Increased tolerance to thermal inactivation of oxygen evolution in spinach Photosystem II membranes by substitution of the extrinsic 33-kDa protein by its homologue from a thermophilic cyanobacterium.

Photosynthetic oxygen evolution is an extremely heat-sensitive process and incubation of spinach Photosystem II (PSII) membranes at 40 degrees C for only several minutes leads to its complete inactivation. Substitution experiments of the spinach 33-kDa manganese stabilizing protein by a homologue protein, isolated either from the thermophilic cyanobacterium Phormidium laminosum, or from Escherichia coli as a recombinant thermophilic cyanobacterial protein, showed a significant increase in tolerance to heat inactivation of the oxygen-evolving activity. The results allow us to suggest that thermal inactivation of oxygen evolution in higher plant PSII membranes is due to dissociation of the 33-kDa protein as a consequence of temperature-induced conformational changes, and stabilization can be provided by substitution by a thermostable homologue whose secondary structure and binding to PSII remain unaltered at moderately high temperatures.

Th1/Th2 cytokine balance and nitric oxide in cerebrospinal fluid and serum from patients with multiple sclerosis.

Tumor necrosis factor (TNF-alpha) and IL-10 are key regulators of the T helper (Th)1/Th2 balance, which is critically skewed in many pathological conditions including immune-mediated inflammatory diseases of central nervous system (CNS) such as multiple sclerosis (MS). Nitric oxide (NO) has been reported to have dual effects on CNS pathology, and to play an important role in MS. We performed a cross-sectional study in 17 randomly selected patients during MS flare-up, and compared levels of TNF-alpha, IL-10 and NO in serum and cerebrospinal fluid (CSF) with the serum values of these mediators in two different control groups, healthy subjects and HIV-infected untreated patients.

Stereocontrolled IMDA reaction of styrene derivatives. A way to enantiopure 3a,4,9,9a-tetrahydrobenz[f]isoindolines.

IMDA reactions on chiral perhydro-1,3-benzoxazines, derived from (-)-8-amino menthol, bearing a styrene substituent at C-2 acting as diene and an acryl amide acting as dienophile occur with high stereoselection and excellent chemical yields. After elimination of the chiral appendage, enantiopure 3a,4,9,9a-tetrahydrobenz[f]isoindolines are prepared in this way. The effect of the substituents at both diene and dienophile are studied, showing that a methyl group at C-1 in the diene inhibited the reaction, while the ene adduct, instead of the IMDA product, was obtained when a methyl group was at C-2.

Abnormal SMN1 gene copy number is a susceptibility factor for amyotrophic lateral sclerosis.

The etiology of amyotrophic lateral sclerosis remains unknown in the majority of cases. Homozygous SMN1 (survival motor neuron) gene deletion causes spinal muscular atrophy, and SMN2 gene deletions are possible risk factors in lower motor neuron disease. We studied SMN1 and SMN2 genes copy numbers in 167 amyotrophic lateral sclerosis patients and in 167 matched controls.

Molecular genetics and animal models in autistic disorder.

Autistic disorder is a behavioural syndrome beginning before the age of 3 years and lasting over the whole lifetime. It is characterised by impaired communication, impaired social interactions, and repetitive interests and behaviour. The prevalence is about 7/10,000 taking a restrictive definition and more than 1/500 with a broader definition, including all the pervasive developmental disorders.

Dry powder inhaler: influence of humidity on topology and adhesion studied by AFM.

In the dry powder inhalers (DPIs), the adhesion results of the interactions between the active substance and the excipient. The carrier and the micronized drug particle morphologies are believed to affect the delivery of the drug. In this work, the couple studied was the lactose monohydrate and micronized zanamivir, used for the treatment of influenza.

[Intracranial tumors simulating transient ischemic attacks].

Introduction: Occasionally intracranial tumors present a clinical picture similar to that seen with transient ischemic attacks (TIA). The mechanism for this is not clear. The differential diagnosis of these two disorders is important since their treatment is quite different.

Frequency and significance of anti-Ro (SS-A) antibodies in multiple sclerosis patients.

Objective: To determine the frequency and significance of antinuclear (ANA), anticardiolipin (ACA) and anti-Ro (SS-A) antibodies in multiple sclerosis (MS) patients.

Methods: ANA (indirect immunofluorescence), ACA and anti-Ro (SS-A) antibodies (ELISA) were tested in sera of 42 patients with Poser defined MS and 50 healthy individuals.

Results: High levels of anti-Ro (SS-A) antibodies were found in 3 patients (7%) (vs 0 in the control group).

Plasma fatty acid levels in autistic children.

Phospholipid fatty acids are major structural components of neuronal cell membranes, which modulate membrane fluidity and hence function. Evidence from clinical and biochemical sources have indicated changes in the metabolism of fatty acids in several psychiatric disorders. We examined the phospholipid fatty acids in the plasma of a population of autistic subjects compared to mentally retarded controls.

No mutations in the coding region of the Rett syndrome gene MECP2 in 59 autistic patients.

Autistic disorder is a pervasive developmental disorder considered to have a multigenic origin. Mental retardation is present in 75% of autistic patients. Autistic features are found in Rett syndrome, a neurological disorder affecting girls and associated with severe mental retardation.

Diastereoselective tandem 6-exo carbolithiation intramolecular ring opening in (-)-8-aminomenthol-derived perhydrobenzoxazines. A new synthesis of enantiopure 4-substituted tetrahydro isoquinolines and 2-azabenzonorbornanes.

