Characterization of the chromosome complement of Helianthus annuus by in situ hybridization of a tandemly repeated DNA sequence

A tandemly repeated sequence isolated from a clone (HAG004N15) of a nebulized genomic DNA library of sunflower (Helianthus annuus L., 2n = 34) was characterized and used to study the chromosome complement of sunflower. HAG004N15 repeat units (368 bp in length) were found to be highly methylated, and their copy number per haploid (1C) genome was estimated to be 7800. After in situ hybridization of HAG004N15 repeats onto chromosome spreads, signals were observed at the end of both chromosome arms in 4 pairs and at the end of only one arm in 8 other pairs. Signals were also observed at the intercalary (mostly subtelomeric) regions in all pairs, in both arms in 8 pairs, and in only one arm in the other 9 pairs. The short arm of 1 pair was labelled entirely. The chromosomal location of ribosomal DNA was also studied by hybridizing the wheat ribosomal probe pTa71. Four chromosome pairs contained ribosomal cistrons at the end of their shorter arm, but a satellite was seen in only 3 pairs. These hybridization patterns were the same in the 3 sunflower lines studied (HA89, RA20031, and HOR). The chromosomal localization of HAG004N15-related sequences allowed all of the chromosome pairs to be distinguished from each other, in spite of small size and similar morphology.

Bone morphogenetic proteins and bone defects: a systematic review

STUDY DESIGN

A systematic review of scientific literature.

OBJECTIVE

The study aimed to determine whether bone morphogenetic proteins (BMPs) are more effective in treating bone defects than traditional techniques, such as grafting autologous bone.

SUMMARY OF BACKGROUND DATA

BMPs were used in several human randomized controlled trials (RCTs). There are both logical arguments and an empirical basis for using RCTs to evaluate the effects of health care interventions and restrict systematic reviews to such a kind of study design.

METHODS

An electronic search was made in the databases of MEDLINE, EMBASE (through MeSH and Emtree), and the Cochrane Central Register of Controlled Trials, extended to May 31, 2006, with no linguistic restrictions. RCTs that compare bone regeneration achieved through BMPs versus that obtained by traditional methods entered the study.

RESULTS

The 17 publications that met the criteria, divided into subgroups by type of bone, were tabulated by salient characteristics and evaluated through the items proposed by van Tulder et al. However, as the studies differed widely (in terms of site, sample size, dosage of active principle, carrier, clinical and radiologic data recording), it was possible to carry out a metaanalysis of clinical and radiologic outcome only for the subgroup that evaluated the vertebrae, where it was observed that BMPs offer a slightly but statistically significant greater efficacy than do traditional techniques.

CONCLUSIONS

The use of BMPs at the vertebrae can eliminate the need for surgery to harvest autologous bone. The only large study carried out on the other sites suggests that BMPs should be used at a concentration of 1.5 mg/mL to treat fractures of the tibia. However, further RCTs of good methodological quality are advisable so as to clarify the effectiveness of BMPs in clinical practice.

Muscle tenderness in different types of facial pain and its relation to anxiety and depression: A cross-sectional study on 649 patients

To evaluate in patients with different types of facial pain the association between muscle tenderness and a set of characteristics, 649 consecutive outpatients with facial myogenous pain (MP), TMJ disorder, neuropathic pain (NP) and facial pain disorder (FPD) (DSM-IV) were enrolled. For each patient a psychological assessment on the Axis 1 of the DSM-IV and standardized palpation of pericranial and cervical muscles were carried out. A pericranial muscle tenderness score (PTS), a cervical muscle tenderness score (CTS) and a cumulative tenderness score (CUM, range 0-6) were calculated. Univariate analyses (one-way analysis of variance or chi(2) test) indicated that both age- and sex-distribution, tenderness scores and prevalence of psychiatric disorders markedly differed between groups. The prevalence of depression was highest in FPD patients (44.9%). Both muscle tenderness scores (either PTS or CTS) and prevalence of anxiety were higher in patients with MP than in those with TMJ or NP. To assess associations between CUM score and patients' demographic and clinical characteristics an ordered logit model was fit and interactions between psychiatric disorders and diagnostic groups were tested. The analysis showed that, regardless of the diagnostic group, anxiety and depression independently increase the likelihood of having one point higher muscle tenderness score (OR=1.55, 95% CI: 1.13-2.12 and OR=1.56, 95% CI: 1.10-2.21, respectively). A careful screening for the presence of an underlying psychiatric disorder, either anxiety or depression, should be part of the clinical evaluation in patients suffering from facial pain.

[Adapting clinical practice guidelines to a regional oncology network: the Piedmont experience]

OBJECTIVE

To develop a method for adapting the best available cancer practice guidelines (CPGs) to the regional oncology network in Piedmont (NW of Italy, with about 4.3 million residents).

METHODS

Four CPG were developed by multidisciplinary working groups, involving local opinion leaders, coordinated by the same team (including epidemiologists and health economists). The major features of these guidelines were: (a) to cover all the phases ofthe disease (from diagnosis to palliative care); (b) to satisfy common standards for evidence based guidelines; (c) to be coherent with the local health organization and resource availability. In the first three CPGs, regarding common cancers (colon-rectum, breast, lung), recommendations were graded according to the underlying level of evidence, from A to C, and treatment was organized by specialty. In the last guideline, regarding a rare condition (soft tissue sarcomas, STS), a grading system reflecting also the clinical importance of the decision was adopted and treatment recommendations were organized by clinical scenarios. In each guideline, some implementation tools, including a set of process and outcome indicators for audit monitoring, were provided.

