[Efficacy of polyetheretherketone rod hybrid surgery in preventing proximal junctional failure after adult spinal deformity surgery]

Objective: To investigate the clinical outcome and preventive effect of polyetheretherketone(PEEK) rod hybrid surgery on proximal junction failure(PJF) after long-segment fusion of adult spinal deformity. Methods: A retrospective study was conducted to analyze patients with degenerative scoliosis/kyphosis who underwent long-segment decompression and fusion surgery at Department of Orthopedics, Peking University First Hospital from January 2017 to December 2021. A total of 75 patients were included in the study, including 14 males and 61 females, aged (67.2±6.8)years (range:55 to 84 years). According to the operation method chosen by the patients, the patients were divided into PEEK rod hybrid group (20 cases) and traditional titanium rod group (55 cases). The general information of the patients was collected, and the coronal and sagittal parameters of the spine were measured before operation, at 1 month after operation, and at the last follow-up. The clinical effect of surgery was judged by the visual analogue scale (VAS) and Oswestry disability index (ODI). Whether proximal junctional kyphosis (PJK) and PJF occurred during the follow-up and the time of occurrence were recorded. Comparisons between groups were performed using independent sample t test, Mann-Whitney U test, χ2 test and Fisher's exact probability method. The data before and after surgery in the same group were compared using the paired sample t test and the Wilcoxon test. Results: There were no significant differences in age, gender, body mass index, bone mineral density, distal instrumented vertebrae, surgical segments, osteotomy method, operation time, and intraoperative bleeding between the two groups (all P>0.05). The follow-up time of the PEEK rod group was shorter(M(IQR)16.5(4.8) vs. 25.0(12.0),Z=-4.230,P<0.01). There were no significant differences in coronal, sagittal parameters, VAS and ODI between the two groups before operation (all P>0.05). Postoperative coronal Cobb angle, pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis, sagittal vertical axis (SVA), VAS and ODI were significantly improved in both groups(all P<0.05). At the last follow-up, the SVA of the PEEK rod hybrid group was(3.74±2.40)cm, which was significantly lower than that of the titanium rod group (6.28±4.06)cm (t'=-3.318, P=0.002). At the last follow-up, the ODI of the PEEK rod hybrid group was 30.7±6.1, significantly better than the titanium rod group 39.3±17.2(t=-3.203, P=0.046). PJK occurred in 2 patients (10.0%) in the PEEK rod hybrid group, and no PJF phenomenon was observed. In the titanium rod group, 18 patients (32.7%) developed PJK, and 11 patients (20.0%) developed PJF. There was a statistically significant difference in the incidence of PJF between the PEEK rod hybrid group and the titanium rod group (P=0.031). Conclusions: PEEK rod hybrid surgery can achieve good clinical results in the treatment of adult spinal deformities. Compared with traditional titanium rod surgery, it can significantly reduce the incidence of postoperative PJF and improve the clinical function of patients.

[How to restore the proper lumbar lordosis in spine surgery]

Sagittal alignment of the spine significantly affects the physical function. In this article, we review the clinical application of several spinal-pelvic parameters, analyze the impact factors of sagittal alignment and provide calculating methods to value the correcting degrees. Spine surgeons should get a deep understanding of the spinal-pelvic parameters, differentiate the functional and structural imbalance. Every patient needs thorough preoperative evaluation to restore the proper alignment during surgery and avoid overcorrection.

[Anterior cervical discectomy and fusion to treat cervical spondylosis with sympathetic symptoms]

OBJECTIVE

To investigate the clinical effectiveness of polytheretherketone (PEEK) cages assisted anterior cervical discetomy and fusion (ACDF) to treat cervical spondylosis with sympathetic symptoms.

METHODS

Retrospective analysis was undertaken for 39 patients who were diagnosed as cervical spondylosis with sympathetic symptoms and underwent ACDF with PEEK cages. Radiographs obtained before surgery, after surgery, and at the final follow-up were assessed for quality of fusion. The following criteria were used for assessing radiographic success of fusion: (1) endplate obliterated with no lucent lines; (2) obliteration of disc space by bony trabeculae; (3) less than 2°of intervertebral motion or 2 mm of motion between the spinous processes at the operated segment on flexion-extension lateral radiographs. The sympathetic symptoms including vertigo, headache, tinnitus, nausea and vomiting, heart throb, hypomnesia and gastroenterological discomfort were scored by 20-point system preoperatively, 2 months postoperatively and at the final follow-up. The recovery rate and clinical satisfaction rate were also evaluated. Surgical complications were also assessed.

