Purines in the Urine of Normal and Schizophrenic Subjects

Although there have been many attempts to discover in the body fluids, chemical peculiarities characteristic of schizophrenic illness, the outcome of most of these investigations has been inconclusive (see for example Altschule, 1953; Kety, 1959). Little attention has been paid, however, to purine metabolism until the recent studies of Kishimoto (1958) who reported peculiarities in the absorption spectra of body fluids in schizophrenia which he attributed to abnormalities in the conversion of adenine through hypoxanthine and xanthine to uric acid. These findings appeared to be supported by evidence which included the determination of urinary xanthine by a xanthine oxidase method based on that of Williams (1950).

The sodium-plus-potassium ion-activated adenosine triphosphatase of cerebral microsomal fractions: treatment with disrupting agents

1. The Na(+)-plus-K(+)-stimulated adenosine triphosphatase [(Na(+),K(+))-ATPase] of microsomal preparations from ox brain was inactivated or diminished in activity by exposure to 2-8m-urea. Similar concentrations of urea diminished the turbidity of the suspensions. 2. Low concentrations (about 2.5mm) of NaATP with the urea gave partial or complete protection of the ATPase, without altering the concomitant change in turbidity. Some protection of the (Na(+),K(+))-ATPase was afforded by tris ATP, but the greatest protection was found with NaATP and in its presence the change in (Na(+),K(+))-ATPase with 3m-urea included a phase in which activity was enhanced by 40%. 3. The protective effect was specific to NaATP: KATP, NaADP, NaAMP and sodium pyrophosphate were without protective effect and in some cases they augmented the action of urea. 4. The turbidity of cerebral microsomal suspensions was diminished also by ultrasonic irradiation; NaATP did not alter this change. After ultrasonic treatment up to 55% of the protein and of the ATPase activity were no longer deposited by centrifugal forces of 4.5x10(6)g-min. 5. Ultrasonic treatment and centrifugation could be carried out with little or no loss of ATPase and ammonium sulphate flocculation of the supernatant then afforded in the first material precipitated a three- to five-fold enrichment of (Na(+),K(+))-ATPase activity. 6. Sodium borohydride and dimethyl sulphoxide also diminished the turbidity of the microsomal fraction but enrichment of the ATPase was not effected by these reagents; ten other compounds were without action on the ATPase. 7. Acetyl phosphate was hydrolysed by the microsomal preparation and this activity was increased by added K(+). Acetyl-phosphatase activity persisted in the ultrasonically treated and ammonium sulphate-fractionated preparations, which were more exacting in their requirements for K(+). 8. The findings are discussed in relation to the mechanism of the (Na(+),K(+))-ATPase.

An estradiol matrix transdermal system for the prevention of postmenopausal bone loss

OBJECTIVE

The aim of this study was to evaluate the efficacy, safety, and tolerability of 2 years' application of an estradiol matrix transdermal system for the prevention of postmenopausal bone loss.

METHODS

In this multicenter, randomized, placebo-controlled, parallel-group study, 261 surgically or naturally postmenopausal women were randomized to apply the estradiol matrix transdermal system (0.025, 0.0375, 0.05, or 0.1 mg/d) or matching placebo twice a week for 2 years. The study was double blind with respect to treatment (active vs placebo) but not to the dose levels of active treatment (because of the differing sizes and shapes of the patches). In addition to receiving the assigned treatment, the 100 nonhysterectomized women received 2.5 mg medroxyprogesterone acetate daily throughout the study.

RESULTS

The evaluable group (n = 259) had a mean age of 52 years and a mean duration of menopause of 32 months. Following 2 years of treatment, there were significant differences in favor of estradiol between all doses of the estradiol matrix transdermal system and placebo in terms of the percentage change from baseline in the bone mineral density (BMD) of the L1-L4 anteroposterior lumbar spine (0.1 and 0.05 mg/d, P < 0.001; 0.0375 mg/d, P = 0.024; 0.025 mg/d, P = 0.002). Percentage changes from baseline in the BMD of the femoral neck after 2 years of treatment also consistently demonstrated the efficacy of the estradiol matrix transdermal system compared with placebo (all, P < or = 0.044). The estradiol matrix transdermal system was well tolerated.

