Posterior/anterior combined surgery for thoracolumbar burst fractures--posterior instrumentation with pedicle screws and laminar hooks, anterior decompression and strut grafting.

STUDY DESIGN: A prospective clinical study. OBJECTIVE: The purpose of this study was to evaluate prospectively a large group of patients with thoracolumbar burst fractures who were treated with a posterior/anterior combined procedure and to report on the surgical outcomes, complications and radiographic results. METHODS: A total of 100 consecutive patients were surgically managed with posterior instrumentation, anterior decompression and anterior strut grafting. There were 71 males and 29 females; the mean age was 36 years. Patients with osteoporotic delayed vertebral body collapse were excluded. The mean follow-up period was 30 months. Surgical outcomes such as operative time, blood loss and sagittal alignment were investigated. A neurological assessment was performed by a rating system based on the American Spine Injury Association impairment scale. An interbody fusion was judged using plain X-ray and computed tomographic scans. RESULTS: The mean operative time was 256 min and the mean operative bleeding was 985 ml. Most of the patients were ambulatory within 3 days after surgery. Of the 76 patients with neurological injury, 54 (71.1%) recovered function following surgery. The mean local kyphosis angle was 12.2° kyphotic preoperatively and 0.8° lordotic at the final observation. The mean correction angle was 15.7° and correction loss was 2.6°. No instrumentation failure was observed and the postoperative fusion rate was 99%. CONCLUSIONS: Posterior/anterior combined surgery with posterior pedicle screws and hooks fixation, and reconstruction by simultaneous strut grafting and anterior decompression, achieved short segment fixation and can be a useful option for surgically treating thoracolumbar burst fractures.

Minimally invasive spinal decompression for degenerative lumbar spondylolisthesis and stenosis maintains stability and may avoid the need for fusion.

Aims: The aim of this study was to investigate the clinical and radiographic outcomes of microendoscopic laminotomy in patients with lumbar stenosis and concurrent degenerative spondylolisthesis (DS), and to determine the effect of this procedure on spinal stability. Patients and Methods: A total of 304 consecutive patients with single-level lumbar DS with concomitant stenosis underwent microendoscopic laminotomy without fusion between January 2004 and December 2010. Patients were divided into two groups, those with and without advanced DS based on the degree of spondylolisthesis and dynamic instability. A total of 242 patients met the inclusion criteria. There were 101 men and 141 women. Their mean age was 68.1 years (46 to 85). Outcome was assessed using the Japanese Orthopaedic Association and Roland Morris Disability Questionnaire scores, a visual analogue score for pain and the Short Form Health-36 score. The radiographic outcome was assessed by measuring the slip and the disc height. The clinical and radiographic parameters were evaluated at a mean follow-up of 4.6 years (3 to 7.5). Results: There were no significant differences in the preoperative measurements between the group and no significant differences between the clinical parameters at the final follow-up. The mean percentage slip was 17.1% preoperatively and 17.7% at the final follow-up (p = 0.35). Progressive instability was noted in 13 patients (8.2%) with DS and 6 patients (7.0%) with advanced DS, respectively (p = 0.81). There was radiological evidence of restabilization of the spine in 30 patients (35%) with preoperative instability. The success rate of microendoscopic laminotomy was good/excellent in 166 (69%), fair in 49 (20%) and poor in 27 patients (11%) in both groups. Conclusion: Microendoscopic laminotomy is an effective form of surgical treatment for patients with DS and stenosis. Preservation of the stabilizing structures using this technique prevents postoperative instability. Cite this article: Bone Joint J 2018;100-B:499-506.

Correction: Bottom-up fabrication of artery-mimicking tubular co-cultures in collagen-based microchannel scaffolds.

Correction for 'Bottom-up fabrication of artery-mimicking tubular co-cultures in collagen-based microchannel scaffolds' by A. Tan, et al., Biomater. Sci., 2016, DOI: 10.1039/c6bm00340k.

