cholesterol secretion, but not to the levels observed in hepatocytes from normal animals. The low rate of hepatic VLDL secretion in diabetes contrasts with the increase in whole-body VLDL production rate. This suggests that the intestine is a major source of plasma VLDL in insulin-deficient diabetes.


2008 ◽  
Vol 43 (4) ◽  
pp. 265-274 ◽  
Author(s):  
Claude Rouleau ◽  
Jagmohan Kohli

Abstract Nonpersistent contaminants represent thousands of chemicals used as pesticides, pharmaceuticals, personal care products, additives, etc. Because of this diversity, the assessment of the environmental risks they may pose for the environment represents a formidable task. Identification of target organs is key information needed to orient further research on newlyinvestigated organic xenobiotics. We used whole-body autoradiography to visualize the distribution of 14C-labelled atrazine, methoxychlor, glyphosate, and bisphenol-A in goldfish (Carassius auratus) and identify target organs. Fish were exposed for 2 days (glyphosate and bisphenol-A) and 7 days (atrazine and methoxychlor) to the radiolabelled compounds at a concentration of 15 nM. They were then frozen, embedded in carboxymethylcellulose gel, 20-μm-thick cryosections were collected, freeze-dried, and exposed to phosphor screens to visualize the tissue distribution of radioactivity. Goldfish did not accumulate glyphosate. The three other compounds were accumulated, mostly in the gall bladder. Nevertheless, unforeseen accumulation sites were observed; atrazine accumulated in the uveal tract of the eye, high levels of radioactivity were found in the cerebrospinal fluid of goldfish exposed to methoxychlor, and an important accumulation of bisphenol-A was seen in urine, oral mucosa, esophagus, and intestinal lumen. The potential toxicological consequences of the accumulation of these chemicals at very specific locations within the fish body are discussed and further research suggested.


1987 ◽  
Vol 1 (2) ◽  
pp. 236-244 ◽  
Author(s):  
T. Kawamoto ◽  
M. Shimizu

The distribution of calcium and phosphate in the cells of the enamel organ of the rat lower incisors was investigated by autoradiography and energy-dispersive x-ray spectrometry (EDS). Radioactive calcium or phosphate was injected i.p. into seven-day-old rats of the Wistar strain. The animals were frozen 0.5, 1, and 10 min after injection, and embedded in 5% carboxymethyl cellulose. Sagittal sections of 10 μm thickness were made in which the lower incisor was included as a part of the whole-body section. For autoradiography, the sections were freeze-dried and placed in contact with dry thin films prepared from autoradiographic emulsion. For EDS, sections were mounted on carbon stubs, freeze-dried, coated with carbon, and examined by EDS in a SEM. 45Ca and 32P autoradiograms showed that the radioactivity was located over the papillary layer cells adjacent to the secretory stage ameloblasts and was much higher here than in the ameloblastic layer. On the other hand, there was no significant difference between the amount of radioactivity of these two cell layers in the maturation stage, although higher radioactivity was detectable in the maturation stage enamel than in the secretory stage enamel. Pronounced Ka x-ray peaks were obtained for P, S, Cl, and K originating from the cells of the papillary and ameloblastic layers in the secretory stage, but only very low peaks were obtained for Ca. On the other hand, in addition to these elements, remarkably high Ca and Fe peaks could be detected in the ameloblastic layer of the maturation stage.


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