Small renal cell carcinomas: resolving a diagnostic dilemma

Thirty-nine patients with pathologically proved renal cell carcinomas 3 cm or les in diameter were examined. Results of intravenous urography (n = 30) were true positive in 20 patients and false negative in ten (sensitivity, 67%). Renal ultrasound (US) (n = 29) had true-positive results in 23 patients and false-negative results in six (sensitivity, 79%); computed tomography (CT) (n = 36) had true-positive results in 34 and false-negative results in two (sensitivity, 94%). For selective renal angiography (n = 35%), the results were true positive in 26 and false negative in nine (sensitivity, 74%), with typical hypervascular renal cell carcinomas demonstrated in 17. Finally, the findings of percutaneous fine-needle aspiration biopsy were true positive in one of five patients when US guidance was used (sensitivity, 20%) and in five of eight when CT guidance was used (sensitivity, 62%). Small renal cell carcinomas are more frequently encountered in clinical practice than heretofore realized, and they are best imaged by CT.     

Differential Effects of the M1–M5 Muscarinic Acetylcholine Receptor Subtypes on Intracellular Calcium and on the Incorporation of Choline Into Membrane Lipids in Genetically Modified Chinese Hamster Ovary Cell Lines

We compared responses of Chinese hamster ovary (CHO) cell lines stably transfected with human genes for the M₁–M₅ muscarinic receptor subtypes to several stimuli. While ATP brought about similar increases in the concentration of intracellular Ca²⁺ ions ([Ca²⁺]_i) in the cell lines expressing all individual receptor subtypes, carbachol acted with much higher potency and efficacy on the cells expressing the M₁, M₃, and M₅ receptor subtypes than on those expressing the M₂ and M₄ subtypes. The maximum [Ca²⁺]_i responses to ATP corresponded to 41–75% of the maximum responses to carbachol in the cells expressing the M₁, M₃, and M₅ receptor subtypes. The responses to ATP were strongly suppressed (> 75% decrease) by a preliminary administration of a maximally active concentration of carbachol in these three cell lines, whereas the responses to carbachol were less sensitive to the preliminary administration of a maximally active concentration of ATP (< 25% decrease). It appears likely that carbachol and ATP release Ca²⁺ ions from identical intracellular stores. Tetradecanoylphorbol acetate (TPA) strongly inhibited the responses of [Ca²⁺]_i to both carbachol and ATP and enhanced the incorporation of [¹⁴C]choline into lipids in all five CHO cell lines investigated. On the other hand, the incorporation of [¹⁴C]choline into lipids was diminished by carbachol in the cell line expressing the M₃ receptor subtype and unchanged in the other cell lines. This effect of carbachol was not dependent on the presence of extracellular Ca²⁺ ions and was not affected by TPA, which diminished the response of [Ca²⁺]_i to muscarinic stimulation. It is suggested that it was due to muscarinic receptor-mediated activation of phospholipase D. Copyright © 1997 Elsevier Science Inc.     

Hyperfunctioning and nonhyperfunctioning benign adrenal cortical lesions: characterization and comparison with MR imaging

The authors evaluated the potential of magnetic resonance (MR) imaging at 0.35 T to permit differentiation of nine hyperfunctioning adrenal cortical lesions from 21 nonhyperfunctioning adrenal cortical adenomas. Both qualitative data (visual assessment) and quantitative data (signal intensity ratios, T1, and T2) were used for tissue characterization. With a 2,000/56-100 sequence (repetition time msec/echo time msec), the majority of lesions were visually isointense to liver. Of 34 quantitative measures, only lesion-liver and lesion-kidney intensity ratios at 2,000/150 showed statistically significant differences among nonhyperfunctioning adenomas, aldosterone-producing lesions, and corticosteroid-producing lesions; however, the authors question the significance of these differences because of the abundant noise associated with the 2,000/150 sequence. The results suggest that nonhyperfunctioning adrenal cortical adenomas cannot be distinguished from benign hyperfunctioning cortical lesions with use of MR imaging at 0.35 T.     

Adrenal masses in oncologic patients: functional and morphologic evaluation

The role of adrenocortical scintigraphy in the evaluation of unilateral adrenal masses detected with computed tomography (CT) in 28 oncologic patients with normal adrenal function was studied prospectively with the use of NP-59 (iodine-131-6-iodomethyl-19-norcholesterol). The diagnosis was proved by means of percutaneous fine-needle aspiration cytologic examination in 20 patients, surgical biopsy in one, and clinical and CT follow-up in seven. In 14 of the 28 patients, there was increased uptake of the NP-59 on the side of the adrenal mass detected at CT (concordant uptake). Thirteen of the 14 masses with concordant uptake were greater than 2 cm in diameter, and one was 1.5 cm; all were found to be adenomas. In 11 of 28 patients there was decreased uptake on the side of the mass detected at CT (discordant uptake). None of these 11 masses were adenomas; nine were metastases and two were adrenal cysts. Uptake was indeterminate (symmetric) in three patients, two of whom had adrenal adenomas and one an adrenal metastasis; each mass with indeterminate uptake was less than 2 cm in diameter.     

Ocular complications in renal transplant patients

One hundred and seventy-six patients who received a renal transplant between 1982 and 1988 were examined for ocular complications of steroid therapy. Posterior subcapsular cataracts (PSC) were present in 60 patients (34.1%). Patients were classified into three groups (HS, LS, NoS) depending on their maintenance immunosuppression therapy. The HS group received high doses of steroids after renal transplantation. LS had low steroid doses, and NoS had no steroids. The incidence of PSC was 21 of 38 in HS (55.3%), 33 of 117 in LS (28.2%), and 1 of 16 in NoS (6.2%). The difference between HS and LS was statistically significant (x²= 8.1, P < 0.01). Grading the severity of PSC (PSC 0, PSC +, PSC > ++) showed a significant correlation between the degree of PSC and the steroid therapy. In the HS group, five patients had PSC +, and 16 had PSC > ++ (76%), compared to 19 patients with PSC +,14 patients with PSC > ++ (42%) in the LS group (x²= 4.6; P < 0.05). There was no correlation between the incidence of PSC and use of steroids for more than three months before dialysis. Comparison with the results of our earlier series (1973 -1981)¹ using high doses of steroids showed a similar incidence of PSC with HS (40.7% Series 1; 55.3% Series 2) but a lower incidence with LS and NoS.     

Refinement of lymphoma cytogenetics by the chromosome 18q21 major breakpoint region

A small (2.8-kilobase, kb) major breakpoint region localized to segment 18q21 rearranges in greater than 70% of t(14;18)(q32;q21) lymphomas. This rearrangement interrupts the Bcl-2 gene and introduces it into the Ig locus at 14q32. The rearrangement between the joining region (JH) of Ig on chromosome 14 and the 18q21 region creates a translocation- specific DNA rearrangement. We generated probes that distinguish the 14;18 juncture on the derivative (der) 14 and der (18) chromosomes, providing a molecular approach to t(14;18) identification. Approximately 60% of unselected follicular lymphomas, 20% of diffuse large cell lymphomas, and 50% of adult undifferentiated non-Burkitt lymphomas demonstrated 14;18 rearrangements within the major breakpoint region. Examination of DNA for 14;18 rearrangements resolved the identity of 14q+ chromosomes in two patient's cells that lacked an obvious reciprocal partner. Identification of the exact restriction fragments that mediate translocations complements routine cytogenetics. The detection of DNA rearrangements does not require dividing cells or the presence of an identifiable reciprocal partner and can detect clonal translocation rearrangements when the neoplastic cells are only a minority of all cells present.