P. Höhn

Differentiation and aging of the rat intestinal mucosa. II. Morphological, enzyme histochemical and disc electrophoretic aspects of the aging of the small intestinal mucosa

At different times of day (08.00, 12.00, 16.00 and 24.00) the small intestinal mucosa of four month (adult) and 30 month (senile) old rats was examined histologically, by scanning electron microscopy, autoradiography, enzyme histochemistry and disc electrophoresis. In senile rats a villous atrophy is found histologically and an irregular architecture is found in scanning electron microscopy. The changes are essentially restricted to the proximal small intestine. The enterocytes of adult and senile rats show an identical enzyme histochemical picture. In the proximal small intestine of adult and senile rats, synchronous statistically significant fluctuations of the activity of alkaline and acid phosphatase were revealed in the disc electropherograms. Likewise statistically significant are the at all times of day low enzyme activities in the intestinal mucosa of senile rats as compared to the findings in adult rats. The fall in activity of alkaline and acid phosphatase in old rats is attributed to the numerical reduction of the enterocytes which is caused by the age atrophy of the intestinal mucosa. These findings are discussed in connection with results of our own studies of proliferation kinetics and those of other authors.

The relation between tumor cell proliferation and vascularization in differentiated and undifferentiated colon carcinomas in the rat

SummaryTumor cell proliferation and tumor vascularization were investigated in differentiated and undifferentiated colon carcinomas of the rat. The following results were found: 1, in both tumor types, vascularization is developed equally well; 2, both in the differentiated and in the undifferentiated carcinomas, the number of proliferating tumor cells decreases with increasing distance from the capillaries; at a distance of about 80 μm, there is no longer any noteworthy tumor cell proliferation; 3, the differentiated and undifferentiated carcinomas differ both in the level of the mitosis index and3H-thymidine labeling index as well as in their local proliferation pattern despite equal vascularization; 4, these differences must be based on factors which are independent of vascularization; they are attributed to proliferation properties which are inherent in the differently differentiated tumor cell populations. It is concluded from this that the actual proliferation behavior of a carcinoma is primarily dependent on the proliferation properties of the tumor cell population.

Grades of atypia in tubular and villous adenomas of the human colon. An electron microscopic study.

SummaryOf a total of 544 tubular, villous and tubulo-villous adenomas of the human colon which were investigated by light microscopy, six tubular and six villous adenomas were examined under the electron microscope. It was shown that the two types of adenoma differ in their tissue architecture, but not in their cytological appearance.Different grades of epithelial atypia occur in both types of adenoma. These are designated as grades I to III, corresponding to mild, moderate and severe atypia respectively. Whereas adenoma cells with atypia grade I clearly show a cytological relationship with the crypt epithelia of the normal colonic mucosa under the electron microscope, adenoma cells with atypia grade III have largely lost the differentiation characteristics of the parent cells and there is no longer intracytoplasmic organization. In the cytoplasm of adenoma cells with atypia grade II, glycogen storage is found as a special feature which does not occur in normal colonic epithelium. A similar finding has been described in the course of malignant transformation of the liver and kidney and thus can be regarded as a further indication of the precancerous nature of the adenomas.

The mechanism of epithelial shedding after ischemic damage to the small intestinal mucosa

SummaryThe intestinal mucosa of the rat was examined by light and electron microscopy 15, 30, 60 and 120 min after complete ligation of the vessel arcades of the proximal jejunum. The characteristic sign of ischemic damage to the small intestinal mucosa and the reason for epithelial shedding is the appearance of membrane enclosed cytoplasmic blebs which arise at the cell base of the enterocytes and detach the epithelium from the basement membrane. This process begins at the tip of the villi before the enterocytes display signs of irreversible damage and progress to the base of the villi with continuation of the ischemia.

Ischemia and post-ischemic regeneration of the small intestinal mucosa. An enzyme-histochemical investigation.

After ligation of the vascular arcades of the upper jejunum in rats, the ischemic damage to the intestinal mucosa and its regenerative behavior after ischemia lasting 120 minutes were investigated with histological and enzyme-histochemical methods. During the ischemic injury of the jejunal mucosa, there is rejection of hydropically swollen epithelial cells into the intestinal lumen advancing from the tip to the base of the villi without a previously detectable loss of activity of the enzymes investigated. At the end of ischemia lasting 120 minutes, there is complete destruction of the villi as well as the upper portions of the crypts. After rapid re-epithelialization of the mucosal surface by a flat epithelium, reformation of villi begins already after a 24 h period of regeneration. On the third day of regeneration, the intestinal mucosa has plump villi again. Their epithelia already show the morphological characteristics of mature enterocytes. On the other hand, enzymatic maturation of the enterocytes is only concluded between the first and second week of regeneration. An altered proliferation kinetics of the crypt epithelia due to the repair process is discussed as cause of this delayed enzymatic maturation of the enterocytes relative to the morphological differentiation. Although the intestinal mucosa has a regular villous structure again after regeneration lasting 8 days, enzyme histochemical finding in the lamina propria indicate that the process of repair is only complete here in the sixth week of regeneration.