Bottom-up fabrication of artery-mimicking tubular co-cultures in collagen-based microchannel scaffolds.

We developed a robust bottom-up approach to construct open-ended, tubular co-culture constructs that simulate the human vascular morphology and microenvironment. By design, these three-dimensional artificial vessels mimic the basic architecture of an artery: a collagen-rich extracellular matrix (as the tunica externa), smooth muscle cells (SMCs) (as the tunica media), and an endothelial cell (EC) lining (as the tunica interna). A versatile needle-based fabrication technique was employed to achieve controllable arterial layouts within a PDMS-hosted collagen microchannel scaffold (330 ± 10 µm in diameter): (direct co-culture) a SMC/EC bilayer to follow the structure of an arteriole-like segment; and (encapsulated co-culture) a lateral SMC multilayer covered by an EC monolayer lining to simulate the architecture of a larger artery. Optical and fluorescence microscopy images clearly evidenced the progressive cell elongation and sprouting behavior of SMCs and ECs along the collagen gel contour and within the gel matrix under static co-culture conditions. The progressive cell growth patterns effectively led to the formation of a tubular co-culture with an internal endothelial lining expressing prominent CD31 (cluster of differentiation 31) intercellular junction markers. During a 4-day static maturation period, the artery constructs showed modest alteration in the luminal diameters (i.e. less than 10% changes from the initial measurements). This argues in favor of stable and predictable arterial architecture achieved via the proposed fabrication protocols. Both co-culture models showed a high glucose metabolic rate during the initial proliferation phase, followed by a temporary quiescent (and thus, mature) stage. These proof-of-concept models with a controllable architecture create an important foundation for advanced vessel manipulations such as the integration of relevant physiological functionality or remodeling into a vascular disease-mimicking tissue.

Microangiographic and histologic analysis of the effects of hyperthermia on murine tumor vasculature.

The effects of hyperthermia on murine tumor vasculature were studied by microangiography and histological examination. The tumors used were SCC VII carcinoma and mammary adenocarcinoma of syngeneic C3H/He mice. For the quantitative analysis of microangiographic changes, the percent (%) vascular area, which was defined as the percentage of opacified tumor vessel area to the entire tumor area, was determined in each microangiogram. The % vascular area after heating in a water bath at 44 degrees C for 30 min was minimized 24 hr after heating in both types of tumors. The histologic study revealed that the initial decrease of the % vascular area was due to congestion, thrombosis, and rupture of tumor vessels, and its subsequent increase was due to angiogenesis. SCC VII was more heat sensitive than mammary adenocarcinoma in terms of tumor growth delay, and tumor vessels of SCC VII were more vulnerable to heat than those of mammary adenocarcinoma. Histological examinations showed a marked difference in the architecture of vessels between the two types of tumors. Tumor vessels of mammary adenocarcinoma were supported by a connective tissue band, whereas those of SCC VII consisted of a single endothelial cell layer. Our findings suggest that the tumor vessels supported by a connective tissue band are less sensitive to heat than those without such support. The vascular damage of SCC VII was temperature dependent, and the critical temperature at which dramatic vascular damage appeared was between 42.7 degrees C and 43.7 degrees C.

In vivo radiosensitizing activity of a new fluorinated hypoxic cell radiosensitizer, KU-2285, in combination with radiation dose fractionation.

Since most clinical radiotherapy is given as multiple small irradiation fractions, the present study was undertaken to test the in vivo radiosensitizing activity of a new hypoxic cell radiosensitizer, KU-2285, in combination with radiation dose fractionation. Radiosensitizing activity was measured by a growth delay assay using a transplanted mammary tumor in C3H/He mice, and by an in vivo-in vitro assay using the SCC VII tumor. KU-2285 was injected intraperitoneally 30 min before irradiation in all experiments. The in vivo-in vitro assay using SCC VII tumors showed that 12.5 micrograms/g of KU-2285 sensitized the tumors to irradiation (5 Gy/fr x 5 fr/48 hr or 6 Gy/fr x 3 fr/48 hr). KU-2285 also sensitized the transplanted mammary tumors to fractionated irradiation. We concluded that KU-2285 was able to sensitize two different murine tumors when given in combination with radiation dose fractionation.

