South African herbal teas: Aspalathus linearis, Cyclopia spp. and Athrixia phylicoides--a review

Rooibos (Aspalathus linearis (Brum.f) Dahlg.) and honeybush (Cyclopia Vent. species) are popular indigenous South African herbal teas enjoyed for their taste and aroma. Traditional medicinal uses of rooibos in South Africa include alleviation of infantile colic, allergies, asthma and dermatological problems, while a decoction of honeybush was used as a restorative and as an expectorant in chronic catarrh and pulmonary tuberculosis. Traditional medicinal uses of Athrixia phylicoides DC., or bush tea, another indigenous South African plant with very limited localised use as herbal tea, include treatment of boils, acne, infected wounds and infected throats. Currently rooibos and honeybush are produced for the herbal tea market, while bush tea has potential for commercialisation. A summary of the historical and modern uses, botany, distribution, industry and chemical composition of these herbal teas is presented. A comprehensive discussion of in vitro, ex vivo and in vivo biological properties, required to expand their applications as nutraceutical and cosmeceutical products, is included, with the main emphasis on rooibos. Future research needs include more comprehensive chemical characterisation of extracts, identification of marker compounds for extract standardisation and quality control, bioavailability and identification of bio-markers of dietary exposure, investigation of possible herb-drug interactions and plant improvement with regards to composition and bioactivity.     

Prader-Willi syndrome: is there a recognizable fetal phenotype?

OBJECTIVES: To determine fetal features, which could lead to the diagnosis of Prader-Willi syndrome (PWS) during pregnancy. METHODS: We analyze the ultrasound features, genetic studies and pathologic findings in two cases of PWS diagnosed during pregnancy. RESULTS: In the first case, diminished fetal movement, polyhydramnios and oddly positioned hands and feet suggested PWS. Methylation studies confirmed diagnosis and a deletion was detected in the 15q11-q13 region. In the second case, similar ultrasound findings led to prenatal diagnosis of PWS with an abnormal methylation pattern compatible with uniparental disomy. Both fetuses had a characteristic appearance at 28 and 30 weeks' gestation, which included a peculiar position of hands with flexed wrists and dorsi-extended feet with flexed toes. CONCLUSIONS: The peculiar position of the extremities combined with diminished fetal movement and polyhydramnios seems to be characteristic and should suggest PWS. Copyright (c) 2008 John Wiley & Sons, Ltd.     

Chemical studies on protease A of Bitis arietans (puff adder) venom

Protease A of Bitis arietans venom is probably a metalloprotease, since it is inhibited by o-phenanthroline and contains 0.77 moles of zinc per mole protein. The enzyme comprises 213 amino acids, including 9 methionine residues and one free sulphydryl group. It contains one polypeptide chain, which is terminated at the carboxyl end by serine. The amino terminal sequence of protease A is: Arg-Ser-Ser-Asp-Pro-Asn-Lys-Tyr-Phe-Asn-Val-Ile-Val-Val-Val-Asp-Asn-Arg- Met-Val-Asn-Tyr-Tyr-Lys-Gly-Glu-Leu-Asn-Lys-Ile-Thr-. Despite difficulties with 'insoluble peptide core' formation, a number of peptides were purified from peptic and tryptic digests of S-derivatized protease A.     

Elderly-onset rheumatoid arthritis

The treatment of elderly-onset rheumatoid arthritis pursues the same objectives as in younger patients: to control the clinical manifestations, to prevent structural damage, to preserve function, and to decrease excess mortality. In the elderly, the presence of co-morbidities and increased rate of drug-related adverse effects raise specific therapeutic challenges. Nonsteroidal anti-inflammatory drugs are associated with cardiovascular, gastrointestinal, and renal adverse events. The role for corticosteroid therapy remains controversial. Although glucocorticoids provide a short-term decrease in clinical activity and probably a medium-term decrease in structural damage, these benefits are offset by numerous adverse effects. Methotrexate was effective in clinical trials and observational studies and did not produce a higher adverse event rate compared to younger patients, provided renal function was normal. Data on the efficacy of TNFα antagonists in therapeutic trials are available only for etanercept. Disease activity decreased and function improved. The adverse event rate was higher in older patients, but this was also true of the conventional drugs used as comparators. Registry data confirm that TNFα antagonist therapy is effective in RA. An increased rate of infections was found only in some registries. To combat the 2-fold cardiovascular risk increase associated with RA, disease activity should be stringently controlled and all cardiovascular risk factors managed aggressively.     

A Dipole with Reflector-Backed Active Metasurface for Linear-to-Circular Polarization Reconfigurability

In recent years, significant advances have been made in diversifying the capabilities of communication systems by using reconfigurable antennas. There are many types of reconfigurable antennas—to achieve pattern, frequency, or polarization reconfigurability. These antennas are reconfigured either by the mechanical rotation of surfaces or by enabling or disabling specific sections of the structure using electrical switches. This paper focuses on the concept of a polarization reconfigurable antenna based on an active reflector-backed metasurface. An antenna system based on an active reflector-backed metasurface combined with a planar dipole is designed to achieve reconfigurable polarization. The polarization of the designed antenna can be switched between linear and circular polarization states using positive-intrinsic-negative diodes located in the unit cell elements of the metasurface. The measured results correlate well with the simulated results. The antenna has a physical size of 308 × 162 × 35 mm³ with an impedance bandwidth of 4.5% in the linear state and 7% in the circular state, as well as an axial ratio bandwidth larger than 8.3%.     

Analysis of core circadian feedback loop in suprachiasmatic nucleus of mCry1-luc transgenic reporter mouse

The suprachiasmatic nucleus (SCN) coordinates circadian rhythms that adapt the individual to solar time. SCN pacemaking revolves around feedback loops in which expression of Period (Per) and Cryptochrome (Cry) genes is periodically suppressed by their protein products. Specifically, PER/CRY complexes act at E-box sequences in Per and Cry to inhibit their transactivation by CLOCK/BMAL1 heterodimers. To function effectively, these closed intracellular loops need to be synchronized between SCN cells and to the light/dark cycle. For Per expression, this is mediated by neuropeptidergic and glutamatergic extracellular cues acting via cAMP/calcium-responsive elements (CREs) in Per genes. Cry genes, however, carry no CREs, and how CRY-dependent SCN pacemaking is synchronized remains unclear. Furthermore, whereas reporter lines are available to explore Per circadian expression in real time, no Cry equivalent exists. We therefore created a mouse, B6.Cg-Tg(Cry1-luc)01Ld, carrying a transgene (mCry1-luc) consisting of mCry1 elements containing an E-box and E′-box driving firefly luciferase. mCry1-luc organotypic SCN slices exhibited stable circadian bioluminescence rhythms with appropriate phase, period, profile, and spatial organization. In SCN lacking vasoactive intestinal peptide or its receptor, mCry1 expression was damped and desynchronized between cells. Despite the absence of CREs, mCry1-luc expression was nevertheless (indirectly) sensitive to manipulation of cAMP-dependent signaling. In mPer1/2-null SCN, mCry1-luc bioluminescence was arrhythmic and no longer suppressed by elevation of cAMP. Finally, an SCN graft procedure showed that PER-independent as well as PER-dependent mechanisms could sustain circadian expression of mCry1. The mCry1-luc mouse therefore reports circadian mCry1 expression and its interactions with vasoactive intestinal peptide, cAMP, and PER at the heart of the SCN pacemaker.