Aryllithiums prepared by bromine-lithium interchange in chiral 2-(o-bromophenyl)-substituted perhydro-1,3-benzoxazines participate in the intramolecular 6-exo carbolithiation reaction with unactivated double bonds attached to the nitrogen substituent of the heterocycle. When the reaction time is extended or no TMEDA is used, the cyclized lithium intermediates react intramolecularly with the N,O-acetal system leading to 2-azabenzonorbornane derivatives. The reactions are highly stereoselective and constitute a high-yielding synthesis of enantiopure 4-substituted tetrahydroisoquinolines or 7-substituted 2-azabenzonorbornanes.

Surface characterizations of variously treated titanium materials.

The attachment of cells to titanium surfaces is an important phenomenon in the area of clinical implant dentistry. A major consideration in designing implants has been to produce surfaces that promote desirable responses in the cells and tissues. To achieve these requirements, the titanium implant surface can be modified in various ways.

A novel straightforward synthesis of enantiopure tetrahydroisoquinoline alkaloids.

A novel, direct,and high-yielding stereoselective method for enantiopure 1-substituted tetrahydroisoquinolines (THIQ) is described. The successful approach, which creates the stereocenter during the formation of the THIQ nucleus is based on (i) formation of chiral 2,3-substituted perhydro-1,3-benzoxazines derived from (-)-8-aminomenthol, (ii) diastereoselective intramolecular ring opening of the N,O-acetal moiety by an arylmetal generated from the substituent at the nitrogen atom in the perhydrobenzoxazine ring, and (iii) removal of the chiral auxiliary appendage. The starting perhydrobenzoxazines are easily prepared from (-)-8-aminomenthol and two different aldehydes, and the intramolecular opening is stereospecific, leading to a single stereoisomer.

Titanium-porcelain system. Part III: effects of surface modification on bond strengths.

During its development, titanium was found to be incompatible with conventional dental porcelains due to weak bond strength brought about by titanium's high yet oxidative nature. In spite of the development of new low-fusing porcelains designed for titanium application, previous studies have shown that sandblasting pre-treatment prior to porcelain application led to weakening of the metal-ceramic bonding. The aim of this study is to search for an effective alternative to sandblasting for the surface treatment of the titanium substrate in the titanium-porcelain system.

On the difficulty of assessing the specific surface area of magnesium stearate.

The water content of as-received commercial magnesium stearate batches from animal and vegetable sources have been modified by ageing in humid air at room temperature or by vacuum treatment. The complete adsorption-desorption isotherms of nitrogen and krypton vapours by samples of these as received and modified materials have been measured at liquid nitrogen temperature after standardised vacuum degassing. They are greatly affected by the initial water content of the material.

MECP2 is highly mutated in X-linked mental retardation.

Following the recent discovery that the methyl-CpG binding protein 2 (MECP2) gene located on Xq28 is involved in Rett syndrome (RTT), a wild spectrum of phenotypes, including mental handicap, has been shown to be associated with mutations in MECP2. These findings, with the compelling genetic evidence suggesting the presence in Xq28 of additional genes besides RabGDI1 and FMR2 involved in non-specific X-linked mental retardation (MRX), prompted us to investigate MECP2 in MRX families. Two novel mutations, not found in RTT, were identified.

Electrochemical corrosion of titanium and titanium-based alloys.

Statement Of Problem: Two varieties of unalloyed titanium, Ti-6Al-4V and NiTi, commonly are used in medical and dental fields. Several other types of alloys for potential use in these fields have been developed, including Ti-4.5Al-3V-2Mo-2Fe and vanadium-free alloys (Ti-5Al-2.

Laboratory-fabricated, acrylic resin cylinders for fixed, provisional implant restorations.

Commercially produced provisional cylinders are commonly used during fabrication of fixed, provisional implant restorations. A procedure is presented for the fabrication of fixed, provisional implant restorations using laboratory-fabricated, autopolymerizing acrylic resin cylinders. These cylinders offer a number of advantages over commercially produced cylinders and may reduce the treatment cost of implant prosthodontics.

Cerebellar ataxia with anti-glutamic acid decarboxylase antibodies: study of 14 patients.

Background: Antibodies to glutamic acid decarboxylase (GAD-Ab) are described in patients with insulin-dependent (type 1) diabetes mellitus (IDDM), in stiff-man syndrome, and, recently, in a few patients with cerebellar ataxia.

Objectives: To show a link between GAD-Ab and some patients with cerebellar ataxia and to clarify their clinical and immunologic profiles.

Methods: Serum samples were selected from 9000 samples of 4 laboratories.

The spray drying of acetazolamide as method to modify crystal properties and to improve compression behaviour.

Acetazolamide shows a very poor compression ability and tablets must usually be produced through a wet granulation process. However, the possibility to obtain pure acetazolamide for direct compression could be interesting for industrial application. With the scope to obtain a material for direct compression, three different crystallisation methods were chosen, with respect to acetazolamide solvent solubility.

Immunohistochemical profiles of 30 monoclonal antibodies against cytokeratins 8, 18 and 19. Second report of the TD5 workshop.

In the first report of the TD5 workshop (TD5-1), the epitope specificities of 30 different monoclonal antibodies against cytokeratins 8, 18 and 19 were determined. This second report presents the immunohistochemical profiles of these antibodies using human appendix and normal skin for evaluation. Each antibody was tested by one or two different laboratories recruited from the Dutch Working Group on Immunohistochemistry and Cytochemistry.

[Approach to quality of life changes in patients with multiple sclerosis].

Introduction And Objectives: Multiple sclerosis (MS), as a chronic, incurable and often severely disabling disease, greatly affects patients normal life. The objectives of the study are to analyze which aspects of daily life are more affected by the disability and to investigate whether the degree of support demanded by patients is related to their level of incapacity.

Patients And Methods: Group of 60 ambulatory patients with Poser defined MS, mean age of 44.