RESULTS

The four CPGs have been published between 2001 and 2004. The number ofrecommendations ranged between 38 (STS) and 103 (colon-rectum), with some differences in the distribution by specialty and grading. The CPGs have been disseminated through the oncology network and local health coordinators have been involved in the implementation. The impact of the CPGs is being evaluated by different approaches (analyses of administrative data, sample surveys and user's interviews).

CONCLUSIONS

To adapt evidence based guidelines to a specific regional health organization is feasible and may be usefil for diseases requiring a multidisciplinary approach and continuity of care.

[Survey among GP's about their smoking habits, opinions and behaviours in smoking prevention in Lombardy (Northern Italy)]

OBJECTIVE

to analyze smoking habits, opinions on smoking, curriculum and smoking prevention activities carried out by general practitioners in the Lombardy Region (Northern Italy).

DESIGN AND PARTICIPANTS

between 2000 and 2002 a questionnaire about tobacco smoke retrieved from the European Project "GPs Empowerment" has been sent to 5348 general practitioners in the Lombardy Region. The questionnaire focuses on the difference of opinions and activity between smoking and non-smoking physicians. We analyzed 3571 questionnaires voluntarily filled.

RESULTS

The prevalence of smokers among the general practitioners in the Lombardy Region was 22.3% (CI95% 21-24%), (M: 24.2%, CI 95% 22-26% and F: 17.8%, CI 95% 15-20%). Physicians could play a role in the prevention of tobacco: 98.7% (CI 95% 98-99%) agree about the effectiveness of counseling but only 65.6% (CI95% 64-67%) regularly counsel their patients about smoking-related diseases and quitting. In this paper, we estimated that 963% (CI95% 96-97%) non smoking GPs consider counseling useful for their patients vs 92.6% (CI 95% 91-94%) of smoking physicians (p <0. 001); GPs who think to represent a model for people are more frequent among non smokers (97.5%, CI95% 97-98% vs 89.3%, CI 95% 87-91%;p <0.001). Those who discuss with their patients about tobacco addiction and cessation are 68.9% (CI95% 67-71%) among non smokers vs 53.4% (CI 95% 50-54%) among smokers (p <0.001). Finally 67% (CI 95 % 65-69%) interviewed physicians lacked a specific training in smoking prevention. Among them, 87.4%(CI 95% 86-89%) would attend the courses.

CONCLUSION

this finding could be useful for planning or enhancing activities aimed at improving preventive and cessation methods.

Chromosome endoreduplication as a factor of salt adaptation in Sorghum bicolor

Nuclear DNA amounts were measured by Feulgen cytophotometry in Sorghum bicolor cv. 610 plants early exposed to 150 mM NaCl, a treatment known to induce an increased tolerance to salinity in plants carrying this genotype. In salt-treated plants, the percentages of 8C, 16C, and 32C nuclei in roots in the primary state of growth were 21.9%, 13.3%, and 4.3%, respectively. By contrast, in nonsalinized plants, only 3.5% of the nuclei had an 8C content and no higher DNA contents were observed. The salt treatment induced chromosome endoreduplication during the differentiation of cells in the root cortex, where 41.2% of the cells displayed a DNA content higher than 4C (versus 1.3% in control plants). No enhancement of endopolyploidy was observed in cells of the root vascular cylinder or the leaves of the salt-treated plants. In another S. bicolor genotype (DK 34-Alabama), noncompetent for salt adaptation, the same NaCl treatment did not induce chromosome endoreduplication in root cortex cells. Endopolyploidy may be considered as a part of the adaptive response of S. bicolor competent genotypes to salinity.

Oral melphalan and prednisone chemotherapy plus thalidomide compared with melphalan and prednisone alone in elderly patients with multiple myeloma: randomised controlled trial

BACKGROUND

Since 1960, oral melphalan and prednisone (MP) has been regarded as the standard of care in elderly multiple myeloma patients. This multicentre randomised trial compared oral MP plus thalidomide (MPT) with MP alone in patients aged 60-85 years.

METHODS

Patients with newly diagnosed multiple myeloma were randomly assigned to receive oral MP for six 4-week cycles plus thalidomide (n=129; 100 mg per day continuously until any sign of relapse or progressive disease) or MP alone (n=126). Analysis was intention-to-treat. This study is registered at , number NCT00232934.

RESULTS

Patients treated with thalidomide had higher response rates and longer event-free survival (primary endpoints) than patients who were not. Combined complete or partial response rates were 76.0% for MPT and 47.6% for MP alone (absolute difference 28.3%, 95% CI 16.5-39.1), and the near-complete or complete response rates were 27.9% and 7.2%, respectively. 2-year event-free survival rates were 54% for MPT and 27% for MP (hazard ratio [HR] for MPT 0.51, 95% CI 0.35-0.75, p=0.0006). 3-year survival rates were 80% for MPT and 64% for MP (HR for MPT 0.68, 95% CI 0.38-1.22, p=0.19). Rates of grade 3 or 4 adverse events were 48% in MPT patients and 25% in MP patients (p=0.0002). Introduction of enoxaparin prophylaxis reduced rate of thromboembolism from 20% to 3% (p=0.005).

CONCLUSION

Oral MPT is an effective first-line treatment for elderly patients with multiple myeloma. Anticoagulant prophylaxis reduces frequency of thrombosis. Longer follow-up is needed to assess effect on overall survival.

