Phosphorus-acquisition strategies of canola, wheat and barley in soil amended with sewage sludges

Crops have different strategies to acquire poorly-available soil phosphorus (P) which are dependent on their architectural, morphological, and physiological root traits, but their capacity to enhance P acquisition varies with the type of fertilizer applied. The objective of this study was to examine how P-acquisition strategies of three main crops are affected by the application of sewage sludges, compared with a mineral P fertilizer. We carried out a 3-months greenhouse pot experiment and compared the response of P-acquisition traits among wheat, barley and canola in a soil amended with three sludges or a mineral P fertilizer. Results showed that the P-acquisition strategy differed among crops. Compared with canola, wheat and barley had a higher specific root length and a greater root carboxylate release and they acquired as much P from sludge as from mineral P. By contrast, canola shoot P content was greater with sludge than with mineral P. This was attributed to a higher root-released acid phosphatase activity which promoted the mineralization of sludge-derived P-organic. This study showed that contrasted P-acquisition strategies of crops allows increased use of renewable P resources by optimizing combinations of crop and the type of P fertilizer applied within the cropping system.

The combined use of platelet rich plasma and hyaluronic acid: prospective results for the treatment of knee osteoarthritis

Osteoarthritis represents an important social economic burden with a high incidence worldwide. Conservative management of knee OA consists in several therapeutic options: pharmacologic therapy such as analgesics, non-steroid and steroid anti-inflammatory drugs, physical therapy, and injective therapy with hyaluronic acid (HA) and platelet-rich plasma injections (PRP). The aim of our study is to evaluate the effect of combined autologous PRP and HHA (Hybrid Hyaluronic Acid) viscosupplementation on clinical outcomes of patients with knee OA, by assessing the subjects before and after injective treatment. The study was conducted on 60 patients with an age between 40 and 70 years old affected by unilateral symptomatic knee osteoarthritis (stage II and III of Kellgren-Lawrence scale) nonresponsive to pharmacologic and rehab treatment. We divided the patients in two groups, and we treated the group A with injection of HHA and group B with HHA+PRP. Each patient received 3 injections at an interval of 1 week for 3 consecutive weeks. The patients were evaluated by the Knee Injury and Osteroartrhitis Outcome Score (KOOS) and Visual Analog Scale (VAS) at 3, 6 and 12 months after treatment. Statistical comparison between groups showed a significantly better result for the group B concerning the KOOS value, at 3 months and at 6 months. This difference, although clinically relevant, lost the statistical significance at 12 months. The VAS trend differently showed a significant difference at 3 and 12 months, while at 6 months the superiority of group B did not achieve statistical significance. Few studies investigated the effects of HA+PRP combined treatment for knee OA. Numerous studies demonstrated the efficacy of HA injection therapy in knee OA for a clinical point of view, reducing the pain and improving the quality of life. PRP preparations also improved functional outcome scores compared to hyaluronic acid and placebo in patients affected by knee OA. Based on our results we can conclude that the combined PRP and HHA treatment is not only a safe and efficacious procedure which can provide functional benefit but is also significantly better than HHA injective therapy alone, as demonstrated by the comparison within our cohort.

Behaviour of S-metolachlor and its oxanilic and ethanesulfonic acids metabolites under fresh vs. partially decomposed cover crop mulches: A laboratory study

At the time of spring pre-emergent herbicide application, the soil surface in conservation agriculture is most of the time covered by cover crops (CC) mulches. The state of these mulches depends on their destruction date and on the selected species. Sorption and degradation of ¹⁴C-S-metolachlor on and within 8 decaying CC-covered (2 species × 4 initial decomposition state) soils corresponding to conservation agriculture were compared to its fate in bare soil (BS) corresponding to conventional agriculture. ¹⁴C-S-metolachlor and its metabolites distribution between mineralized, extractable and non-extractable (NER) fractions was determined at 5 dates during a 20 °C/84-d period. Herbicide mineralization was weak (<2%) for both CC and BS. Extractability of ¹⁴C in BS was intermediate between CC that were decomposed 28 or 56 days and 0 or 6 days before application. Degradates consisted in up to 43% of total radioactivity, with specificities according to the CC or soil compartment. NER formation was equivalent in BS and in the much decomposed CC-amended microcosms, and was stronger in less decomposed CC. S-metolachlor DT₅₀ was 23-d in BS, and 9, 15, 39 and 25-d for CC ordered by increased decomposition state at the time of application. These results were attributed to the proportion of ¹⁴C intercepted by CC, and to higher levels of organic matter and microbial activity in less decomposed CC as compared with more decomposed ones. Then the state of decomposition level of CC residues determines the behaviour of SMOC (S-metolachlor) sprayed on the mulch in the conditions of conservation agriculture.

