Determining the neurocognitive profile of children with tuberous sclerosis complex within the Western Cape region of South Africa

BACKGROUND

Tuberous sclerosis complex (TSC) is a multisystem genetic disorder associated with a wide spectrum of cognitive impairments that can often result in impaired academic, social and adaptive functioning. However, studies investigating TSC have found it difficult to determine whether TSC is associated with a distinct cognitive phenotype and more specifically which aspects of functioning are impaired. Furthermore, children with TSC living in low-income and middle-income countries, like South Africa, experience additional burdens due to low socio-economic status, high mortality rates and poor access to health care and education. Hence, the clinical population of South Africa may vary considerably from those populations from high-income countries discussed in the literature.

METHODS

A comprehensive neuropsychological battery composed of internationally recognised measures examining attention, working memory, language comprehension, learning and memory, areas of executive function and general intellectual functioning was administered to 17 children clinically diagnosed with TSC.

RESULTS

The exploration of descriptive data indicated generalised cognitive difficulties in most cognitive domains, aside from memory. With only two participants performing in the average to above-average ranges, the rest of the sample showed poor verbal comprehension, perceptual reasoning, working memory, processing speed, disinhibition, and problems with spatial planning, problem solving, frustration tolerance, set shifting and maintaining a set of rules. Furthermore, correlational findings indicated several associations between socio-demographic and cognitive variables.

CONCLUSIONS

Importantly, this is the first study to comprehensively examine multiple domains of neurocognitive functioning in a low-resource setting sample of children with TSC. Current study findings showed that children with TSC have generalised impairments across several cognitive domains, rather than domain-specific impairments. Therefore, although examining individual aspects of cognition, such as those found in previous literature, is important, this approach is limiting. With a comprehensive assessment, including understanding the associations between domains, appropriate and directed support can be provided to ensure all aspects of development are addressed and considered.

Quercinol, an anti-inflammatory chromene from the wood-rotting fungus Daedalea quercina (Oak Mazegill)

The fungus Daedalea quercina (oak mazegill) was examined for its capability of producing antioxidative and anti-inflammatory compounds. Bioactivity guided fractionation of the extract from a mycelial culture led to the isolation of quercinol, which was identified as (-)-(2S)-2-hydroxymethyl-2-methyl-6-hydroxychromene 1 by NMR and X-ray analyses. The cryptic hydroquinone 1 shows a broad anti-inflammatory activity against cyclooxygenase 2 (COX-2), xanthine oxidase (XO), and horseradish peroxidase (HRP) at micromolar concentrations.

An European survey of structure and organisation of nutrition support teams in Germany, Austria and Switzerland

BACKGROUND & AIMS

Nutritional support teams (NST) have been demonstrated to be an excellent mechanism for identifying patients in need of nutrition support, improving the efficacy of nutrition support in a variety of hospital environments. Focus of this study was the investigation of function, structure and organisation of NST in Germany (D), Austria (A) and Switzerland (CH).

METHODS

Prospective investigation of the function, structure and organisation of NST in D, A and CH, using standardised questionnaires.

RESULTS

From a total of 3071 hospitals in D, A and CH, NST have been established at 98 hospitals (3.2%). Their main activities were creating nutritional regimes (100%), education (87%) and monitoring nutrition therapy (92%). In general, the NST are not independently operating units but are affiliated to a special discipline. Seventy-one per cent of the physicians, 40% of the nurses and 69% of the dieticians in the NST held a nutrition-specific additional qualification. A total of 12% of the physicians, 37% of the nurses and 46% of the dieticians are exclusively responsible for the NST. A reduction of complications (88%) and cost saving (98%) were indicated since their establishment. The NST received in 32% funding support.

CONCLUSION

In D, A, CH neither a uniform nor comprehensive patient care by NST existed in 2004. Standards of practice, development of guidelines in clinical nutrition and better documentation in NSTs are necessary. Special efforts should be aimed at education of NST members and financing of teams.

High-dose intravenous vitamin C is not associated with an increase of pro-oxidative biomarkers

OBJECTIVE

High-dose vitamin C therapy might mediate beneficial clinical effects by counteracting reactive oxygen species. However, concerns are raised whether this approach might provoke diametrical (ie pro-oxidative) effects. The objective was to determine ascorbyl free radical (AFR) concentrations and potential variables of pro-oxidative damage.

