Outcome of surgery for a symptomatic herniated thoracic disc in relation to preoperative characteristics of the disc

BACKGROUND

This report presents general information on herniated thoracic discs, their clinical manifestations as well as surgical treatment, and examines the differences in the surgical outcome based on disc characteristics.

METHODS

This study includes 33 thoracic discectomies in 29 patients with a ventrally situated herniated thoracic disc reaching to the thoracic cord. Using preoperative computed tomography scanning and magnetic resonance imaging, the direction of the disc was classified as either central or lateral, and disc consistency classified as either soft or hard. Clinical outcome was assessed according to the Japanese Orthopedic Association (JOA) Score for thoracic myelopathy. The score was obtained by analysing motor, sensory and bladder function. Recovery rate was assessed, comparing preoperative and postoperative status based on disc characteristics. The correlations between outcome, symptom duration and recovery rate were also investigated.

FINDINGS

Clinical outcome according to the JOA Score showed significant postoperative improvement, increasing from 7.0 +/- 3.1 points to 8.2 +/- 2.7 points postoperatively (p < 0.01). The mean recovery rate was 12.4 +/- 56.9%, and 16 patients (55.2%) showed improvement. In the soft disc group, there was improvement in all categories, but the hard disc group showed no improvement. The central disc group showed improvement in sensory function, but the lateral disc group showed little improvement. Regression analysis revealed a statistically significant correlation between the preoperative and postoperative score, symptom duration and recovery rate.

CONCLUSIONS

Clinical outcome after surgery of a herniated thoracic disc proved successful, especially when the disc was considered to have a soft consistency. In order to decide the optimal surgical strategy and prospective surgical outcome, disc characteristics, including consistency and direction of prolapse should be considered preoperatively.

Cervical arthroplasty in a patient with Klippel-Feil syndrome

This is the first published report of a patient with Klippel-Feil syndrome treated with cervical arthroplasty. A 36-year-old man presented with posterior neck pain and myelopathic symptoms. A radiograph demonstrated congenital fusion of the vertebral bodies at C2-3, C4-5 and C5-6. On MRI, the spinal cord was compressed by a protruding cervical disc and bony spurs at C6-7. After anterior discectomy and decompression of the spinal cord at the C6-7 level, the disc was replaced with the Bryan cervical disc system (Medtronic Sofamor Danek, Memphis, TN, USA) to restore normal motion. The absence of adjacent segment degeneration and the preservation of cervical motion were noted 2 years after surgery. Arthroplasty may be performed in selected patients with Klippel-Feil syndrome in order to restore motion and to prevent degeneration of the adjacent segment by reducing hypermobility.

Novel quantum phases of dipolar bose gases in optical lattices

We investigate the quantum phases of polarized dipolar bosons loaded into a two-dimensional square and three-dimensional cubic optical lattices. We show that the long-range and anisotropic nature of the dipole-dipole interaction induces a rich variety of quantum phases, including the supersolid and striped supersolid phases in two-dimensional lattices, and the layered supersolid phase in three-dimensional lattices.

Irinotecan monotherapy as second-line treatment in advanced pancreatic cancer

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Background: The aim of this phase II study was to determine whether second line therapy with single agent irinotecan could provide any clinical benefit in patients with gemcitabine- pretreated advanced pancreatic cancer. Methods: From January 2004 to October 2006, patients with advanced pancreatic cancer previously treated with gemcitabine alone or combination were treated with single agent irinotecan(150 mg/m2, biweekly), until unacceptable toxicity or disease progression. Primary endpoint was response rate with single stage design. Results: Twenty-eight patients were enrolled(22 male, 6 female, median age : 54.5 years (39–76)). Nine patients are still alive and 3 remain on therapy with stable disease. The median number of cycles was 3.5(1–12). Twenty-four patients were assessable for toxicity and 21 for response. The most common toxicities was diarrhea (grade 3, 12.5%). Grade 3 neutropenia in 1 patient was observed. Other hematological and non-hematological toxicities were mild and manageable. Partial responses were observed in 3 patients (3/21, 14%). An additional 9 patients (9/21, 43%) had stable disease as their best response. 12 patients have progressed with a median time-to-progression of 4.0 months. Conclusions: Single-agent irinotecan was tolerated with manageable toxicity, offering encouraging activity as second-line treatment of patients with advanced pancreatic cancer, refractory to gemcitabine.