Comparing hybrid hyaluronic acid with PRP in end career athletes with degenerative cartilage lesions of the knee

Cartilage lesions are very common causes of chronic knee pain in athletes. Current treatment options consist in conservative strategies, such as viscosupplementation and platelet-rich plasma injections. This randomized controlled trial aims to investigate the effect of intra-articular Hybrid Hyaluronic Acid injections compared to PRP for the treatment of cartilage lesions among athletes at the end of their career. Since March 2015, 48 professional soccer players were randomized into two groups: 24 patients received 3 injections of HHA and 23 patients received 3 intra-articular injections of PRP. All patients achieved a statistically significant clinical improvement from preoperative to postoperative time in both groups. Patients in the HHA group showed a significant superiority compared to PRP group at 3 and 6 months. Intergroup differences decrease gradually until loss of significance at 12 months follow-up. Athletes with chronic degenerative cartilage lesions of the knee responded positively both to HHA and PRP until last follow up.

Intraoperative application Platelet rich fibrin, postoperative injections OF PRP or microfracture only for osteochondral lesions of the knee: a five-year retrospective evaluation

Cartilage lesions are the most common cause of chronic knee pain. Micro-fracturing is reliable, effective, easy to perform and inexpensive. We propose a novel approach to cartilage lesions where microfractures are performed contextually to intra-operative or post-operative administration of platelet concentrates. We retrospectively evaluate 48 patients divided in 3 groups. Group 1: 15 patients underwent microfractures and intraoperative administration of PRF (PRF group); group 2: 16 microfractures and postoperative injections of PRP (PRP group); group 3: 17 patients with isolated microfractures (Microfractures group). Clinical scores (IKDC, VAS pain) were administered at 2 and 5 years postoperative and MRI was performed to evaluate the lesions of patients according to the MOCART criteria (2006). Patients treated with platelet concentrates achieved better clinical results compared to patients treated with microfracture only. The PRF group showed better results than the PRP group at 2 years, with loss of significance at 5 years. At MOCART score, PRF group obtained better results earlier than the other two groups.

LGI1 microdeletion in autosomal dominant lateral temporal epilepsy

OBJECTIVES

To characterize clinically and genetically a family with autosomal dominant lateral temporal epilepsy (ADLTE) negative to LGI1 exon sequencing test.

METHODS

All participants were personally interviewed and underwent neurologic examination. Most affected subjects underwent EEG and neuroradiologic examinations (CT/MRI). Available family members were genotyped with the HumanOmni1-Quad v1.0 single nucleotide polymorphism (SNP) array beadchip and copy number variations (CNVs) were analyzed in each subject. LGI1 gene dosage was performed by real-time quantitative PCR (qPCR).

RESULTS

The family had 8 affected members (2 deceased) over 3 generations. All of them showed GTC seizures, with focal onset in 6 and unknown onset in 2. Four patients had focal seizures with auditory features. EEG showed only minor sharp abnormalities in 3 patients and MRI was unremarkable in all the patients examined. Three family members presented major depression and anxiety symptoms. Routine LGI1 exon sequencing revealed no point mutation. High-density SNP array CNV analysis identified a genomic microdeletion about 81 kb in size encompassing the first 4 exons of LGI1 in all available affected members and in 2 nonaffected carriers, which was confirmed by qPCR analysis.

CONCLUSIONS

This is the first microdeletion affecting LGI1 identified in ADLTE. Families with ADLTE in which no point mutations are revealed by direct exon sequencing should be screened for possible genomic deletion mutations by CNV analysis or other appropriate methods. Overall, CNV analysis of multiplex families may be useful for identifying microdeletions in novel disease genes.

Familial temporal lobe epilepsy with psychic auras associated with a novel LGI1 mutation

BACKGROUND

Autosomal dominant lateral temporal epilepsy (ADLTE) is characterized by focal seizures with auditory features or aphasia. Mutations in the LGI1 gene have been reported in up to 50% of ADLTE pedigrees. We report a family with temporal lobe epilepsy characterized by psychic symptoms associated with a novel LGI1 mutation.

