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Biomedical subjects

Z Lojda

Publications and source records attributed to Z Lojda.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Alkaline phosphatase activity in goblet cells in the small intestine of piglets experimentally infected with the coccidium Isospora suis].

Alkaline phosphatase activity (EC. 3.1.3.1.) in goblet cells was investigated in the small intestine of 16 gnotobiotic piglets infected one day after delivery (DAD) by different rates of oocysts of Isospora suis coccidia. At a high infection rate of I. suis (750,000) the goblet cells were found to be highly positive to alkaline phosphatase on day 3 to day 4 after infection (DAI). In piglets infected by a low infection rate of I. suis oocysts (100,000) the activity of alkaline phosphatase activity in goblet cells was proved on days 4 to 10 after infection. In the first group of piglets, the positive goblet cells prevailed in the middle region of jejunum, with the peak on 4th DAI. It the second group of piglets a marked increase in the alkaline phosphatase activity was recorded in the goblet cells in the posterior part of jejunum on days 4 to 5 after infection and on 10th DAI. No alkaline phosphatase activity in the goblet cells was demonstrated in the control gnotobiotic piglets at the age of two to seven days.

Alkaline Phosphatase↗
PubMed1990

[Activity of mucosubstances and the goblet cell count in the large intestine of piglets infected with the coccidium, Isospora suis].

In a group of conventional and gnotobiotic piglets experimentally infected with the Isospora suis coccidia the quantitative presence of acid and neutral mucous substances in the large intestine and the counts of goblet cells in the surface mucosa and in Lieberkühnis crypts (in the following text called just the crypts) were investigated. In conventional piglets infected with the dose of 200,000 oocysts of I. suis coccidia the lowest content of acid mucous substances was recorded from the eighth to tenth day after infection (DAI). A decrease in the activity of neutral mucous substances was somewhat slower. The lowest count of goblet cells was found on DAI 9, especially on the surface mucosa (4.89 to 4.91 goblet cells per 10 enterocytes). There was observed no difference in the piglets infected the first and fifth day after parturition (DAP). Gnotobiotic piglets infected with the dose of 100,000 oocysts of I. suis coccidia on DAP 1 showed the lowest content of mucous substances in the large intestine from the ninth to tenth day after infection. Unlike the conventional piglets, in gnotobiotic piglets there was recorded a decrease in the content of acid and neutral mucous substances. The gnotobiotic piglets had the lowest counts of goblet cells in the surface mucosa (10:4.57) and in the crypts (10:7.71) on DAI 9. As to the quantitative proportions, in the conventional and gnotobiotic piglets neutral mucous substances prevailed on the other days (DAI 3-7 and DAI 11), similarly like on DAI 8. The results of this investigation revealed a functional disease of the large intestine in conventional and gnotobiotic piglets infected experimentally with the Isospora suis coccidia.

Animals↗
PubMed1990

[Morphometric analysis of the activity of alkaline phosphatase in the small intestine of piglets infected with the coccidium Isospora suis].

Gnotobiotical one-day-old piglets were infected with 100,000 Isospora suis coccidia oocysts, and were immediately killed. In piglets killed on the 3rd to 11th day after infection (DAI), the morphometric analysis of alkaline phosphatase activity was performed in the area of the microvillus zone of small intestine. In the control 2-7 days old animals, the small intestine was not equally supplied with alkaline phosphatase. In duodenum the activity reached 88.37 per cent of the active length of absorbent surface (% LAac), in the middle jejunum 95.98 per cent LAac, in the dorsal jejunum 78.63% LAac and the ileum 90.55 % LAac. The width of the active area was more balanced and ranged from 5.003 microM in the ileum to 6.129 microM in the dorsal jejunum. In infected gnotobiotical piglets the lowest activity was found out on the 3rd to 4th DAI, with a greater decline on the 9th day after infection. The range from 25.99 to 40.50 per cent LAac with minimum in the duodenum and maximum in the ileum was observed on the 3rd DAI. In the middle and dorsal ileum the activity was nearly equal (28.34 and 27.69 per cent LAac). nI the dorsal jejunum a moderate increasing was up to 47.13% LAac on the 4th DAI, with the exception of the ileum, where the activity of alkaline phosphatase decreased to 24.96% LAac. On the 9th DAI the activity of alkaline phosphatase was nearly equal in the whole small intestine (from 55.70 to 60.01% LAac) with the maximum in the middle jejunum. In the width of the reaction product a direct dependence on the total activity of alkaline phosphatase was evident only in the segment of the middle and dorsal jejunum and ileum, but merely on the period of the 3rd to 4th DAI. The lowest values were measured in the middle jejunum (0.982 micron on the 3rd DAI and 0.709 micron on the 4th DAI). No dependence was observed between the total activity and the reaction product in the middle jejunum (0.982 micron on the 3rd DAI and 0.709 micron on the 4th DAI), there was no general stabilisation of the activity of alkaline phosphatase.