CONCLUSION

The estradiol matrix transdermal system was effective in preventing postmenopausal bone loss at dosages of 0.025 to 0.1 mg/d, and had a safety profile consistent with the known effects of estrogen/progestin.

Effect of specific COX-2 inhibition in osteoarthritis of the knee: a 6 week double blind, placebo controlled pilot study of rofecoxib. Rofecoxib Osteoarthritis Pilot Study Group

OBJECTIVE

To determine the efficacy and safety of the cyclooxygenase 2 (COX-2) specific inhibitor, rofecoxib in patients with osteoarthritis (OA) of the knee.

METHODS

Rofecoxib, 25 mg or 125 mg once daily, was compared with placebo in a 6 week, double blind, parallel group, randomized, multicenter study of 219 patients with knee OA.

RESULTS

Both doses of rofecoxib produced clinically significant improvement as assessed by primary (e.g., WOMAC Pain Subscale 0-100 mm, decrease from baseline: placebo: 7.1 mm; rofecoxib 25 mg: 28.1 mm, rofecoxib 125 mg: 28.0 mm; p < 0.001 rofecoxib vs placebo) and secondary efficacy (p < 0.05) criteria compared with placebo. Clinical improvement with the 25 mg dose was similar to that with the 125 mg dose. Both rofecoxib doses were generally well tolerated.

CONCLUSION

Specific inhibition of COX-2 by 25 and 125 mg rofecoxib, administered once daily, resulted in clinically meaningful improvements in patients with OA. This study confirms that COX-2 derived prostanoids are important clinical mediators of pain and other symptoms of knee OA and that inhibition of COX-1 is not required to provide clinical benefit.

An open-label extension study of alendronate treatment in elderly women with osteoporosis

We have recently reported the results of a 24-month, double-blind, placebo-controlled study in 359 elderly osteoporotic women who were treated with daily oral alendronate (ALN) 1, 2.5, or 5 mg or placebo (PBO). We report the results of a 12-month, open-label, extension study during which 246 patients from the original study were treated with ALN 10 mg/day. Significant increases in lumbar spine bone mineral density (BMD) were observed in patients who had previously received PBO or ALN 1 and 2.5 mg/day for 24 months. Significant gains in trochanter BMD were seen in all treatment groups. Small changes were observed in femoral neck, total body, and forearm BMD during the course of this extension study. In general, the greatest increases in BMD during the open-label extension year occurred in patients who received either PBO or the lower doses of ALN during the previous 2-year blinded study. The frequencies of all categories of upper gastrointestinal adverse experiences (AEs) were less during months 25-36 (open-label extension) than during months 0-24 (original study). In conclusion, treatment with ALN 10 mg/day for 12 months in elderly women with osteoporosis who were previously treated for 24 months with PBO or ALN 1, 2.5, or 5 mg/day increased or maintained BMD of the spine, trochanter, and forearm, and was generally safe and well tolerated, especially in the upper gastrointestinal tract.

Comparative study of alendronate versus etidronate for the treatment of Paget's disease of bone

Alendronate, an aminobisphosphonate, is much more potent than etidronate, an older bisphosphonate, in inhibiting osteoclast-mediated bone resorption, and unlike etidronate, therapeutic doses of alendronate are not associated with abnormal mineralization. In the present study, we compared the effectiveness, safety, and tolerability of 6 months of daily oral administration of alendronate (40 mg) with those of etidronate (400 mg) in 89 patients with clinically active Paget's disease. The primary efficacy end point was the percent change in serum alkaline phosphatase. Other end points included changes in urinary deoxypyridinoline excretion, pain, functional impairment scores, and radiological osteolysis. Tetracycline-labeled bone biopsies were obtained for histomorphometric analysis from a subset of 43 patients at the 6-month visit. The alendronate-treated group had significantly greater decreases in both serum alkaline phosphatase (79% vs. 44%) and urinary deoxypyridinoline (75% vs. 51%) than the etidronate-treated group (P < 0.001 in both cases). Normalization of serum alkaline phosphatase was much more frequent in alendronate-treated patients (63.4% vs. 17.0%; P < 0.001). Alendronate was well tolerated and had a safety profile similar to that of etidronate. Histomorphometry revealed decreased bone turnover and no qualitative abnormalities, including no direct negative effects on bone mineralization, with alendronate treatment. One patient receiving etidronate developed frank osteomalacia. Alendronate appears to be a highly effective treatment for Paget's disease of bone that offers an important therapeutic advance over etidronate.