RESULTS

They were followed up for at least one year. The mean follow-up was 15.6 months. Radiographs of the cervical spine at the last follow-up revealed a solid fusion with no signs of a pseudoarthrosis in 36 cases. In two patients delayed union and bony fusion were achieved at the end of 9 and 11 months. Pseudoarthosis was found in 1 case but the patient had no symptoms. The score of sympathetic symptoms before surgery, 2 months after surgery and at the final follow-up were 8.4±1.0,2.2±0.3,and 2.4±0.3, respectively. There were 22 excellent cases, 15 good cases, 1 fair case and 1 bad case in terms of RR. Good to excellent results were attained in 95% of theses patients. The sympathetic symptoms improved in all the patients and the score was significantly improved after surgery. There was one patient who had cerebral spinal fluid leakage but he recovered one week after surgery. Two patients felt a mild swallowing discomfort, but it disappeared within one month after surgery. Subcutaneous hematoma occurred in one patient due to obstructed drainage. It was cleared two days after surgery.

CONCLUSION

Cervical spondylosis patients with sympathetic symptoms may be managed successfully with ACDF using PEEK cages. Successful clinical results regarding symptom improvement and general satisfaction with the surgical procedure depend not only on obtaining successful decompression and radiographic fusion but also on patient selection.

[Efficacy of transforaminal endoscopic nerve root decompression in the treatment of degenerative lumbar spinal stenosis]

OBJECTIVE

To evaluate the feasibility of transforaminal endoscopic nerve root decompression for degenerative lumbar spinal stenosis (DLSS).

METHODS

From July 2011 to April 2016, 96 cases of single segment DLSS were involved. All the patients had unilateral lower extremity neurological symptoms, signs, neurogenic intermittent claudication of less than 500 m. Imaging examinations (CT or MRI) or diagnostic nerve root block confirmed single segment degeneration. The mean age was (71.6±5.4) years, male: 55 cases, female: 41 cases. Their intraoperative blood loss, operation time, complications, ambulation time and discharge time were recorded. Leg pain VAS, ODI were used to evaluate the pain and lumbar function of the patients. The clinical efficacy was evaluated by Nakai evaluation.

RESULTS

All the patients were performed endoscopic decompression of the lateral recess and nerve root by removing the ventral part of the superior facet joint, the ligamentum flavum and the intervertebral disc. The decompression range was from the inferior edge of the upper pedicle to the superior edge of the lower pedicle. The nerve root was detected to have no compression and the pulse of nerve root returned to normal. The patient got ambulant on the operation day and discharged if he had no discomfort symptom. In the study, 68 cases got follow up. The mean follow-up time was 12.1 months (6-63 months). The VAS at different follow-up time points was improved relative to the baseline, and the difference was statistically significant (F=491.60, P<0.001). The ODI at different follow-up time points was improved relative to the baseline, and the difference was statistically significant (F=189.91, P<0.001). The excellent and good rates of Nakai evaluation were 79.4% (excellent in 42 cases, good in 12 cases, fair in 10 cases and poor in 4 cases). The mean intraoperative blood loss was (49.29±11.86) mL. The mean operation time was (92.46±21.34) min. The mean ambulation time was 1.8 h. The mean discharge time was 2.3 days. Postoperative epidural hematoma was found in 1 case. Foot drop was found in 1 case. Second stage open surgery was performed in 6 cases.

CONCLUSION

We can apply transforaminal endoscopic decompression for the patients of lumbar spinal stenosis who have unilateral nerve root irritation. Patients with transforaminal endoscopic decompression can get less surgical trauma, quick recovery and obtain good short-term outcome.

[Polymethylmethacrylate augmentation of bone cement injectable cannulated pedicle screws was used to treat degenerative lumbar scoliosis with osteoporosis]

OBJECTIVE

To describe the application of polymethylmethacrylate (PMMA) augmentation of cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar scoliosis with osteoporosis.

METHODS

Retrospective cohort study was used to compare cement injectable cannulated pedicle screws (CICPs) group with PMMA augmentation and control group with traditional method in the correction surgery for Lenke-silva level III and level IV degenerative scoliosis cases with osteoporosis. Both groups were followed up for 1 year. The clinical results were assessed by visual analog scale (VAS) of pain on lumbar and lower limbers, Oswestry disability index (ODI) score and EuroQol-5 dimensions (EQ-5D) score. The coronal major curve Cobb angel in coronal plane and thoracic kyphosis Cobb angle, lumbar lordosis Cobb angle and sagittal vertical axis (SVA) in sagittal plane were tested in whole long spine X ray. The fusion rates were evaluated by lumbar X ray and dynamic X ray.

