Involuntary hospitalization of first-episode psychosis with substance abuse during a 2-year follow-up.

OBJECTIVE: To investigate whether substance abuse (alcohol or illegal drugs) in patients with first-episode psychosis (FEP) influenced treatment outcomes such as involuntary hospitalization during follow-up. METHOD: First-episode psychosis patients (n = 103) with consecutive admissions to a comprehensive early psychosis program were included and followed for 2 years. Assessment measures were the Positive and Negative Syndrome Scale, Global Assessment of Functioning, and the Clinician Rating Scale (for substance abuse). RESULTS: Twenty-four per cent of patients abused either alcohol or drugs at baseline. The dropout rate at 2 years was the same for substance abusers as for non-abusers. Substance use was not reduced over the 2-year period. At 2-year follow-up, 72% of substance abusers and 31% of non-abusers had experienced at least one occasion of involuntary hospitalization. Patients with substance abuse had significantly higher risk for involuntary hospitalization during follow-up (OR 5.2). CONCLUSION: To adequately treat patients with FEP, clinicians must emphasize treatment of the substance abuse disorder, as well as the psychotic illness. Patients with defined comorbid substance use disorders and FEP are likely to have poorer treatment response than those with psychosis alone.

Clinical severity and prognosis of hand eczema.

BACKGROUND: Hand eczema (HE) is a frequent, long-lasting disease with both personal and societal repercussions. Consequently, more information is needed on factors that maintain symptoms. OBJECTIVES: In this study, patients with HE were followed for 6 months from the first visit to a dermatologist to identify factors associated with severe disease and a poor prognosis. METHODS: Study participants were 799 patients with HE from nine dermatological clinics in Denmark. Severity assessment of the HE was done at baseline and at the 6-month follow-up using the Hand Eczema Severity Index (HECSI) and by patients using a self-administered photographic guide. Additional information was obtained from a baseline questionnaire. RESULTS: At baseline, 60.3% assessed their HE as moderate to very severe using the self-administered photographic guide compared with 36.1% at follow-up. The mean HECSI value decreased from 19.9 points at baseline to 11.2 points at follow-up (P < 0.001). In a multivariable logistic regression analysis, statistically significant associations with severe HE at baseline were older age (P < 0.001), atopic dermatitis (P = 0.01) and > or = 1 positive patch test (P < 0.001). Being an unskilled worker was a predictor for a poor prognosis at follow-up (P = 0.04), and the presence of frequent symptoms during the previous 12 months was associated with severe initial disease (P = 0.02) and a poor prognosis (P = 0.04). CONCLUSIONS: Overall, the disease had improved 6 months after the dermatological examination: nevertheless, many patients continued to have significant symptoms. Dermatologists should pay special attention to patients with frequent eruptions and to unskilled workers.

The aminothiol redox status in haemodialysis patients does not improve with folate therapy.

BACKGROUND: Patients on haemodialysis suffer from high cardiovascular morbidity and mortality, and oxidative stress may play a role in the pathophysiology of cardiovascular disease in these patients. Hyperhomocysteinemia is common in dialysis patients and may have pro-oxidant effects. Moreover, the redox status of the major plasma aminothiols (homocysteine [Hcy], cysteine and cysteinylglycine) may be regarded as a biomarker of oxidative stress. In the present study, we investigated the aminothiol redox status during a period of homocysteine-lowering therapy with folinic acid. MATERIAL AND METHODS: In the first part of the study, 32 stable patients receiving maintenance haemodialysis were compared with 32 reference subjects. In the second part, the patients were given folinic acid intravenously for 3 months. RESULTS: Before intervention with folinic acid, the patients had elevated concentrations of all redox species of Hcy. The aminothiol redox ratios were low. Folinic acid therapy lowered the concentrations of all Hcy redox species; however, the redox ratios did not improve. CONCLUSIONS: The low aminothiol redox ratios indicate the presence of oxidative stress in haemodialysis patients. Therapy with folinic acid lowered total Hcy concentrations, but did not improve the redox status. Thus, hyperhomocysteinemia appears to be of little importance in regard to the total level of oxidative stress in uraemia.