Workspace analysis and performance of a binary actuated parallel manipulator with flexural joints

In this paper the design of a miniaturized parallel architecture is investigated in terms of basic performances concerning mobility and workspace characteristics. The miniature requirements have been achieved with a milli-scaled parallel manipulator requiring flexural joints and binary actuation with shape memory alloy wires or small pneumatic pistons. The mechanical design is analysed by considering the mobility of the flexural joints in order to size them and model the kinematics of the joints. The reachability is analysed through a suitable formulation of the direct kinematics by also taking into account binary actuation. Workspace performance has been determined in terms of position and orientation capabilities.

Numerical and experimental analyses of radial cams with circular-arc profiles

Cam profiles with circular arcs can be useful for low-cost transmissions and for applications in micromachines. They are usually designed by means of graphical techniques. Recently, at Laboratory of Robotics and Mechatronics (LARM) in Cassino, a research line addressed the problems of modern design and characterization of cams with circular-arc profiles by looking at computer-oriented formulations and by investigating experimentally the operation characteristics. In this article, we have given an overview of the results achieved for radial cams and also attempted to extend to a general case that is useful for studying and validating any planar cam profile. The approach is algebraic, because it is based on the geometry of the mechanical design of circular-arc profiles. The experimental analysis has been conceived for a low-cost easy-operation performance of the circular-arc profiles, using a suitable test-bed that has been designed at LARM in Cassino. The results of the experimental tests are useful to validate both the numerical design procedure and the designed cam profiles. Examples are reported to illustrate the practical engineering feasibility of the proposed analysis procedures for radial cams with circular-arc profiles.

Resin-bonded fixed partial dentures: ten-year follow-up

PURPOSE

The aim of the study was to evaluate the survival rate of resin-bonded fixed partial dentures delivered between 1993 and 2003 in the Department of Prosthodontics of the University of Turin and in several private practices.

MATERIALS AND METHODS

The analysis took into consideration the following variables: preparations, metallic alloys, metal preparation and conditioning of the inner surfaces, isolation during cementation, type of cement, kind of prostheses, number of abutments, and number of missing teeth included in the prostheses.

RESULTS

The estimated survival probability for the first debonding or failure was 85% after 5 years and 71% after 10 years.

CONCLUSIONS

The use of dental dam during cementation reduced the risk of debonding. No differences in survival rate were found for the other parameters.

The Microscopic Switching Mechanism of a [2]Catenane

We apply numerical simulations at an all-atom level to investigate the switching mechanism of a [2]catenane, a prototype of a molecular machine. This system is able to switch reversibly between two different stable states, upon external stimuli, with a time scale ranging from microseconds up to milliseconds, well over the typical domain of molecular dynamics (MD) computer simulations. However, combining a strategy recently developed for investigating rare events with ordinary MD, we are able to unravel the microscopic mechanism of the conformational rearrangements involved in the switching process, including dynamical effects. Along the path that connects the product and reactant state, we find several intermediate states characterized by pi-pi stacking interactions and hydrogen bonds. Moreover, counterions interact strongly with the system in a correlated way, in agreement with recent static calculations performed on [2]rotaxanes.

Cytogenetics of Triticum × Dasypyrum hybrids and derived lines

Genomic in situ hybridization was used to study Triticum x Dasypyrum wide hybrids and derived lines. A cytogenetic investigation was carried out in progenies of (i) amphiploids derived from T. turgidum var. durum (T. durum; 2n = 14; genomes AABB) x D. villosum (2n = 14; genome VV), (ii) three-parental hybrids (T. durum x D. villosum) x T. aestivum (2n = 42, genomes A'A'B'B'D'D'), and (iii) T. aestivum aneuploid lines carrying D. villosum chromosomes or chromatin. The amphiploids derived from T. durum x D. villosum showed a stable chromosomal constitution, made up of 14 V chromosomes, 14 chromosomes carrying the wheat A genome and 14 chromosomes carrying the B genome. High karyological instability was observed in the progenies of three-parental hybrids ([T. durum x D. villosum] x T. aestivum). Plants having the expected 14 A chromosomes, 14 B chromosomes, 7 D chromosomes, and 7 V chromosomes were rather rare (4.5%). Many progeny plants (45.5%) had the hexaploid wheat genome with 42 chromosomes and lacked any detectable D. villosum chromatin. Other plants (50%) had 14 A chromosomes and 14 B chromosomes, plus variable numbers of D and V chromosomes, the former being better retained than the latter in most cases. Some T. aestivum lines carrying D. villosum chromosomes or chromatin, as the result of addition, substitution, or recombination events or even a combination of these karyological events, were found to be stable. Other lines were unstable, and these lines carried 1V, 3V, or 5V chromosomes or their portions. Substitution or recombination events where 1V chromosomes were involved could concern the homeologous counterparts in both the A and B and D genomes of wheat. No line could be recovered where the shorter arm of 3V chromosomes was present. Changes in the morphology and banding pattern of V chromosomes were observed in hybrids that did not carry the entire D. villosum complement. By comparing the results of our cytogenetic analyses with certain phenotypic characteristics of the lines studied, genes for discrete traits could be assigned to specific V chromosomes or V chromosome arms. From the frequency of V chromosomes that were involved in chromatin exchanges with or substituted for one of their homeologous counterparts in the A, B, and D wheat genomes, it was inferred that D. villosum belongs to the same phyletic lineage as T. urartu (donor of the A genome of wheat) and Aegilops speltoides (B genome), and that Ae. squarrosa (D genome) diverged earlier from D. villosum.

