Deep phenotyping of facioscapulohumeral muscular dystrophy type 2 by magnetic resonance imaging.

BACKGROUND AND PURPOSE: The aim was to define the radiological picture of facioscapulohumeral muscular dystrophy 2 (FSHD2) in comparison with FSHD1 and to explore correlations between imaging and clinical/molecular data. METHODS: Upper girdle and/or lower limb muscle magnetic resonance imaging scans of 34 molecularly confirmed FSHD2 patients from nine European neuromuscular centres were analysed. T1-weighted and short-tau inversion recovery (STIR) sequences were used to evaluate the global pattern and to assess the extent of fatty replacement and muscle oedema. RESULTS: The most frequently affected muscles were obliquus and transversus abdominis, semimembranosus, soleus and gluteus minimus in the lower limbs; trapezius, serratus anterior, latissimus dorsi and pectoralis major in the upper girdle. Iliopsoas, popliteus, obturator internus and tibialis posterior in the lower limbs and subscapularis, spinati, sternocleidomastoid and levator scapulae in the upper girdle were the most spared. Asymmetry and STIR hyperintensities were consistent features. The pattern of muscle involvement was similar to that of FSHD1, and the combined involvement of trapezius, abdominal and hamstring muscles, together with complete sparing of iliopsoas and subscapularis, was detected in 91% of patients. Peculiar differences were identified in a rostro-caudal gradient, a predominant involvement of lower limb muscles compared to the upper girdle, and in the higher percentage of STIR hyperintensities in FSHD2. CONCLUSION: This multicentre study defines the pattern of muscle involvement in FSHD2, providing useful information for diagnostics and clinical trial design. Both similarities and differences between FSHD1 and FSHD2 were detected, which is also relevant to better understand the pathogenic mechanisms underlying the FSHD-related disease spectrum.

Enhancement of electrorheological effect by particle-fluid interaction.

The influence of interactions between particle surface and host fluids in electrorheological suspensions is explored. It is observed that dispersions of nanosized particles of titania in octanoid acid exhibit an anomalously large electrorheologic effect when compared with a similar dispersion of micrometric particles or with a more conventional colloidal suspension of silica in silicone oil. The effect is interpreted as originated by the formation of a thin layer of octanoid acid molecules with the surface of the titania solid particle. The experimental data are fitted with the outcomes of a modified version of conductive models existing in the literature. It is suggested that anomalous large electrorheological effect is mainly originated by the increasing of the effective radius of the nanometric particles, which results in an increasing of the effective volume fraction of the dispersed phase. It is also shown that the deformation of the soft shell around the solid particles, induced by Coulombic force, plays a not negligible role. Some hints for tailoring electrorheologic fluids suitable for different applications are proposed.

Physicochemical investigation of acrylamide solubilization in sodium bis(2-ethylhexyl)sulfosuccinate and lecithin reversed micelles.

The state of acrylamide confined within dry sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and lecithin reversed micelles dispersed in CCl(4) has been investigated by FTIR and (1)H NMR spectroscopy. Measurements have been performed at 25 degrees C as a function of the acrylamide-to-surfactant molar ratio (R) at a fixed surfactant concentration (0.1 mol kg(-1)). The analysis of experimental data, corroborated by the results of SAXS measurements, is consistent with the hypothesis that acrylamide is quite uniformly distributed among reversed micelles mainly located in proximity to the surfactant head-group region and that its presence induces significant unidimensional growth of micellar aggregates. Moreover, the confinement of acrylamide within reversed micelles involves some changes of the typical H-bonded structure of pure solid acrylamide attributable to the establishment of system-specific acrylamide/surfactant head group interactions. Preliminary experiments showed that, by exposure to X-rays, the polymerization of acrylamide can be induced in the confined space of dry AOT and lecithin reversed micelles.

Genetic heterogeneity of variable number tandem repeats in thymidylate synthase gene in colorectal cancer patients.

