Photostimulated reactions of phenylacetic acid dianions with aryl halides. Influence of the metallic cation on the regiochemistry of arylation.

[reaction: see text]Phenylacetic acid dianions react via what appears to be an S(RN)1 process with aryl halides under photostimulation to afford aryl substitution products 5 and 6. When the counterion is K+, only 4-biphenylacetic acids 5 are obtained. Both alpha- and para-coupling occurs with Na+ to give a mixture of 5 and 6, while exclusive formation of diphenylacetic acids 6 is observed with the dilithio salt of 1.

Synthesis and evaluation of N-(phenylacetyl)trifluoromethanesulfonamides as anticonvulsant agents.

A series of N-(phenylacetyl)trifluoromethanesulfonamides (3a-g) was prepared according to the Topliss scheme in order to determine if aryl substituents would influence anticonvulsant activity. In initial (phase I) screening and quantitative (phase II) evaluation, all seven compounds exhibited significant activity against MES- and scMet-induced seizures. N-(Phenylacetyl)trifluoromethanesulfonamide (3a) was then advanced through five additional testing phases (phases III-VII). Compound 3a displayed good oral bioavailability, low toxicity, and a larger protective index in mice than the prototype drugs, phenytoin, phenobarbital, valproate, and ethosuximide. Additionally, 3a exhibited a longer time to peak effect in all tests and a greater 24-h margin of safety (HD(50)/ED(50)) than the prototypes. Compound 3a blocked picrotoxin-induced seizures but was ineffective against seizures induced by bicuculline or strychnine. In vitro receptor binding studies revealed that 3a did not displace [(3)H]-labeled gamma-aminobutyric acid or [(3)H]-labeled flunitrazepam, and tolerance did not develop during a 5-day chronic administration.

Synthesis and anticonvulsant evaluation of some new 2-benzylsuccinimides.

A series of 2-benzylsuccinimides (4a-f) were prepared for evaluation as potential anticonvulsants. Primary (Phase I) screening of these compounds indicated that succinimides 4d and 4e, containing lipophilic (+ pi), electron-withdrawing (+ sigma) phenyl substituents, were the most effective in controlling seizures induced by maximal electroshock (MES) and subcutaneous pentylenetetrazol (scMet). Compounds 4a, 4c, and 4d showed activity against scMet-induced seizures equal to that of their 2-phenylsuccinimide analogues and were somewhat more effective in the MES test. In quantitative (Phase II) testing, when administered ip in mice, 4d and 4e both demonstrated anticonvulsant potency superior to that of the prototype drug (ethosuximide) by the MES and scMet assays. However, they also exhibited greater neurotoxicity than ethosuximide in the rotorod test.

Synthesis and anticonvulsant activity of 2-benzylglutarimides.

A series of 2-benzylglutarimides (4) and their N-methyl analogues (5) were prepared according to the Topliss scheme for the selection of benzyl substituents to maximize anticonvulsant activity. A total of 22 such compounds were subjected to initial (phase I) screening in mice against seizures induced by maximal electroshock (MES) and pentylenetetrazol (scMet) and in the rotorod assay for neurotoxicity. From this series of test compounds, 10 were advanced to quantitative (phase II) testing. Of these, 2-(4-chlorobenzyl)glutarimide (4b) emerged as the most promising anticonvulsant drug candidate by demonstrating both good anti-scMet and anti-MES activity combined with low neurotoxicity after intraperitoneal administration in mice. In drug differentiation tests, 4b was also effective in nontoxic doses against seizures induced by bicuculline, picrotoxin, and strychnine. When compared with the clinically useful drugs phenytoin, carbamazepine, phenobarbital, valproate, and ethosuximide, 4b exhibited an overall pharmacological profile most closely resembling that of valproate.

Synthesis and anticonvulsant activity of some new 2-substituted 3-aryl-4(3H)-quinazolinones.

A series of 4(3H)-quinazolinones structurally related to 2-methyl-3-o-tolyl-4(3H)-quinazolinone (methaqualone, 3) were synthesized and evaluated for anticonvulsant activity. Preliminary screening of these compounds revealed that 2-[2-oxo-2-(4-pyridyl)ethyl]-3-aryl-4(3H)-quinazolinones 6l and 8i, 8k, and 8p-r having a single ortho substituent on the 3-aryl group had the most promising anticonvulsant activity. Compounds 6l and 8i possessing 3-o-tolyl and 3-o-chlorophenyl groups, respectively, showed good protection against MES- and scMet-induced seizures, combined with relatively low neurotoxicity after intraperitoneal administration in mice. They also exhibited low toxicity in tests for determining the mean hypnotic dose (HD50) and the median lethal dose (LD50). Although these compounds were markedly more potent as anticonvulsants when administered orally in mice and rats, they were also more neurotoxic. This neurotoxicity was particularly acute in oral tests with rats, which resulted in marginal protective indices. In drug differentiation tests, compound 6l was ineffective against seizures induced by bicuculline, picrotoxin, and strychnine, while 8i showed some protection against picrotoxin-induced seizures.

Clinical relevance of PM-1 antibody and physiochemical characterization of PM-1 antigen.

Using an improved immunodiffusion test with partially purified antigen, PM-1 antibody was identified in the serum of 18 patients. In 67% this system was associated with a polymyositis-scleroderma overlap, it occurred less frequently in polymyositis, dermatomyositis and scleroderma, and was not detected in other rheumatic diseases. The predominant clinical features of PM-1 positive patients were muscle weakness, sclerodactyly, Raynaud's phenomenon and pulmonary disease; widespread sclerodermatous features with infrequent. Characterization of the PM-1 antigen showed it to be a heat sensitive, trypsin sensitive acidic protein associated with the cell nucleus and possibly with nucleoli.