Dimerization effect of sucrose octasulfate on rat FGF1.

Fibroblast growth factors (FGFs) constitute a family of at least 23 structurally related heparin-binding proteins that are involved in regulation of cell growth, survival, differentiation and migration. Sucrose octasulfate (SOS), a chemical analogue of heparin, has been demonstrated to activate FGF signalling pathways. The structure of rat FGF1 crystallized in the presence of SOS has been determined at 2.2 A resolution. SOS-mediated dimerization of FGF1 was observed, which was further supported by gel-filtration experiments. The major contributors to the sulfate-binding sites in rat FGF1 are Lys113, Lys118, Arg122 and Lys128. An arginine at position 116 is a consensus residue in mammalian FGF molecules; however, it is a serine in rat FGF1. This difference may be important for SOS-mediated FGF1 dimerization in rat.

A randomized study of two interferon-beta treatments in relapsing-remitting multiple sclerosis.

OBJECTIVE: To investigate whether the efficacy of interferon-beta (IFNbeta) treatment of relapsing-remitting MS (RR-MS) was influenced by type, dose, and frequency of administration. METHODS: From June 1996 through October 1997, the authors offered participation to all Danish RR-MS patients who met the following criteria: definite MS, at least two relapses within 2 years, age 18 to 55, and an Expanded Disability Status Scale (EDSS) score of < or = 5.5. The study was multicenter, controlled, open-label, randomized, head-to-head comparing IFNbeta-1a 22 microg once a week (n = 143) with IFNbeta-1b 250 microg every other day (n = 158), both subcutaneously, for 24 months. Patients who declined randomization were offered treatment with IFNbeta-1b 250 microg every other day (n = 120). The primary end-points were the annualized relapse rate, the time to first relapse, and neutralizing antibody formation. The secondary endpoint was time to sustained progression. RESULTS: The annual relapse rates were virtually equal in the two arms of the randomized study (IFNbeta-1a: 0.70; IFNbeta-1b: 0.71); so were the time to first relapse and the time to sustained progression. In the nonrandomized patients (IFNbeta-1b), the annual relapse rate was not significantly different, but the time to progression was shorter. CONCLUSION: In this study, 250 microg interferon-beta-1b administered every other day did not prove clinically superior to once-a-week administration of 22 microg interferon-beta-1a.

Structure of ribosomal protein TL5 complexed with RNA provides new insights into the CTC family of stress proteins.

The crystal structure of Thermus thermophilus ribosomal protein TL5 in complex with a fragment of Escherichia coli 5S rRNA has been determined at 2.3 A resolution. The protein consists of two domains. The structure of the N-terminal domain is close to the structure of E. coli ribosomal protein L25, but the C-terminal domain represents a new fold composed of seven beta-strands connected by long loops. TL5 binds to the RNA through its N-terminal domain, whereas the C-terminal domain is not included in this interaction. Cd(2+) ions, the presence of which improved the crystal quality significantly, bind only to the protein component of the complex and stabilize the protein molecule itself and the interactions between the two molecules in the asymmetric unit of the crystal. The TL5 sequence reveals homology to the so-called general stress protein CTC. The hydrophobic cores which stabilize both TL5 domains are highly conserved in CTC proteins. Thus, all CTC proteins may fold with a topology close to that of TL5.

Folate, homocysteine and methionine loading in patients on carbamazepine.