High efficiency production and genomic in situ hybridization analysis of Brassica aneuploids and homozygous plants

Interspecific and intergeneric hybridizations have been widely used in plant genetics and breeding to construct stocks for genetic analysis and to introduce into crops the desirable traits and genes from their relatives. The intergeneric crosses between Brassica juncea (L.) Czern. & Coss., B. carinata A. Braun and Orychophragmus violaceus (L.) O. E. Schulz were made and the plants produced were subjected to genomic in situ hybridization analysis. The mixoploids from the cross with B. juncea were divided into three groups. The partially fertile mixoploids in the first group (2n = 36-42) mainly contained the somatic cells and pollen mother cells (PMCs) with the 36 chromosomes of B. juncea and additional chromosomes of O. violaceus. The mixoploids (2n = 30-36) in the second and third groups were morphologically quite similar to the mother plants B. juncea and showed nearly normal fertility. The plants in the second group produced the majority of PMCs (2n = 36) with their chromosomes paired and segregated normally, but 1-4 pairs of the O.violaceus chromosomes were included in some PMCs. The plants in the third group produced only PMCs with the 36 B. juncea chromosomes, which were paired and segregated normally. The mixoploids (2n = 29-34) from the cross with B. carinata produced the majority of PMCs (2n = 34) with normal chromosome pairing and segregation, but some plants had some PMCs with 1-3 pairs of chromosomes from O. violaceus and other plants had only PMCs with the B. carinata chromosomes. The Brassica homozygous plants and aneuploids with complete or partial chromosome complements of Brassica parents and various numbers of O. violaceus chromosomes were derived from these progeny plants. The results in this study provided the molecular cytogenetic evidence for the separation of parental genomes which was previously proposed to occur in the hybridizations of these two genera.

Diversity of Olea genotypes and the origin of cultivated olives

Tandem repeats belonging to three DNA sequence families ( OeTaq80, OeTaq178, and OeGEM86) were isolated from the nuclear DNA of Olea europaea cv. Carolea and dot-hybridized to the genomic DNA of 14 hypothetically different Olea species, 78 olive cultivars, and 14 wild olives. The copy number per unreplicated haploid genome of OeTaq80- and OeTaq178-related sequences was in the 10(7)-10(6) range and that of OeGEM86-related sequences was in the 10(5) range in cultivars, wild olives and some Olea species. A large variation in the frequency of repeats belonging to each sequence family was observed within each group of plants. Positive correlations existed in each genome between the frequencies of repeats belonging to each family, and their overall frequency was positively correlated to the genome size. Duncan grouping showed that the frequency variation of tandem repeats within each group of plants was not continuous. Two main groups and several subgroups of genotypes could be separated within both the olive cultivars and the wild olives. Discrete areas in the Mediterranean Basin could be delimited by the geographic distribution of cultivated olives with different genotypes and the wild plants were associated with the cultivars in these areas according to genotypic similarity. The Olea species could be divided into four genotypic groups. Three of these, comprising accessions from Asia and North Africa, showed similarity with the genotypes of cultivars and wild olives. These results suggest a polyphyletic origin of cultivated olives from different wild Olea forms distributed throughout the Mediterranean Basin.

Genome plasticity in Festuca arundinacea: direct response to temperature changes by redundancy modulation of interspersed DNA repeats

The response of the genome of Festuca arundinacea seedlings to changes in the temperature at which they were grown was investigated. Fifteen repeated sequences in the nuclear DNA were isolated and hybridized to the genomic DNA of seedlings grown at 10 degrees C or 30 degrees C. The redundancies of sequences recognized by four probes ( FaA5, FaH8, FaH13 and FaH14), were found to differ significantly in the two DNAs. DNA sequences recognized by FaH8, FaH13 and FaH14 were more represented in the genome of the 30 degrees C-raised seedlings than in the genome of the 10 degrees C-raised seedlings (76.5 x 10(3), 1.9 x 10(3), and 111.8 x 10(3) copies per haploid, 1C genome vs 62.7 x 10(3), 1.3 x 10(3), and 80.8 x 10(3) copies, respectively). In contrast, FaA5-related sequences were more represented in the genome of seedlings grown at the lower temperature (15.5 x 10(3) vs 10.2 x 10(3) copies, respectively). Southern-blot hybridization of these repeats to digested genomic DNA produced patterns which indicated that the probe sequences were part of longer repeated sequences having a limited degree of structural heterogeneity. These patterns were partly different when the probes were hybridized to the DNA from seedlings grown at 10 degrees C or 30 degrees C. In situ hybridization showed that the DNA sequences recognized by each probe were scattered along the length of all the chromosomes, with preferential location of FaA5- and FaH13-related sequences at given, mainly centromeric, regions of certain chromosomes. These findings suggest that redundancy modulations of interspersed repeated sequences allow direct responses of the genome of F. arundinacea to changes in environmental temperature.