RESULTS

In this study 34 cases were enrolled, 15 cases in CICPs group and 19 cases in control group. The general characteristics including age, gender, weight, height, BMI and BMD were without statistical difference between the two groups. There were (5.7±2.2)PMMA augmentation screws in CICPs group. The operation time, blood loss and blood transfusion were higher in CICPs group than in control group, but without statistical difference. Lumbar VAS, lower limbers VAS, ODI score and EQ-5D were all better in 1 month postoperation, 6 months postoperation and 1 year postoperation than in preoperation in both groups. lumbar VAS scores of CICPs group in 6 months postoperation (CICPs group 3.1±1.3 vs. control group 4.4±1.4, P<0.01) together with lumbar VAS scores (CICPs group 3.3±1.0 vs. control group 5.2±1.4, P<0.01), ODI scores (CICPs group 22.7±17.2 vs. control group 31.4±18.5, P<0.01) and EQ-5D in 1 year postoperation (CICPs group 2.9±2.0 vs. control group 3.5±2.5, P<0.01)were lower than those of control group. The coronal major curve Cobb angels were all lower in 1 month postoperation, 6 months postoperation and 1 year postoperation than in preoperation in both groups; thoracic kyphosis Cobb angle and lumbar lordosis Cobb angle were all higher in 1 month postoperation, 6 months postoperation and 1 year postoperation than in preoperation in both groups. The coronal major curve Cobb angel was lower in CICPs group than that in control group in 1 year postoperation (CICPs group 17.6°±6.9° vs. control group 21.2°±7.2°, P<0.01)and thoracic kyphosis Cobb angle was higher in CICPs group than that in control group in 6 months postoperation (CICPs group -33.5°±8.8 ° vs. control group -28.9°±8.3°, P<0.01) and 1 year postoperation (CICPs group -33.0°±8.1° vs. control group -26.3°±7.4°, P<0.01) together with lumbar lordosis Cobb angle were higher in CICPs group than that in control group in 1 year postoperation (CICPs group 26.4°±8.1° vs. control group 22.1°±7.3°, P<0.01).

CONCLUSION

Polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar scoliosis with osteoporosis was effective and safe, the short-term clinical result was good.

[Polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar diseases with osteoporosis]

OBJECTIVE

To describe the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar diseases with osteoporosis.

METHODS

Observation group included 14 cases of degenerative lumbar diseases with osteoporosis received polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws from November 2014 to July 2015, control group included 12 cases of degenerative lumbar diseases with osteoporosis received polymethylmethacrylate augmentation with traditional pedicle screws.The operation time, blood loss, number of pedicle screws and number of augmented pedicle screws in the two groups were compared. The bone cement leakage and pulmonary bone cement embolism in the two groups were also compared. The fusion rate and pedicle screws loosening by lumbar X ray and dynamic X ray were evaluated. The clinical results were assessed by visual analog scale (VAS) of pain on lumbar and lower limbers, lumbar Japanese Orthopaedic Association scores (JOA), Prolo functional scores and Oswestry disability (ODI) scores.

RESULTS

Differences of operation time and blood loss in the two groups were not statistically significant. The average number of pedicle screws was 9.9±4.7 and the average number of augmented pedicle screws was 5.9±2.6 in observation group while the average number of pedicle screws was 7.1±2.8 and the average number of augmented pedicle screws was 3.0±1.9 in control group. The ratio of augmented pedicle screws was higher in observation group than in control group (0.69±0.30 vs.0.47±0.30,P<0.05). The bone cement leakage rate was lower in observation group than in control group (5/83 vs. 12/42, P<0.01). All the cases in observation group were without leakage to the interspinal canal while one case in control group suffered from bone cement leakage to the interspinal canal with augmentation of 3 pedicle screws. The follow up period was (10.6±2.3) months in observation group and (36.5±7.2) months in control group. In final follow up, no case with non-fusion or pedicle screws loosening was found in both groups. Lumbar VAS, lower limbers VAS, lumbar JOA scores, Prolo functional scores and ODI scores were all better than pre-operation (P<0.01).

CONCLUSION

Polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar diseases with osteoporosis was effective, with simple working processes and lower risk of bone cement leakage. The short-term clinical result was good.

[Analysis of the clinical outcomes of the over 5-year follow-up study of degenerative lumbar scoliosis treated with posterior decompression and instrumented fusion]

OBJECTIVE

To evaluate the over 5-year follow-up clinical outcomes of degenerative lumbar scoliosis treated with operation of decompression and fusion, and the effectiveness and risks factors about revision surgery cases.