OBJECTIVES: Some antiepileptic drugs (AEDs) are associated with low levels of serum (S-FA) and erythrocyte folate (E-FA) and high levels of plasma total homocysteine (p-tHcy). We have explored the concentrations of S-FA, E-FA and p-tHcy in patients on carbamazepine (CBZ). The methionine loading test was applied for better assessment of mildly impaired homocysteine metabolism. MATERIAL AND METHODS: The study comprised 42 adult patients on CBZ and 42 matched healthy controls. Blood samples were drawn prior to and 6 h post methionine loading (6 h-PML) (0.1 g/kg body weight). RESULTS: The patients on CBZ had significantly lower concentrations of fasting S-FA and E-FA than the controls (P=0.0004, P=0.003, respectively). Fasting and 6 h-PML p-tHcy concentrations were significantly higher in the patients than in the controls (P=0.03 and P=0.0001, respectively). The methionine loading test identified additional patients with hyperhomocysteinemia undetected by fasting p-tHcy. CONCLUSION: CBZ therapy may be associated with low folate and high p-tHcy levels.

Saliva and serum concentration of lamotrigine in patients with epilepsy.

The authors examined the interindividual correlation between saliva and serum concentrations of lamotrigine (LTG) and the relationship between LTG concentration in saliva and the free LTG concentration in serum in 40 patients with epilepsy, aged 16 to 73 years, receiving stable doses of LTG and comedication. Saliva was collected before and after stimulation of salivary flow. The free LTG fraction was determined by equilibrium dialysis and ultrafiltration. Drug analysis was performed by high-performance liquid chromatography. The correlation between LTG daily dose and serum concentration was weak but significant (r = 0.47). There was high correlation between LTG concentration in serum and unstimulated (r = 0.85) or stimulated (r = 0.94) saliva, and between total LTG concentration in serum and the free LTG fraction as determined by ultrafiltration (r = 0.95) and equilibrium dialysis (r = 0.93). Lamotrigine concentration in stimulated saliva was significantly correlated to the free LTG fraction. Protein binding of LTG calculated from concentration in stimulated saliva, as determined by ultrafiltration and equilibrium dialysis, was 51.8% +/- 13.03%, 68.05% +/- 7.59%, and 58.72% +/- 7.68% (mean +/- standard deviation) respectively. The differences between the three methods were significant. The authors conclude that saliva sampling may be a useful alternative to blood tests for monitoring LTG treatment.

Structure of a mutant EF-G reveals domain III and possibly the fusidic acid binding site.

The crystal structure of Thermus thermophilus elongation factor G (EF-G) carrying the point mutation His573Ala was determined at a resolution of 2.8 A. The mutant has a more closed structure than that previously reported for wild-type EF-G. This is obtained by a 10 degrees rigid rotation of domains III, IV and V with regard to domains I and II. This rotation results in a displacement of the tip of domain IV by approximately 9 A. The structure of domain III is now fully visible and reveals the double split beta-alpha-beta motif also observed for EF-G domain V and for several ribosomal proteins. A large number of fusidic acid resistant mutations found in domain III have now been possible to locate. Possible locations for the effector loop and a possible binding site for fusidic acid are discussed in relation to some of the fusidic acid resistant mutations.

Designed protein tetramer zipped together with a hydrophobic Alzheimer homology: a structural clue to amyloid assembly.

Limited solubility and precipitation of amyloidogenic sequences such as the Alzheimer peptide (beta-AP) are major obstacles to a molecular understanding of protein fibrillation and deposition processes. Here we have circumvented the solubility problem by stepwise engineering a beta-AP homology into a soluble scaffold, the monomeric protein S6. The S6 construct with the highest beta-AP homology crystallizes as a tetramer that is linked by the beta-AP residues forming intermolecular antiparallel beta-sheets. This construct also shows increased coil aggregation during refolding, and a 14-mer peptide encompassing the engineered sequence forms fibrils. Mutational analysis shows that intermolecular association is linked to the overall hydrophobicity of the sticky sequence and implies the existence of "structural gatekeepers" in the wild-type protein, that is, charged side chains that prevent aggregation by interrupting contiguous stretches of hydrophobic residues in the primary sequence.

A decade of progress in understanding the structural basis of protein synthesis.