Dynamics of hydration in hen egg white lysozyme

We investigate the hydration dynamics of a small globular protein, hen egg-white lysozyme. Extensive simulations (two trajectories of 9 ns each) were carried out to identify the time-scales and mechanism of water attachment to this protein. The location of the surface and integral water molecules in lysozyme was also investigated. Three peculiar temporal scales of the hydration dynamics can be discerned: two among these, with sub-nanosecond mean residence time, tau(w), are characteristic of surface hydration water; the slower time-scale (tau(w) approximately 2/3 ns) is associated with buried water molecules in hydrophilic pores and in superficial clefts. The computed tau(w) values in the two independent runs fall in a similar range and are consistent with each other, thus adding extra weight to our result. The tau(w) of surface water obtained from the two independent trajectories is 20 and 24 ps. In both simulations only three water molecules are bound to lysozyme for the entire length of the trajectories, in agreement with nuclear magnetic relaxation dispersion estimates. Locations other than those identified in the protein crystal are found to be possible for these long-residing water molecules. The dynamics of the hydration water molecules observed in our simulations implies that each water molecule visits a multitude of residues during the lifetime of its bound with the protein. The number of residues seen by a single water molecule increases with the time-scale of its residence time and, on average, is equal to one only for the water molecules with shorter residence time. Thus, tau(w) values obtained from inelastic neutron scattering and based on jump-diffusion models are likely not to account for the contribution of water molecules with longer residence time.

A family of dispersed repeats in the genome of Vicia faba: structure, chromosomal organization, redundancy modulation, and evolution

A family of repeated DNA sequences of about 1200 bp in length and bordered by well-conserved, 18 bp inverted repeats (VfB family) was found in the nuclear genome of Vicia faba. The structure, chromosomal organization, redundancy modulation and evolution of these sequences were investigated. They are enriched in A+T base pairs (about 40% G+C) and lack any obvious internally repeated motif. A 64%-73% nucleotide sequence identity was found when pairwise comparisons between VfB sequences were carried out (average 69%). Direct repeats were not found to flank the inverted repeats that border these DNA sequences. The results obtained by hybridizing VfB repeats to Southern blots of V. faba genomic DNA digested with EcoRI indicated that these DNA elements are interspersed in the genome. The appearance of bands in these Southern blots and comparison of the structure of the sequences that flank different VfB elements showed that these repeats might be part of other, longer repeated DNA sequences. A high degree of dispersion throughout the genome was confirmed by cytological hybridization, which showed VfB sequences to be scattered along the length of all chromosomes and to be absent or rare only at heterochromatic chromosomal regions. These sequences contribute to intraspecific alterations of genomic size. Indeed, dot-blot hybridizations proved that their redundancy, which is positively correlated with the overall amount of nuclear DNA in each accession, varies between V. faba land races (27x10(3)-230x10(3) copies per 1C DNA). Southern blot hybridization of VfB repeats to restriction endonuclease-digested genomic DNAs of V. faba, V. narbonensis, V. sativa, Phaseolus coccineus, Populus deltoides, and Triticum durum revealed nucleotide sequence homology of these DNA elements, whatever the stringency conditions, only to the DNAs of Vicia species, and to a reduced extent to the DNAs of V. narbonensis and V. sativa compared with that of V. faba. It is concluded that VfB repeats might be descended from mobile DNA elements and contribute to change genomic size and organization during evolution.

Amount and organization of the heterochromatin in Olea europaea and related species

The amount and spatial organization of the heterochromatin in nuclei of the shoot meristem and the frequency in the nuclear DNA of sequences belonging to a family of tandem repeats were investigated in cultivars of Olea europaea and related species. Significant differences between Olea species and between cultivars of O. europaea were observed: (i) in the spatial organization of the heterochromatin in interphase nuclei as determined by the number and surface area of the chromocentres; (ii) in genome size; and (iii) in the amount of condensed chromatin as measured by cytophotometry carried out at different thresholds of optical density. DNA elements belonging to a family of tandem repeats about 80 bp in length (OeTaq80 repeats) were isolated from the genomic DNA of an olive cultivar. It was shown: (i) by nucleotide sequence comparisons, that these repeats display variability in structure even within the same array, where different elements may share no more than 74% homology; (ii) by in situ hybridization, that OeTaq80-related DNA sequences are mainly localized in the heterochromatin at the chromosome ends; (iii) by dot-blot hybridization experiments, that these sequences are highly represented in the genome of all the olive cultivars and the majority of Olea species studied, and that their frequency may differ significantly even between olive cultivars; and (iv) by calculating the copy number of OeTaq80-related sequences per haploid (1C) genome, that the redundancy of these DNA elements may differ significantly between the genomes tested. It is suggested that the inter- and intraspecific changes in the nuclear and genomic traits observed can contribute to the understanding of the phylogenetic relationships between Olea species and in defining parameters to be exploited in varietal identification within cultivated olives.

Molecular dynamics simulation of POPC at low hydration near the liquid crystal phase transition

We report results of a preliminary molecular dynamics study of a 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) bilayer at low hydration (5% in weight). Our results suggest a gel phase structure where the oleic chain is bent recalling the crystalline oleic acid structure. We have also found a discontinuity in the volume/temperature curve which might be related to the gel to liquid crystal phase transition in POPC.

[Atypical and incomplete Kawasaki disease]

Kawasaki Disease (KD) is an acute systemic vasculitic disorder of childhood of unknown etiology. Initially KD was thought to be a benign disease, but later on it became obvious that cardiac manifestations are present in about 25-30% of patients and lead to death in about 0.5-2% of them. An early diagnosis and treatment are important to avoid an unfavourable prognosis. In recent years, a number of publications described patients in which the diagnosis was delayed because they did not fulfil the required criteria of KD. These forms of KD are known as atypical or incomplete KD. The aim of this work is to describe two cases of atypical KD observed at the Department of Pediatrics, University of Pisa during the year 1992.