Alkaline Phosphatase↗
PubMed1989

Histochemical study of alkali-burned rabbit anterior eye segment in which severe lesions were prevented by aprotinin treatment.

Activities of different enzymes (acid glycosidases, phosphatases, Na+ - K+ -dependent ATPase, proteases, dehydrogenases) and acid glycosaminoglycans were studied by histochemical methods in sections of rabbit anterior eye segments after experimental alkali burn and treatment with aprotinin, an inhibitor of plasmin and other serine proteinases. Solutions of sodium hydroxide (0.25-1.0 M) were applied on corneas using 12-mm-diameter plastic tube for 15-60 s. After wiping with cotton and rinsing with tap water aprotinin solutions were applied in saline (in experimental animals) and saline (in control animals) dropwise in 12-h intervals for a month. Within the first two weeks aprotinin was used at a concentration of 5000 IU/ml. During the subsequent two weeks the aprotinin concentration was reduced to 2500 IU/ml. Striking differences in enzyme activities and in the healing between treated and untreated eyes were found. Without aprotinin, ulcers developed in most corneas within 3 weeks and plasmin was regularly demonstrated in tears and in the aqueous. When aprotinin treatment was started within 24 h after the burn, the number of enzymatically active inflammatory cells was significantly lower, not only in the cornea itself but also in the whole anterior eye segment. With aprotinin treatment no ulcerations and no plasmin in tears and the aqueous were observed and the corneas healed within a month. The healing process started from the zone of enzymatically activated corneal cells in the unburned zone at the corneal periphery. In the regenerating epithelium and endothelium high activities of Na+ -K+ -dependent ATPase, gamma-glutamyltransferase, lactate and succinate dehydrogenases appeared very soon.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1989

Histochemical detection of alpha-D-galactosidase with 5-Br-4-Cl-3-indoxyl alpha-D-galactoside.

5-Br-4-Cl-3-indoxyl alpha-D-galactoside was used as a new substrate in azoindoxyl, indigogenic, and tetrazolium procedures for the detection of alpha-D-galactosidase in the light microscope. Compared with the simultaneous azo-dye methods using 1-naphthyl or 6-Br-2-naphthyl alpha-D-galactoside as substrates and hexazotized pararosaniline for simultaneous coupling, primarily the azoindoxyl method with hexazotized pararosaniline and the indigogenic technique proved to be superior. The azoindoxyl reaction is recommended for the localization of alpha-D-galactosidase in lysosomes when freeze-dried celloidin-coated cryostat sections are used: the indigogenic procedure should be employed for the detection of the total activity of the enzyme in combination with the technique of semipermeable membranes. The tetrazolium reaction delivered high amounts of formazan as the final reaction product; however, its localization was less precise than with the azoindoxyl and indigogenic methods. Conspicious species differences were found; except for the small intestine of suckling mice the highest activities of alpha-D-galactosidase were present in different immature and mature rat organs when compared with mouse, hamster, guinea-pig, marmoset monkey, and human tissues.

Aging↗
PubMed1989

Histochemistry of the gastric and duodenal mucosa under cimetidine and carbenoxolone treatment.

Histological and histochemical patterns of the gastric and duodenal mucosa was investigated in nine subjects with duodenal ulcer or ulcerlike syndrome after 4 to 5 weeks treatment with cimetidine or carbenoxolone. No spectacular changes were found after carbenoxolone except for a slight increase in goblet cells in the duodenal bulb. In the patients treated with cimetidine, findings suggesting an influence of this drug on the biochemical cytology of parietal cells and some interference in the differentiation of enterocytes were established.

Adult↗
PubMed1989

[The ratio of enterocytes and goblet cells in the mucosa of the small intestine in experimental infection of piglets with the coccidium Isospora suis].