No significant financial relationships to disclose.

Androgen activates PEG10 to promote carcinogenesis in hepatic cancer cells

The molecular mechanism of striking higher prevalence of hepatocellular carcinoma (HCC) in male subjects has not yet been fully elucidated. Here, we report that androgen receptor (AR) is differentially expressed in different HCC cell lines. AR agonist dihydrotestosterone (DHT) enhances HCC cell growth and apoptotic resistance. Antagonist flutamide (FLU) blocks the effects of DHT on the HCC cell lines. Paternally expressed gene 10 (PEG10) is expressed in HCC cell lines at substantial high level. Using small interfering RNAs against AR and PEG10 in AR- and PEG10-expressing BEL-7404 hepatoma cells and HuH7 hepatoma cells (HuH7) cells, and AR-transfection technique in AR-lacking and PEG10-expressing HepG2 cells, we have confirmed that through upregulation and activation of PEG10, DHT enhances HCC cell growth and apoptotic resistance. We have further demonstrated that DHT upregulates expression of human telomerase reverse transcriptase (hTERT) in HCC cell lines in a PEG10-dependent manner. Moreover, AR directly interacts in vivo with androgen-responsive elements in the regions of promoter and exon 2 of PEG10 gene in HCC cell lines. DHT promotes the hepatoma formation in vivo nude mice through PEG10 activation. AR antagonists (FLU and valproate) inhibit the hepatoma formation. These findings suggest that PEG10 plays an essential role in hepatocarcinogenesis. The PEG10 inhibition can be a novel approach for therapy of HCC.

Ikaros is a mutational target for lymphomagenesis in Mlh1-deficient mice

Deficiencies in DNA mismatch repair (MMR) result in replication errors within key tumor suppressor genes or oncogenes, and cause hereditary nonpolyposis colorectal cancer (HNPCC). Hematological malignancy with microsatellite instability is also associated with defective MMR, but little is known about the target genes for MMR. Here we identified Ikaros, a master transcription factor of lymphoid lineage commitment and differentiation, as a mutational target in spontaneous and radiation-induced T-cell lymphomas in Mlh1-deficient mice. Three quarters of lymphomas lacked Ikaros protein expression, which resulted from a frameshift mutation that created a stop codon. Mononucleotide repeat sequences at 1029-1034(C)6 and 1567-1572(G)6 in Ikaros were mutational hot spots with a one-base deletion occurring with a frequency of 45 and 50%, respectively. Point mutations and splicing alterations were also observed. In total, 85% of the lymphomas showed aberrations in Ikaros. The characteristic of Mlh1-deficient lymphomas is harboring of multiple mutations simultaneously in the same tumor, displaying a combination of two frameshift mutations at different repeats, frameshift and point mutations, and/or deletion mutations. This is the first report of Ikaros mutations coupled with Mlh1 deficiency in lymphomagenesis.

Recombinant adenoviruses expressing TRAIL demonstrate antitumor effects on non-small cell lung cancer (NSCLC)

INTRODUCTION

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in a variety of malignant cells, but not in normal cells. This preferential toxicity to the abnormal cells renders TRAIL potentially a very powerful therapeutic weapon against cancer. However, a requirement for large quantities of TRAIL to suppress tumor growth in vivo is one of the major factors that has hindered it from being widely applied clinically. To overcome this, we constructed a replication-deficient adenovirus that carries a human full-length TRAIL gene (Ad-TRAIL) and tested its efficacy against a lung cancer model system in comparison to that of the recombinant soluble TRAIL protein.

METHODS

To investigate the antitumor activity and therapeutic value of the Ad-TRAIL on the non-small cell lung cancer (NSCLC), four NSCLC cell lines, namely, YTMLC, GLC, A549, and H460 cells, were used. TRAIL protein expression was determined by Western blotting and flow cytometry. Cell viability was analyzed by proliferation assay, and DNA ladder and cell-cycle analysis were used to identify apoptosis. To further evaluate the effect of Ad-TRAIL in vivo, YTMLC cells were inoculated to the subcutis of nude mice. The Ad-TRAIL was subsequently administered into the established tumors. Tumor growth and the TRAIL toxicity were evaluated after treatment.

RESULTS

YTMLC cells infected with Ad-TRAIL showed decreased cell viability and a higher percentage of apoptosis. Similar, Ad-TRAIL treatment also significantly suppressed tumor growth in vivo.

