Should percutaneous transluminal renal artery angioplasty be applied to ostial renal artery atherosclerosis?

PURPOSE: The purpose of this study was to review the results of percutaneous transluminal renal artery angioplasty (PTRA) in patients with atherosclerosis to assess safety, anatomic and functional outcome, and differences in outcome between ostial and nonostial lesions. METHODS: We used retrospective review of 52 consecutive patients who had undergone attempted PTRA for renal artery atherosclerosis during the calendar years 1987 to 1992. RESULTS: Fifty-two patients had 60 renal arteries on whom PTRA was attempted. The mean age was 68 years. Atherosclerosis was generalized in 81% of the patients. The indication for angioplasty was salvage of functioning renal parenchyma in 81% of patients. Eight patients were undergoing dialysis at the time of attempted PTRA. Five arteries (8%) could not be dilated. There were one cardiac death and two arterial complications requiring surgery within 30 days. Thirty-five percent of patients with available angiograms had an anatomic improvement above a threshold of one stenotic group (30% to 40% diameter improvement), with residual stenosis of less than 50%. Half of patients treated for hypertension had improvement in their hypertension. Overall, there was no change in creatinine levels before and after the procedure. Four of eight patients undergoing dialysis at the time of PTRA were able to discontinue dialysis during follow-up. Four patients (11%) required surgical bypass and five patients (14%) required chronic dialysis during follow-up. CONCLUSIONS: Modest success at low risk can be expected from PTRA in a group of patients with severe atherosclerosis. No significant difference in results between ostial and nonostial lesions was noted.

Chemical dosimetry of ethyl nitrosourea in the mouse testis.

[3H-Et]Nitrosourea was administered to male (101 X C3H) mice by i.p. injection at exposure levels of 10 mg/kg or 100 mg/kg. At intervals from 1 h to 6 days following treatment, the ratio of O6-ethylguanine to N7-ethylguanine in testis DNA averaged 1.13 following the 100 mg/kg exposure and 0.72 following the 10 mg/kg exposure. The amount of O6-ethylguanine recovered after the 100 mg/kg exposure was 40% greater than predicted from a linear extrapolation of the amount of O6-ethylguanine recovered after the 10 mg/kg exposure. We suggest that the high (100 mg/kg) exposure to ethyl nitrosourea results in depletion of the O6-alkylguanine acceptor protein within the testis and permits O6-ethylguanine to persist at higher levels than would be predicted from lower exposure data. W.L. Russell et al. (1982), W.L. Russell (1984) have found that specific-locus mutation frequencies induced in mouse spermatogonial stem cells are 5.8-fold greater after a single 100 mg/kg exposure to ethyl nitrosourea than after 10 weekly exposures to 10 mg/kg. The finding that the corresponding ratio for O6-ethylguanine formed in the testis is only 1.4 may be interpreted in a number of possible ways. If O6-ethylguanine is an important lesion for producing specific-locus mutations, then its formation in the stem cells must be at least 4-fold greater than that for the whole testis as the ENU exposure goes from 10 to 100 mg/kg: alternatively, the rate of repair of this lesion by the stem cells must decrease at least 4-fold relative to the average testicular cell. Other explanations for the difference in mutation response of the stem cells to acute vs. chronic ethyl nitrosourea-exposures include the possibility that other DNA lesions may be responsible for many of the mutations or that two hits on the DNA may be required to produce an effect.

The use of the Iatroscan TH-10 analyzer to quantify total lipids in a variety of sample types and lipid classes in human gallbladder bile.

Two methods for the measurement of total lipid weight in biological and geological samples and the major lipid classes in human gallbladder bile using the Iatroscan TH-10 analyzer are described. Total lipid determination involves the application of small (5 microliter) volumes to Chromarods, focusing of the sample into one band by partial development in chloroform-methanol (1:1), and quantification by flame ionization detection (FID). The response variation between different sample types did not affect the linearity of response, allowing a reproducibility of +/- 10% of the mean or better for samples ranging from 0.5 to 32 micrograms. Total lipid determinations in 10 samples could be performed in 30 min. The three major components of human gallbladder bile (cholesterol, phospholipids and bile acids) also were quantified with the Iatroscan. Samples focused on Chromarods were separated using a double development scheme in two solvent systems. All three components exhibited a linear response over the range of 0.25 to 8 micrograms. The repeated scanning of rods required at concentrations greater than 3 micrograms did not affect linearity of response. Samples from 10 patients could be processed in less than one hr. Several techniques are discussed to increase reproducibility when performing quantitative lipid analysis with the Iatroscan.

Aztec arithmetic: positional notation and area calculation.

Texcocan-Aztec peoples in the Valley of Mexico used both picture symbols and lines and dots for numerical notation. Decipherment and analysis of mid-16th-century native pictorial land documents from the Texcocan region indicate that the line-and-dot system incorporated a symbol for zero and used position to ascribe values. Positional line-and-dot notation was used to record areas of agricultural fields, and analysis of the documentary data suggests that areas were calculated arithmetically. These findings demonstrate that neither positional notation nor the zero were unique to the Maya area, and they imply an equally sophisticated mathematical development among the Aztecs.

Malignant APUDoma (carcinoid) of the anterior mediastinum. Simplified methods of demonstrating biogenic amines in endocrine neoplasms.

Endocrine neoplasms of the thymus and mediastinum are uncommon. This report describes such a carcinoma and the difficulty in determining its true nature. A simple modification of the technique for formaldehyde-fume-induced fluorescence (FIF) demonstrated biogenic amines in the cells. Electron microscopy and histochemical findings confirmed the close relationship of these neoplasms with neural-crest cells capable of amine precursor uptake and decarboxylation (APUD). The FIF technique is also a more sensitive method of detecting these tumors, since it has less of the sampling problems of electron microscopy, and the fluorescent granules are more easily seen than those stained by the usual methods. The techniques are simple enough for screening all poorly differentiated carcinomas in this area to determine a more accurate incidence figure.