The proportions of cup-shaped cells and enterocytes were studied in piglets infected the first and fifth day after birth with 200,000 oocysts of Isospora suis. The greatest imbalance was found in the ratio of the cells of the intestinal mucous membrane in the region of middle and lower jejunum (ratio of 10:1.75)--this was recorded the third to fourth day after infection when the ratio made 10:0.62, whereas in the control animals it was 10:5.7. On the eighth to ninth day after infection the number of cup-shaped cells began to increase, the ratio reaching the values of 10:2.62. Even the 13th day after infection the ratio remained far from normal (10:2.50).

Animals↗
PubMed1989

Enzyme histochemistry in the developing suprarenal gland of human embryos.

The localization of the activities of some selected phosphatases, peptidases and dehydrogenases were studied in cryostat sections of the developing anlage of the suprarenal gland of human embryos from 8 to 20 weeks of the intra-uterine life. In the youngest fetuses under our notice (weeks 8-12), the activity of alkaline phosphatase (AP) on the cellular membranes of the fetal cortex was very low. In contrast, the activity of acid phosphatase (AcP) was comparatively high. Peak activity was found in the cells of the central zone of the fetal cortex. Compared to the activity of the latter, the activity of non-specific esterase (ANE) was somewhat lower. Both its localization and the gradient were identical with those of acid phosphatase. Of the peptidases studied, only dipeptidyl peptidase IV (DPP IV) exhibited slight activity in deeper layers of the primitive fetal cortex after week 8. The other peptidases exhibited only traces of activity. As early as in the first stages followed, the activity of glycero-3-phosphate-dehydrogenase (alpha-GPDH) was very high in all cells of the differentiating fetal cortex. The intensity of the activity of succinate dehydrogenase (SDH) was markedly lower. In older fetuses (weeks 13-20) there was a gradual increase in the activities of most enzymes, seen, after week 15 of the intrauterine life, also in the cells of the so-called definitive cortex. Most pronounced were the increases in the activities of acid phosphatase and non-specific esterase. The relatively low activities of the enzymes under study point to a relatively low degree of cell differentiation of both the primitive and, after week 15, the definitive cortex. Pronounced morphological and functional changes occur after the 20th week of the intrauterine life.

Adrenal Glands↗
PubMed1989

[Comparison of tolerance to hydrophilic contact lenses made of Hema (37% H2O) and Hema-Degma (55%, 65% H2O) in the rabbit eye. I. Changes in corneal transparency due to disturbed hydration].

The authors compared on the rabbit eye the tolerance of hydrophilic contact lenses with equal parameters (0.2 mm central and peripheral thickness, 7.4 radius, 15 mm diameter) with a different degree of hydration (37% H2O-Hema), (55% and 65% H2O-Hema-Degma) during continuous wear for a period of two weeks (1, 2, 3, 4, 7 and 14 days). Special attention was devoted to changes in the transparency of the cornea. Changes of the transparency due to wearing of contact lenses were due to changes of corneal hydration. The cause of increased corneal hydration were metabolic and later also morphological disorders in the corneal endothelium. The activity of Na+-K+-dependent adenosine triphosphatase and gamma-glutamyl transferase were reduced, followed by a change in the shape and size of endothelial cells. Later the activities of both enzymes were reduced also in the epithelium. Keratocytes had reduced alkaline phosphatase and gamma-glutamyl transferase activities. The staining properties of glycosaminoglycans in the stroma remained, however, unaltered, similarly as the activity of acid glycosidases and other investigated lysosomal enzymes. The onset of increased corneal hydration caused by a disorder of the active water ion transport and of metabolites in the cornea depended on the percentage of water in hydrophilic contact lenses. It was observed latest after application of contact lenses with 65% water.

Animals↗
PubMed1989

[Comparison of tolerance to hydrophilic contact lenses made of Hema (37% H2O) and Hema-Degma (55%, 65% H2O) in the rabbit eye. II. Changes in corneal transparency due profound degenerative processes].