Contributions to neurochemical knowledge considered ecologically

The development of neurochemical knowledge is traced through the following stages: (1) Beginnings with academic medicine: a dissertation of 1719, (2) Relations with chemistry and scientific journals of around 1800, (3) A review and the naming of neurochemistry in 1856, (4) Government publication of neurochemistry; a full-time chemist of the brain, (5) Success in a biochemical environment, 1900-1940, (6) Neurochemistry with the neurosciences, (7) Neurochemical environments of 1955-1957.

How neurochemistry regained its specific biological components: experimental and cognitive advance, 1935-1955

Neurochemistry in the 1850s was part of comparative animal chemistry, which became incorporated into physiological chemistry. By 1900, the connection with physiological chemistry had largely lapsed or been vehemently repudiated. Growth of biochemistry, especially from the 1920s to 1950s, provided techniques and findings sufficient to reintegrate chemical knowledge of neural systems with neural functioning. Vitamin, coenzyme, respiratory and other metabolic studies made large contributions to this outcome. Regarding mental illness as a social problem and scientific challenge gave impetus and funds to such work, which resulted in major experimental and cognitive progress.

Intra-articular orgotein in osteoarthritis of the knee: a placebo-controlled efficacy, safety, and dosage comparison

PURPOSE

Superoxide dismutase (orgotein for injection) has been used in managing osteoarthritis for more than seven years in Europe; however, well-controlled studies to establish an optimum dosage regimen have not been conducted. In this study, three orgotein dose/regimens were compared with placebo in terms of efficacy, safety, and duration of effect in patients with active osteoarthritis of the knee.

PATIENTS AND METHODS

A total of 139 patients with osteoarthritis of the knee were enrolled in the study. Nonsteroidal anti-inflammatory agents were withdrawn to induce a flare of disease activity. Patients were then randomly assigned to receive one intra-articular injection of either placebo or orgotein (8 mg to 32 mg) each week for three weeks. Both investigators and patients evaluated disease activity and adverse experiences at a series of follow-up visits for three months.

RESULTS

Orgotein was effective in reducing symptoms of osteoarthritis for up to three months after treatment; 16 mg given twice was the most effective and most best-tolerated regimen. Discomfort at the injection site was drug related, although this effect also occurred occasionally after injection of placebo.

CONCLUSION

The long-lasting effects of intra-articular superoxide dismutase contribute to a favorable risk-benefit ratio and support the importance of the free-radical anion, superoxide (O2-), in the biochemical pathology of osteoarthritis.

Adenosine in cerebral homeostatic role: appraisal through actions of homocysteine, colchicine, and dipyridamole

Mammalian neocortical tissues were incubated in [14C]adenine-containing fluids and their newly-synthesized adenine derivatives examined after periods of superfusion. Increased [K+] released adenine derivatives from the tissues, a release diminished by homocysteine. Homocysteine acted also to diminish the tissue content of adenosine plus its metabolites hypoxanthine and inosine, while increasing that of S-adenosylhomocysteine. Hypoxia also increased the tissue content and the output of adenosine plus its metabolites, and again homocysteine augmented the S-adenosylhomocysteine. Glutamic acid also increased tissue content and output of adenosine and derivatives, an action diminished by homocysteine and associated with augmented S-adenosylhomocysteine. Colchicine or dipyridamole did not prevent augmentation of S-adenosylhomocysteine by the reagents described; the sequence from adenosine phosphates to S-adenosylhomocysteine is concluded to be intracellular and not to involve extracellular formation of precursor adenosine. Adenosine displayed properties consistent with its being involved in two distinct categories of homeostasis, and also with its exerting an inhibitory tone in normal cerebral systems.

In the beginning: to celebrate 20 years of the International Society for Neurochemistry (ISN)

The antecedents of the International Society for Neurochemistry are described, especially the parts played by the International Neurochemical Symposia held between 1954 and 1962; the Journal of Neurochemistry between 1956 and 1965; and by other organizations concerned with neural systems though not primarily neurochemical. Description is also given of the foundation of the Society in 1965 and of its first International Meeting in 1967.