METHODS

All participants were personally interviewed and underwent neurologic examination and video-EEG recordings. LGI1 exons were sequenced by standard methods. Mutant cDNA was transfected into human embryonic kidney 293 cells; both cell lysates and media were analyzed by Western blot. In silico modeling of the Lgi1 protein EPTP domain was carried out using the structure of WD repeat protein and manually refined.

RESULTS

Three affected family members were ascertained, 2 of whom had temporal epilepsy with psychic symptoms (déjà vu, fear) but no auditory or aphasic phenomena, while the third had complex partial seizures without any aura. In all patients, we found a novel LGI1 mutation, Arg407Cys, which did not hamper protein secretion in vitro. Mapping of the mutation on a 3-dimensional protein model showed that this mutation does not induce large structural rearrangements but could destabilize interactions of Lgi1 with target proteins.

CONCLUSIONS

The Arg407Cys is the first mutation with no effect on Lgi1 protein secretion. The uncommon, isolated psychic symptoms associated with it suggests that ADLTE encompasses a wider range of auras of temporal origin than hitherto reported.

Genetic analysis of the LGI/Epitempin gene family in sporadic and familial lateral temporal lobe epilepsy

Mutations in the LGI1/Epitempin gene cause autosomal dominant lateral temporal lobe epilepsy (ADLTE), a partial epilepsy characterized by the presence of auditory seizures. However, not all the pedigrees with a phenotype consistent with ADLTE show mutations in LGI1/Epitempin, or evidence for linkage to the 10q24 locus. Other authors as well as ourselves have found an internal repeat (EPTP, pfam# PF03736) that allowed the identification of three other genes sharing a sequence and structural similarity with LGI1/Epitempin. In this work, we present the sequencing of these genes in a set of ADLTE families without mutations in both LGI1/Epitempin and sporadic cases. No analyzed polymorphisms modified susceptibility in either the familial or sporadic forms of this partial epilepsy.

Increased expression of LGI1 gene triggers growth inhibition and apoptosis of neuroblastoma cells

The LGI1 gene has been implicated in the malignant progression of glioblastoma and it has also been genetically linked to a form of partial epilepsy (ADLTE). In this study, we investigated the relevance of LGI1 expression for neuroblastoma cells. The analysis of two cell lines (SH-SY5Y and SK-N-BE) revealed unpredictably low levels of LGI1 and stable cell transfection with LGI1 cDNA yielded moderate increases of LGI1 expression. Neuroblastoma cell clones exhibited impaired cell growth and survival ability in relation to LGI1 levels. The process of growth inhibition could be discerned under experimental conditions of low cell density, since conditions of elevated cell density, which enhance the requirement for survival stimuli, resulted in massive cellular death. At high cell density, spontaneous apoptosis of LGI1 cells was clearly shown by the release of cytochrome c and apoptosis inducing factor (AIF) from mitochondria and by phosphatydil serine exposure and nuclear fragmentation. Activation of apoptotic effectors caspase-3/7 also occurred, however, the broad caspase inhibitor Z-VAD-FMK substantially failed to block cell death. Thus the possibility that LGI1-triggered apoptosis may involve initiator caspases linked to activation of death receptors, appears unlikely. The decreased ratio of Bcl-2 to Bax suggests that apoptosis is initiated by the intrinsic mitochondrial pathway through the release of caspase-dependent and -independent apoptogenic molecules. This study provides the first evidence that LGI1 controls neuronal cell survival, suggesting its role in the development of the nervous system in relation to the pathogenesis of neuroblastoma and ADLTE.

Idiopathic partial epilepsy with auditory features (IPEAF): a clinical and genetic study of 53 sporadic cases