PURPOSE: To analyze the genetic variability in a variable number of tandem repeats (VNTR) in the thymidylate synthase (TS) enhancer promoter region and assess the influence of functional alterations in mismatch repair genes by analyzing constitutional and tumoral DNA from patients with colorectal adenocarcinoma with a high microsatellite instability (MSI-H) or microsatellite stability (MSS) status. PATIENTS AND METHODS: Patients who underwent surgery for colorectal adenocarcinoma were selected from the colorectal database of our institute and, on the basis of MSI status, assigned to a study group and a control group: group A, MSI-H; group B, MSS. Microsatellite status was investigated using the Bethesda recommended panel (BAT-26, BAT-25, D2S123, D5S346, D17S250). In MSI-H patients an additional analysis was made of the microsatellite loci D18S61 and D18S58, both mapping in the region containing the TS gene (18p11.2-11.32). Based on the number of altered microsatellites (> or = 2, 1, or 0), tumors were considered as having high (MSI-H) or low (MSI-L) instability or microsatellite stability (MSS), respectively. Genotyping for thymidylate synthase promoter polymorphism was carried out on constitutional and tumor DNA of each patient by PCR amplification of the polymorphic region. RESULTS: MSI-H was found in 55 patients (group A) and MSS in 50 patients (group B). In none of the MSI-H patients was microsatellite instability found in the additional D18S61 and D18S58 loci. In five group A and ten group B cases the analysis was not performed because constitutional DNA and/or tumoral DNA were not amplifiable. Homozygotes for the triple repeat variant (3R/3R) displayed only the large PCR product, homozygotes for the double repeat variant (2R/2R) displayed only the smaller PCR product, while heterozygotes (2R/3R) displayed both the larger and smaller PCR products. In 3/50 (6%) group A patients and 5/40 (12%) group B patients repeat variations were found in tumoral DNA. CONCLUSION: Our findings demonstrate that there is genetic homogeneity between constitutional and tumoral DNA but do not support the hypothesis that mismatch repair genes are involved in VNTR recombinant events in TS gene variability.

Two helices plus a linker: a small model substrate for eukaryotic RNase P.

Using precursor tRNA molecules to study RNA-protein interactions, we have identified an RNA motif recognized by eukaryotic RNase P (EC 3.1.26.5). Analysis of circularly permuted precursors indicates that interruptions in the sugar-phosphate backbone are not tolerated in the acceptor stem, in the T stem-loop, or between residues A-9 and G-10. Prokaryotic RNase P will function with a minihelix consisting of the acceptor stem connected directly to the T stem-loop. Eukaryotic RNase P cannot use such a minimal substrate unless a linker sequence is added in the gap where the D stem and anticodon stem-loop were deleted.

Adrenoleucodystrophy: dermatological findings and skin surface lipid study.

X-linked adrenoleucodystrophy (ALD) is a rare disorder of the very-long-chain fatty acid (VLCFA) metabolism. Cutaneous findings observed in a 29-year-old man included patchy non-cicatricial alopecia of the scalp, intense oily seborrhoea of the head, mild dry-scaling ichthyosis-like appearance of the trunk and legs and pseudo-acanthosis nigricans of the folds. Scanning electron-microscopic examination of the scalp hair showed trichorrhexis-nodosa-like fractures and several structural anomalies of the hair shaft. The skin surface lipid profile showed a marked increase in lignoceric acid (C24:0) which comprised over 60% of the fatty acid detectable in the fractions of triglycerides, diglycerides and free fatty acids. This behaviour of the VLCFA in the surface lipids corresponds to that observed in the plasma. If this finding were confirmed, the investigation of surface lipid composition could represent a useful non-invasive technique for the study of ALD.

An RNA molecule copurifies with RNase P activity from Xenopus laevis oocytes.

Utilizing a procedure for the purification of RNase P from Xenopus laevis germinal vesicle (GV) extracts, according to which the contamination by a large, cytoplasmic, cylindrical structure (1) is avoided, we demonstrate that the X.laevis enzyme, like the HeLa RNase P, is precipitated by anti-Th antibodies and an RNA molecule (XL RNA), 320 nucleotides long, copurifies with the activity. The sequence of XL RNA is 60% homologous to HeLa H1 RNA, therefore the two molecules seem related.

Site selection by Xenopus laevis RNAase P.

Investigation of the mechanism of cleavage site selection by Xenopus RNAase P reveals that the acceptor stem, a 7 bp helix common to all tRNA precursors, is required for cleavage. We propose that Xenopus RNAase P recognizes conserved features of the mature tRNA and that the cleavage site is selected by measuring the length of the acceptor stem. In support of this, we demonstrate that insertion of 2 bp in the acceptor stem of yeast pre-tRNA(3Leu) relocates the cleavage site 2 bases 3' to the original one. In addition, insertion of 1 bp in the acceptor stem of the end-matured yeast pre-tRNA(Phe) generates an RNAase P cleavage site: the enzyme produces a mature tRNA with the characteristic 7 bp stem and releases one 5' flanking nucleotide. Since it has previously been shown that cleavage sites of the splicing endonuclease are determined by the length of the anticodon stem, RNAase P and the splicing endonuclease apparently use different stems to determine their cutting sites.