Groin pain associated with lower lumbar disc herniation.

STUDY DESIGN: Retrospective clinical and magnetic resonance imaging study of patients with groin pain associated with lower lumbar disc herniation. OBJECTIVES: To demonstrate the clinical features and magnetic resonance imaging findings of these patients. SUMMARY OF BACKGROUND DATA: Patients with lumbar disc herniation sometimes report groin pain. Little mention has been made, however, regarding the clinical features of groin pain stemmed from lower lumbar disc herniation until now, with only Murphey referring to groin pain in disc disease. METHODS: A total of 512 patients were diagnosed with singular lower lumbar disc herniation (L4-L5 and L5-S1) at Kakegawa City General Hospital between July 1990 and December 1993. Of these patients, 21 (4.1%) reported groin pain. The characteristic clinical features and magnetic resonance imaging findings of the 21 patients were investigated and compared with the features and findings of patients with no groin pain. RESULTS: Patients with groin pain had a higher mean age and lower rate of low back pain, and L4-L5 discs were more likely to be involved than L5-S1 discs. In their magnetic resonance images, herniation tended to be more central than in patients with no groin pain. CONCLUSIONS: Elderly patients with L4-L5 protruding herniation of the anulus fibrosus were most likely to experience groin pain. The sinuvertebral nerve that innervates the posterior anulus fibrosus, the posterior longitudinal ligament, and the dura was indicated as the afferent nerve of groin pain.

Studies in radiosensitizing effects of misonidazole and SR-2508 on C3H/He mouse mammary tumors.

The radiosensitizing efficacy of SR-2508, a new 2-nitroimidazole, which is less neurotoxic than misonidazole (MISO) was studied using transplantable mammary carcinoma of C3H/He mice. Tumor responses to treatments were evaluated by growth-delay time assay. In single irradiations, the enhancement ratios of 0.5 mmole/kg of MISO and 1.5 mmole/kg of SR-2508, which were equitoxic to C3H/He mice, were 1.42 and 1.84 respectively. In fractionated irradiations with three fractions over two days or five fractions over four days, the enhancement ratios of 1.5 mmole/kg of SR-2508 were 1.40 and 1.34 respectively. On the other hand the enhancement ratios of MISO at the above mentioned dose in respective fractionated irradiations were 1.15 or 1.11. SR-2508 is considered promising as a hypoxic cell radiosensitizer for clinical use.

C5 palsy after cervical laminoplasty: a multicentre study.

We have reviewed 1858 patients who had undergone a cervical laminoplasty and identified 43 (2.3%) who had developed a C5 palsy with a MMT (MRC) grade of 0 to 2 in the deltoid, with or without involvement of the biceps, but with no loss of muscular strength in any other muscles. The clinical features and radiological findings of patients with (group P; 43 patients) and without (group C; 100 patients) C5 palsy were compared. CT scanning of group P revealed a significant narrowing of the intervertebral foramen of C5 (p < 0.005) and a larger superior articular process (p < 0.05). On MRI, the posterior shift of the spinal cord at C4-5 was significantly greater in group P, than in group C (p < 0.01). This study is the first to correlate impairment of the C5 nerve root with a C5 palsy. It may be that early foraminotomy in susceptible individuals and the avoidance of tethering of the cord by excessive laminoplasty may prevent a post-operative palsy of the C5 nerve root.

Treatment of distal radius fractures with a wrist-bridging external fixation: the value of alternating electric current stimulation.