The purpose of our study was to describe the clinical characteristics of sporadic (S) cases of partial epilepsy with auditory features (PEAF) and pinpoint clinical, prognostic and genetic differences with respect to previously reported familial (F) cases of autosomal dominant partial epilepsy with auditory features (ADPEAF). We analysed 53 patients (24 females and 29 males) with PEAF diagnosed according to the following criteria: partial epilepsy with auditory symptoms, negative family history for epilepsy and absence of cerebral lesions on NMR study. All patients underwent a full clinical, neuroradiological and neurophysiological examination. Forty patients were screened for mutations in LGI1/epitempin, which is involved in ADPEAF. Age at onset ranged from 6 to 39 years (average 19 years). Secondarily generalized seizures were the most common type of seizures at onset (79%). Auditory auras occurred either in isolation (53%) or associated with visual, psychic or aphasic symptoms. Low seizure frequency at onset and good drug responsiveness were common, with 51% of patients seizure-free. Seizures tended to recur after drug withdrawal. Clinically, no major differences were found between S and F patients with respect to age at onset, seizure frequency and response to therapy. Analysis of LGI1/epitempin exons failed to disclose mutations. Our data support the existence of a peculiar form of non-lesional temporal lobe epilepsy closely related to ADPEAF but without a positive family history. This syndrome, here named IPEAF, has a benign course in the majority of patients and could be diagnosed by the presence of auditory aura. Although LGI1 mutations have been excluded, genetic factors may play an aetiopathogenetic role in at least some of these S cases.

Identification and characterization of a novel human brain-specific gene, homologous to S. scrofa tmp83.5, in the chromosome 10q24 critical region for temporal lobe epilepsy and spastic paraplegia

We describe the structure, genomic organization, and some transcription features of a human brain-specific gene previously localized to the genomic region involved in temporal lobe epilepsy and spastic paraplegia on chromosome 10q24. The gene, which consists of six exons disseminated over 16 kb of genomic DNA, is highly homologous to the porcine tmp83.5 gene and encodes a putative transmembrane protein of 141 amino acids. Unlike its porcine homolog, from which two mRNAs with different 5'-sequences are transcribed, the human gene apparently encodes three mRNA species with 3'-untranslated regions of different sizes. Mutation analysis of its coding sequence in families affected with temporal lobe epilepsy or spastic paraplegia linked to 10q24 do not support the involvement of this gene in either diseases.

Adolescent motor vehicle crashes: the relationship between behavioral factors and self-reported injury

PURPOSE

To examine the relative importance of demographic and behavioral factors, as well as alcohol use, in motor vehicle crash (MVC)-related injuries in an adolescent sample.

METHODS

Data were collected from two samples of adolescents. In Study 1, a total of 1576 9th through 12th graders from three different high schools provided information on risk-taking behavior and injuries experienced during the previous six months. Study 2 involved a more fine-grained analysis of behavioral factors related to MVC-related injuries. A sample of 573 adolescent males from an all-boys parochial high school completed questionnaires assessing risk-taking, attention and behavior problems, alcohol use, driving behavior, and self-reported injury.

RESULTS

Rates of self-reported MVC-related injuries for a 6-month period were consistent across the two studies, ranging from 10% in the mixed-gender sample to 16% in the all-male sample. Consistent with previous findings, males reported more frequent MVC-related injuries and higher rates of risk-taking behavior. In Study 1, age and risk-taking behaviors were predictive of injuries while riding or driving in a car. In the all-male sample, risk-taking behavior and conduct problems were significant predictors of MVC-related injuries.

CONCLUSIONS

Risk-taking is a consistent predictor of both general and MVC-related injuries. Intervention efforts with adolescents may be targeted at increasing safe driving strategies as well as decreasing risk-taking behaviors.

Autosomal dominant partial epilepsy with auditory features: description of a new family

PURPOSE

To report the clinical and genetic study of a new family with autosomal dominant partial epilepsy with auditory features (ADPEAF).

METHODS

All the living affected members underwent a full clinical, neurophysiological, and magnetic resonance imaging (MRI) study. Genetic analysis was performed by typing their DNA with seven microsatellite markers previously found to cosegregate with ADPEAF on chromosome 10q24.

RESULTS

The three living affected members had a childhood onset of rare and drug-responsive tonic-clonic seizures constantly preceded by a humming sensation. Routine and sleep electroencephalograms revealed rare and inconstant focal abnormalities over both temporal regions. MRI detected atrophy with increased T2 signal in the subcortical lateral portion of the right temporal lobe in one case. Analysis of 10q24 polymorphic alleles showed the same haplotype in all three affected members but different alleles in unaffected individuals.

CONCLUSIONS

ADPEAF is a distinct condition with homogeneous clinical features. Genetic findings are consistent with linkage of ADPEAF to chromosome 10q24.