The key reaction of protein synthesis, peptidyl transfer, is catalysed in all living organisms by the ribosome - an advanced and highly efficient molecular machine. During the last decade extensive X-ray crystallographic and NMR studies of the three-dimensional structure of ribosomal proteins, ribosomal RNA components and their complexes with ribosomal proteins, and of several translation factors in different functional states have taken us to a new level of understanding of the mechanism of function of the protein synthesis machinery. Among the new remarkable features revealed by structural studies, is the mimicry of the tRNA molecule by elongation factor G, ribosomal recycling factor and the eukaryotic release factor 1. Several other translation factors, for which three-dimensional structures are not yet known, are also expected to show some form of tRNA mimicry. The efforts of several crystallographic and biochemical groups have resulted in the determination by X-ray crystallography of the structures of the 30S and 50S subunits at moderate resolution, and of the structure of the 70S subunit both by X-ray crystallography and cryo-electron microscopy (EM). In addition, low resolution cryo-EM models of the ribosome with different translation factors and tRNA have been obtained. The new ribosomal models allowed for the first time a clear identification of the functional centres of the ribosome and of the binding sites for tRNA and ribosomal proteins with known three-dimensional structure. The new structural data have opened a way for the design of new experiments aimed at deeper understanding at an atomic level of the dynamics of the system.

Homocysteine concentrations and methionine loading in patients on antiepileptic drugs.

OBJECTIVES: A few reports have shown elevated fasting total plasma homocysteine (tHcy) in patients taking antiepileptic drugs (AEDs). In this study we determined the influence of AEDs on plasma tHcy levels prior to and following methionine loading. MATERIAL AND METHODS: Thirty-four patients on different AEDs and 34 matched controls were recruited. Blood samples were drawn prior to and 6 h post-methionine loading (6h-PML). RESULTS: The patients on AEDs inducing the cytochrome P450 (carbamazepine, phenytoin, phenobarbital, primidone), had higher fasting and 6h-PML plasma tHcy concentrations than the controls (P = 0.01 and P<0.001). Patients on AED inhibiting the cytochrome P450 (valproate [VPA]), had lower 6h-PML p-tHcy concentrations than controls (P = 0.01). CONCLUSIONS: Our data indicate that not only fasting but also 6h-PML tHcy levels should be determined in order to identify hyperhomocysteinemia among patients on AEDs. Inducer AEDs seem to have an opposite effect than the inhibitor VPA on plasma tHcy, erythrocyte folate and serum folate levels.

Correlation between plasma total homocysteine and copper in patients with peripheral vascular disease.

BACKGROUND: Increased concentrations of both plasma total homocysteine and copper are separately associated with cardiovascular disease. Correlations between plasma total homocysteine, trace elements, and vitamins in patients with peripheral vascular disease have not been investigated. METHODS: The concentrations of trace elements in plasma were determined by the multielement analytical technique of total-reflection x-ray fluorescence spectrometry. Plasma total homocysteine was determined by HPLC. RESULTS: In the univariate and multivariate regression analyses, copper was positively correlated with plasma total homocysteine in all subjects (coefficient +/- SE, 0.347 +/- 0.113; P = 0.0026 and coefficient +/- SE, 0.422 +/- 0.108; P = 0.0002, respectively), and in patients with peripheral vascular disease (coefficient +/- SE, 0.370 +/- 0.150; P = 0.016; and coefficient +/- SE, 0.490 +/- 0.151; P = 0.0025, respectively). Correlation between copper and plasma total homocysteine was not detected in healthy control subjects. The concentration of calcium in plasma (67.5 vs 80. 8 microg/g) was significantly lower in the patients than in the control subjects (P = 0.02). When the patients were divided into groups, the patients with suprainguinal lesions had significantly higher copper concentrations (P = 0.04) and significantly lower selenium and calcium concentrations (P = 0.01 and 0.008, respectively) than the healthy subjects. Patients had higher concentrations of autoantibodies against oxidized LDL and concentrations of thiobarbituric acid-reactive substance than the healthy subjects (P <0.0001 and P = 0.001, respectively). The concentrations of plasma total homocysteine and alpha-tocopherol were significantly higher, and the concentrations of vitamin B(6) and beta-carotene were lower in the patients than the healthy subjects. CONCLUSION: Our findings suggest that the atherogenicity of homocysteine may be related to copper-dependent interactions.

