A general synthetic approach for obtaining cationic and anionic inorganic nanoparticles via encapsulation in amphiphilic copolymers.

A series of amphiphilic copolymers with variable charge densities on their backbone is synthesized. Positively charged N,N,N-trimethylammonium-2-ethyl methacrylate iodide or negatively charged 2-(methacryloyloxy)ethylphosphonic acid and lauryl methacrylate are used as building blocks. When wrapped around hydrophobically capped inorganic nanoparticles (NPs), the latter are able to disperse in aqueous solutions. Using this method, positively as well as negatively charged colloidal NPs can be synthesized in a reliable way. The method presented herein allows the charge on the NPs to be adjusted to different negative and positive values by using polymers with a variable ratio of charged monomers and lauryl methacrylate. Virtually all kinds of hydrophobic inorganic NPs could be coated with these amphiphilic polymers. The coating procedure is demonstrated for Au particles as well as for CdSe/ZnS quantum dots. To date, wrapping amphiphilic polymers around NPs has led only to anionic NPs. The polymers synthesized in this work allow for positively charged NPs with a high colloidal stability.

Differential expression of alternative Acyl-CoA binding protein (ACBP) transcripts in an inducible human preadipocyte cell line.

Understanding the function of fat metabolism during differentiation of human preadipocytes to fully developed fat tissue has been the aim of various studies in the past decades. Due to the lack of suitable human cell culture lines, experimental research predominantly focused on rodent models and nonhuman cell culture systems. Here, we demonstrate that a human preadipocyte cell line SGBS is well suited to examine differential expression of the Acyl-CoA binding protein (ACBP) during adipogenesis. The Acbp gene expresses various alternative high- and low-abundant transcript variants encoding ACBP protein isoforms, which play a central role in fat metabolism. Whereas the low-abundant transcript Acbp-1G is downregulated during SGBS adipogenesis, the high-abundant and well established transcripts Acbp-1A (1) and -1B are moderately (2-4-fold) upregulated. In contrast, the alternative high-abundant transcript Acbp-1C is strongly (29-fold) upregulated at mRNA and protein level indicating that particularly ACBP-1C functions in lipogenic processes during fat cell differentiation in humans.

Association between functional FABP2 promoter haplotype and type 2 diabetes.

Fatty acid-binding protein 2 (FABP2) is a cytosolic protein expressed exclusively in epithelial cells of the small intestine. Some, albeit not conclusive, evidence indicates that the Thr-allele of FABP2 Ala54Thr polymorphism is associated with type 2 diabetes. More recently, common FABP2 promoter polymorphisms have shown association with postprandial increase of triglycerides, body composition and plasma lipid levels. Therefore, we reasoned that variants in the FABP2 promoter may also predispose to type 2 diabetes mellitus. In our Caucasian study population, we found three SNPs and three insertion-deletion polymorphisms that are in complete linkage disequilibrium defining promoter haplotype A and B within 1kb 5' of the FABP2 initiation codon. Haplotype calculations indicated that the FABP2 promoter and Ala54Thr variants were strongly linked. Functional analysis of promoter fragments demonstrated that haplotype difference is caused by polymorphisms within 260 bp downstream of the FABP2 initiation codon. Using a prospective case-control study nested within the EPIC-Potsdam cohort of 192 incident type 2 diabetes cases and 384 sex-/age-matched controls, male subjects carrying the FABP2 haplotype B allele showed significantly decreased risk of type 2 diabetes when adjusted for BMI (OR = 0.50, 95 % CI = 0.28 - 0.87, p < 0.05) and additional covariates (OR = 0.42, 95 % CI 0.22 - 0.81, p < 0.01). Further adjustment for the Ala54Thr polymorphism revealed an OR of 0.18 (95 % CI 0.06 - 0.49, p < 0.001). Similarly, Ala/Ala homozygote males carrying the promoter haplotype B had decreased risk (0.33, 0.11 - 0.94, p < 0.05) of type 2 diabetes after stratification for the Ala54Thr polymorphism. FABP2 promoter haplotypes or genotype combinations defined by the promoter and Ala54Thr polymorphism were not associated with BMI, body fat, leptin, HbA (1c), total cholesterol or HDL. In conclusion, our findings suggest that the functional FABP2 promoter haplotype may contribute to type 2 diabetes in a sex-specific manner.

Nonendemic pemphigus foliaceus presenting as fatal bullous exfoliative erythroderma.

Pemphigus foliaceus is a cutaneous autoimmune blistering disease that is characterized by lower morbidity and mortality than those observed in pemphigus vulgaris or paraneoplastic pemphigus. However, erythrodermic forms of the endemic variant of pemphigus foliaceus have been associated with a higher mortality. We report a case of nonendemic pemphigus foliaceus that presented as fatal bullous exfoliative erythroderma, and thus, we will emphasize the inclusion of this entity in the differential diagnosis and the use of skin direct immunofluorescence in the evaluation of patients with erythroderma.

