No abstract

The response of corticolous lichens to artificially induced chemical damage was compared to symptoms found on damaged lichens in the field. Experimental thalli were damaged and observed (1) in situ in a relatively pristine area, and (2) in a growth chamber either hydrated continuously or periodically. Lichenicolous fungi encountered included Cornutispora lichenicola, Lichenoconium erodens, Phoma cytospora, Vouauxiomyces truncatus, Hobsonia christiansenii, Pronectria oligospora, Nectria rubefaciens and its anamorph, Acremonium rhabdosporum, and a variety of hyphomycetes. The results support the idea that both thallus necrosis and moist conditions are necessary to produce the full suite of symptoms observed on ailing lichens in the field.

In the course of a cytological investigation of mouse ascites tumors ( 1 :2 ) and of neoplastic cells of chickens(3), it was observed that under certain conditions small cytoplasmic granules could be stained with toluidine blue. The appearance and distribution of these granules were identical with those of the mitochondria as revealed by phase microscopy and supravital staining( 2,3 ) . This paper describes a simple stain for mitochondria based on these observations, and presents a study of the chemical basis of the method employed.Experimental. Tissues. The following tissues were used. Ehrlich, Krebs 2B, sarcoma 3 7. MC 1 J1: sarcoma, TA3 carcinoma, lymphoma # I , 6C3 HED and DBA lymphoma mouse ascites tumors (4)' chicken, rat and mouse liver and spleen, rat pancreas and the RPL-12 chicken lymphoma( 5 ) . Staining. 1. a) Prepare smears of ascites tumors or of cells scraped from the freshly cut surface of tissues. Drop the smears rapidly while still wet, face downwards, into 1070 formalin, freshly saturated with HgC12 at 37°C and fix a t this temperature for at least 10 minutes. b) Fix blocks of tissue (less than 3 mm thick) in the same way for 2 or 3 hours; prepare frozen sections ( 6 p thick), float in 70% alcohol, mount on dried, albuminized slides and allow to dry. 2. Wash the slides in tap water for 10 minutes; if necessary, they can be stored in water for several days. 3. Stain for 5 minutes in 0.01% toluidine blue 0 in McIlvaine buffer of pH 6.0. This solution will keep for at least a month. 4. Wash for one minute in distilled water. 5. Immerse in a freshly prepared mixture of equal parts of 5% aqueous ammonium molybdate and 1 a/o aqueous potassium ferrocyanide for 5 minutes. 6 . Wash for one minute in distilled water. The nuclei may be counterstained with carmalum at this stage. Dehydrate in alcohol, clear in xylol and-_ -*The authors wish to thank Marie J. Warford for her valuable technical assistance and Leslie McWilliam for the photomicrographs. mount in Permount. The mitochondria are stained dark blue, the cytoplasm pale blue; and the chromatin pale purple (Fig. 1-3).t Rationale of the method. 1. Fixation. In order to investigate the role of fixation in demonstrating the mitochondria, smears were fixed in the following solutions: 1070 formalin saturated with HgClz (formol sublimate), 5% glacial acetic acid in saturated aqueous HgC12, 10% formol saline, formol Zenker, acetic Zenker, Bouin and Worcester (6) fluids. A few granules resembling mitochondria were stained capriciously only when mercurial fixatives were used; the mitochondria appeared larger and staining was more intense after fixation in formol sublimate. Fixation was sometimes inadequate at room temperature, and the more rapid fixation of smear preparations produced by raising the temperature of the fixative caused the cells to adhere better to the slide. Extension of the time of fixation in formol sublimate led to an increase in the precipitation of mercurial salts, but had no effect on the number and size-of the mitochondria stained, Prolo...

Periodic comparisons were made of sera from two groups of patients, ten who rejected their renal transplants within a year after transplantation and ten who successfully maintained their transplanted kidneys for five years or more. What appeared to be anti-kidney cytotoxic antibodies were found in much higher levels in the sera of those patients with the short-lived transplants, the difference in titer levels between the two groups being significant at the .0001 levels. This antibody showed no correlation with either the presence or the absence of lymphocytotoxic antibodies, nor did it appear to have any relationship to the HL-A antigens or the previous renal disease of the recipient patient. While it was cytotoxic to tissue cultures of cells obtained from random human kidneys, human kidney tumor cells (Wilms), and human embryonic kidneys, this antibody did not react with non-renal human tissues (lung, spleen, deltoid muscle, foreskin). It did not react with nonhuman (simian) kidney tissue culture cells. The findings suggest the appearance of an organ-specific, cytotoxic anti-kidney antibody in patients undergoing renal homograft rejection.

A technic for demonstrating a complement-dependent cytotoxic response specific for human kidney cells was developed. Positive and negative sera from kidney-transplant recipients were subjected to several assay and adsorption procedures. The cytotoxic antibody reaction appeared to be specific against human kidney in tests with a variety of target cells. Manifestation of the typical cytotoxic effect depended on kidney explant target-cell surface changes following attachment, outgrowth, and dispersion of the first passage monolayer. A comparison of serum responses to lymphocytes and to kidney cells indicated that the cytotoxic response by human kidney cells is not related to the lymphocytotoxic antibodies associated with the HLA system.