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We examine the dynamics and the statistical mechanics of a nonlinear diatomic model for a solid which may undergo a displacive structural phase transition. In addition to the familiar linear (phonon) oscillations, nonlinear (kink soliton) vibrations are found which behave as elementary excitations of the system. The nonlinear kinks give rise to a central peak in the dynamical structure factor. The analytic results obtained are supported by constant temperature molecular dynamics simulations of the lattice.

1. The principles applied in gastroenterostomy may be applied to a simplified gastric resection. 2. The simple gastroenterostomy anastomosis makes gastric surgery a safe procedure for it is necessary for one to learn only one simplified procedure. 3. Repeated performance of one simple standard procedure makes for perfection of technique and fewer complications, resulting in a very low morbidity and mortality.

1.1. A patient with atresia of the left atrioventricular valve associated with a corrected transposition of the great vessels is presented. The pathological and hemodynamic findings are discussed. 2.2. This lesion produces pulmonary hypertension equal to systemic systolic pressure and a right-to-left shunt. It is considered to be a previously unreported cause of the Eisenmenger syndrome.

Summary Constitutional mutations of the WT1 gene, encoding a zinc-finger transcription factor involved in renal and gonadal development, are found in most patients with Denys-Drash syndrome (DDS), or diffuse mesangial sclerosis (DMS) associated with pseudohermaphroditism and/or Wilms tumor (WT). Most mutations in DDS patients lie in exon 8 or exon 9, encoding zinc finger 2 or zinc finger 3, respectively, with a hot spot (R394W) in exon 9. We analyzed a series of 24 patients, 10 with isolated DMS (IDMS), 10 with DDS, and 4 with urogenital abnormalities and/or WT. We report WT1 heterozygous mutations in 16 patients, 4 of whom presented with IDMS. One male and two female IDMS patients with WT1 mutations underwent normal puberty. Two mutations associated with IDMS are different from those described in DDS patients. No WT1 mutations were detected in the six other IDMS patients, suggesting genetic heterogeneity of this disease. We analyzed genotype/phenotype correlations, on the basis of the constitution of a WT1 mutation database of 84 germ-line mutations, to compare the distribution and type of mutations, according to the different symptoms. This demonstrated (1) the association between mutations in exons 8 and 9 and DMS; (2) among patients with DMS, a higher frequency of exon 8 mutations among 46,XY patients with female phenotype than among 46,XY patients with sexual ambiguity or male phenotype; and (3) statistically significant evidence that mutations in exons 8 and 9 preferentially affect amino acids with different functions.

We have compared the constitutional and tumor genotypes in two patients with Wilms tumor and adrenocortical carcinoma. The allelic distribution of chromosome 11-specific markers spanning chromosome 11 from pter to qter (HRAS1-HBB-[CALCA/PTH]-FSHB-CAT-APOAl) and an approach combining RFLP analysis and gene copy number determination showed that a mitotic deletion had occurred in both tumors. The loss of one copy of the gene for α-calcitonin-gene-related poly peptide (CALCA), together with that of a more distal marker (HRASl or HBB), indicates that CALCA is distal to the gene for parathyroid hormone (PTH), which was not deleted in either tumor. These results suggest that mitotic deletion mapping may be as useful as meiotic deletion or recombination mapping in ordering closely linked markers, such as CALCA and PTH, for which other approaches, including physical mapping and multipoint linkage analysis, have failed to accurately identify the gene order.

The description of the electronic states of an atom or ion with one electron within a plasma is based on an electrostatic model where the complete inclusion of the plasma energy is possible. The resulting polarisation shift agrees with experiments better than other models. Consequences for the Inglis-Teller effect and drowning of levels are discussed.

Type XI collagen is a minor and poorly characterized structural component of cartilage. Recently, cDNA and genomic clones coding for the pro alpha 1 chain of human Type XI collagen, formerly 1 alpha collagen, have been isolated and fully characterized. Here we have used one such probe to establish the chromosomal localization of the pro alpha 1 (XI) collagen gene (COL11A1) by hybridization to filter-bound DNA isolated from flow-sorted chromosomes and by in situ hybridization on metaphase chromosomes. This combination of approaches has enabled us to locate COL1A11 in the p21 region of chromosome 1. This represents the first mapping of a Type XI collagen gene and the first assignment of a collagen locus to chromosome 1. These studies also provide additional evidence for the nearly uniform dispersion of the human fibrillar collagen genes in the human genome.

To define more precisely, in molecular terms, the region involved in Beckwith-Wiedemann syndrome (BWS), we have studied patients with BWS and a constitutional duplication of 11p15 using eight 11p15 markers. In the first case with a de novo duplication and extra material on 11p, the region spanning pter to CALCA, excluded, was duplicated. In the second case, the rearrangement was characterized using somatic cell hybrids established with lymphocytes from the father who carried a balanced translocation t(11;18)(p15.4;p11.1). The breakpoint lay exactly in the same region. It could thus be inferred that the two sons, who were the first cases reported of BWS with dup11p15 and adrenocortical carcinoma (ADCC), carried a duplication similar to that observed in the first case. Together with evidence for specific somatic chromosomal events leading to loss of 11p15 alleles in familial cases of ADCC, it can be hypothesized that a gene involved in predisposition to ADCC maps to region 11p15.5.