METHODS

A total of 47 cases of diagnosis of degenerative lumbar scoliosis treated with posterior decompression and instrument fusion recorded from Jun. 2003 to Jun. 2008 were analyzed. Lumbar Japanese Orthopedic Association (JOA) score and visual analogue score (VAS) were applied to evaluate the improvement of the clinical effect after surgery treatment, and the clinical effect and reasons of revising operation were recorded and analyzed.

RESULTS

All the 47 patients had finished the over 5-year followed-up time with an average time of (8.2±3.6) years (range from 5.2 years to 12.5 years). The patient's mean age was (67.0±9.6) years and the age of patient range from 56 years to 81 years. There were 10 patients who underwent revision surgery since primary operation, in whom 8 cases because of proximal failure of internal fixation and the other 2 cases because of distal failure of fusion segment. The average clinical improvement excellent rate was 83.3% after 5 years since primary operation of 37 cases while the average fine rate of revision operation was 67.6%.

CONCLUSION

In the over 5-year follow-up, there was a better clinical outcome of degenerative lumbar scoliosis treated with posterior decompression and instrumented fusion, which had a certain rate of revision operation and had a worse effect of clinical results compared with primary operation. The risks of revision surgery included the poor bone quality of patients, with fusion to L1 at proximal terminal and the fusion end to S1 at distal terminal.

The effects of bortezomib alone or in combination with 5-fluorouracil on proliferation and apoptosis of choriocarcinoma cells

PURPOSE

To investigate the effects of bortezomib alone and in combination with 5-fluorouracil (5-FU) on proliferation and apoptosis in the human choriocarcinoma cell line JEG-3.

MATERIALS AND METHODS

Cells were treated with bortezomib, 5-FU or with a combination. Proliferation and apoptosis were measured. NF-iB protein expression was examined using immunofluorescence.

RESULTS

Following treatment with ten nM bortezomib, rates of apoptosis were significantly higher than controls (p < 0.05) and NF-kB expression increased. 5-FU at 0.025 μg/ml or 0.25 μg/ml resulted in 60.1 ± 0.4% and 67.0 ± 0.2% growth inhibition, respectively, an increase compared to individual treatment (p < 0.05). Apoptosis in cells treated with bortezomib +5-FU was significantly higher than either treatment alone (p < 0.05). Inhibition of proliferation by the combination treatment was synergistic.

CONCLUSION

Bortezomib alone or in combination with 5-FU inhibited JEG-3 cell proliferation and induced apoptosis by increasing NF-kB expression. Combination treatment exerted synergistic effects on growth inhibition.

[Clinical research of percutaneous vertebroplasty or percutaneous kyphoplasty for treating osteoporotic vertebral compression fractures induced by glucocorticosteroid]

OBJECTIVE

To investigate the clinical characteristics of vertebral compression fracture (VCF) in glucocorticosteroid-induced osteoporosis (GIOP) and risk of vertebral refracture after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP).

METHODS

In the study, 570 cases who received PVP or PKP as treatments of VCF from January 2010 to December 2013 were retrospective reviewed, of which 42 were GIOP and 21 were followed up as GIOP group, and the other 528 were primary osteoporosis and 391 were followed up, of which 84 were selected as Control group based on age and gender. The fracture location, ratio of single segment fracture and multiple segments fracture in the two groups were compared. In the final follow up, the reoperation rates for vertebral refractures by the Kaplan-Meier method in the two groups were compared.

RESULTS

The follow up periods were (24.0± 13.1) months in GIOP group and (25.8±14.4) months in control group(P>0.05). In GIOP group, there were 11 cases with one-segment fracture, 2 with two-segments fracture, 3 with three-segments fracture, 2 with four-segments fracture, 2 with five-segments fracture and 1 with eight-segments fracture. In Control group, there were 67 cases with one-segment fracture, 12 with two-segments fracture, 3 with three-segment fracture, and 2 with four-segments fracture. The ratio of single segment fracture in GIOP group was significantly lower than that in Control group(52.4% vs. 79.8%,P=0.01). There were 50 fracture segments in GIOP group and 109 fracture segments in Control group. The ratios of fracture segments located in thoracic segments(T1-T10), thoracolumbar segments(T11-L1)and lumbar segments(L2-L5)were 18%, 46% and 36% in GIOP group and 11.9%, 58.7% and 29.4% in Control group (P>0.05). The refracture rate in GIOP group was higher than that in control group (23.8% vs. 6.0%). The survival rate was lower in GIOP group than that in control group (P<0.01).

CONCLUSION

The predilection site of VCF was similar in GIOP and primary osteoporosis (thoracolumbar segments> thoracic segments> lumbar segments). The risk of multiple segments VCF was higher in GIOP than in primary osteoporosis. The risk of vertebral refractures after PVP or PKP was higher in GIOP than in primary osteoporosis.