A prospective evaluation emphasizing pulmonary involvement in patients with mixed connective tissue disease.

Pulmonary involvement in mixed connective tissue disease (MCTD) is common, frequently severe, and is often clinically inapparent and variably responsive to corticosteroid/cyclophosphamide treatment. Serial pulmonary evaluation of patients with MCTD is important, since deterioration, as in the diffusing capacity over time, may alert the physician to the need for more invasive evaluation. Patients with a greater degree of overlap in rheumatological symptoms with an element of systemic sclerosis (PSS) may later develop severe disease. Nailfold capillary microscopy also may help in determining which patients will develop severe pulmonary involvement. Significant pulmonary hypertension occurs and cannot be accurately predicted on the basis of history, physical examination, pulmonary function tests, gallium scanning, or exercise testing. The characteristic pathological finding was intimal proliferation with medial muscular hypertrophy in the pulmonary arterioles. In contrast, pulmonary interstitial abnormalities were minimal, suggesting the proliferative vascular lesions are more closely associated with pulmonary hypertension in MCTD. Some patients develop rapidly progressive disease with varying response to corticosteroid and cytotoxic agents. More commonly, however, MCTD patients with long-term disabling disease, including pulmonary dysfunction, have had significant improvement with steroid and/or cyclophosphamide treatment, and clinical remission has occurred in 38% of the patients in this series.

Diagnostic potential of in vivo capillary microscopy in scleroderma and related disorders.

The prevalence of scleroderma-type capillary abnormalities, as observed by in vivo microscopy, was determined in 173 patients from three rheumatic disease centers. The patients had a variety of connective tissue diseases: scleroderma (systemic sclerosis) 50; systemic lupus erythematosus 60; mixed connective disease 26; Raynaud's disease 11; other rheumatic disorders 26. Enlarged and deformed capillary loops surrounded by relatively avascular areas, most prominently in the nail-folds, were found in 82% of patients with scleroderma and in 54% with mixed connective tissue disease. The rarity of these abnormalities in systemic lupus erythematosus (2%) despite the presence of Raynaud's phenomenon suggests that they are not an expression of the Raynaud's phenomenon frequently associated with scleroderma and mixed connective tissue disease. The single patient with Raynaud's disease and sclerodermatype capillary changes subsequently developed scleroderma.

Identification of a clinical subset of systemic lupus erythematosus by antibodies to the SM antigen.

The clinical and renal histologic attributes of 135 systemic lupus erythematosus (SLE) patients with DNA and/or Sm antibodies were compared to determine if the presence of the Sm antibodies served as a marker for a specific subset of SLE. Although Raynaud's phenomenon was more frequent in patients with Sm antibodies (P less than 0.005), serious central nervous system disease was over three times as common in patients with DNA antibodies (P less than 0.005). Only one of 23 patients with Sm antibodies had diffuse proliferative glomerulonephritis on renal biopsy, whereas 6 of 14 patients with only DNA antibodies had this histologic finding (P = 0.01). The Sm antibody system may therefore identify a subset of SLE patients with milder central nervous system and renal disease.

Characterization of a distinct nuclear acidic protein antigen (MA) and clinical findings in systemic lupus erythematosus patients with MA antibodies.

Circulating antibodies against certain nuclear acidic protein antigens have been shown to have diagnostic and prognostic importance in connective tissue disease. We describe a new precipitin system found in the sera of patients with systemic lupus erythematosus. The antigen, called MA, was prepared from calf thymus nuclei, and was shown to be distinct from other nuclear acidic protein antigens by physicochemical and immunologic techniques. MA antibodies were detected in the serum of 12 of 66 lupus patients and in none of 554 sera from normal controls or patients with other rheumatic diseases. Lupus patients having MA antibodies had more severe disease than did lupus patients with Sm or native DNA antibodies, manifested by recalcitrant skin rashes and a significantly greater incidence of hypocomplementemia, serious renal disease, hypertension, hepatosplenomegaly, lymphadenopathy, and neurological disease (P values range from 0.025 to 0.005). The presence of circulating MA antigen was demonstrated in three lupus patients immediately before a flare of nephritis. These data suggest that MA is a nuclear acidic protein antigen that may identify a subset of lupus patients with very severe disease. The presence of the antigen in the circulation before clinical flares suggests a possible biologic role for the MA system in an immune complex nephritis.

Antinuclear antibody with distinct specificity for polymyositis.

In the course of studying antinuclear antibodies in the rheumatic diseases, a new precipitin reaction (provisionally referred to as PM-1) was observed between calf thymus nuclear extract and polymyositis sera. Objectives of this study were to further define the immunologic nature of this reaction and to determine its specificity for polymyositis. Immunodiffusion studies using calf thymus nuclear extract revealed the PM-1 precipitin line in 17 of 28 patients with polymyositis. This reaction was not produced by sera of 460 patients with other diseases. Enzyme and heat treatments of the nuclear extract showed that PM-1 was distinct from native DNA, ribonucleoprotein, and Sm antigens. Fractionation of PM-1-positive serum by 30% ammonium sulphate and Sephadex G-200 chromatography revealed that the factor producing the PM-1 precipitin reaction was in a serum fraction which showed only IgG by immunoelectrphoresis against anti-whole human serum. Because of the apparent strong specificity, the PM-1 system may represent a marker antibody for polymyositis.