The radiological and functional outcomes of two groups of comminuted intraarticular fractures of the distal radius that were treated with wrist-bridging external fixation, with or without an alternating electric current stimulation (EF + ES or EF group, respectively), were compared. The radial length, radial inclination and palmar tilt were measured on radiographs taken immediately after removal of wrist external fixator and also after bone union had occurred. Furthermore, active range of motion was compared at the final consultation. Bridging callus was observed earlier postoperatively in the EF + ES group than in the EF group. The radial length and palmar tilt were significantly larger, and the loss of radial length and radial inclination significantly smaller, in the EF + ES group. We believe that callus maturation is enhanced by alternating electric current stimulation, which enables the early removal of external fixator.

Isolated spinal cord sarcoidosis mimicking an intramedullary tumor.

A case of cervical intramedullary sarcoidosis and its uncommon magnetic resonance imaging with contrast medium are reported. Spinal cord sarcoidosis is very rare. It is difficult to diagnose intramedullary sarcoidosis without a previous diagnosis of systemic sarcoidosis or other apparent symptom. The patient had subacute myelopathy. Contrast-enhanced images revealed intense focal enhancement of the C6-7 cervical cord. The preoperative diagnosis was an intramedullary tumor. Subtotal resection was performed after intraoperative frozen section study was interpreted as malignant lymphoma. Subsequent pathologic examination of the biopsied specimens revealed spinal cord sarcoidosis. After surgery, steroid therapy was performed, but the patient's symptoms hardly improved. Even if imaging study and intraoperative frozen section show neoplasm, the first surgery should be limited to decompressing the cord and biopsy in cases of suspected sarcoidosis.

Efficient in vitro transcription of plant nuclear tRNA(Ser) genes in a nuclear extract from tobacco cultured cells.

A nuclear extract derived from tobacco cultured BY-2 cells supports RNA polymerase III-dependent transcription of Arabidopsis tRNA(Ser) genes. Primer extension analysis indicated that the transcription starts at 6 bp upstream from the 5' end of tRNA coding region. Procedures for nuclear extraction and in vitro reaction conditions have been optimized for tRNA transcription, which allows direct detection of de novo synthesized tRNA by gel electrophoresis. This improved in vitro system yields a mature-sized tRNA of 85 nucleotides from the Arabidopsis tRNA(Ser) gene, indicating that efficient processing of the pre-tRNA also occurs in the tobacco nuclear extract.

Serial gadolinium-enhanced MR imaging after lumbar disc resection: observation of the affected root.

A prospective study was undertaken to clarify the relationship between postoperative morphological/pathological changes in the affected root and the clinical developments after disc resection. Gadolinium-enhanced magnetic resonance (MR) imaging was performed at 1 week, 5 weeks, 3 months, and 6 months after surgery for 28 patients of 34 consecutive patients who underwent single-level disc resection. Enhancement/thickening of the affected root was found to be 100%/89% at 1 week, 50%/57% at 3 months, and 32%/37% at 6 months after surgery. Patients with root enhancement and thickening at 3 and 6 months after surgery had less clinical improvement than patients without it. There was consistent correlation between postoperative clinical developments and nerve root enhancement/thickening in enhanced MR imaging. To use enhanced MR imaging as an evaluation tool after disc surgery might increase the diagnostic accuracy and reduce failed back surgery syndrome.

Synthesis of stable crystals of a self-assembled centered icosahedral samarium cluster formed by bis(L-prolinato)nickel(II) ligands.