DESIGN

Crossover study; six healthy males received daily infusions of 750 or 7500 mg vitamin C for six consecutive days. Fasting concentrations of vitamin C and AFR were determined daily. On day 1, concentrations of vitamin C and AFR were measured at 0.25, 0.5, 1, 2, 4 and 8 h post infusion. Plasma concentrations of thiobarbituric acid-reactive substances (TBARS), tocopherol and urine concentrations of 8-oxoguanosine were determined on days 1 and 6.

RESULTS

Kinetic studies on day 1 showed that concentrations of vitamin C and AFR displayed parallel dose- and time-dependent kinetics and elimination was highly efficient. Vitamin C and AFR fasting concentrations on days 2-6 were slightly above the baseline, suggesting new, stable steady states. TBARS decreased in both groups, whereas tocopherol and 8-oxoguanosine concentrations remained unchanged.

CONCLUSION

Kinetics of AFR largely depend on plasma vitamin C concentrations and AFR is eliminated efficiently. Our data do not support induction of pro-oxidative effects in healthy volunteers given intravenous high-dose vitamin C.

SPONSORSHIP

Pascoe Pharmazeutische Präparate GmbH, Giessen, Germany.

[Penicillium expansum, a resident fungal strain of the orbital complex Mir, producing xanthocillin X and questiomycin A]

It was demonstrated that the fungus Penicillium expansum 2-7, a resident strain of the orbital complex Mir, which became dominating at the end of a long-term space flight, formed biologically active secondary metabolites (antibiotics). Using physicochemical methods, these metabolites were identified as xanthocyllin X and questiomycin A. Time courses of their biosyntheses during growth and development of the producer culture were studied. Addition of zinc to the culture medium affected both the growth of the culture and the biosyntheses of the antibiotics. The concentrations of zinc in the medium, optimum for xanthocyllin X and questiomycin A production, amount to 0.3 and 3.0 mg/l, respectively.

Differences in ion-channel formation by ampullosporins B, C, D and semisynthetic desacetyltryptophanyl ampullosporin A

Peptaibol-type ampullosporins B (2) and D (4) are capable of forming ion-conducting pores in planar lipid bilayer membrane prepared from soybean phosphatidylcholine in a similar manner as it was shown for ampullosporin A (1). However, the isomeric ampullosporin C (3) was required in 20-fold higher concentration to afford a comparable effect. In contrast to 1, 2, 3 and 4, the desacetyltryptophanyl ampullosporin A (5) failed to form ion channels. The results suggest that the sequence of amino acids especially at positions 8-10, the nitrogen-terminal acetyl residues and tryptophane are major factors determining ion-channel formation within bilayer membranes. The differences in membrane activities were comparable to the observed biological activities.

New homoserine lipids from Xerocomus langbianensis

New diacylglycerotrimethyl homoserine lipids 1 (2 O,3 O-bislinolylglycero-4'-O-(N,N,N-trimethyl)homoserine) and 2 (2 O,3 O-linolyl-palmitylglycero-4'-O-(N,N,N-trimethyl)-homoserine) were isolated from the fruiting body of a Vietnamese species of Xerocomus langbianensis. The chemical structures were settled on the basis of mass spectrometry and NMR spectroscopy.

(-)-Terpestacin and L-tenuazonic acid, inducers of pigment and aerial mycelium formation by Fusarium culmorum JP 15

Surface cultures of Fusarium culmorum JP15 were found to respond to extracts of other fungi by enhanced production of orange-red fusarubin pigments and formation of aerial mycelium. Two inducers from strain Ulocladium sp. HKI 0226, the new (-)-terpestacin (1) and L-tenuazonic acid (2), were isolated. 1 inhibited syncytium formation by cells infected with respiratory syncytial virus (RSV).

The effect of beta-carotene on the expression of interleukin-6 and heme oxygenase-1 in UV-irradiated human skin fibroblasts in vitro

beta-Carotene is discussed as an anti-oxidant micronutrient and singlet oxygen quencher in human skin, protecting against UV light-induced damage. However, we recently demonstrated that beta-carotene has a pro-oxidant potential in cultured human skin fibroblasts because it enhances the UVA induction of heme oxygenase-1 (HO-1). Herein, we further show that beta-carotene also strongly promotes the UVA induction of pro-inflammatory interleukin-6 (IL-6) in skin fibroblasts in vitro. Singlet oxygen quencher sodium azide abrogated up-regulation of IL-6, and likewise also of HO-1. In UVB-irradiated cells, beta-carotene did not modulate levels of IL-6 and HO-1. The observed effects might be relevant for UV-induced inflammatory processes.