Parental and self-report of sleep in children with attention-deficit/hyperactivity disorder

OBJECTIVE

To determine the prevalence of parent-reported and self-reported sleep disturbances in a sample of school-aged children with attention-deficit/ hyperactivity disorder (ADHD).

DESIGN

Cross-sectional survey questionnaire.

SETTING

A multidisciplinary ADHD evaluation clinic in a children's teaching hospital (ADHD sample) and 3 elementary schools in southern New England (control sample).

PARTICIPANTS

Forty-six unmedicated, school-aged children (mean age, 89.4 +/- 18.7 months; 74% male) diagnosed as having ADHD by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria who had been screened for marked symptoms of sleep-disordered breathing, and 46 normal control children (mean age, 86.5 +/- 16.9 months; 70% male).

INTERVENTION

None.

MAIN OUTCOME MEASURE

Sleep habits and sleep disturbances reported by parents and children.

RESULTS

Children with ADHD had significantly higher (more sleep-disturbed) scores on all sleep subscales of the Children's Sleep Habits Questionnaire (parent measure) than did controls; average sleep duration as reported by parents was also significantly shorter in the ADHD group. Children with ADHD also reported their own sleep to be more disturbed than controls did on the Sleep Self-report, particularly on items relating to bedtime struggles (P range, .05-.001). There was a much higher correlation between parent and child sleep report items for the children with ADHD (mean correlation, 0.55) than for the control children.

CONCLUSIONS

Sleep disturbances, particularly at bedtime, are frequently reported by both parents and children with ADHD. Children undergoing evaluation for ADHD should be routinely screened for sleep disturbances, especially symptoms of sleep-disordered breathing. The causes of sleep-onset delay in children with ADHD should be considered in designing intervention strategies for children with difficulty falling and staying asleep.

Sleep habits and sleep disturbance in elementary school-aged children

Relatively little is known about sleep habits, sleep disturbances, and the consequences of disordered sleep in school-aged children. This descriptive study examined a variety of common sleep behaviors in a group of 494 elementary school children, grades kindergarten through fourth, using a battery of sleep questionnaires that included parent, teacher, and self-report surveys. The prevalence of parent-defined sleep problems ranged from 3.7% (Sleep-Disordered Breathing) to 15.1% (Bedtime Resistance), with 37% of the overall sample described as having significant sleep problems in at least one sleep domain. Younger children were more likely than older children to have sleep problems noted by parents (particularly bedtime struggles and night wakings), as well as by teacher and self-report. Children tended to identify more sleep problems by self-report, particularly sleep-onset delay and night wakings, than did their parents. Overall, approximately 10% of the sample was identified by all three measures as having significant problems with daytime sleepiness. The results of this study emphasize the importance of screening for sleep disorders in this age group in the clinical setting. The need for consensus regarding the use of sleep screening instruments and the definition of "problem" sleep in school-aged children is also discussed.

Expression analysis of 21 transcripts physically anchored within the chromosomal region 10q24

Chromosome band 10q24 harbors the critical regions for inherited neurological disorders such as partial epilepsy (EPT), urofacial syndrome, and a distinct form of spastic paraparesis. To facilitate the selection of candidate genes for these diseases, we determined the mRNA sizes and analyzed the expression patterns of 21 brain transcripts defined by expressed sequence tags previously localized along a 7.4-Mb interval of 10q24. In addition to a number of widely expressed transcribed sequences, we identified several transcripts exclusively or predominantly expressed in the brain, which represent potential candidates for the neurological diseases associated with this genomic region.

Television-viewing habits and sleep disturbance in school children

OBJECTIVE

To investigate the relationship between specific television-viewing habits and both sleep habits and sleep disturbances in school children.

METHODS

The parents of 495 children in grades kindergarten through fourth grade in three public elementary schools completed two retrospective survey questionnaires, one assessing their children's sleep behaviors and the other examining television-viewing habits of both the child and the family. Sleep domains assessed included bedtime resistance, sleep onset delay, sleep duration, anxiety around sleep, parasomnias, night wakings, and daytime sleepiness. Teachers from all three schools also completed daytime sleepiness questionnaires (N = 402) for the sample.