We have compared constitutional and tumor genotypes in nine cases of hereditary Wilms tumor (WT) and in three unrelated cases of familial adrenocortical carcinoma (ADCC). Since susceptibility to these tumors can be observed in malformation syndromes associated with a constitutional deletion of band 11p13 (WT) and with a constitutional duplication of band 11p15.5 (WT, ADCC), we investigated these two candidate regions by using 11p polymorphic markers. As expected, somatic chromosomal events, resulting in a loss of heterozygosity limited to region 11p15.5, were observed in the tumor of two familial cases of adrenocortical carcinoma. Surprisingly, however, analysis of the WT of two patients with a constitutional deletion of band 11p13, associated with aniridia, genitourinary abnormalities, and mental retardation (WAGR syndrome), revealed a loss of heterozygosity limited to region 11p15.5. These data therefore suggest that observation of a specific loss of heterozygosity may not necessarily point to the site of the initial germinal mutation. Together with previous similar observations of a loss of heterozygosity limited to 11p15.5 in breast cancer and in rhabdomyosarcoma, our data suggest that region 11p15.5 may carry a non-tissue-specific gene that could be involved in genetic predisposition, in tumor progression, or in both.

A cytogenetic study performed on 6 human renal cell carcinomas after short-term culture on extracellular matrix with serum-free medium showed aneuploidy without structural changes in 2 tumors and a rearrangement of the short arm of chromosome 3 in 4 tumors, including deletions and a translocation involving the 3p14 and 3p21 bands. Chromosomal in situ hybridization with a c-raf 1 probe demonstrated that in 2 renal cancers with del3(p14 or 21) the cellular oncogene had shifted from 3p25 to 3p14 as a result of an interstitial deletion.

A few cases of Beckwith-Wiedemann syndrome (BWS) have in common a duplication of 11p15. Among the genes located in 11p15, c-Ha-ras 1 (HRAS1), insulin (INS), and insulin-like growth factor II (IGF2) may account for the clinical features and the increased risk for malignancy. Using eight 11p15 markers including HRAS1, INS and IGF2 we have studied eight sporadic and hereditary cases of BWS whether or not associated with a nephroblastoma. By gene dosage determination and family studies, we have shown the following: the eight patients examined had an apparent diploid representation of all of the eight markers studied, thus indicating that a microduplication of these markers or of the region characterized by these markers is not a common event in BWS; in a family with three affected sibs the genes for HRAS1 and INS/IGF2 did not cosegregate with BWS and therefore may not participate in the pathogenic processes here observed.

Summary We used a cloned cDNA probe for the B subunit of human aldolase (ALDB) and Southern blotting techniques to analyse DNA from a series of rodent x human somatic cell hybrids for the presence of specific ALDB-related sequences. Our results provide evidence for the assignment of the gene for ALDB to chromosome 9. Moreover, by direct gene dosage determination in two patients with chromosome 9 unbalanced rearrangements and by in situ hybridization we refined the regional chromosomal assignment to 9q13q32 and most probably to 9q21.39q22.2.

A cytogenetic study performed on 6 human renal cell carcinomas after short-term culture on extracellular matrix with serum-free medium showed aneuploidy without structural changes in 2 tumors and a rearrangement of the short arm of chromosome 3 in 4 tumors, including deletions and a translocation involving the 3p14 and 3p21 bands. Chromosomal in situ hybridization with a c-raf 1 probe demonstrated that in 2 renal cancers with del3(p14 or 21) the cellular oncogene had shifted from 3p25 to 3p14 as a result of an interstitial deletion.

A 1.1-kb cDNA clone for human 2,3-bisphosphoglycerate mutase (BPGM) (EC 2.7.5.4) was used to map the structural gene to metaphase chromosomes. In situ hybridization experiments localized the human BPGM gene to chromosome 7 and, more precisely, to region 7q34----7q22.

We have used a cDNA clone for Chinese hamster 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase to isolate a genomic recombinant for human HMG-CoA reductase. The identity of the gene was confirmed by partial sequence analysis. Several unique fragments that will be useful for restriction fragment length polymorphism (RFLP) studies were identified. In situ hybridisation of a 2.6 kb unique fragment of the gene to human metaphase chromosomes localised the human HMGCoA reductase gene to human chromosome 5q12.

Summary We have used a eDNA clone for human lecithin: cholesterol acyl transferase (LCAT) and Southern blotting techniques to identify the human LCAT gene in DNA from a series of rodent x human somatic cell hybrids. Our results are compatible with the location of the gene on human chromosome 16, and this has been confirmed using in situ hybridization of the LCAT eDNA to human metaphase chromosomes. These results confirm the earlier studies on LCAT-deficient patients, indicating that the structural gene for LCAT is on human chromosome 16g22.

