Ultrastructural alterations of pulmonary surfactant in rat lungs after inhibition of protein synthesis by puromycin.

The effects of systematically administered puromycin on the fine structure of the lung were studied. The effects varied depending on the duration of exposure and the time interval between the last injection and sacrifice. After short term exposure most surfactant had separated from the epithelial surface and profound alterations in the tubular myelin structure were seen. After moderate duration of exposure a previously undescribed multilamellar lining layer was observed which was often detached from the alveolar epithelium. Six hours after the last injection the regular tubular myelin pattern reappeared. Puromycin treatment results in inhibition of various proteins synthesized by type II epithelial cells. Inhibition of synthesis of some proteins, most probably that of glycoprotein A, causes a primary effect on the structure of surfactant. The loss of at least some of the cytoskeletal proteins in Type II epithelial cells apparently results in interference with exocytosis of lamellar body contents.

[Nephrotoxicity of aminoglycosides. I: Preventive intraperitoneal calcium administration]. / Nefrotoksycznosc aminoglikozydów. Czesc I. Próby zapobiegania dootrzewnowym podawaniem wapnia szczurom.

UNLABELLED: The effect was studied of intraperitoneal intake of calcium on gentamicin nephrotoxicity in the rats. Two groups of Wistar were studied: G--in the first group gentamicin was injected in single daily dose 100 mg/kg b.w. subcutaneously, GCa--in the second group gentamicin was given s.c. and calcium intraperitoneal in single daily dose 45 mg Ca++/kg b.w. Results were evaluated after 3, 7, and 10 days of gentamicin injections and after ten days of gentamicin removal, Mean creatinine level after ten days of gentamicin administration was in G group 4.52 +/- 0.77 mg%, GCa--1.87 +/- 0.21 mg%, p less than 0.02, mean urea 192. 62 +/- 21.88 mg%, 77.09 +/- 8.68 mg%, p less than 0.01, serum calcium 8.39 +/- 0.15 mg%, 9.96 +/- 0.21 mg%, p less than 0.001, gentamicin in the renal cortex 384.68 +/- 67.62 micrograms/g tissue, 327.38 +/- 81.89 micrograms/g tissue p less than 0.05. Urinary calcium excretion was higher in the GCa group than in the group of control rats. Statistical differences were significant after 3 and 7 days of gentamicin intake. Differences were found also in the light and electron microscopic examination. CONCLUSION: Intraperitoneal calcium loading significantly reduced the gentamicin nephrotoxicity in the rats and lowered gentamicin level in the renal cortex of the rats.

[Nephrotoxicity of aminoglycosides. II. Preventive studies with oral administration of verapamil]. / Nefrotoksycznosc aminoglikozydów. Czesc II. Próby zapobiegania doustnym podawaniem werapamilu szczurom.

The effect was studied of oral verapamil administration in two different doses on gentamicin nephrotoxicity. Three groups of Wistar male rats were studied: 1) treated with gentamicin 100 mg/kg b.w. subcutaneously, 2) treated with gentamicin s.c. and verapamil 5 mg/100 ml given in drinking water, 3) treated with gentamicin s.c. and verapamil 20 mg/100 ml. The examinations were performed after 3, 7 and 10 days of gentamicin administration and after 10 days of gentamicin removal. Oral verapamil administration in these doses did not prevent the renal functional and histological damage after gentamicin administration. Renal cortex content of gentamicin was lower only after 3 days of gentamicin administration (statistically significantly) in the verapamil groups.

[Nephrotoxicity of aminoglycosides. III. Preventive studies with subcutaneous administration of converting enzyme inhibitor, captopril]. / Nefrotoksycznosc aminoglikozydów. Czesc III. Próby zapobiegania podskórnym podawaniem blokera enzymu konwertujacego, kaptoprylu szczurom.

The effect was studied of the converting enzyme inhibitor (captopril) on the gentamicin nephrotoxicity in rats. Captopril 25 mg/kg b.w. and gentamicin 100 mg/kg b.w. were injected subcutaneously in a single daily dose. Three groups of Wistar male rats were studied: 1) treated with gentamicin 3 and 7 days, 2) treated with gentamicin and captopril, 3) treated with captopril. The mean serum creatinine and urea levels and proteinuria in the second group were significantly higher than in the first one. Light and electron microscopy examinations demonstrated increased renal cortex damage in the second group. There were not differences between mean urea and creatinine levels in the third examined group and normal rats. Mechanism of gentamicin nephrotoxicity enhancement in the second group is unknown.

Immunohistochemical study of the distribution of secretory component and IgA in the normal and diseased uterine mucosa.

The distribution of secretory component (SC) and IgA in the normal and diseased uterine mucosa was studied by means of an immunoperoxidase method. Both substances could not be demonstrated in ectocervical epithelium, whereas in endocervical epithelium both were present and staining intensity appeared to be related to the degree of inflammatory activity in the underlying stroma. Local IgA-containing plasma cells most likely are the source of epithelial IgA. Well-differentiated adenocarcinomas of the endocervix were shown to display SC immunoreactivity. In endometrial glands SC was observed in the postovulatory phase of the menstrual cycle, in increasing quantities toward menstruation. Hyperplastic conditions of the endometrium showed a weak focal staining for SC. In contrast, in most well-differentiated adenocarcinomas of the endometrium, SC and IgA could be detected in most neoplastic elements, whereas poorly differentiated carcinomas were largely negative. It is concluded that: (a) in contrast to the endometrium, in the endocervix a local secretory immune system operates similar to that of the gastrointestinal tract; (b) the ability of the endometrium to synthesize SC is at least partly regulated by hormonal factors and, as such, is confined to the progestagen-dominated phase of the menstrual cycle; and (c) immunohistochemical detection of SC may be of help in the grading of adenocarcinomas of the endometrium.