RESULTS

Most of the television-viewing practices examined in this study were associated with at least one type of sleep disturbance. Despite overall close monitoring of television-viewing habits, one quarter of the parents reported the presence of a television set in the child's bedroom. The television-viewing habits associated most significantly with sleep disturbance were increased daily television viewing amounts and increased television viewing at bedtime, especially in the context of having a television set in the child's bedroom. The sleep domains that appeared to be affected most consistently by television were bedtime resistance, sleep onset delay, and anxiety around sleep, followed by shortened sleep duration. The parent's threshold for defining "problem sleep behavior" in their child was also important in determining the significance of the association between sleep disturbance and television-viewing habits.

CONCLUSION

Health care practitioners should be aware of the potential negative impact of television viewing at bedtime. Parents should be questioned about their children's television-viewing habits as part of general screening for sleep disturbances and as part of anticipatory guidance in regards to healthy sleep habits in children. In particular, the presence of a television set in the child's bedroom may be a relatively underrecognized, but important, contributor to sleep problems in school children.

Sleep and daytime behavior in children with obstructive sleep apnea and behavioral sleep disorders

OBJECTIVE

The purpose of this study was: 1) to examine both bedtime sleep behaviors and daytime behaviors associated with daytime sleepiness in a group of children with a primary medical sleep disorder (obstructive sleep apnea syndrome [OSAS]) compared with a group of children with a primary behavioral sleep disorder (BSD) (limit setting sleep disorder or sleep onset association disorder); and 2) to investigate the impact of a comorbid BSD on sleep and daytime behavioral consequences of OSAS.

METHODS

Children referred to a pediatric sleep disorders clinic during a 3-year period with a primary diagnosis of either polysomnographically-confirmed OSAS (n = 100) or a BSD (n = 52) were compared on several parent report measures assessing the following domains: symptoms of sleep disordered breathing, other sleep behaviors (primarily parasomnias), bedtime behaviors, and externalizing daytime behavior problems. The OSAS sample was then divided into a pure OSAS group (n = 78) and an OSAS plus a behavioral sleep diagnosis group (n = 22) based on the presence or absence of delayed sleep onset and/or prolonged nightwakings and compared on the parent-report symptom domains.

RESULTS

Almost one-quarter of the OSAS group had clinically significant behavioral sleep problems, primarily bedtime resistance, in addition to OSAS. Bedtime resistance was associated with a significantly shortened sleep duration in both the BSD and OSAS-BSD groups. Although the OSAS-BSD group had less severe disease, as defined by polysomnographic variables, than the pure OSAS group, they were rated by their parents as having more daytime externalizing behavior problems associated with daytime sleepiness.

CONCLUSIONS

The results of this study suggest that evaluation for comorbid BSD should be done in all children presenting with symptoms of OSAS. The coexistence of such BSDs may contribute significantly to sleep deprivation, and thus to behavioral manifestations of daytime sleepiness in these children.

Incidence of parasomnias in children with obstructive sleep apnea

The incidence of parent-reported parasomnias in children with obstructive sleep apnea (OSA) is increased in comparison with a normative age-matched sample of children but is not higher than that for a similar clinical sample of children with a diagnosed behavioral sleep disorder.

Exon-intron organization of the human dystrophin gene

Analysis of the exon-intron organization of the human dystrophin gene has been hampered by its enormous size. By using a YAC-based exon mapping approach and long PCR, we have succeeded in defining the size of the gene and its organization. Our results, compared with data on the distribution of deletion breakpoints by intron, elucidate the topography of the intragenic deletion-prone regions. Within the central high-frequency deletion region, the small, 6.6-kb, intron 49 shows a much higher density of deletion breakpoints than intron 44, which was previously believed to coincide with the most mutable zone of the gene. On the other hand, in the proximal part of the gene, deletion breakpoints do not preferentially occur in a few introns, but are spread over a large DNA segment containing introns 2 to 42.

Detailed physical analysis of a 1.5-megabase YAC contig containing the MXI1 and ADRA2A genes

The distal long arm of chromosome 10 harbors genes of biomedical interest such as MXI1, a putative tumor suppressor gene, and those encoding the adrenergic receptors alpha2A (ADRA2A) and beta1 (ADRB1). As part of a physical and genetic study of this genomic region, we constructed a 1.5-Mb YAC contig mapping to 10q25 that contains MXI1 and ADRA2A as well as a number of STSs. Rare cutting restriction site analysis of overlapping YACs allowed fine mapping of these genes and markers along the contig and revealed the presence of four CpG islands. MXI1 and ADRA2A appear to be about 600 kb apart, whereas ADRB1 is separated from ADRA2A by a distance larger than previously reported.

