The effect of certain variables on the tumor and tissue distribution of tracers V: false carrier effect, II, Fe

The effect of Fe3+ citrate on carrier-free 67Ga and 59Fe kinetics was studied in a Buffalo rat-Morris 7777 hepatoma model. Two mg Fe3+ citrate/Kg were administered intravenously in a variety of time sequences, prior to and following the tracers, and the rats were killed at 4 or 24 hours. 67Ga concentrations could be increased in tumor and decreased in most normal tissues. Administering Fe3+ both one half hour before and 2 hours after the tracers produced 67Ga values equivalent to 72-hour carrier-free values after 4 hours, while simultaneously decreasing gut secretion and increasing urinary excretion. The 59Fe and 67Ga kinetics suggested that events at both vascular and cellular levels were responsible for these changes. This study demonstrated the potential utility of Fe3+ citrate for improving both conventional 67Ga and positron (68Ga) imaging of tumors.

Cytotoxic activity, tumor accumulation, and tissue distribution of ruthenium-103-labeled bleomycin

Bleomycin (BLM) was labeled with gamma-emitting 103Ru. Yields of 103Ru-labeled BLM as high as 50.6% were attained. 103Ru-labeled BLM was stable in vitro and the 103ru label was not displaced by large excesses of Cu (II) and Co (II) or Fe (III). Chromatography of the urine following 103Ru-labeled BLM injection indicated no in vivo decomposition. Pharmacokinetic studies in healthy inbred SD and tumor-bearing inbred BUF rats demonstrated tumor accumulations, tissue distributions, and clearance nearly identical with those reported for 3H-labeled BLM. Cytotoxicity studies on a WI-L2 human B-cell line showed that BLM labeled with nonradioactive Ru retained 100% of the activity demonstrated by native BLM. Thus BLM may be labeled with isotopes of Ru to form stable complexes by a simple, rapid reaction without loss of its chemotherapeutic properties or variations in its in vivo distribution. BLM labeled with the proper Ru isotope should prove useful as a gamma-emitting tracer for BLM or a beta-emitting compound capable of providing combination chemotherapy and radiotherapy of tumors.

Prevalence of farmer's lung in Scotland: a pilot survey

In a survey of the farming population of Orkney, Ayrshire, and East Lothian the prevalence of farmer's lung was estimated at 86 per 1,000 in both Orkney and Ayrshire and 23 per 1,000 in East Lothian. If cases with a negative farmer's lung hay (F.L.H.) precipitin test are excluded these figures are reduced to 43, 36, and nil respectively, but those for Orkney and Ayrshire are still about 20 times higher than any figure previously reported for the prevalence of farmer's lung in Britain.Regional variations in prevalence are probably related both to climatic conditions and to differences in agricultural methods, the latter often being dictated by economic circumstances. Nevertheless the prevalence of farmer's lung could be reduced considerably by the energetic application of preventive measures, backed by financial incentives. The most important of these are efficient drying of hay and cereals before storage, more extensive use of silage, better ventilation of farm buildings, and the introduction of mechanical feeding systems. Individual farmworkers could be taught how to recognize the early symptoms of the disease and encouraged to wear respirators when handling mouldy fodder.

The corneomandibular reflex

Seven patients are presented in whom a prominent corneomandibular reflex was observed. These patients all had severe cerebral and/or brain-stem disease with altered states of consciousness. Two additional patients with less prominent and inconsistent corneomandibular reflexes were seen; one had bulbar amyotrophic lateral sclerosis and one had no evidence of brain disease. The corneomandibular reflex, when found to be prominent, reflects an exaggeration of the normal. Therefore one may consider the corneomandibular hyper-reflexia as possibly due to disease of the corticobulbar system.

Preparation and evaluation of standardized amoeba antigen from axenic cultures of Entamoeba histolytica

The successful mass cultivation of Entamoeba histolytica strains in pure culture has made it possible to produce pure amoeba antigens, which should improve the prospects for immunodiagnostic research and simplify the interpretation of the results obtained in tests for amoeba antibodies.The authors have mass-produced immunodiagnostic antigens for amoebiasis serology from 2 axenic strains of E. histolytica and standardized them as dry powders, which upon reconstitution contained approximately 1.8 mg N/ml, or roughly the equivalent of 10 x 10(6) amoebae per ml.The antigens were evaluated with 121 sera from subjects in Costa Rica, South Africa, Taiwan, Thailand and the USA, 49 of the sera being from cases of amoebic liver abscess, 41 from symptomatic intestinal amoebiasis, 19 from asymptomatic intestinal amoebiasis, and 12 from subjects presumed not to have amoebiasis.Positive results with the indirect haemagglutination test were obtained with 100% of amoebic liver abscess sera, 90.2% of those from symptomatic intestinal amoebiasis, 57.9% of those from asymptomatic intestinal amoebiasis, and 16.7% of the normal sera. Positive complement-fixation tests for the respective groups were obtained in 83.8%, 63.3%, 10.5% and 0%, and positive agar-gel diffusion in 79.6%, 53.7%, 0% and 0%.These results compare favourably with earlier reports of similar studies in which non-axenic cultures were used and agree well with those of investigators in different parts of the world to whom samples of the axenic antigens were sent.The authors conclude that the axenic antigens from either strain used, or from the 2 strains pooled, are of broad usefulness in the detection of amoebic antibodies, but point out that the limitations of the tests now used in amoeba serology are not yet clearly understood and that the pattern of antibody persistence after infection requires further study.