Assay-guided isolation of naturally-occurring neuroactive substances

Ways in which chemical techniques could be applied to the understanding of neural systems, their functioning and their disorders were devised only gradually during the present century. In a particularly successful procedure, now termed assay-guided isolation, neural defects were made good by means of tissue-extracts and the restoration of function was established as an assay-system to guide the chemical separation and identification of the active tissue constituent. Thiamin was so isolated, using an experimental polyneuritis assay; subsequent instances among other metabolites, hormones, neurotransmitters and nerve growth factors are recounted. Procedures of assay-guided characterization ensured that links were retained between specific, sparsely-occurring substances and chosen aspects of their biological roles while their chemical nature was first explored and then established. The procedures discouraged the too-facile postulating of hypothetical molecules and contributed to the distinctiveness of neurochemistry as a subject within the neurosciences.

Colchicine-binding measurements of tubulin in variously sampled and incubated tissues from the mammalian brain

Tissue preparations from the brain of rats and guinea-pigs were examined for their activity in binding isotopically labelled colchicine, as a measure of their content of tubulin. The amount of binding material extracted into a cold buffered solution was unaffected by keeping tissues at 0 degrees C. It diminished by one quarter when tissues were incubated at 37 degrees C in bicarbonate glucose salines for 1-2 h. This diminution increased when glucose was omitted from incubating solutions and was less when tissues were stimulated electrically. It was modified also by the calcium content of the incubation fluids. Of the binding activity lost on incubation only a little was recovered in surrounding fluids. About half the colchicine-binding activity of the tissues was not extracted by the solution employed; this particulate-attached activity changed little, if at all, on normal incubation but diminished when incubating fluids contained a cyclic AMP-fluoride theophylline mixture which was known to modify tubulin assembly. The retention of both categories of colchicine-binding under normal conditions of incubation is consistent with the ability of such tissues to perform microtubule-dependent processes, notably cytoplasmic transport. Examination of the isolated tissues by the methods reported is of value in indicating which of various factors known to affect separated tubulin and microtubule structures, operate in a cell-containing system under chosen experimental conditions.

Wernicke-Korsakoff syndrome in monozygotic twins: a biochemical peculiarity

A pair of monozygotic twins, one suffering from the Wernicke-Korsakoff syndrome, verified at autopsy, and the other healthy, was studied biochemically. The erythrocyte transketolase of each twin showed abnormalities, though these differed in the two individuals. In the healthy twin, the basal transketolase was low, but responded normally to thiamine pyrophosphate (TPP) added in vitro. In the twin with the Wernicke-Korsakoff syndrome the basal level of the enzyme and its response in vitro were normal, but a period of treatment with thiamine tetrahydrofurfuryldisulphide, led to loss of the in vitro response. It is suggested that, initially, an inborn error of metabolism may have been common to both twins.

Erythrocyte transketolase activity in the Wernicke-Korsakoff syndrome

Erythrocyte transketolase activity and the effect of adding thiamine pyrophosphate (% TPP effect) were measured in subjects suffering from Wernicke-Korsakoff syndrome both before and during treatment with thiamine and/or thiamine tetrahydrofurfuryldisulphide (TTFD). Transketolase activity was significantly lower in untreated patients than in healthy volunteers. Treatment with either thiamine or with TTFD restored enzyme levels to control values but TTFD produced a greater increase than thiamine in enzyme activity. In a group of seven patients there was no correlation between duration of TTFD therapy and either increase in erythrocyte transketolase activity or % decrease in the TPP effect. However, when three patients were followed at intervals during treatment with TTFD, their erythrocyte transketolase increased progressively. Neither thiamine nor TTFD produced clinical improvement in the mental symptoms of Wernicke-Korsakoff psychosis unless administered early in the course of the disease.