Aktivitätsbestimmungen der sauren phosphatase in verschiedenen biologischen medien unter verwendung von o-Carboxyphenylphosphat

SummaryOn investigation of human seminal traces the evidence of high activity of acid phosphatase implies important information. Some substrates are known for measurement of this enzyme activity. With the aid of o-Carboxyphenylphosphate in 0.1 M sodium acetate/acetic acid buffer the conditions for quantitative measurement of human seminal acid phosphatase were found to be optimal at pH 4.6–5.8 and pS 2.3–2.7 (Walther). As the acid phosphatase is present in many biological fluids, it is necessary to know the rate of hydrolysis by these enzymes. Therefore in this paper the activity of acid phosphatase in the following biological fluids was measured: Human and bull ejaculates, vaginal smears, urines, anal swabs, secretes of snails, plant juices (cauli flower and painters flower) and some bacteria.In the human ejaculates were notized activities about 104–106 U, in bovine ejaculate about 102–104 and in fluid of cauli flower 103–104 U. In the other investigated fluids substrate splitting was very low or negative (see table). It is impossible to detect a very small trace of acid phosphatase because the substrate is splitting spontaneously. But this is not important because anyway activities from 104–106 U have diagnostical information.ZusammenfassungUnter den für die Bestimmung der menschlichen sauren Spermaphosphatase festgestellten Bedingungen wurden die Spaltungsraten verschiedener Substanzen menschlicher, tierischer und pflanzlicher Herkunft bestimmt. Im Humansperma wurden etwa 104–106 U, im bovinen etwa 102–104 und im Blumenkohlpreßsaft 103–104 U festgestellt. In den übrigen Substanzen ist zwar eine geringe Hydrolyserate, die auch durch saure Phosphataseaktivität bedingt sein kann, nicht auszuschließen, jedoch ist dieses Ferment nicht mit Sicherheit nachweisbar. Die Untersuchungsergebnisse zeigen, daß die saure Phosphatase des menschlichen Ejaculates o-Carboxyphenylphosphat sehr schnell hydrolysiert, aber auch im Blumenkohlpreßsaft ist eine relative hohe Aktivität vorhanden.

Discelektrophoretische Differenzierung saurer Phosphatasen verschiedener Herkunft

SummaryHuman seminal fluid contents a very high activity of acid phosphatase. Therefore this enzyme attaches medico-legal importance to the evidence of seminal traces. But this enzyme is present in many other biological fluids—even in a very high activity almost like in human seminal fluid. Comparisms of the qualitative reaction on acid phosphatase gave positive results as well with older human seminal spots as with those of fresh fluids of plant or animal origin.Discelectrophoretical examinations in polyacrylamide gels evidence the heterogeneity of human acid phosphatase and that of plant or animal origin. The best results of separation were obtained by means of the following conditions: Spacer gel2.5% AcrylamidSeparating gel7.5% AcrylamidVoltage180 V, 2.5 mA each tubuliTime of separating110 minCooling the anode puffer with tap water. Under these conditions in the human seminal fluid could be detected 2 zones of enzyme activity. After a storing periode of 4 weeks in seminal traces on textile spots appears a 3rd zone between the two bands.Other investigated biological fluids (plants and snails) showed 3–8 zones of enzyme activity.This bands became unsharp and mixed up after one week of storage.These investigations implay conditional informations in medico-legal experience of seminal traces.Zusammenfassung1. Im menschlichen Ejaculat konnten discelektrophoretisch unabhängig vom Spurenalter konstant 2 Isoenzyme der sauren Phosphatase nachgewiesen werden.2. Spuren verschiedener Pflanzenpreßsäfte (Studentenblume, Blumenkohl und Schneckenschleime — Weinbergschnecke, Schnirkelschnecke —) zeigten 3–8 Isoenzymbanden. Diese Isoenzyme waren in mehr als 7 Tage alten Spuren nicht mehr scharf zu trennen.3. Die discelektrophoretische Untersuchung der Isoenzyme der sauren Phosphatase bringt für den gerichtsmedizinischen Spermaspurennachweis weitere wertvolle Informationen.

Does uremic enterocolitis exist? A morphological and functional investigation of rat intestine in chronic renal insufficiency.

SummaryIn rats a severe but compensated chronic renal insufficiency was induced by stepwise 9/10 nephrectomy. Despite this severe chronic renal insufficiency we observed no relevant pathological changes in the intestinal mucosa. In particular, we found no evidence of mucosal erosions, ulceration or pseudomembranous colitis, findings which are traditionally thought to be characteristic of the uremic state. This was also true of those animals dying prematurely from uremia. Thus serious doubts arise about the existence of “uremic enterocolitis”, doubts which also proved justified after a critical review of the literature on human pathology.