Classification of hypothalamic hamartoma and prognostic factors for surgical outcome

OBJECTIVES

The main aims of this study were to classify patients with hypothalamic hamartoma (HH) based on neuroimaging features and describe the clinical manifestations of HH.

MATERIALS AND METHODS

A retrospective review of 214 consecutive patients with HH treated in Beijing Tiantan Hospital was performed.

RESULTS

HH were diagnosed and divided into Types I-IV based on MRI. Types I and II were defined as the HH attached to the floor of the third ventricle with narrow (Type I) or broad (Type II) interfaces. Type III ('straddling') was defined by the HH extending into the third ventricle and interpeduncular cistern. Type IV was defined as the HH located totally within the third ventricle. The percent distribution of patients was 35.9% Type I, 12.1% Type II, 40.7% Type III, and 11.2% Type IV. The percentage of patients with precocious puberty was highest in Type I (81.8%). The percentage of patients with gelastic seizures was highest in Type IV (91.7%). After surgery, 20% (1/5) of patients with Type II HH, 48.8% (20/42) with Type III, and 91.7% (11/12) with Type IV were free of epileptic seizures. Significant prognostic factors for surgical outcome were HH size, surgical approach, and resection level.

CONCLUSIONS

The clinical manifestations of HH are correlated with the topology of the HH in relation to the hypothalamus. Our results suggest that patients with Type IV HH have the best outcome from surgery and neurosurgeons should be cautious about performing surgery on patients with Type II and Type III HH.

Molecular detection of QTL controlling plant height components in a doubled haploid barley population

Yield losses caused by lodging in barley can be partially controlled by reducing plant height. In order to understand dwarfing mechanisms and efficiently use new dwarf germplasms for a breeding program, it is important to identify QTL of plant height components. QTL analysis was performed for seven plant height component traits using a DH population of 122 lines derived from the cross of Huaai 11 x Huadamai 6. Composite interval mapping procedures detected 20 QTL, which were mapped onto chromosomes 2H, 3H, 5H, 6H, and 7H. Eleven QTL were detected in 3 years and four QTL were detected in 2 years. QTL controlling all seven plant height component traits were found near the dwarfing gene btwd1 on chromosome 7H. These QTL accounted for 27.19 to 59.73% of phenotypic variation in seven plant height component traits. Positive transgressive segregation was found for all traits. Some of the QTL identified in this study will be useful for understanding the dwarfing mechanism and for developing new dwarf varieties using marker-assisted selection.

Two recessive genes controlling thermophotoperiod-sensitive male sterility in wheat

Male sterility of wheat-breeding line 337S (Triticum aestivum L.) is sensitive to both short day-length/low temperature and long day-length/high temperature. 337S was crossed with the common wheat variety, Huamai No. 8 and the F1 was highly fertile. The F2 population segregated in a 15:1 ratio for fertility/sterility in 243 individuals under long day-length/high-temperature. The two thermophotoperiod-responsive male sterile genes were mapped to chromosomes 5B and 2B using Simple Sequence Repeat (SSR) markers and bulked segregant analysis. Partial linkage maps around the sterility loci of chromosomes 2B and 5B were constructed using the 243 individuals in the F2 population. One gene (wptms1) for male sterility was flanked by the SSR markers Xgwm335 and Xgwm371 at a genetic distance in chromosome 5B of 4.1 and 24.4 cM, respectively. The second gene (wptms2) was mapped between markers Xgwm374 and Xgwm120 at a genetic distance of 6.6 and 20.9 cM, respectively. The closest linked markers Xgwm335 (wptms1) and Xgwm374 (wptms2) explained 53 and 38% of phenotypic variation for the fertility. The SSR markers provide a useful tool to transfer the male sterile genes into elite wheat germplasm.

WITHDRAWN: Isolation and Identification of a Multilineage Potential Mesenchymal Cell from Human Placenta

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Mapping and QTL analysis of the barley population Chebec × Harrington

A doubled haploid population of 120 individuals was produced from the parents Chebec, an Australian 2-row barley of feed quality with resistance to the cereal cyst nematode, and Harrington, a 2-rowed, Canadian variety of premium malting quality. This paper describes 18 field and laboratory experiments conducted with the population and summarises the traits mapped and analysed. The genomic location of 25 traits and genes is described and marker–trait associations for 5 traits (malt extract, diastatic power, resistance to cereal cyst nematode, early flowering, resistance to pre-harvest sprouting) important to Australian efforts to improve malting barley varieties have been used in practical breeding programs. Detailed maps for these populations are shown in this paper, while a consensus map incorporating these maps and further experiments on the populations are described elsewhere in this issue.