The authors investigated on the rabbit eye the effect of long-term continuous wearing (14, 21, 28 days) hydrophilic contact lenses (h. c. l.) with varying degrees of hydration (37%, 55%, 65% water). Long-term wearing of the lenses caused disorders in all corneal layers. These changes are identical in all types of contact lenses, only their onset is earlier and the extent is more marked in contact lenses with a low hydration (37% water). Contrary to epithelial changes in the corneal stroma, the changes are qualitatively different depending on the degree of hydration of the contact lens. Prolonged application of contact lenses with 37% water leads to infiltration of the stroma by inflammatory cells which carry the activities of destructive lysosomal enzymes. The latter are gradually released into tissues and local degenerative processes develop which in some instances culminate by ulceration. Other corneas are vascularized. The described changes in stroma were not found in hydrophilic contact lenses with 55% and 65% water. After prolonged application of highly hydrated contact lenses (65% water) the authors, however, observed uptake of liquid from the upper third of the stroma due to the contact lens which dried on the eye and acted on the cornea as a hypertonic solution. In this subepithelial zone the staining of glycosaminoglycans was reduced, similarly as the enzymatic activities in keratocytes which suggests serious degenerative processes, i. e. disorders in the synthesis of components of the ground substance of the corneal stroma.

Animals↗
PubMed1989

[Mucus synthesis in the goblet cells of the small intestine in experimental infection with the coccidium Isospora suis in piglets].

The state of mucus synthesis in the goblet cells of the small intestine was studied in conventional piglets infected with a dose of 200,000 oocytes of the coccidium Isospora suis the first and fifth day after parturition. The synthesis of mucus and its chemical characteristics undergo significant changes during the third and fourth day after infection. The activity of acid and neutral mucous substances declines; their level and the physiological synthetic function of goblet cells begin to return to the normal during the period starting on the eight to tenth day after infection. However, there were no fully functioning goblet cells in the broken numerical ratio even at the end of the period of investigation, i.e. the 13th day after infection. The thin surface layer of mucus remained almost unchanged within the whole extent of the small intestine parts studied.

Animals↗
PubMed1989

[Alkaline phosphatase activity levels during infection with the coccidia Isospora suis in piglets].

The activity of alkaline phosphatase (EC 3.1.3.1.) was studied in the small intestines of piglets infected with the coccidia Isospora suis on the first and fifth day of age. Alkaline phosphatase activity is reduced significantly the third to fourth day after infection (DAI) throughout the small intestine in piglets infected on the fifth day of age. Similar results were obtained in the piglets killed the eighth to tenth DAI which had also been infected on the fifth day of their age. Piglets infected the first day of age and killed on the 8th to 13th DAI exhibited no larger differences from the above-mentioned groups, but alkaline phosphatase activity was distributed more regularly all over the surface of the villi. The normal values, comparable with the controls, were not obtained within 13 days after infection (piglet age 14 days).

Alkaline Phosphatase↗
PubMed1989

[Activity of selected dehydrogenases and monoamine oxidases in the small intestine of gnotobiotic piglets infected with the coccidium Isospora suis].

In the small intestine of 16 gnotobiotic piglets infected a day post partum (DPP) by Isospora suis coccidia the activities were studied of selected dehydrogenases and monoaminoxidase (O2 oxidoreductase, MAOx, EC 1.4.3.4.). The following dehydrogenases were investigated: succinate dehydrogenase (SDH, EC 1.3.99.1.), glycerol-3-phosphate dehydrogenase (glycerol-3-phosphate:menadion oxidoreductase, GPOX, EC 1.1.99.5.) and tetrazolium oxidoreductase (NADH, ES 1.6.99.3.). The activities of NADH and GPOX were found to decrease, a decrease being somewhat milder in MAOx, at a high infection dose of I. suis oocysts (750,000 oocysts), in comparison with the control, already on the first day after infection (DAI). The SDH levels did not change. In piglets infected by a low infection dose of I. suis oocysts a double marked decrease (negative to slightly positive finding) was recorded in the period from the third to the eighth day after infection (DAI). A similar pattern with a longer time interval between the decreases was observed in GPOX (4th to 11th day after infection). The findings of SDH and MAOx activities were different. The SDH activity is maintained at the same level (++) for the whole period of investigation and there occurs a decrease (+) only on the 9th day after infection, persisting until 11 DAI. The MAOx activity and its change correspond to the SDH activity; the difference being that in the second group the starting level is high ( ) and on the eleventh day after infection it is low or medium (0-++), in comparison with the standard. This variability is discernible from 8th DAI.

Animals↗
PubMed1988

Disturbances in the rabbit cornea after short-term and long-term wear of hydrogel contact lenses. Usefulness of histochemical methods.