An integrated physical and genetic map spanning chromosome band 10q24

Chromosome band 10q24 is rich in genes involved in development, tumorigenesis, neurological disorders, hormone metabolism, and environmentally induced disease susceptibility. We have constructed an STS-based integrated physical and genetic map of 10q24 derived from the CEPH-Généthon mega-YAC contig data for this region. This map consists of 42 fluorescence in situ hybridization-mapped overlapping CEPH mega-YACs spanning approximately 15 Mb to which 49 STS markers have been assigned, including 24 Généthon CA repeat genetic markers, 10 known gene loci from the 10q24 region (IFI56, IDE, PDE6C, RBP4, CYP2C, CD39, DNTT, GOT1, WNT8B, and PAX2) and 11 additional expressed sequences of unknown function.

A 2.4-megabase physical map spanning the CYP2C gene cluster on chromosome 10q24

The CYP2C gene cluster on chromosome 10q24 encodes the P450IIC enzymes, members of the cytochrome P450 monooxygenase superfamily. The P450-IIC enzymes are required for the metabolism of a number of foreign compounds, including the drugs mephenytoin and tolbutamide, and are also thought to be involved in the metabolism of endogenous steroid hormones. Several different CYP2C cDNA clones have been isolated; however, the exact number of genes and the genomic arrangement of the CYP2C cluster have remained unknown. Using a combination of STS and restriction mapping to characterize YAC clones, we have constructed a 2.4-Mb physical map that incorporates the CYP2C gene cluster. The cluster spans approximately 500 kb on proximal 10q24 and comprises four genes arranged in the order CYP2C8-CYP2C9-CYP2C19-CYP2C18. The map also includes an adjacent gene, the serum retinol binding protein gene (RBP4). The incorporation of Généthon CA repeat genetic markers suggests the orientation of the loci to be Cen-RBP4-CYP2C18-CYP2C19-CYP2C9-CYP2C8-Tel .

Genomic organization of the human dystrophin gene across the major deletion hot spot and the 3' region

The genomic organization of most of the human dystrophin gene has not been defined at single-exon level, owing to its enormous size (2300 kb). By taking advantage of a YAC-based restriction map of the gene previously constructed, we have localized individual dystrophin exons from 42 to 79 along the central and 3' regions of the gene. These data elucidate the general organization of this large portion of the gene (1250 kb) and, in particular, characterize the genomic region most frequently involved in deletion mutations responsible for Duchenne and Becker muscular dystrophies.

A refined restriction map of YAC clones spanning the entire human dystrophin gene

The enormous size of the human dystrophin gene (2300 kb) has so far hindered the analysis of its organization and the characterization at the genomic level of the deletion and duplication mutations causing Duchenne or Becker muscular dystrophy. A detailed physical map of the gene locus would considerably simplify these studies. We constructed a refined, long-range restriction map of the entire human dystrophin gene, using 12 overlapping YAC clones as DNA sources. The sites for six rare cutting enzymes (SfiI, NruI, EagI, BssHII, SacII, and NotI) were mapped by partial digest analysis of YACs over a region of 2600 kb, within a level of resolution of about 10 kb. Such a map provides the first detailed representation of the physical structure of the dystrophin gene. It will be useful for mapping unlocalized exons and, eventually, for the characterization of deletions and duplications leading to disease.

Concurrent mapping of an adenovirus 5/SV40 integration site and the U1 snRNA cluster (RNU1) within 400 kb of the chromosome region 1p36.1

Previous reports from our group suggested the preferential integration of the viral construct Ad5/SV40 at the short arm subtelomeric region of human chromosome 1. The present study narrows the region of viral integration to site 1p36.1 in a close cytogenetic overlap with the U1 snRNA gene cluster (RNU1) within a distance necessarily smaller than 400 kb as suggested by the size of the YAC in which the two markers were found to coexist. This finding supports the hypothesis that the chromosomal site in question may have a constitutional propensity to genetic recombination.

An improved method for partial restriction digestion of ultraviolet irradiated DNA

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Molecular analysis of the Rett syndrome using cDNA synapsin I as a probe

A cDNA encoding for rat synapsin I, a neuron-specific protein localized on the cytoplasmic surface of synaptic vesicles and probably involved in the regulation of neurotransmitter release from nerve terminals, has been used to map the human gene to the short arm of the X chromosome. We have screened, using this cDNA, the DNAs of six unrelated girls with the Rett Syndrome (RS) to test the hypothesis that mutations of the human synapsin I gene might cause RS. We found no alterations at the synapsin I (Syn I) locus in the vicinity of the probe sequence.