An influenza virus inhibitor that acts late in the replication cycle.

An inhibitor which is active against influenza A virus was found in Neuramide, a complex tissue extract that is used as an anti-herpes zoster virus treatment. Kinetic studies showed that significant inhibition of virus production occurred when the inhibitor was added to infected cultures up to 5 h after virus penetration. Molecular sieving fractionation showed that the antiviral activity was contained in a low-molecular-weight fraction (molecular weight, less than 1,000).

[Warty dyskeratoma. Analysis and case reports]. / Discheratoma verrucoso. Analisi e contributo casistico.

Warty dyskeratoma (WD) may be observed in both whites and negros. It is usually small single isolated brown nodule with a prevalent localization of the head of aged males. During the last 4 1/2 years 20 cases were recognized at the Perugia Dermatological Clinic, representing 3.8% of 522 biopsied clinically similar skin tumors. The ratio of WD with keratoacanthoma was 1.3 and with squamous-cell carcinoma 1:5. In 4 cases a lesion clinically similar to squamous-cell carcinoma but with histological picture of WD was localized of the lower prolabium. The excision was the treatment of choice. On the basis of our findings and from a survey of the literature a clinico-pathological picture of the disease is described. Three points are emphasized: 1. WD is frequently localized on the head; when localized on the lower prolabium squamous-cell carcinoma mast be considered in differential diagnosis; 2. no clinical feature is peculiar of the disease; 3. surgical excision is essential for a correct diagnosis when histological examinations are performed on orthogonal and medial sections.

Identification of tryptophan metabolites in the healthy epidermis of diabetics.

The urinary excretion of metabolites of the tryptophan leads to niacin pathway after an L-tryptophan load in patients with potential and latent diabetes, and in a third of those with chemical diabetes, was normal. In the remaining subjects with chemical diabetes and in those with clinical diabetes it was altered and characterized by an increase of xanthurenic acid and by a reduction of kynurenines and 3-hydroxyanthranilic acid. The thin-layer chromatographic pattern of tryptophan metabolites in the epidermis of patients with potential, latent, chemical, clinical diabetes was characterized by the kynurenine pathway metabolites that were also present in the epidermis of healthy subjects. Morevoer, the above pattern was characterized by the appearance of 5-hydroxytrptamine, and in patients with chemical and clinical diabetes by the appearance of xanthurenic acid.

Statistical association between psoriasis and diabetes: further results.

In a group of 200 psoriatic patients from the area of Umbria, Italy, diabetes mellitus occurred in a statistically highly significant association with psoriasis. Similar observations were made earlier in a series of 600 patients. The above correlation also occurred significantly more frequently in patients under 50 years and in male patients. Previous and present experience also demonstrate that psoriasis is statistically correlated with heredity for diabetes and obesity. The possible biological basis of psoriasis/diabetes association are tentatively outlined.

Research on tryptophan metabolites "via kynurenine" in epidermis of man and mouse.

The pattern of tryptophan metabolites "via kynurenine" was determined in the epidermis of man and mouse using semiquantitative method of one- and two-dimensional thin-layer-chromatography. In the epidermis of healthy man the following metabolites were present: tryptophan, kynurenine, anthranilic acid, 3-hydroxyanthranilic acid, 3-hydroxykynurenine, kynurenic acid, nicotinic acid; the same metabolites, with the exception of kynurenine, were present in the epidermis of healthy mouse. In the epidermis of patients with porphyria cutanea tarda and of those with pellagra, the above pattern was modified and resulted similar to that found in the urine. In the epidermis of patients with pellagroid erythema an alteration of "via kynurenine" metabolites was present. In epithelioma tissues all the above mentioned metabolites were increased while in keratoacanthoma were normal. In burnt epidermis xanthurenic acid was present. In the epidermis of mouse with DDC-porphyria the pattern was characterised by absence of tryptophan, anthranilic and nicotinic acids. These data and those obtained by determination of tryptophan-pyrrolase and kynureninase activities are presented and discussed.