Clinical and quantitative EEG studies of mania.

BACKGROUND: Earlier EEG studies reported essentially normal findings during acute manic episodes but some atypical EEG characteristics and distinctions between familial and sporadic cases were described. Recently quantitative EEG (qEEG) studies differentiating mania from schizophrenia and depression have been published. METHODS: Clinical EEGs were obtained in 202 patients hospitalized for acute mania. EEGs were repeated in 75 patients rehospitalized for subsequent manic attacks. Quantitative EEGs were recorded in 37 patients who were able to cooperate after drug washout and again on completion of randomly assigned pharmacotherapy. RESULTS: Normal EEGs were obtained in most patients. Moderately abnormal EEGs in 16% were significantly associated with absent family histories of affective disorder. Left sided abnormalities were more common than right. "Small sharp spikes" and "microsleep" were encountered in 17% and 10% respectively of patients who drowsed. EEG findings during subsequent episodes did not suggest increasing CNS vulnerability. qEEGs showed significant differences between each of the therapeutic agents compared-lithium, carbamazepine, and lithium combined with carbamazepine, haloperidol or risperidone. Nonresponders at baseline had significantly more diffuse theta activity than responders. During pharmacotherapy nonresponders had higher amplitudes in the left temporoparietal areas. LIMITATION: Clinical EEG findings confirmed previous reports but did not contain original observations. Applications of qEEG were limited by requirements for patient cooperation.

Use of the glyceraldehyde-3-phosphate dehydrogenase promoter for production of functional mammalian membrane transport proteins in the yeast Pichia pastoris.

The promoter of the glyceraldehyde-3-phosphate dehydrogenase gene (PGAP) was employed to produce the mammalian peptide transporters hPEPT1 and rPEPT2 as models for polytopic transmembrane proteins in the methylotrophic yeast Prichia pastoris. Cells of a recombinant renal peptide transporter (rPEPT2) clone produced constitutively the functional carrier protein. The level of functional expression of rPEPT2 with PGAP varied depending on the carbon source used for cell growth, but was up to five times higher than that obtained with the commonly employed inducible alcohol oxidase 1 promoter (PAOX1). Similar results were obtained for the expression level of the human intestinal peptide transporter hPEPT1 controlled by either PGAP or PAOX1. Therefore, the PGAP seems to be an attractive alternative to PAOX1 for generation of transgenic P. pastoris cells expressing functional mammalian membrane transport proteins at high levels.

Topographic EEG studies of mania.

QEEG findings from 39 hospitalized manic patients were accomplished after a drug free period and following pharmacotherapy with lithium or carbamazepine alone or lithium combined with carbamazepine, haloperidol or risperidone. A subsample of 10 drug-free manic patients was compared with normal controls, which revealed lower qEEG amplitudes in the left anterior and midtemporal regions in the patients. Comparisons of drug therapies showed increased delta amplitudes and total power with lithium compared with carbamazepine. Increased fast frequencies were observed in the lithium and carbamazepine plus lithium groups compared with carbamazepine alone. Comparisons of the three drug combination groups revealed increased alpha and beta 1 amplitudes, most with risperidone and least with carbamazepine. Anterior delta and beta 2 amplitudes and interhemispheric coherence were increased directly proportional to plasma lithium levels. Nonresponders to treatment were identified at baseline by increased generalized theta amplitudes. After treatment, the nonresponders had higher amplitudes in the left temporal areas. Numerous qEEG associations with individual ratings of manic symptoms were found, more at baseline than after treatment. In general levels of psychopathology were negatively correlated with qEEG amplitudes. The qEEG findings appear to implicate dominant temporal lobe dysfunctions in mania.

Assembly of A- and B-type lamins studied in vivo with the baculovirus system.

We have expressed an A-type lamin (Xenopus lamin A), a probable A-type lamin (Drosophila lamin C), two B-type lamins (Xenopus lamin LI, Drosophila lamin Dmo), and two mutants of Xenopus lamin A in Sf9 cells. All proteins were synthesized at high levels resulting in formation of paracrystals with an axial repeat of 18.5-20.0 nm by A-type lamins; in contrast B-type lamins assembled into aggregates with a fibrillar ultrastructure. Of the four wild-type proteins analyzed only lamin Dmo was found in the nuclear compartment of Sf9 cells in association with the lamina whereas the three other lamins assembled into polymers localized in the cytoplasm as well as the nucleoplasm. The Xenopus lamin A mutant lacking the complete carboxy-terminal tail assembled in the cytoplasm into long filament bundles consisting of fibrils of less than 6 nm diameter. In vitro the non-helical amino-terminal head domain of lamins is required for the formation of 'head-to-tail' polymers. A lamin A mutant lacking this domain could be efficiently extracted from Sf9 cells with physiological buffers containing Triton X-100, demonstrating the importance of this domain for lamin assembly in vivo.

