Early-onset ataxia with cardiomyopathy and retained tendon reflexes maps to the friedreich's ataxia locus on chromosome 9q

Absence of lower limb tendon reflexes has been considered an essential diagnostic criterion for Friedreich's ataxia (FA). However, preservation of knee and ankle jerks has been reported in a few patients. Linkage analysis to FA locus (FRDA) on chromosome 9q13-21.1 was performed in 11 patients from 6 families with FA phenotype, including cardiomyopathy, but retained reflexes (FARR). A maximal lod score of 3.38 at recombination fraction theta equal to 0.00 was obtained demonstrating that FARR maps to the FRDA locus. These results suggest that FARR is a variant phenotype of FA.     

Diagnostic approach to a case of a complex cystic mass of the pelvis

The diagnostic approach to a patient with a complex pelvic cyst incidentally found on CT and come to the Emergency Department for lumbar pain, is discussed. To better define the location and nature of the cyst MRI was performed. It supported the diagnostic hypothesis of cystic endosalpingiosis, confirmed at the histological examination of the surgical specimen.     

The role of ultrasound of sentinel nodes in the pre- and post-operative evaluation of stage I melanoma patients

We have investigated the role of high-resolution ultrasound (US) in the analysis of sentinel node(s) in melanoma patients in pre-operative staging and follow-up. One hundred and six lymph node basins in 88 melanoma patients undergoing sentinel node biopsy (SNB) were examined: 25 (23.6%) were US positive for metastases and 81 (76.4%) were negative. Subsequent histological analysis of the 81 negative lymph nodes confirmed the absence of metastases in 80 cases (98.8%), whereas, in the 25 US-positive lymph nodes, metastases were found in 16 cases (64%). The follow-up of all patients submitted to SNB in our unit included a US investigation of operated and contralateral nodal basins every 4 months for the first 3 years and then every 6 months. Of a total of 300 patients, four (1.6%) were found to have locoregional nodal disease during follow-up. In three of these four patients, US was crucial in indicating the presence of nodal metastases, which would have gone undetected on physical examination. The result of this study (negative predictive value of 98.7%) introduces the possibility of selecting patients who may avoid an SNB procedure based on the results of pre-operative US examination.     

Update: current management issues in malignant melanoma

The incidence of melanoma has increased continuously during the last decade. Surgery is the mainstay of therapy but, for patients with thick lesions or regional metastatic lymph nodes, there is a high risk of relapse. For this group of patients, there is no standard therapy or general agreement amongst oncologists. In this article, we review the current management of melanoma with regard to past completed adjuvant trials and open trials. Moreover, we discuss the role of chemotherapy in metastatic melanoma, in particular with attention to the use of fotemustine.     

Exploring soft matter: liposomal vesicles and their tethers

The malleability of soft matter such as vesicular systems, allows their mechanical manipulation into various interesting structures. Their inherent elastic membrane properties can be utilized in fabricating micro-scaled transport machineries. In this paper, we have described several features of research carried out in our laboratory. This includes the self-healing ability of multilamellar liposome on removal of their inner core. The formation of tethers from their outer bilayers into complex networks has been demonstrated. Photo enhancement of images has revealed the apparent existence of narrow channels inside such tethers. The tethers channels were subsequently used as transport conduits to carry solid polystyrene microspheres as well as large liposomes larger than the tether diameter under controllable speeds of up to 2 microm s(- 1). The possibility of producing multi-compartment liposomal systems connected to each other directly by fusion or indirectly via tether networks has provided us with a system capable of transporting components from one vesicle entity to another.     