Platelet serotonin transporter in coeliac disease

We investigated a peripheral serotonergic marker, i.e. platelet tritiated imipramine (3H-IMI) binding sites, which are part of the 5-HT transporter complex similar to that present in the brain, in 20 patients affected by coeliac disease (CD), as compared with 20 healthy controls. Platelet membranes and 3H-IMI binding were carried out according to a standardized protocol. The results showed that coeliac patients had significantly lower 3H-IMI binding sites than controls. This finding would suggest the presence of a dysfunction at the level of the 5-HT transporter that might underline the psychic disturbances frequently observed in coeliac patients.

FokI DNA repeats in the genome of Vicia faba: species specificity, structure, redundancy modulation, and nuclear organization

Tandemly repeated DNA sequences about 60 bp in length, which may be isolated by digestion with FokI restriction endonuclease, were studied by means of molecular and cytological hybridization in Vicia faba and other Vicia species. The results obtained can be summarized as follows: (i) FokI repeats are almost species specific to V. faba, since they hybridize to a minimum extent to genomic DNA of only two out of five related species; (ii) these tandemly repeated elements display variability in structure even within one and the same array, where different repeats may share not more than 71% homology; (iii) their redundancy in the genome of V. faba is remarkably high and varies largely between land races (copy numbers per haploid, 1C, genome range from 21.51 x 10(6) to 5.39 x 10(6)); (iv) FokI repeats are clustered in differing amounts in each subtelocentric pair of the chromosome complement and are missing or present in a nondetectable amount in the submetacentric pair; (vi) chromosome regions that bear these repeats associate closely to varying degrees in interphase nuclei. These results are discussed in relation to possible functional roles that tandemly repeated DNA sequences such as the FokI elements might play.

[Apparent life threatening events (ALTE): prelude to SIDS? Description of 14 cases]

The peak incidence of the Sudden Infant Death Syndrome (SIDS) is between 2 and 4 months of age. Its pathology is extremely heterogenous, infection, hypoxia and many others factors are all implicated. We examine here the possible relation between SIDS and Apparent Life Threatening Event (ALTE). We describe 14 cases that we have observed to establish a primary connection between these two situations and to identify a risk-group for an accurate follow-up.

[Intestinal intussusception in children]

Enteric intussusception is one f the most frequent causes of acute abdomen in early childhood, with an incidence of 1.3-2/1000 children born and higher frequency from the third to the twelfth month. Primary intussusception is related to predisponsing factors such as peristalsis disorders or Peyer's patch hypertrophy induced by viral infection. Secondary intussusception is due to organic injury in the intestinal wall. The most involved sites are the terminal ileum and the ileocecum, the most frequent type is ileocolic intussusception. Many clinical forms exist, including acute enteric intussusception with its pathognomonic triad intermittent abdominal pain, emesis and rectal bleeding and the atypical form with a neurological presentation, where sopor, myosis and muscular atonicity are dominating, Intussusception can also present in a subacute or chronic form with a slow and apsecific onset. In a retrospective investigation we examined 30 cases of intussusception in children hospitalized at the Pediatric Clinic of Pisa from the 1960s up to today. Our patients (16 males and 14 females) were aged between one month and two years. Clinical presentations resulted in; typical forms (60%), atypical forms (16%), subacute forms 13%) and recurrent forms (10%). Clinical suspicion was confirmed either by the presence of blood observed during rectal exploration, which is a pathognomonic sign, or by the opaque enema which led to recovery by means of hydrostatic reduction in 40% of the cases. The remaining patients (60%) underwent surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

[Description of two cases of Munchausen syndrome by proxy]

The Munchausen syndrome by proxy, or Polle syndrome can be considered as a form of child abuse in which parents falsify or even produce a real pathology in their children submitting them to frequent hospitalizations and pointless medical examinations. The authors discuss two cases and emphasize the importance of an early identification of these cases to avoid psychical impairments that inevitably stem from this "new" form of child abuse.

Varicella in immunocompetent children in the first two years of life: role of treatment with oral acyclovir. Italian Acyclovir-Chickenpox Study Group

An open multicenter study has been carried out to evaluate efficacy and tolerability of oral acyclovir in the treatment of varicella in immunocompetent patients in the first two years of life. Fifty-three children aged 3-24 months received acyclovir at 80 mg/Kg/day in four divided doses for 4 to 6 days; 24 of them were treated in the first 24 hours following disease onset, while the remaining 29 patients were enrolled within 48 hours. The assessment of evolution of disease signs and symptoms showed a rapid resolution of fever, itching and other constitutional symptoms, with interruption of vesicle formation and acceleration of cutaneous healing processes. No statistically significant differences have been demonstrated as to disease progression between patients treated in the first 24 hours, when compared with subjects receiving acyclovir in the following 24 hours. Acyclovir confirmed its excellent clinical and laboratory safety profile. By acting favorably on both the duration and severity of disease signs and symptoms, acyclovir treatment should be recommended in young children and infants with varicella, since a higher incidence of severe and complicated disease has been observed in these patient groups.

[Celiac disease and cystic fibrosis: casual association?]

The authors describe a case of association cystic fibrosis coeliac disease, which they have observed. The frequency of this association in the general population is of 1:2,000,000. M.A. presents little growth in terms of height and weight and intestinal alterations (an abundance of fatty and mucous stool). The initial diagnosis was that of coeliac disease. After two months of diet without gluten one observed an increase in weight, but o result for the intestinal disturbances. The positive result revealed from the sweat-test and the study of genomic mutation (delta F508) showed the diagnosis of cystic fibrosis associated with coeliac disease. The specific treatment of both syndromes resolved intestinal alterations and caused the diminution of the acute bronchitis frequent during the first and the second infancy.