Partial digestion with restriction enzymes of ultraviolet-irradiated human genomic DNA: a method for identifying restriction site polymorphisms

A method for partial digestion of total human DNA with restriction enzymes has been developed on the basis of a principle already utilized by P.A. Whittaker and E. Southern (1986, Gene 41: 129-134) for the analysis of phage lambda recombinants. Total human DNA irradiated with uv light of 254 nm is partially digested by restriction enzymes that recognize sequences containing adjacent thymidines because of TT dimer formation. The products resulting from partial digestion of specific genomic regions are detected in Southern blots by genomic-unique DNA probes with high reproducibility. This procedure is rapid and simple to perform because the same conditions of uv irradiation are used for different enzymes and probes. It is shown that restriction site polymorphisms occurring in the genomic regions analyzed are recognized by the "allelic" partial digest patterns they determine.

Nucleosome phasing on a DNA fragment from the replication origin of simian virus 40 and rephasing upon cruciform formation of the DNA

Nucleosomes were reconstituted in vitro from a fragment of DNA spanning the simian virus 40 minimal replication origin. The fragment contains a 27-base-pair palindrome (perfect inverted repeat). DNA molecules with stable cruciform structures were generated by heteroduplexing this DNA fragment with mutants altered within the palindromic sequence (C. Nobile and R. G. Martin, Int. Virol., in press). Analyses of the structural features of the reconstituted nucleosomes by the DNase I footprint technique revealed two alternative DNA-histone arrangements, each one accurately phased with respect to the uniquely labeled DNA ends. As linear double-stranded DNA, a unique core particle was formed in which the histones strongly protected the regions to both sides of the palindrome. The cruciform structure seemed to be unable to associate with core histones and, therefore, an alternative phasing of the histone octamer along the DNA resulted. Thus, nucleosome positioning along a specific DNA sequence appears to be influenced in vitro by the secondary structure (linear or cruciform) of the 27-base-pair palindrome. The formation of cruciform structures in vivo, if they occur, might therefore represent a molecular mechanism by which nucleosomes are phased.

Analysis of deletions in DNA from patients with Becker and Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder for which the biochemical defect is as yet unknown. Recently, two cloned segments of human X-chromosome DNA have been described which detect structural alterations within or near the genetic locus responsible for the disorder. Both of these cloned segments were described as tightly linked to the locus and were capable of detecting deletions in the DNA of boys affected with DMD. In an attempt to determine more precisely the occurrence of these deletions within a large population of DMD patients and the accuracy of one of the segments, DXS164 (pERT87), in determining the inheritance of the DMD X chromosome, the subclones 1, 8 and 15 were made available to many investigators throughout the world. Here we describe the combined results of more than 20 research laboratories with respect to the occurrence of deletions at the DXS164 locus in DNA samples isolated from patients with DMD and Becker muscular dystrophy (BMD). The results indicate that the DXS164 locus apparently recombines with DMD 5% of the time, but is probably located between independent sites of mutation which yield DMD. The breakpoints of some deletions are delineated within the DXS164 locus, and it is evident that the deletions at the DMD locus are frequent and extremely large.

Stable stem-loop and cruciform DNA structures: isolation of mutants with rearrangements of the palindromic sequence at the simian virus 40 replication origin

With the objective of generating DNA molecules that form stable stem-loop structures or cruciform structures in solution, we have altered the palindromic sequence at the Simian Virus 40 (SV40) replication origin. These alterations include: deletion of 18 of the 27 base pairs (bp) in the 13-bp inverted repeat; deletion of 26 of the 27 bp; substitution of the entire 27 bp with a totally different 26-bp sequence containing a 13-bp inverted repeat; and substitution of the 27 bp with an 8-bp sequence containing a 4-bp inverted repeat. The DNA from these mutants was purified. Mutant DNAs were hybridized to wild-type SV40 DNA or to each other, and the heteroduplexes were purified. The predicted structures were verified by S1 and restriction endonuclease digestion. The mutants - the heteroduplexes have not been tested - are capable of complementing tsA mutants and/or transforming mouse cells.