Mapping and QTL analysis of the barley population Sloop × Halcyon

A genetic linkage map of Hordeum vulgare L. 1280 cM in length, composed of 257 AFLP, RFLP, SNP, and microsatellite markers, has been constructed. The map was based on a doubled haploid population made from the cross Sloop (spring type) × Halcyon (winter type). The genetic map was used to identify qualitative major genes and quantitative trait loci (QTLs) affecting traits related to growth and flowering, grain colour, and disease resistance. Nine QTLs associated with grain colour (brightness, redness, yellowness, blue aleurone colour), plant height, 'intrinsic lateness', awn emergence, response to photoperiod, and spring or winter habit were located on 1H, 2H, 3H, 4H, and 5H. Eight QTLs associated with resistance to scald, net form of net blotch, leaf rust and powdery mildew were identified on chromosomes 1H, 2H, 3H, 4H, 5H, and 7H. The estimated magnitude of the QTL effects ranged from 9 to 85% of the total phenotypic variance. Resistances to leaf scald, net blotch, and leaf rust, and photoperiod and grain colour, were each controlled by at least one major gene.

Conventional and molecular genetic analysis of factors contributing to variation in the timing of heading among spring barley (Hordeum vulgare L.) genotypes grown over a mild winter growing season

Factors contributing to variation in heading date in spring barley were examined in several studies commencing with a survey of developmental variation in a large collection of genotypes and concluding with the molecular genetic analysis of 7 doubled haploid populations. Genotypes varied considerably in their specific responses to photoperiod and vernalisation, and in the duration of a pre-inductive (or juvenile) phase defined in this paper as a 'basic vegetative period'. The latter includes differential genotype responses to ambient temperature and their interaction with photoperiod. Combinations of these largely independent environmental variables account for variation in heading date associated with differences in growing season conditions, particularly geographic region, sowing dates, and cultivar adaptation. Under extended and natural (short) photoperiods, in both summer and winter field plantings, conventional genetic analysis was characterised by simple Mendelian segregation combined with considerable transgressive segregation within distinct early and late flowering subpopulations. Equivalent transgressive segregation characterised molecular genetic analysis that identified 16 quantitative trait loci (QTLs) with contributions ranging from >50% of the variation recorded to <10%. These were dominated by 2 QTLs located on chromosome 2, one of which on 2HS was associated with response to extended photoperiod and the other, located near the centromere, with variation in the duration of the basic vegetative period. As only one population segregated for response to vernalisation, all analyses were restricted to parents and progeny homozygous for no response. Three other QTLs on 1HL, 3HL, and 5HL were primarily associated with vernalised parents and progeny characterised by prostrate seedling growth habits, which questions any assumption of a pleiotrophic association between genes for vernalisation and growth habit.The potential for exploiting markers for selection is considered to be limited by the considerable transgressive segregation observed in lines homozygous for parental alleles, and the limited understanding of the causes of variation in the phenotypic expression of the QTLs identified. Such markers would be useful in the selection of backcrossed progeny and in developing materials for investigating fundamental mechanisms contributing to developmental variation.

Molecular basis of barley quality

The quality of barley for the range of end uses from animal feed to brewing is determined by many genes, making the breeding of new barley varieties difficult. Understanding of the molecular basis of barley quality has been advanced by biochemical studies. More recently, molecular genetic tools are allowing the analysis of the biochemical factors contributing to grain quality. Many genetic loci influencing key quality attributes have been identified by gene mapping. Limited success has been reported in using this information to select for quantitative trait loci for these quality traits in plant breeding. Genomic techniques allowing more detailed analysis of variations in the barley genome in relation to quality promise to extend significantly the value of molecular genetic approaches to barley quality improvement. Definition of the genetic basis of malting quality requires the identification of the genes involved in germination and endosperm modification. Feed quality remains difficult to define. Recent advances are likely to accelerate the rate of discovery, providing new options for analysis of barley quality.

Mapping and validation of the genes for resistance to Pyrenophora teres f. teres in barley (Hordeum vulgare L.)