The influence of soft contact lenses (SCL) with low (37%, L) and high (65%, H) water content on rabbit corneas was investigated. The lenses were worn continuously for 1, 2, 4, 7, 10, 14, 21 or 28 days. The changes in corneal transparency, hydration and enzyme activities were studied. A slight change in corneal transparency due to higher hydration caused by a decreased activity of Na+-K+-dependent adenosine triphosphatase (Na+-K+-ATPase) in the corneal endothelium is followed by a decrease in the activity of gamma-glutamyl transferase (GGT). Slight morphological disturbances appear within 4 days in animals wearing SCL (L). SCL (H) produce similar changes one week later. Subsequently, the corneal epithelium becomes thinner and changes in the size of corneal endothelial cells are obvious. Disturbances of enzyme activities in cells of all corneal layers are present. In the epithelium highly increased activities of acid glycosidases, acid phosphatase, and dipeptidyl peptidase I and II, in keratocytes decreased activities of alkaline phosphatase and GGT, and in the endothelium decreased activity of Na+-K+-ATPase and GGT were found. These changes are more severe after SCL (L). In this case, inflammatory cells displaying high activities of lysosomal hydrolases appear in the anterior part of the stroma during the 3rd and 4th weeks and local degradation of glycosaminoglycans and proteins takes place. In contrast, after SCL (H) a remarkable thinning of the corneas was observed during extended wear, accompanied by decreased stainability of stromal glycosaminoglycans and highly decreased enzyme activities in keratocytes. The histochemical methods proved very useful in the assessment of lesions caused by a continuous wear of SCL.

Animals↗
PubMed1988

Are Z-Arg-Gly-Phe-Phe-Leu-MNA and Z-Arg-Gly-Phe-Phe-Pro-MNA suitable substrates for the demonstration of cathepsin D activity?

The suitability of Z-Arg-Gly-Phe-Phe-Leu-MNA and Z-Arg-Gly-Phe-Phe-Pro-MNA for the assessment of cathepsin D activity was tested in biochemical and histochemical experiments. Substrates were dissolved in dimethylformamide and used at 0.1-0.5 mM in various buffers over a pH range of 3.5-7.4. Homogenates of various rat organs and isolated purified enzymes [cathepsin D from bovine spleen, dipeptidyl peptidase (DPP) IV from porcine kidney and rat lung] were used as enzyme sources. Pepstatin, di-isopropylfluorophosphate (DFP), p-chloromercuribenzoate, o-phenanthroline and a series of DPP IV inhibitors were used in inhibitor experiments. At pH 3.5 and 5.0, substrates were used in a two-step postcoupling procedure with aminopeptidase M and dipeptidyl peptidase IV as auxiliary enzymes and Fast Blue BB as coupling agent. Results were compared with those obtained with haemoglobin. Above pH 5.0 substrates were used in a one-step postcoupling procedure. Cryostat sections of snap-frozen or cold aldehyde-fixed tissue pieces of various rat organs and biopsies of human jejunal mucosa were used in histochemical experiments. As in biochemical tests a two-step procedure was used in the pH range 3.5-5.0, but Fast Blue B was used in the second step for the simultaneous coupling. Above pH 5.0 a one-step simultaneous azo coupling procedure was used with Fast Blue B as coupling agent. At pH 3.5 the hydrolysis rate of both synthetic substrates was about 100x lower than that of haemoglobin when cathepsin D from bovine spleen was used.(ABSTRACT TRUNCATED AT 250 WORDS)

2-Naphthylamine↗
PubMed1988

Histochemistry of proteases in ependyma, choroid plexus and leptomeninges.

Aminopeptidase M (APM), aminopeptidase A (APA), dipeptidyl peptidase IV (DPP IV) and gamma-glutamyl transferase (GGT) were demonstrated histochemically in cryostat sections of the rat brain to show the reaction pattern of ependyma, choroid plexus and leptomeninges. GGT was only demonstrable in the cell membranes of ependymal cells and in the leptomeninges; however, APA, APM and DAP IV showed a variable degree of activity in the capillary endothelium of the choroid plexus as well as in the leptomeninges. On the basis of these results, it is postulated that peptides in the cerebrospinal fluid can be cleaved extraventricularly by the enzymes demonstrated in the leptomeninges.

Animals↗