Disclosure of new and recurrent microbial metabolites by mass spectrometric methods

The application of modern mass spectrometry methods (SI-CID-MS/MS; MSn) in the disclosure of new and recurrent microbial metabolites is discussed. Spray ion (SI) sources coupled to different kinds of mass analyzers enable the determination of molecular weights and chemical formulas of given samples even in mixtures. Diagnostic fragment formation by collision-induced dissociation (CID-MS/MS) and MSn experiments using ion trap mass analyzers are shown as another indispensable source of structural information. Due to the development of benchtop-type mass spectrometers coupled to high-performance liquid chromatography (HPLC), MS can be practised in almost every laboratory as a powerful tool in natural product analysis. Examples are given for special MS applications in identification of bioactive metabolites from screening strains.

Differentiation between inducers of apoptosis and nonspecific cytotoxic drugs by means of cell analyzer and immunoassay

Differentiation between specific and nonspecific cytotoxic drugs by means of cell analyzer and immunoassay is described. The determination of antiproliferative, cytotoxic, and apoptotic effects as well as enlargement of cells in response to toxic compounds can be used for the disclosure of compounds with a specific mode of action. The usefulness of the procedure was demonstrated with camptothecin (1) as a cytotoxic drug and established inducer of apoptosis. Aphidicolin (2) and the new compound oxoaphidicolin (3) were shown to display no comparable effect. Isolation and structural data of 3 are reported.

Colossolactones, new triterpenoid metabolites from a Vietnamese mushroom Ganoderma colossum

Seven new triterpenoid metabolites (colossolactones; 1-7) were isolated from a fruiting body of Ganoderma colossum, and their structures were determined by MS and NMR methods.

HMG-CoA reductase inhibitors and the risk of fractures

CONTEXT

Recent animal studies have suggested that 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) increase bone formation, volume, and density. It is unknown whether use of statins is associated with a decreased risk of fractures in humans.

OBJECTIVE

To determine whether exposure to statins, fibrates, or other lipid-lowering drugs is associated with reduced bone fracture risk.

DESIGN

Population-based, nested case-control analysis.

SETTING

The UK-based General Practice Research Database (GPRD), comprising some 300 practices, with data collection from the late 1980s until September 1998.

SUBJECTS

Within a base population of 91,611 individuals aged at least 50 years (28,340 individuals taking lipid-lowering drugs, 13,271 untreated individuals with a diagnosis of hyperlipidemia, and 50,000 randomly selected individuals without diagnosis of hyperlipidemia), we identified 3940 case patients who had a bone fracture and 23,379 control patients matched for age (+/-5 years), sex, general practice attended, calendar year, and years since enrollment in the GPRD.

MAIN OUTCOME MEASURES

Use of statins, fibrates, or other lipid-lowering drugs in case patients vs control patients.

RESULTS

After controlling for body mass index, smoking, number of physician visits, and corticosteroid and estrogen use, current use of statins was associated with a significantly reduced fracture risk (adjusted odds ratio [OR], 0.55; 95% confidence interval [CI], 0.44-0.69) compared with nonuse of lipid-lowering drugs. Current use of fibrates or other lipid-lowering drugs was not related to a significantly decreased bone fracture risk (adjusted OR, 0.87; 95% CI, 0.70-1.08 and adjusted OR, 0.76; 95% CI, 0.41-1.39, respectively).

CONCLUSIONS

This study suggests that current exposure to statins is associated with a decreased risk of bone fractures in individuals age 50 years and older. This finding has a potentially important public health impact and should be confirmed further in controlled prospective trials. JAMA. 2000;283:3205-3210

Childhood secondary (symptomatic) epilepsy, seizure control, and intellectual handicap in a nontropical region of South Africa

PURPOSE

To determine the prevalence of secondary (symptomatic) epilepsy and to ascertain levels of seizure control and intellectual function in a clinic population of children drawn from a poor community in a temperate region of South Africa.

METHODS

Detailed review of the records of every child with recurrent seizures who attended a special epilepsy outpatient clinic during 1995.

RESULTS

A total of 1,017 children was studied. In 432 (43%), there was historic, clinical, and radiologic evidence to suggest that epilepsy was symptomatic of underlying brain damage or defect. Acceptable seizure control was maintained with a single standard anticonvulsant drug (AED) in 65% of cases. In the 6 months preceding the study, 37% of the subjects had remained seizure free. Forty-seven percent of the study population were considered to be of subnormal intelligence.