Identification and deployment of disease resistance genes are key objectives of Australian barley breeding programs. Two doubled haploid (DH) populations derived from Tallon × Kaputar (TK) and VB9524 × ND11231 (VN) crosses were used to identify markers for net type net blotch (NTNB) (Pyrenophora teres f. teres). The maps included 263 and 250 markers for TK and VN populations, respectively. The TK population was screened with 5 pathotypes and the VN population with 1 pathotype of NTNB as seedlings in the glasshouse. In addition, the TK population was subjected to natural infection in the field at Hermitage Research Station, Qld. Analyses of the markers were performed using the software packages MapManager and Qgene. One region on chromosome 6H was strongly associated with resistance to NTNB in both populations (R2 = 83% for TK and 66% for VN). In the TK population, 2 more quantitative trait loci (QTLs) were identified on chromosomes 2H and 3H, with R2 values of 30% and 31%, respectively. These associations were consistent over all pathotypes studied during the seedling stage. The same QTL on chromosome 6H was also found to be highly significantly associated (R2 = 65%) with the adult plant (field) response in the TK population. There are several very closely linked markers showing strong associations in these regions. Association of the 4 markers on chromosome 6H QTL with resistance to the NTNB has been validated in 2 other DH populations derived from barley crosses Pompadour × Stirling and WPG8412 × Stirling. These markers present an opportunity for marker assisted selection of lines resistant to NTNB in barley breeding programs.

Typing Mlo alleles for powdery mildew resistance in barley by single nucleotide polymorphism analysis using MALDI-ToF mass spectrometry

Single nucleotide polymorphisms (SNPs) have been identified in a range of plant genomes. Development of rapid, low-cost methods to enable their validation and implementation as molecular markers is now required for practical applications. We report the development of single and multi-nucleotide primer extension assays to genotype co-dominant SNPs from small quantities of barley leaf tissue. In the single nucleotide primer extension assay, a genotyping primer with its 3′ end directly flanking a SNP was annealed to a target sequence and extended by a single dideoxynucleotide triphosphate complementary to the polymorphic base. In the multi-nucleotide primer extension assay, designed to facilitate allele calling, the genotyping primer with its 3′ end flanking the SNP was extended by either 1 or 2 nucleotides, depending on the allele encountered. Extension products were analysed using MALDI-ToF mass spectrometry and, making use of the molecular weight difference between DNA bases, the incorporated nucleotides were identified by the increase in mass of the extended primers. Based on a SNP identified in the barley Mlo gene, primer extension assays were designed and used for co-dominant marker-assisted selection of barley seedlings segregating for mlo-mediated resistance to powdery mildew. This allowed accurate selection of progeny lines carrying alleles for resistance to powdery mildew, including heterozygotes. Doubled haploid barley progenies were screened for Mlo alleles and a complete correlation between mlo/mlo genotype and resistant phenotype was found The method has been used by barley breeders for routine selection of barley genotypes resistant to powdery mildew.

Mapping and QTL analysis of the barley population Galleon × Haruna Nijo

A genetic linkage map consisting of 435 molecular markers has been constructed using a doubled-haploid mapping population derived from a cross between the Australian barley feed variety Galleon and Haruna Nijo, a Japanese barley cultivar of high malting quality. This map was used to locate the genes conferring CCN and SFNB resistance from Galleon and to locate malting and brewing quality genes from Haruna Nijo. Closely linked markers to the trait loci have been identified and are now being widely implemented in Australian breeding programs.

Mapping and QTL analysis of the barley population Tallon × Kaputar

A genetic map of barley with 224 AFLP and 39 simple sequence repeat (SSR) markers was constructed using a doubled haploid (DH) mapping population from a cross between the varieties Tallon and Kaputar. Linkage groups were assigned to individual barley chromosomes using the published map locations of the SSR markers as reference points. This genetic map was used to identify markers with linkage to agronomic, disease, and quality traits in barley. The population, which comprised 65 lines, was tested in a range of environments across Australia. Quantitative trait loci (QTLs) analyses were performed using software packages MapMaker, MapManager, and Qgene. Significant associations with markers were found for several traits. Grain yield showed significant association with regions on chromosomes 2H, 3H, and 5H over a range of sites throughout Australia. Regions on chromosomes 2H and 3H explained 30% and 26% of variation in lodging, respectively. Among quality traits, diastatic power was associated with regions on chromosomes 1H, 2H, and 5H (R2 = 37%). Hot water extract was associated with a region on chromosome 6H and a marker not assigned to a chromosome (R2 = 45%). There were also environment-specific QTLs for the traits analysed. The markers identified here present an opportunity for marker assisted selection of lines for these traits in barley breeding programs.Mapping and QTL analysis of Tallon × Kaputar

Quantitative trait loci controlling kernel discoloration in barley (Hordeum vulgare L.)