Comparison of therapeutic modalities for mania.

The results of sequential therapeutic trials in hospitalized manic patients conducted over a 16-year period are summarized, followed by an analysis of pooled data to assess relative efficacy. No clinically important baseline differences were found in the patients admitted to these studies despite the long time span. They were not overly "difficult to treat" or treatment resistant, and most were discharged to the community. Nearly all outcome measures showed statistically significant differences between groups after 8 weeks of treatment. The best responses occurred in the patients who received a mean series of nine electroconvulsive therapy (ECT) treatments with sparing use of neuroleptics followed by lithium maintenance. The next best outcome was observed with lithium combined with low doses of standard neuroleptics or risperidone. The combination of carbamazepine and lithium had significantly fewer neurological side effects than moderate doses of haloperidol with lithium, with equivalent therapeutic results. Monotherapy with either lithium or carbamazepine was less effective than the combination treatments. Minor differences in study design may contribute to the variance in outcome.

Lithium combined with carbamazepine or haloperidol in the treatment of mania.

Hospitalized manic patients were withdrawn from psychoactive medications for 2 weeks after which they were randomized to double-blind treatment with carbamazepine plus lithium [CBZ-Li] or haloperidol plus lithium [HAL-Li] with benztropine. Unit dosages of Li 300 mg, CBZ 200 mg and HAL 2 mg were titrated to therapeutic plasma levels and maintained for 8 weeks. No rescue medications were permitted after 3 weeks. Standard ratings of psychopathology and side effects were accomplished weekly. Sixty patients entered the study but only 33 remained for randomization after drug washout. By 8 weeks both groups were improved from baseline without statistically reliable differences between them. However HAL-Li patients had more extrapyramidal side effects that were major reasons for dropout, whereas CBZ-Li patients were more often noncompliant and initially required more rescue medications. We conclude that either combination treatment can be beneficial but CBZ-Li has the advantage because of fewer neurologic side effects.

Long range electron transfer along an alpha-helix.

The many observations of long range electron transfer in proteins raises the question of whether a protein's structure can influence the rate or path of such transfers, and if so, then how. To answer these questions requires information on which of the various structural elements composing proteins support long range electron transfer. In this report, we present evidence for long range electron transfer along the alpha-helix of a synthetic leucine zipper dimer. We also present electron transfer rate data obtained with other helical peptides.

[Silicone molding compounds and latex gloves. The effect of latex gloves on addition and condensation silicones]. / Silikonabformmassen und Latexhandschuhe. Der Einfluss von Latexhandschuhen auf Additions- und Kondensationssilikone.

Inhibited setting of addition silicones has been observed using latex gloves in the dental office. Therefore four addition silicones as well as four condensation silicones were mixed with seven latex gloves with different properties (sterility, powder, accelerator, inner layer). The masses were mixed with bare hands as a control and--additionally--with powdered hands. Condensation silicones stayed unaffected when put together in exact amounts, while some addition silicones showed nearly complete inhibition. Mixing the condensation silicones under the conditions of daily practice--one spoon of body plus a distinct amount of catalyst-resulted in hardness differences compared to using the exact dose. Nevertheless the resulting impressions were of satisfying quality. The powder-component (Bio-sorb, Surgikos) leads to an accelerated setting. The general dental practitioner/dental hygienist have to consider these aspects while choosing gloves and silicone putties for taking impressions.

Carbamazepine compared with lithium in the treatment of mania.

Fifty-two hospitalized manic patients were randomized to treatment with either carbamazepine or lithium carbonate after a 2-week drug withdrawal period. All of the probands were tertiary referrals with a high proportion of failures of previous lithium and other treatment. Weekly ratings of manic, depressive, and psychotic symptoms were obtained for 8 weeks, and responders were followed up for up to 2 years. One third of patients responded favorably. Double-blind assessments revealed no statistically reliable differences between the two treatment groups. Patients receiving carbamazepine were somewhat more manageable than patients treated with lithium early in the study, whereas lithium-treated patients remained longer in the follow-up phase. However, numbers of long-term survivors were too small to be conclusive. This study adds to the growing body of evidence that acutely manic patients respond as well to carbamazepine as to lithium. However, monotherapy with either drug is not sufficient for the majority of manic patients who are referred for tertiary care.

Long range electron transfer between tyrosine and tryptophan in hen egg-white lysozyme.