CONCLUSIONS

TRAIL gene therapy provides a promising therapy for the treatment of NSCLC.

Dipolar effect in coherent spin mixing of two atoms in a single optical lattice site

We show that atomic dipolar effects are detectable in the system that recently demonstrated two-atom coherent spin dynamics within individual lattice sites of a Mott state. Based on a two-state approximation for the two-atom internal states and relying on a variational approach, we have estimated the spin dipolar effect. Despite the absolute weakness of the dipole-dipole interaction, it is shown that it leads to experimentally observable effects in the spin mixing dynamics.

Clinical and radiological results following cervical arthroplasty

BACKGROUND

This was a retrospective study of clinical and radiological results of cervical arthroplasty using the Bryan cervical disc prosthesis to evaluate the efficacy of arthroplasty in clinical applications.

METHODS

A total of 46 patients underwent arthroplasty of a single level using the Bryan disc prosthesis. Clinical outcome was assessed using the visual analogue scale (VAS) and the neck disability index (NDI). All patients were evaluated using preoperative and postoperative static cervical spine radiographs to compare cervical sagittal balance. Dynamic cervical spine radiographs were used to compare movement at the level of the procedure, movement at the adjacent level and movement of the whole cervical spine.

FINDINGS

With the exception of four patients with aggravated neck pain, the NDI and VAS scores decreased significantly in late follow-up evaluations. The range of movement of the whole cervical spine, the functional segmental unit, and the adjacent segments were preserved after arthroplasty. The sagittal alignment of the cervical spine showed kyphosis after surgery but restored lordosis at a later time. The postulated cause of kyphotic changes include "over-milling" at the dorsal endplate, inappropriate angle of disc insertion, structural absence of lordosis in the Bryan disc, removal of posterior longitudinal ligament, and pre-existing kyphosis.

CONCLUSIONS

Arthroplasty using the Bryan disc appears to be safe and provided a favorable preliminary clinical and radiological outcome. Postoperative kyphosis can be prevented by understanding the biomechanical properties of the Bryan disc. Future studies will need to address the association between postoperative kyphosis, clinical outcome and adjacent segment disease.

Spontaneous spin textures in dipolar spinor condensates

We have mapped out a detailed phase diagram that shows the ground state structure of a spin-1 condensate with magnetic dipole-dipole interactions. We show that the interplay between the dipolar and the spin-exchange interactions induces a rich variety of quantum phases that exhibit spontaneous magnetic ordering in the form of intricate spin textures.

Genome size is negatively correlated with effective population size in ray-finned fish

A recent theory suggesting that genome size and complexity can increase as a passive consequence of small effective population size has generated much controversy. In this article, we demonstrate that freshwater fish species, which have smaller effective population sizes than marine fish species, have larger genomes. We show that genome size is negatively correlated with genetic variability, independent of phylogeny, body size and generation time. Genome duplication is also observed predominantly in freshwater fish. These results suggest that the raw materials of complexity originate under conditions of reduced selection efficiency.

Islet-1 expression and its colocalization with luteinising hormone, thyroid-stimulating hormone and oestrogen receptor alpha in the developing pituitary gland of the sheep foetus

Islet-1 has been reported to be involved in pituitary development in the early stages of mouse embryogenesis. Oestrogen receptor (ER) and its expression may be involved in regulating pituitary development and its hormone-secreting function. Islet-1 expression and its correlations to ER in the developing pituitary gland are unknown. We therefore determined the pituitary cell specific expression of Islet-1 and its colocalization with ER alpha (ERalpha) in sheep foetus by immunohistochemistry. The results demonstrated that Islet-1-immunoreactive (ir) cells were distributed throughout the pituitary gland from day 60 of gestation until birth. The Islet-1-ir cell number was significant higher at day 90 and 120 of gestation compared to that at day 60 and at birth. All of the ERalpha-ir cells were colocalized with Islet-1 at day 60 of gestation, although a few ERalpha-ir cells were negative for Islet-1 in the later stage of gestation. The dominant cell type expressing Islet-1 is the gonadotroph, although small proportions of thyrotrophs and lactotrophs also express Islet-1. The proportion of luteinising hormone-ir gonadotrophs possessing Islet-1 kept rising from day 60 to day 120 of gestation and persisted until birth. The proportion of thyroid-stimulating hormone-ir cells expressing Islet-1 was at a high level from day 60-120 of the gestation and significantly declined at birth. The percentage of prolactin (PRL)-ir cells expressing Islet-1 was about 20% at day 60 of gestation. Very few PRL-ir cells contained Islet-1 in later stages of gestation. These data suggest that the development and functional establishment of pituitary gonadotrophs, thyrotrophs and lactotrophs might be regulated by the expressions of Islet-1 and ERalpha and by their interactions, although any mechanisms need to be elucidated further.

