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Although soluble gold has been widely used in the treatment of rheumatoid arthritis, little is known about the distribution of gold deposits in extra-articular tissues. In the synovial lining cells and articular cartilage, the morphology of lysosomes containing gold, the aurosomes, is well documented. Because gold may cause pulmonary injury, the morphology and distribution of gold deposits in pulmonary tissue should be recognized. We found morphologically typical aurosomes with electron-dense membranes and granules, giving the spectrum of gold in electron microprobe analysis, in the interstitial and alveolar macrophages in the open lung biopsies of 3 patients who had received gold treatment but not in 12 patients who had not received gold treatment. In contrast to previous studies, aurosomes were not found in the endothelial cells.

The growth-inhibitory effect of 6-methylmercaptopurine riboside (MMPR) against leukemia L1210 cells in culture was dramatically potentiated by the addition of guanine nucleosides to the medium. In the presence of either deoxyguanosine or guanosine, the concentration of MMPR that caused 50% inhibition of growth was 35 times lower than in the absence of these nucleosides. Similar potentiation was also observed against Sarcoma 180 cells in culture by guanosine. The metabolic basis of this synergism was approached in a study of the incorporation of [14C]glycine into 5'-phosphoribosyl-N-formylglycinamide in Sarcoma 180 cells. The results show that the site of inhibition resulting in synergism is an early step in purine biosynthesis, probably phosphoribosyl pyrophosphate amidotransferase (EC 2.4.2.14). In the L1210 cell system, the addition of hypoxanthine to the medium prevented the potentiation of MMPR by guanine nucleosides supporting the conclusion that the site of the synergistic interaction involves purine biosynthesis de novo. While hypoxanthine partially reversed the growth-inhibitory effects of MMPR, an even higher degree of protection was observed in the presence of both uridine and hypoxanthine, suggesting that MMPR may have additional sites of action concerned with pyrimidine metabolism.

A case of symptomatic non-union of the clavicle occurred in a 12-year-old boy. Differential diagnosis roentgenographic and histologic observations, including the results of resection of the non-union site and stablization of the proximal clavicle using the coraco-acromial ligament demonstrated that this rare condition can be restored to full asymptomatic function without any internal metallic fixation devices.

Twenty-eight patients with rheumatoid pleural effusion were investigated to examine the frequency of HLA antigens as compared with 56 rheumatoid arthritis (RA) patients without this intrathoracic manifestation of RA and with 283 healthy controls. HLA-B8 was strongly associated with the presence of pleural effusion (PE) in RA patients. A high prevalence (71%) of B8/Dw3 was found among male RA patients of the PE group in whom the joint disease had begun at an age over 50 years and who also had besides pleuritis other intrathoracic manifestations of RA associated with high rheumatoid factor titres and low complement (C4) levels in sera. Actually, the HLA-B8 association was not seen in the rest of the PE group. The finding may be related to the heterogeneity of RA, a male subgroup of the disease being characterized by multiple intrathoracic manifestations and genetically associated with the large group of autoimmune disorders, such as SLE, characterized by high prevalences of HLA-B8 and D(R)3.

The authors examined the effects of controlled hypotension induced with sodium nitroprusside (SNP) with and without propranolol on the cardiovascular, pulmonary, and renin-angiotensin systems in 10 consecutive anesthetized patients with kyphoscoliosis undergoing posterior spinal fusion. SNP infusion (4.1 microgram . kg-1 . min-1) alone decreased mean systemic arterial pressure (SAP) by 25 torr +/- 3 SE (P less than 0.001), systemic vascular resistance index (SVRI) by 1113 dyne . sec. cm-5 . m2 +/- 125 SE (P less than 0.001), mean pulmonary artery pressure (PAP) by 6 torr +/- 2 SE (P less than 0.02), pulmonary capillary wedge pressure (PCWP) by 4 torr +/- 1 SE (P less than 0.01), pulmonary vascular resistance (PVR) by 50 dyne . sec . cm-5 +/- 18 (P less than 0.05), and PaO2 by 16 torr +/- 7 SE (P less than 0.05), whereas cardiac index increased by 1.08 l . min-1 . m2 +/- 0.24 SE (P less than 0.01) and heart rate increased 16 beats/min +/- 5 SE (P less than 0.02). After 40 min of hypotension, 0.03 mg/kg propranolol was injected intravenously while the SNP infusion rate was held constant. Ten min later there was a significant decrease in the heart rate (10 beats/min +/- 4 SE, P less than 0.02) and cardiac index (0.65 l . min-1 . m-2 +/- 0.21, P less than 0.02). Plasma renin activity (PRA) increased from 2.37 ng . ml-1 . h-1 +/- 0.7 SE before anesthesia to 6.50 ng . ml-1 . h-1 +/- 1.45 SE (P less than 0.05) after 40 min of nitroprusside infusion. Forty min after propranolol there was a significant reduction in PRA to 4.07 ng . ml-1 . h-1 +/- 0.73 SE (P less than 0.05). Thus propranolol, when given during SNP hypotension, exhibits an early cardiovascular response manifested as a decrease in cardiac output and heart rate and a delayed action of the kidney resulting in an inhibition of renin release.

The purpose of this study was to compare the pools of free FdUMP derived from 5-fluorouracil (FUra) and of dUMP synthesized de novo in Hep-2 and S-180 cells, their relationship to inhibition of thymidylate synthase (dTMP synthase; EC 2.1.1.45), and the effect of excess folinic acid (CF) on these parameters. These cells differ 50-fold in their sensitivity to FUra and, in the absence of thymidine, dTMP synthase is the growth-limiting site of action of FUra in S-180 cells, but in Hep-2 cells this site becomes growth-limiting only in the presence of excess folates. In both cells after a 3-hr incubation with varied concentrations of FUra, FdUMP comprised only 0.1-0.2% of the total acid-soluble pools derived from FUra. The changes in dUMP and FdUMP pools paralleled each other, dUMP being 1000-2000 times higher than FdUMP. The pools of dUMP increased only when dTMP synthase was significantly inhibited. This occurred in S-180 cells above 3 microM FUra and in Hep-2 cells above 30 microM, where the residual dTMP synthase was similar in both cells. Under these conditions, the dUMP and FdUMP pools in Hep-2 cells were 2 and 4 times higher, respectively, than in S-180 cells. After FUra removal, both pools continued to increase, dUMP and FdUMP pools in Hep-2 cells rising 6-fold and 10-fold higher, respectively, than in S-180 cells. The dTMP synthase inhibition and the high nucleotide pools in Hep-2 were short-lived, whereas in S-180 cells the inhibition and the pools were maintained longer. Excess CF retarded the recovery of dTMP synthase after FUra removal only in Hep-2 cells and led to a further increase in dUMP and FdUMP pools in these cells, while having no effect in S-180 cells. These data indicate that a high capacity of cells to accumulate free FdUMP does not alone guarantee that dTMP synthase inhibition will be growth-limiting. The relationship shown here between excess CF, dTMP synthase recovery, and the nucleotide pools suggests that some cell types, such as Hep-2, in spite of high levels of FdUMP, require in addition an excess of folates to retard dTMP synthase recovery and make it growth-limiting.