A centered icosahedral 12-coordinate samarium cluster formed by six bis(L-prolinato)nickel(II) ([Ni(pro)2]) ligands, [Sm(Ni(pro)2)6]3+, was prepared. The reaction of Sm with [Ni(pro)2] in a small excess (a 2-fold excess) and also in a large excess (even a 10-fold excess) of the latter produced the cluster. Therefore, this system is a self-assembly. In the cluster, each nickel atom is surrounded by six atoms: two amino nitrogens, two carboxylate oxygens which form chelate rings with the nitrogen atoms, and two carboxylate oxygen atoms which link the neighboring nickel atoms. The samarium atom is coordinated by six [Ni(pro)2] ligands, and the metal is in an icosahedral environment formed by 12 oxygen atoms. The icosahedral geometry is almost ideal. Crystals of [Sm(Ni(pro)2)6](ClO4)3.6MeOH, which were prepared from a methanol solution, immediately decompose after filtration because of loosely trapped MeOH molecules in the crystal lattice. Therefore, crystals without MeOH molecules, which must be stable, were prepared by recrystallization from acetonitrile with tetramethylammonium perchlorate (TMAP). According to the X-ray crystal analysis, the cluster is TMA[Sm(Ni(pro)2)6](ClO4)4, cubic of space group F23, with a = 21.273(9) A, V = 9626(1) A3, and Z = 4; R = 0.053 (Rw = 0.049) for 1296 reflections. In addition, several crystals of cluster salts that have different counteranions, i.e., tetrafluoroborate (BF4-), hexafluorophosphate (PF6-), iodide (I-), and nitrate (NO3-), were prepared. The order of increasing ease of crystallization of the cluster salts was I- > PF6- approximately ClO4- > BF4- >> NO3-. The cluster structure is retained in alcohol and acetonitrile solutions; the UV-vis spectra of the solutions are perfectly consistent with the powder diffuse reflection spectrum. Cyclic voltammograms of [Sm(Ni(pro)2)6]3+ in acetonitrile proved that the structure of [Sm(Ni(pro)2)6]3+ is retained in the redox process and that the nickel atoms electrochemically interact with one another. Thermal analysis of the cluster salts with different counteranions was investigated. The results imply that the cluster is very stable until bis(L-prolinato)nickel(II) ligands, which form the cage structure, disintegrate and that the thermal decomposition processes of the cluster salts depend on their counteranions.

Plant cytosolic tRNAHis possesses an exceptional C54 in the canonical TPsiC loop.

A nuclear gene coding for tRNAHis from Arabidopsis has been reported to contain C54in the TPsiC loop, although the corresponding nucleotide is an invariant U or a derivative in nearly all other tRNAs. The only previously reported plant cytosolic tRNAHis sequence, from lupin, has U54. To re-examine plant cytosolic tRNAsHis and their genes we have used DNA and RNA sequence analyses, restriction enzyme digestion of PCR-amplified tRNA genes, RNA hybridization and in vivo aminoacylation assays. Our results suggest that Arabidopsis nuclear tRNAHis genes ubiquitously contain C54, as do those from tobacco, lupin and pea. The C54 nucleotide is maintained in the mature tRNAHis, which is aminoacylated in vivo , but to a relatively low level compared with other tRNAs examined. Finally, it was shown that an Arabidopsis tRNAHis gene with T54in place of C54 is over 5-fold more transcriptionally active than the wild-type gene using an in vitro system derived from plant nuclei. A possible role for this apparently sub-optimal tRNAHis sequence is suggested.

The radiological appearances of familial metaphyseal dysplasia.

Familial metaphyseal dysplasia (FMD) is a rare genetical conditional characterised by symmetrical metaphyseal splaying of the tubular bones. The diagnosis of FMD was made in four patients from two families in Japan; abnormal modelling defects were observed in the flat bones as well as tubular bones in some of the patients. In addition, quantitative measurement of the mineral content of the bone was carried out and was found to be one-quarter of the normal value.

The TATA motif, the CAA motif and the poly(T) transcription termination motif are all important for transcription re-initiation on plant tRNA genes.

The effect of alteration of 5' and 3' flanking sequences on the transcription of plant tRNA genes was analysed using an RNA polymerase III-dependent in vitro transcription system derived from nuclei of cultured tobacco cells. A TATA-like sequence and the CAA motif frequently observed upstream of plant tRNA genes, and the poly(T) stretch usually present downstream, were shown to be necessary for efficient re-initiation of transcription. The CAA motif was shown to be a transcription initiation site. Introduction of the CAA and TATA-like motifs into a gene naturally lacking them greatly enhanced transcription by promoting efficient re-initiation.