The plant-type ferredoxin-NADP+ reductase/ferredoxin redox system as a possible drug target against apicomplexan human parasites

Apicomplexa are unicellular, obligate intracellular parasites of great medical importance. They include human pathogens like Plasmodium spp., the causative agent of malaria, and Toxoplasma gondii, an opportunistic parasite of immunosuppressed individuals and a common cause of congenital disease (toxoplasmosis). They alone affect several hundred million people worldwide so that new drugs, especially for plasmodial infections, are urgently needed. This review will focus on a recently emerged, potential drug target, a plant-type redox system consisting of ferredoxin-NADP(+) reductase (FNR) and its redox partner, ferredoxin (Fd). Both reside in an unique organelle of these parasites, named apicoplast, which is of algal origin. The apicoplast has been shown to be required for pathogen survival. In addition to other pathways already identified in this compartment, the FNR/Fd redox system represents a promising drug target because homologous proteins are not present in host organisms. Furthermore, a wealth of structural information exists on the closely related plant proteins, which can be exploited for structure-function studies of the apicomplexan protein pair. T. gondii and P. falciparum FNRs have been cloned, and the T. gondii enzyme was shown to be a flavoprotein active as a NADPH-dependent oxidoreductase. Both phylogenetic and biochemical analyses indicate that T. gondii FNR is similar in function to the isoform present in non-photosynthetic plastids whereby electron flow is from NADPH to oxidized Fd. The resulting reduced Fd is then presumably used as a reductant for various target enzymes whose nature is just starting to emerge. Among the likely candidates is the iron-sulfur cluster biosynthesis pathway, which is also located in the apicoplast and dependent on reducing power. Furthermore, lipoic acid synthase and enzymes of the isoprenoid biosynthetic pathway may be other conceivable targets. Since all these metabolic steps are vital for the parasite, blocking electron flow from FNR to Fd by inhibition of either FNR activity or its molecular interaction with Fd should also interfere with these pathways, ultimately killing the parasite. Although the three-dimensional structure of FNR from T. gondii is not yet known, experimental and computational evidence shows that apicomplexan and plant enzymes are very similar in structure. Furthermore, single amino acid changes can have profound effects on the enzyme activity and affinity for Fd. This knowledge may be exploited for the design of inhibitors of protein-protein interaction. On the other hand, specifically tailored NAD(P) analogues or mimetics based on previously described substances might be useful lead compounds for apicomplexan FNR inhibitors.     

Can an inert sleeping pill affect sleep? Effects on polysomnographic,behavioral and subjective measures

RATIONALE: Since two recent meta-analyses on sleep changes associated with placebo in clinical trials suggested a beneficial effect of placebo treatments, pointing to a dissociation between subjective and objective measures of sleep, the current experiment was directly aimed to assess the effects of an inert compound, administered with the suggestion that it was a hypnotic substance in subjects with mild sleep complaints. OBJECTIVES: The aim of this study was to compare subjective, behavioral, polysomnographic (PSG), and quantitative electroencephalographic (EEG) changes during a night preceded or not by the intake of two 50-mg lactose capsules. METHODS: Ten female students, selected by the Pittsburgh Sleep Quality Index, slept for three consecutive nights in a sleep laboratory, with the experimental (EXP) night defined by the administration of two 50-mg lactose pills. Self-ratings of sleep quality and performance were assessed upon morning awakening of baseline (BSL) and EXP nights. RESULTS: The EXP nights were self-rated as more restful and characterized by a decreased number of nocturnal awakenings than the BSL nights. PSG measures showed that wakefulness after sleep onset significantly decreased during the EXP night as compared to the BSL night. The EXP nights also showed an increase of 0.5-4.0 Hz power during nonrapid eye movement sleep and a decrease of EEG activity in the beta frequency range during rapid eye movement sleep only at central brain sites. A specific improvement of behavioral measures was also found upon morning awakening after the EXP night compared to the BSL night. CONCLUSIONS: The administration of an inert pill improves both the subjective and objective quality of sleep. The reduced sleep fragmentation and the effects on some quantitative EEG markers of sleep homeostasis suggest that the experimental manipulation induced coherent changes in the subsequent sleep, resembling an enhancement of sleep pressure. The regional differences of EEG activity suggest the involvement of a specific physiological mechanism distinct from that of effective treatments.