[Williams-Beuren syndrome and celiac disease]

The authors describe a case of Williams syndrome-Coeliac Disease that they have observed at the age of three years and 10/12. There are few reports in the literature. We focus on the variability of clinical and biochemical aspects of Williams Disease and the necessity for an adequate gastroenterologic follow-up (anti-gliadine antibody and anti-endomisium antibody) in these patients with little growth in terms of weight and height and intestinal alterations present in superior measure in companion with the reported standards for the same syndrome.

[Bacterial meningitis. Review of literature and retrospective study of 208 cases observed]

Bacterial meningitis is a particularly dangerous infection of the central nervous system involving quite a number of mortal cases and frequent neurological sequelae. Etiology varies in relation to the patient's age. In the first 2 months of life Streptococcus B, Listeria monocytogenes, Escherichia coli and other Gram negative enteric bacilli are more frequently isolated while in older children Haemophilus influenzae, Neisseria meningitidis and Streptococcus pneumoniae are more common. Clinical symptoms take a different form according to the patient's age: symptoms of a general kind prevail in the first 2 months of life while in older children signs of meningeal irritation predominate. In a review of the survey of cases of bacterial meningitis observed at the Clinica Pediatrica in Pisa from 1970 to July 1993, with a retrospective research, 208 patients have been examined, considering age, etiology, clinical course especially observing the course of temperature, liquor characteristics, normalisation of the index of phlogosis, mortality and neurological sequelae. In the last ten years the availability of 3rd generation cephalosporin has provided the possibility of comparing two groups of patients of an age ranging between 1 month and 14 years. Twenty cases were treated with ampicillin and chloramphenicol and 30 cases with cephalosporins the evaluation made considering the course of temperature, the normalization of the liquor index has revealed a more favourable clinical course in the second group of patients.

Tissue-specific nuclear repatterning in plant cells

Tissue-specific nuclear repatternings, consisting of changes in the number and size of the chromocenters, were observed by analyzing, in Feulgen squashes and sections, different tissues of several plant species, particularly of Ionopsidium savianum. Nuclear repatternings occur mainly near the base of the meristems. They are due to associations of chromosomes at their heterochromatic regions. This was confirmed by the results of cytophotometric measurements, showing the same contents of both Feulgen/DNA and heterochromatin in nuclei with a different number of chromocenters. These data also showed that chromosome association does not occur in endoreduplicating or endoreduplicated cells. Autoradiographic results after [3H]thymidine treatments indicated that DNA synthesis does not occur in nuclei with extensive chromosome association. A highly significant, positive correlation was found between the number of chromocenters in each nucleus and the amount of RNA synthesis as indicated by [3H]uridine incorporation. It is suggested that chromosome association plays some role in the regulation of the functional activity of the nucleus and in tissue differentiation.Key words: functional regulation, heterochromatin, nuclear repatterning, plant cell nucleus, tissue differentiation.

[Celiac disease associated with chronic autoimmune hepatitis. Description of a case]

The authors describe a case of coeliac disease and autoimmune chronic hepatitis in the same patient. Case description allows a critical review of the literature and evaluation of pathogenetic hypotheses.

[Acute osteoarthritis in the newborn and infants]

The Authors report two cases of acute osteomyelitis, in a newborn and in an infant. Bone and joint sepsis in the first years of life is rare. The metaphases of long bones are the most common sites of hematogenous osteomyelitis. The hip and the knee are especially at risk. The patients were treated with pharmacologic and orthopedic therapy. The Authors describe the clinical features, radiographic changes, the diagnosis and management of this disease.

[Diencephalic syndrome. Case report and review of literature]

We report the case of a twenty-three month old, normally eating child, affected by organic macies and severe dystrophy. After the negative response of blood and laboratory examinations let us exclude a malabsorption syndrome, only the performance of neuro-radiologic exams showed evidence of a subthalamic tumor as the cause of a "Diencephalic syndrome". Diencephalic syndrome or Russel's syndrome is a diencephalic tumor induced disease, which sets in the first three years of life. The disease clinical markers are a severe emaciation with appetite preservation and absence or very scarce evidence of any telltale neurological sign. the tumoral histo-pathology most frequently shows a low grade of malignancy astrocytoma, whose eradication is very often difficult because of the particular anatomic site. Choice treatment includes an excisional biopsy associated to chemotherapy and to radiotherapy.

[Reiter's syndrome. Apropos a pediatric case]

The authors report the case of a 13-year-old girl affected with urethritis, conjunctivitis, and oligoarticular arthritis. These symptoms represent the classical triad of Fiessinger-Leroy-Reiter's syndrome. The research for HIV was negative and the antigen HLA B27 was absent. The young patients has been treated by FANS and tetracycline. The authors reviewed the literature and analyses the epidemiology-cal, etiological and clinical problems of this disease.