CONCLUSIONS

In a children's hospital outpatient population in the Western Cape region of South Africa, the prevalence of secondary epilepsy is higher than is found in developed countries. There is need within the community for preventive measures aimed at reducing the prevalence of perinatal insults, meningitis, tuberculosis, neurocysticercosis, and cerebral trauma.

Ampullosporin, a new peptaibol-type antibiotic from Sepedonium ampullosporum HKI-0053 with neuroleptic activity in mice

Ampullosporin (I; Ac-Trp-Ala-Aib-Aib-Leu-Aib-Gln-Aib-Aib-Aib-Gln-Leu-Aib-Gln-Leuol) was isolated from the mycelium of Sepedonium ampullosporum as a new 15-membered peptaibol-type antibiotic. The structure was determined by mass spectrometric and two-dimensional NMR experiments. Ampullosporin displays narrow-spectrum antibacterial and antifungal activity, induces pigment formation by Phoma destructiva, causes hypothermia and decreased spontaneous locomotor activity in mice in dosages > 1 mg/kg.

Lipohexin, a new inhibitor of prolyl endopeptidase from Moeszia lindtneri (HKI-0054) and Paecilomyces sp. (HKI-0055; HKI-0096). I. Screening, isolation and structure elucidation

Lipohexin was isolated as a novel lipohexapeptide (I) (C39H68N6O9) from three fungal strains, Moeszia lindtneri HKI-0054, Paecilomyces sp. HKI-0055 and Paecilomyces sp. HKI-0096. The structure was elucidated by detailed mass spectrometric and NMR experiments. The proline-containing peptide displays moderate antibacterial activity against Bacillus subtilis ATCC 6633 and inhibits competitively the prolyl endopeptidase from human placenta.

Chrysospermins, new peptaibol antibiotics from Apiocrea chrysosperma Ap101

Four new members of peptaibol antibiotics, designated as chrysospermins A, B, C, and D, were isolated from the mycelium of Apiocrea chrysosperma Ap101 by solvent extraction, silica gel chromatography and preparative recycling HPLC. Their structures as new nonadecapeptides were settled by detailed spectroscopic analysis and chemical degradation experiments. The chrysospermins display antibacterial and antifungal activity, and induce pigment formation by the fungus Phoma destructiva.

Helioferins; novel antifungal lipopeptides from Mycogone rosea: screening, isolation, structures and biological properties

Helioferins A and B were detected as novel aminolipopeptides in cultures of Mycogone rosea DSM 8822 in the course of a screening for mediators of helianthate anion transfer from aqueous to toluene phases. Their structures as novel antibiotics and cytotoxic agents were elucidated by mass spectrometry and NMR spectroscopic methods. Antimicrobial activity was estimated against Candida albicans and Gram-positive bacteria including Mycobacterium spp.

Analysis of Gz alpha by site-directed mutagenesis. Sites and specificity of protein kinase C-dependent phosphorylation

The G protein alpha subunit Gz alpha is a substrate for phosphorylation by protein kinase C. The phosphorylation has been documented both in human platelets and in vitro and is characterized by a high degree of selectivity in relation to other G protein alpha subunits. We have demonstrated previously by phosphoamino acid analysis and CNBr peptide mapping that phosphorylation occurs at a serine residue(s) within the NH2-terminal 53 residues of Gz alpha. In this study, we have examined the site of phosphorylation using site-directed mutagenesis. Gz alpha variants containing selected substitutions of alanine for serine residues were expressed in human kidney 293 cells, and the ability of each to be phosphorylated in response to phorbol 12-myristate 13-acetate was examined. A focus was placed on Ser25 and Ser27, the 2 serine residues within a sequence of Gz alpha used to obtain a phosphorylation-sensitive antibody. The results demonstrate that Ser27 is the primary site of phosphorylation. Conversion of Ser27 to an alanine resulted in a 65% decrease in incorporation of [32P] phosphate; conversion of Ser25 had no effect. Conversion of Ser16, which like Ser25 and Ser27 conforms to a consensus site for protein kinase C, resulted in a modest (15%) decrease. The conversion of both Ser16 and Ser27 resulted in an 80% suppression of incorporation. In addition to these results, we have extended studies of the subunit and kinase selectivity of phosphorylation in platelets. We show here that under conditions promoting phorbol 12-myristate 13-acetate-stimulated phosphorylation of Gz alpha in permeabilized platelets, Gq alpha is not phosphorylated. Moreover, Gi alpha, Gz alpha, and Gq alpha were not phosphorylated in response to analogues of cAMP or cGMP. Thus, only Gz alpha is phosphorylated in platelets and only in response to activation of protein kinase C.