The flow of thought and the flow of substance in the brain

Many neuroactive substances undergo cytoplasmic transport along the axons and dendrites of cerebral neurons, and the expression of their activities is determined by the time occupied by their transport. Such substances include cyclic nucleotides which are formed postsynaptically as mediators by several neurotransmitters including catecholamines, and which are capable of acting at numerous postsynaptic sites during their subsequent intracellular translocation. Temporally patterned changes in cell-firing tendency during some seconds or minutes following brief stimuli are attributed to movement of such compound, as is also the subjective sense of a flow of thought. Descriptions are appraised which indicate that components experienced as part of a stream of thought can be initiated by drive-inducing catecholaminergic systems acting through cyclic nucleotides, thus affording endogenous signals that contribute to electrophysiological matching processes in perception and recall. Roles for satiety mechanisms involving opioid peptides are also assessed.

The binding of [3H]adenosine to synaptosomal and other preparations from the mammalian brain

1. A high-affinity adenosine-binding site with Kd(adenosine) 0.5-1.3 microM was demonstrated in particulate and synaptosomal fractions isolated from the cerebral cortex of guinea pig, rat and ox. 2. Binding of [3H]adenosine to this site was inhibited by theophylline and by 2-chloroadenosine, but not by four other adenosine analogues. 3. Endogenous adenosine, found to be present in some preparations at approx. 1 pmol/mg of protein, diminished the binding capacity of the preparations for [3H]adenosine. 4. Addition of the adenosine deaminase inhibitor erythro-9-[1-(1-hydroxyethyl)heptyl]-adenine revealed the presence of a second lower affinity binding site with Kd (adenosine) 5-9 microM and a higher maximal adenosine-binding capacity. The inhibitor partially blocked binding to the high-affinity site in preparations from which adenosine deaminase had been removed by washing. 5. To preparations of particulate fractions maintained under iso-osmotic conditions, adenosine attachment was non-saturable and temperature-dependent, indicating the existence of an active uptake process. 6. The location and binding constant of the high-affinity adenosine-binding site suggest that it corresponds to the receptor site for adenosine-activated adenylate cyclase.

Cyclic AMP-binding capacities and histone kinase activation in subcellular components of neocortical tissue. Differential responses to three neurohumoural agents

1. Noradrenaline and histamine, when added to superfused guinea-pig cerebral-cortical tissues, increased both cyclic AMP-dependent and -independent histone kinase activities of some, but not of all, subsequently isolated subcellular fractions, and decreased their cyclic [(3)H]AMP-binding capacity, which was concluded to be due to an increase in endogenously bound cyclic AMP. 2. Adenosine and 2-chloroadenosine also diminished the cyclic [(3)H]AMP-binding capacities, but did not affect the histone kinase activities. 3. DEAE-cellulose chromatography and stability to KCl additions showed that the greater part of the histone kinase of the present preparations corresponded to the type II enzyme [of Corbin, Keely & Park (1975) J. Biol. Chem.250, 218-225], with a lesser amount of type I activity. Different sites of cyclic AMP accumulation in relation to these or other kinases are considered in interpreting the differential tissue responses to the neurohumoural agents examined.

Erythrocyte transketolase activity in suspected cases of Leigh's disease, or subacute necrotising encephalomyelopathy

Erythrocyte transketolase activity and the effect of adding thiamine pyrophosphate (% thiamine pyrophosphate effect) were measured in 111 subjects suspected to suffer from Leigh's disease (subacute necrotising encephalomyelopathy). From clinical evidence these subjects were divided into five groups: (1) necropsy-proved cases of subacute necrotising encephalomyelopathy, (2) cases positive for urinary thiamine pyrophosphate: adenosine triphosphate phosphotransferase inhibitor, (3) clinically likely cases of subacute necrotising encephalomyelopathy (patients still alive, or on whom no necropsy was performed), (4) cases diagnosed as diseases other than subacute necrotising encephalomyelopathy (control group), (5) cases for which no diagnosis had been made. Comparison of erythrocyte transketolase activities with and without added thiamine pyrophosphate and of the % thiamine pyrophosphate effect for each group compared with the control group showed no statistically significant differences from normal values for any of these parameters. Similarly, there were no differences between the two sexes in transketolase activity, and no correlation between transketolase activity and age. These results indicate that erythrocyte transketolase activity is not altered in subacute necrotising encephalomyelopathy and is unlikely to be of value for the diagnosis of Leigh's disease.