The azide, dibromide and dichloride radicals oxidize one or more tryptophan side chains in hen egg-white lysozyme. The indolyl radical produced in this second-order 1-electron oxidation subsequently oxidizes a tyrosine side chain to the phenoxy radical in an intramolecular reaction with a rate constant of 130 +/- 10 s-1 at pH 7, 25 degrees C. The final indolyl and phenoxy equilibrium mixture then decays with a t1/2 approximately 2 s. The faster intramolecular reaction exhibits a pH dependence; on decreasing the pH from 9 the first-order rate constant increases to a maximum near pH 5.4 and then declines as the pH is lowered further. In contrast, the first-order rate constant for the intramolecular electron transfer between the tyrosine and tryptophan of the peptide trpH-pro-tyrOH remains unchanged between approx. pH 11 and 6.5 and then increases as the pH is lowered further. This difference in the observed pH dependence suggests that changes in structure or ionization state influence the protein electron transfer rate. We also discuss the radiation inactivation of lysozyme in light of these observations.

Semiquinone radicals of methylamine dehydrogenase, methoxatin, and related o-quinones: a pulse radiolysis study.

Methoxatin is a novel o-quinone coenzyme found in a variety of dehydrogenases and oxidases. In this paper we present the visible absorption spectra, apparent pKa, and midpoint potentials of the methoxatin and two analogous phenanthrolinedione semiquinones. We have also obtained absorption spectra for the semiquinone forms of the methoxatin-containing holoenzyme methylamine dehydrogenase and of its resolved methoxatin-containing subunit. The two protein and the methoxatin semiquinone spectra all differ from one another.

Intramolecular long-range electron transfer in the hemerythrin monomer: a pulse radiolysis study.

The single sulfhydryl group (Cys-50) of the methemerythrin from Phascolosoma gouldii reacts with 5,5'dithiobis(2-nitrobenzoic acid) to form a mixed disulfide. The pulse radiolytically generated formate radical reduces this mixed disulfide to its radical anion. In turn, the disulfide radical anion reduces the protein two-iron center over a nominal distance of 13 A. The rate constant for this intramolecular electron transfer is approximately 15 s-1 at room temperature, pH 7. Between the two redox centers there is an equilibrium driving force of 0.78 V, measured by differential pulsed polarography.

Pulse radiolytic measurement of redox potentials: the tyrosine and tryptophan radicals.

With the technique of pulse radiolysis we have measured the redox midpoint potentials of the tryptophan side chain neutral indolyl radical (1.05 +/- 0.01 V vs NHE, pH 7.0 and 25 degrees C) and the tyrosine side chain neutral phenoxy radical (0.94 +/- 0.01 vs NHE, pH 7.0 and 25 degrees C). These potentials were obtained by using a variety of inorganic reference compounds in both kinetic and equilibrium protocols. We compare these results with others already in the literature, and we also present data useful in establishing a pulse radiolysis redox reference scale over the range 0.42-1.28 V.

Electroconvulsive treatment compared with lithium in the management of manic states.

Thirty-four hospitalized manic patients were randomized to treatment with either lithium carbonate or an average series of nine bilateral electroconvulsive treatments (ECTs), followed by maintenance with lithium carbonate. Weekly ratings of manic, depressive, and psychotic symptoms were obtained for eight weeks, and patients were followed up monthly for up to two years. Ratings by nonblind and blind observers indicated that the patients who underwent ECT improved more during the first eight weeks than did patients who were treated with lithium carbonate. This was especially true of patients with mixed symptoms of mania and depression and/or extreme manic behavior. Clinical ratings after eight weeks showed no significant differences between the lithium carbonate- and ECT-treated patients. Likewise, the two groups had comparable rates of relapse, recurrence, and rehospitalization during the follow-up period.

Permeable membrane/mass spectrometric measurement of solvent 1H/2H, 12C/13C, and 16O/18O kinetic isotope effects associated with alpha-chymotrypsin deacylation: evidence for reaction mechanism plasticity.

We have measured, by permeable membrane/mass spectrometry, the 16O/18O, 12C/13C, and solvent H2O/D2O kinetic isotope effects (kie) associated with acyl-alpha-chymotrypsin hydrolysis and transesterification. The hydrolysis of alpha-chymotrypsinyl 2-furoate has a 12C/13C kie of approximately 1.06. Transesterification of the same acyl enzyme shows 16O/18O, 12C/13C, and solvent H2O/D2O kinetic isotope effects of 1.015 (0.003), 1.01-1.02, and 2.226 (0.007), respectively. From the temperature independence of the 16O/18O transesterification kinetic isotope effect and kinetic data reported elsewhere [Wang, C.-L. A., Calvo, K. C., & Klapper, M. H. (1981) Biochemistry 20, 1401-1408], we conclude that there are two active forms of acylchymotrypsin. We also propose that formation of the tetrahedral intermediate is the rate-limiting step in both hydrolysis and transesterification and that the position of the transition state in the transesterification is closer to the starting enzyme ester while that for the hydrolytic reaction is closer to the tetrahedral intermediate. These results are discussed in terms of reaction mechanism plasticity.