[Plasma L-carnitine levels in children with celiac disease]

Carnitine is a very important co-factor for the metabolism of fatty acids, because it is the necessary carrier for the passage of acyl groups inside the mitochondria, where beta-oxidation takes place. In the human body the total pool of carnitine is made by two fractions, one being endogenous and the second exogenous. The absorption of exogenous carnitine takes place mainly at duodenal-jejunal level by an active transport mechanism based on amino acid carrier. Plasma L-carnitine concentrations have been measured in 66 coeliac patients (mean age: 7 years and 4 months). Thirty three of them were on a free diet and the other 33 were on a gluten-free diet for at last six month. In 10 patients we studied plasma L-carnitine levels both on a free diet and on a gluten-free diet. As controls we examined 33 healthy children comparable for age. Plasma L-carnitine concentrations have been measured by a spectrophotometrical method according to Marquis and Fritz's technique and subsequently modified by Pearson and Seccombe. In the 66 coeliac patients the mean values of serum L-carnitine were significantly lower than those in the controls (p < 0.001). The levels were significantly lower in patients a free diet with respect to those on gluten-free diet (p < 0.01). The 10 subjects who were examined both on free diet and on gluten-free diet showed an increase of plasma concentrations in the latter condition.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hypertrophic pyloric stenosis in infants. A retrospective study of cases observed in the years 1970-1990]

Although the definitive cause of infantile hypertrophic pyloric stenosis is unknown, it's probable that several predisposing risk factors would be associated with the condition. We analysed some perinatal factors in relation to the incidence of infantile hypertrophic pyloric stenosis among children observed during the period 1970-90. We examined 61 infants with surgically confirmed hypertrophic pyloric stenosis and, as controls, 61 healty children comparable for age. In every child we studied: sex, birth rank, pregnancy and delivery, birthweight, parental age, type of feeding, familial history of hypertrophic pyloric stenosis and of atopy, seasonal variation in incidence, AB0 and Rh blood phenotypes. In the 61 infants with hypertrophic pyloric stenosis, the incidence of three factors (male sex, primogeniture and feeding with artificial milk) was significantly higher than that in the controls. We conclude that infantile hypertrophic pyloric stenosis probably has a particular genetic basis, but perinatal factors are responsible for the rising of the condition. However the true aetiology remains to be elucidated.

Clinical and electrophysiological reports in a case of early onset myotonia congenita (Thomsen's disease) successfully treated with mexiletine

A sporadic event of myotonia congenita in a infant admitted to the Paediatric Clinic for frequent crises of apnoea, cyanosis, vomiting and difficult feeding is reported. EMG analysis was consistent with the dominant variety of myotonia congenita. Mexiletine therapy showed excellent results in reducing myotonic activity. It is worthwhile stressing that early symptoms may go unnoticed or may be misinterpreted and that information on the genetic form of the disease can be obtained also from the EMG analysis through a repetitive stimulation test.

[24-hour esophageal pH-metry in the evaluation of gastroesophageal reflux pathology]

Gastro-esophageal reflux (GER) in infants was studied using 24-hour esophageal pH monitoring. Gastro-esophageal reflux was detected in 32/41 subjects. In our patients the main symptoms were vomiting, regurgitation, failure-to-thrive, chronic respiratory problems such as asthma, apnea, recurrent pneumonia. All patients with GER were treated appropriately with prone positioning and medical therapy (prokinetic agent and, eventually, ranitidine). Successful treatment of the reflux was obtained in all patients. In our opinion the 24-hour intraesophageal pH monitoring is a highly diagnostic test to identify the presence of GER and evaluate its gravity.

[Use of intravenous immunoglobulins in Guillain-Barré syndrome]

The aim of the study was to assess the utility of intravenous integral molecule immunoglobulin treatment in Guillain-Barré syndrome. The etiopathogenesis of this syndrome is still unclear but it seems increasingly likely that immune phenomena are involved in the genesis of the neurological lesions. This would explain the efficacy of iv immunoglobulin treatment even if the effective mechanism of action can still only be hypothesised.

[Celiac disease and autoimmunity]

Immune mechanisms have been invoked to explain coeliac disease and associations between this and other immunologically mediated diseases have been described. A direct relationship proposed is that coeliac disease may be associated with a range of autoimmune disease through the formation of immune complexes in the small intestine. It's more probable a common origin in an inherited predisposition to hypersensitive immuno responses to extrinsic antigens or auto-antigens. The association between coeliac disease and particular histocompatibility antigens was recognised.

The unbalanced offspring of the male carriers of the 11q;22q translocation: nondisjunction at meiosis II in a balanced spermatocyte

Carriers of the standard translocation t(11;22) (q23.3;q11.2) produce only one type of unbalanced offspring, a tertiary trisomy resulting into the karyotype 47,XX or XY, +der(22)t(11;22)(q23.3;q11.2), usually derived from the mother. The exception is one single patient 47,XY,t(11;22)(q23.3;q11.2), +der(22)t(11;22) (q23.3;q11.2)pat. We report a second case with the same karyotype, also of paternal origin. Thus, the rare unbalanced offspring of a carrier father (only 5 cases known) may receive a supernumerary der(22), as a consequence of tertiary trisomy, but also as a consequence of nondisjunction at meiosis II of a balanced spermatocyte.

Variation of genome size and organization within hexaploid Festuca arundinacea

Cytophotometric, karyological, and biochemical analyses were carried out in the meristems of seedlings obtained from seeds collected from 35 natural populations of hexaploid Festuca amndinacea in Italy. Highly significant differences between populations were observed in the amount of nuclear DNA (up to 32.3%). These changes are linked to variations in the amount of heterochromatin and in the frequency of repeated DNA sequences, and particularly of a fraction of them. Differences between populations in the arm ratios and total length of the chromosomes were also observed. The genome sizes of the populations are correlated positively with the mean temperature during the year and with that of the coldest month at the stations, and correlate negatively with their latitudes. The intraspecific genome changes observed are discussed in relation to other pertinent data to be found in the literature and in relation to their possible role in environmental adaptation.