Plasma total homocysteine response to oral doses of folic acid and pyridoxine hydrochloride (vitamin B6) in healthy individuals. Oral doses of vitamin B6 reduce concentrations of serum folate.

Plasma total homocysteine response was compared in four groups of healthy individuals given orally divided doses of vitamin supplementations for a duration of 5 weeks. The vitamin supplements; A, 0.3 mg folic acid; B, 120 mg vitamin B6; C, combination of 0.3 mg folic acid and 120 mg vitamin B6 or D, 0.6 mg folic acid reduced the concentrations of plasma total homocysteine 20, 17, 32 and 24%, respectively. However, the intergroup comparisons did not show a significant difference in the effects of vitamin supplements. Multivariate analysis with correction for differences in pre-supplement values indicated a significant effect of vitamin B6 supplementation on plasma total homocysteine and serum folate. Our data show that plasma total homocysteine concentrations are reduced with low to medium divided doses of folic acid alone or in combination with vitamin B6.

Structural changes in the transition state of protein folding: alternative interpretations of curved chevron plots.

The interpretation of folding rates is often rationalized within the context of transition state theory. This means that the reaction rate is linked to an activation barrier, the height of which is determined by the free energy difference between a ground state (the starting point) and an apparent transition state. Changes in the folding kinetics are thus caused by effects on either the ground state, the transition state, or both. However, structural changes of the transition state are rarely discussed in connection with experimental data, and kinetic anomalies are commonly ascribed to ground state effects alone, e.g., depletion or accumulation of structural intermediates upon addition of denaturant. In this study, we present kinetic data which are best described by transition state changes. We also show that ground state effects and transition state effects are in general difficult to distinguish kinetically. The analysis is based on the structurally homologous proteins U1A and S6. Both proteins display two-state behavior, but there is a marked difference in their kinetics. S6 exhibits a classical V-shaped chevron plot (log observed rate constant vs denaturant concentration), whereas U1A's chevron plot is symmetrically curved, like an inverted bell curve. However, S6 is readily mutated to display U1A-like kinetics. The seemingly drastic effects of these mutations are readily ascribed to transition state movements where large kinetic differences result from relatively small alterations of a common free energy profile and broad activation barriers.

A structural basis for transition-state stabilization in antibody-catalyzed hydrolysis: crystal structures of an abzyme at 1. 8 A resolution.

The three-dimensional structure of a catalytic antibody, 6D9, has been solved as a complex with a transition state analog. The structure was determined from two different crystal forms, and was refined at a resolution of 1.8 A. The antibody 6D9, which was induced by immunization with the phosphonate transition state analog 3, hydrolyzes a prodrug of chloramphenicol monoester 1 to generate the parent drug 2. The kinetic studies have shown that the antibody is catalytic by virtue of the theoretical relationship between the affinity for the transition state and the catalytic efficiency (kcat/kuncat=KS/KTSA). The crystal structure makes it possible to visualize the theoretical relationship. A side-chain (Nepsilon) of HisL27D is placed in a key position to make a hydrogen bond to the phosphonate oxygen of the transition state analog with a distance of 2.72 A, suggesting a hydrogen bond to the oxyanion developing in the transition state of the hydrolysis. There are no catalytic residues, other than the histidine, around the phosphonate moiety. In addition, in the antibody-hapten complex, the hapten bears a folded conformation and the two stacked aromatic rings are buried deep in the antigen-combining site through aromatic-aromatic interaction with TrpH100I and TyrH58. The conformation of the bound hapten suggests that the antibody binds the substrate to change the conformation of the ester moiety to a thermodynamically unstable E-form, thereby making it easy for the substrate to reach the transition-state during catalysis. These observations reveal that the catalytic mechanism is explained purely on the basis of the stabilization of the transition state. The refined high resolution structures reported here are envisaged to have an impact on the understanding of other hydrolytic antibodies, since their haptens share some unique features with the hapten used in this study.