Structural phase transitions of vortex matter in an optical lattice

We consider the vortex structure of a rapidly rotating trapped atomic Bose-Einstein condensate in the presence of a corotating periodic optical lattice potential. We observe a rich variety of structural phases which reflect the interplay of the vortex-vortex and vortex-lattice interactions. The lattice structure is very sensitive to the ratio of vortices to pinning sites and we observe structural phase transitions and domain formation as this ratio is varied.

A role for platelet-derived growth factor beta-receptor in a newborn rat model of endothelin-mediated pulmonary vascular remodeling

Newborn rats exposed to 60% O2 for 14 days develop endothelin (ET)-1-dependent pulmonary hypertension with vascular remodeling, characterized by increased smooth muscle cell (SMC) proliferation and medial thickening of pulmonary resistance arteries. Using immunohistochemistry and Western blot analyses, we examined the effect of exposure to 60% O2 on expression in the lung of receptors for the platelet-derived growth factors (PDGF), which are implicated in the pathogenesis of arterial smooth muscle hyperplasia. We observed a marked O2-induced upregulation of PDGF-alpha and -beta receptors (PDGF-alphaR and -betaR) on arterial smooth muscle. This led us to examine pulmonary vascular PDGF receptor expression in 60% O2-exposed rats given SB-217242, a combined ET receptor antagonist, which we found prevented the O2-induced upregulation of PDGF-betaR, but not PDGF-alphaR, on arterial smooth muscle. PDGF-BB, a major PDGF-betaR ligand, was found to be a potent in vitro inducer of hyperplasia and DNA synthesis in cultured pulmonary artery SMC from infant rats. A critical role for PDGF-betaR ligands in arterial SMC proliferation was confirmed in vivo using a truncated soluble PDGF-betaR intervention, which attenuated SMC proliferation induced by exposure to 60% O2. Collectively, these data are consistent with a major role for PDGF-betaR-mediated SMC proliferation, acting downstream of increased ET-1 in a newborn rat model of 60% O2-induced pulmonary hypertension.

Molecular evolution of recombination hotspots and highly recombining pseudoautosomal regions in hominoids

We examined the effects of recombination on the molecular evolution of noncoding regions in pseudoautosomal regions (PARs) and recombination hotspots in hominoids. The PAR-linked regions analyzed had on average longer branch lengths than those of the recombination hotspots. Moreover, contrary to previous observations, we found no correlation between recombination rate and silent site divergence in our data set and little change in the GC content during recent hominoid evolution. This suggests that the current rate of recombination is not a good indicator of the past rates of recombination for these highly recombining regions. Furthermore, human recombination hotspots show increased AT to GC substitutions in the human lineage, while no such pattern is detected for PAR-linked regions. Together, these observations suggest that recombination hotspots in hominoids are transient in the evolutionary time-scale. Interestingly, the 16p13.3 recombination hotspot locus violates a local molecular clock, though the locus appears to be noncoding and should evolve neutrally. We hypothesize that sudden changes in recombination rate have caused the changes in substitution rate at this locus.

Patterns of selection on synonymous and nonsynonymous variants in Drosophila miranda

We have investigated patterns of within-species polymorphism and between-species divergence for synonymous and nonsynonymous variants at a set of autosomal and X-linked loci of Drosophila miranda. D. pseudoobscura and D. affinis were used for the between-species comparisons. The results suggest the action of purifying selection on nonsynonymous, polymorphic variants. Among synonymous polymorphisms, there is a significant excess of synonymous mutations from preferred to unpreferred codons and of GC to AT mutations. There was no excess of GC to AT mutations among polymorphisms at noncoding sites. This suggests that selection is acting to maintain the use of preferred codons. Indirect evidence suggests that biased gene conversion in favor of GC base pairs may also be operating. The joint intensity of selection and biased gene conversion, in terms of the product of effective population size and the sum of the selection and conversion coefficients, was estimated to be approximately 0.65.