SEVERAL developments suggest the possibility of a new means of assessing the exposure of human populations to chemical carcinogens. Carcinogens such as 2-acetylaminofluorene (AAF) and p–dimethylaminoazobenzene (DAB) have been shown1–4 not to be carcinogenically active agents themselves, but to be converted into such agents by metabolic processes in the target organs (in these instances, liver). These studies also show that actively carcinogenic metabolites (as well as other metabolic products which are not carcinogenic) may be excreted in the urine, apparently as glucuronides4,5. Similar results have been obtained with human subjects ingesting aflatoxin B1 from contaminated peanut butter6.

A recombinant probe specific for the pro alpha 2 chain of human Type V collagen has been used for the localization of the corresponding gene (COL5A2) to chromosome 2. Regional mapping by in situ hybridization and analysis of DNA from human X rodent cell lines indicated that COL5A2 is confined within the segment 2q14----2q32, thus syntenic to the pro alpha 1 (III) collagen gene (COL3A1).

The short arm of chromosome 11 carries genes involved in malformation syndromes, including the aniridia/genitourinary abnormalities/mental retardation (WAGR) syndrome and the Beckwith-Wiedemann syndrome, both of which are associated with an increased risk of childhood malignancy. Evidence comes from constitutional chromosomal aberrations and from losses of heterozygosity, limited to tumor cells, involving regions 11p13 and 11p15. In order to map the genes involved more precisely, we have fused a mouse cell line with cell lines from patients with constitutional deletions or translocations. Characterization of somatic cell hybrids with 11p-specific DNA markers has allowed us to subdivide the short arm into 11 subregions, 7 of which belong to band 11p13. We have thus defined the smallest region of overlap for the Wilms' tumor locus bracketed by the closest proximal and distal breakpoints in two of these hybrids. The region associated with the Beckwith-Wiedemann syndrome spans the region flanked by two 11p15.5 markers, HRAS1 and HBB. These hybrids also represent useful tools for mapping new markers to this region of the human genome.

Electron spin resonance (ESR) studies at 8 G modulation of X-ray irradiated biological tissue have revealed a narrow absorption signal in radiation sensitive tissues which rises sharply at the onset of X-ray irradiation and decays rapidly after the termination of X-ray irradiation (Kenny, P. and Commoner, B. (1969) Nature 223, 1229–1233). This absorption is attributed to the ascorbic acid radical after examination of ESR spectra obtained at 1 G modulation. The observation of the ascorbic acid radical is associated with radiation sensitive tissues such as normal testis and thymus as well as tumorous liver but not with radiation-resistant normal liver.

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Here we report Wilms' tumor, gonadal dysgenesis and a bifid uterus in an 18-month-old female with a terminal deletion of the long arm of chromosome 2 [46, XX, del(2)(q37.1)]. Since Wilms' tumor has been previously reported in the 2q37 deletion syndrome, the present observation raises the question of whether a tumor susceptibility gene maps to chromosome 2q37 and suggests giving consideration to the possible occurrence of Wilms' tumor in the course of disease.

We investigate the dynamics and the statistical mechanics of a nonlinear diatomic model for a solid which may undergo a displacive structural phase transition (DSPT), using the molecular dynamics (MD) technique. Snapshots of the lattice displacement pattern reveal the presence of kinks at low temperatures. MD collision experiments show that the kinks exhibit soliton-like behaviour. Phonon wave packets are observed to pass through kinks and kinks and anti-kinks interact with one another with little distortion. The MD data are used to calculate the dynamical structure factor for the displacement fields in the diatomic chain. The dynamical structure factor is found to exhibit a central peak when the lattice displacement pattern is dominated by kinks. At small but finite wave vectors the central peak splits producing a new excitation branch in addition to the usual soft-mode phonon side-band. The central peak does not arise from self-consistent phonons but is dependent on the presence of kinks. The height of the peak increases and the width of the peak decreases as the temperature goes to zero.

We examine nonlinear lattice excitations in a model for a solid which may undergo a displacive structural phase transition. In particular, we investigate the field equations for a diatomic chain of atoms including nonlinear potentials on one species. We identify three classes of excitations in this model. These are linearized phonons, large amplitude solitary waves, and nonlinear phonons. Interactions between the linear phonons and the nonlinear modes give rise to a translation mode which is a further solution of the field equations. The linear and nonlinear phonons are also direct solutions of the discrete equations of motion. However, using the molecular dynamics technique we find that kink-type configurations occur for a much larger parameter space in the discrete lattice than they do in the continuum description. All the stable excitations of the field equations should be included in a formal description (e.g. statistical mechanics) of the model.

We compute the free energy density of a nonlinear diatomic model for a solid which may undergo a displacive structural phase transition using (i) a two-component transfer integral operator equation and (ii) an ideal gas phenomenology incorporating the stable solutions of the coupled Euler-Lagrange equations as elementary excitations. The agreement between the two calculations formally establishes that the low temperature excitation spectrum is dominated by both the familiar linearized phonon solutions and by nonlinear domain wall or kink soliton solutions. The ideal gas phenomenology is then used to compute the kink density, order parameter correlation functions, and the kink contribution to the dynamical structure factor. The dynamical structure factor is found to exhibit a central peak.