Unusual pattern of single nucleotide polymorphism at the exuperantia2 locus of Drosophila pseudoobscura

We have investigated the pattern of DNA sequence variation at the exuperantia2 locus in Drosophila pseudoobscura. This adds to the increasing dataset of genetic variation in D. pseudoobscura, a useful model species for evolutionary genetic studies. The level of silent site nucleotide diversity and the divergence from an outgroup Drosophila miranda are comparable with those for other X-linked loci. One peculiar pattern at the exu2 locus of D. pseudoobscura is a complete linkage disequilibrium between two SNPs, one of which is a replacement site. As a result, there are two distinct haplotype groups in our dataset. Based upon the comparisons with the outgroup sequences from D. miranda and Drosophila persimilis, we show that the newly derived haplotype group has lower diversity than the ancestral haplotype group. The pattern of protein evolution at exu2 shows some deviation from the neutral model. Together, these and other characteristics of the exu2 locus suggest the action of selection on the pattern of SNP variation, consistent with a partial selective sweep associated with the newly derived haplotype.

Quantum phases of dipolar spinor condensates

We study the zero-temperature ground state structure of a spin-1 condensate with magnetic dipole-dipole interactions. We show that the dipolar interactions break the rotational symmetry of the Hamiltonian and induce new quantum phases. Different phases can be reached by tuning the effective strength of the dipolar interactions via modifying the trapping geometry. The experimental feasibility of detecting these phases is investigated. The spin-mixing dynamics is also studied.

Calibrating dipolar interaction in an atomic condensate

We reexamine the topic of a dipolar condensate with the recently derived more rigorous pseudopotential for dipole-dipole interaction [Phys. Rev. A 67, 033607 (2003)]]. Based on the highly successful variational technique, we find that all dipolar effects estimated before (using the bare dipole-dipole interaction) become significantly larger, i.e., are amplified by the new velocity-dependent pseudopotential, especially in the limit of large or small trap aspect ratios. This result points to a promising prospect for detecting dipolar effects inside an atomic condensate.

Recombination has little effect on the rate of sequence divergence in pseudoautosomal boundary 1 among humans and great apes

Recent studies indicated that recombination is strongly mutagenic. In particular, data from the mouse pseudoautosomal boundary (PAB) suggested that locally intensive recombination increased the nucleotide substitution rate by more than 100-fold and greatly increased the GC content. Here we study the rates of nucleotide substitution in eight introns of the human and great ape XG gene, which spans the boundary between the pseudoautosomal region 1 (PAR1) and the X-specific region. Contrary to what is expected under the above hypothesis, our sequence data from humans and great apes reveal that the PAR1 introns of XG have actually evolved slightly slower than X-specific introns. Only when a New World monkey was compared with hominoids were the rates slightly increased in the PAR1 introns. In terms of base composition, although the intergenic regions of the human PAR1 show a significant increase of G and C nucleotides, the base composition of the surveyed PAR1 introns is similar to that of the X-specific introns. Direct and indirect evidence indicates that the recombination rate is, indeed, much higher in PAR1 introns than in X-specific introns, and that the present PAB has persisted since the common ancestor of hominoids. Therefore, the mutagenic effect of recombination is far weaker than previously proposed, at least in hominoid PABs.

A survey of chromosomal and nucleotide sequence variation in Drosophila miranda

There have recently been several studies of the evolution of Y chromosome degeneration and dosage compensation using the neo-sex chromosomes of Drosophila miranda as a model system. To understand these evolutionary processes more fully, it is necessary to document the general pattern of genetic variation in this species. Here we report a survey of chromosomal variation, as well as polymorphism and divergence data, for 12 nuclear genes of D. miranda. These genes exhibit varying levels of DNA sequence polymorphism. Compared to its well-studied sibling species D. pseudoobscura, D. miranda has much less nucleotide sequence variation, and the effective population size of this species is inferred to be several-fold lower. Nevertheless, it harbors a few inversion polymorphisms, one of which involves the neo-X chromosome. There is no convincing evidence for a recent population expansion in D. miranda, in contrast to D. pseudoobscura. The pattern of population subdivision previously observed for the X-linked gene period is not seen for the other loci, suggesting that there is no general population subdivision in D. miranda. However, data on an additional region of period confirm population subdivision for this gene, suggesting that local selection is operating at or near period to promote differentiation between populations.