Barley kernel discoloration (KD) leads to substantial annual loss in value through downgrading and discounting of malting barley. KD is a difficult trait to introgress into elite varieties as it is controlled by multiple genes and strongly influenced by environment and maturity. As the first step towards marker assisted selection for KD tolerance, we mapped quantitative trait loci (QTLs) controlling KD measured by grain brightness [Minolta L; (Min L)], redness (Min a), and yellowness (Min b) in 7 barley populations. One to 3 QTLs were detected for grain brightness in various populations, and one QTL could account for 5–31% of the phenotypic variation. The QTL located around the centromere region of chromosome 2H was consistently detected in 6 of the 7 populations, explaining up to 28% of the phenotypic variation. In addition, QTLs for grain brightness were most frequently identified on chromosomes 3H and 7H in various populations. Australian varieties Galleon, Chebec, and Sloop contribute an allele to increase grain brightness on chromosome 7H in 3 different populations. A major gene effect was detected for grain redness. One QTL on chromosome 4H explained 54% of the phenotypic variation in the Sloop/Halcyon population, and was associated with the blue aleurone trait. A second QTL was detected on the long arm of chromosome 2H in 3 populations, accounting for 23–47% of the phenotypic variation. The major QTLs for grain yellowness were mapped on chromosomes 2H and 5H. There were strong associations between the QTLs for heading date, grain brightness, and yellowness. The molecular markers linked with the major QTLs should be useful for marker assisted selection for KD.

A major QTL controlling seed dormancy and pre-harvest sprouting/grain α-amylase in two-rowed barley (Hordeum vulgare L.)

Barley seed dormancy is controlled by multiple genes that have a strong interaction with the environment. Lack of adequate dormancy results in pre-harvest sprouting in the field under wet weather conditions. On the other hand, too much dormancy has a detrimental effect in the malting house. There is only a very 'narrow window' of dormancy for malting barley. Harrington barley, which has been a dominant malting variety in the international market and widely used in Australia barley breeding programs, is highly susceptible to pre-harvest sprouting. A doubled haploid (DH) population derived from a cross of Chebec/Harrington was used to search for molecular markers linked with seed dormancy and pre-harvest sprouting. One major quantitative trait locus (QTL) was identified to control pre-harvest sprouting measured by α-amylase activity in barley grains, and could explain >70% of the phenotypic variation. This QTL was located on chromosome 5HL and flanked by restriction fragment length polymorphism (RFLP) marker CDO506 and simple sequence repeat (SSR) marker GMS1. The SSR marker (GMS1) linked with this QTL was further validated in a Stirling/Harrington DH population. A minor QTL on chromosome 2H accounted for 8% of phenotypic variation. Two QTLs for seed dormancy were located on chromosomes 2H and 5HL. The major QTL for dormancy coincided with the QTL for pre-harvest sprouting at chromosome 5HL and explained 61% of phenotypic variation. Since the presence of the Harrington allele at this locus favoured not only pre-harvest sprouting, but also increased malting extract, diastatic power, α-amylase, and free amino acid nitrogen, development of high malting quality varieties with pre-harvest sprouting tolerance would appear to be difficult.

[Relationship between memory enhancement induced by nitric oxide donor and brain ADP-ribosyltransferase in rats]

In order to explore the signal transduction pathway of nitric oxide (NO) related to learning and memory, the effects of intracerebral ventricular injection (icv) of NO donor sodium nitroprusside (SNP) alone or along with ADP-ribosyltransferase (ADPRT) inhibitor nicotinamide (NIC) on learning and memory behavior were investigated in rats. Brain ADPRT activity was analyzed using high performance liquid chromatography. The results showed that SNP (0.36 microgram, icv) facilitated short-term and long-term memory in passive avoidance response and elevated learning and memory ability in active avoidance response. NIC (1.5 mg, icv) blocked the effect of SNP. Training in active avoidance task raised ADPRT activity in hippocampus. Treatment with SNP (icv) before training caused significant elevation of ADPRT activity in hippocampus and cerebral cortex. The results above support the view that ADPRT may be one of the target molecules of NO action.

NH-S hydrogen bonding in zinc enzyme model complex with S2N2 binding set studied by normal coordinate analysis of vibrational spectra

In order to provide theoretical evidence for the existence and effect of NH-S hydrogen bonding in the zinc enzyme model complex [Zn(S-2-C6H4NHCOC6H5)2(1-MeIm)2] (1-MeIm = 1-methylimidazole) in addition to the spectroscopic and crystallographic investigations, normal coordinate analysis (NCA) was carried out using a modified Urey-Bradley force field. The vibrational frequencies of the complex with and without the NH-S hydrogen bonding as well as the corresponding internal coordinates were obtained. The good agreement found between the calculated and observed frequencies in the presence of the NH-S hydrogen bond, supports the reliability of the analysis. The stretching force constant of the NH-S hydrogen bond obtained from the calculation is 0.18 mdyne per A. The calculation shows that the N-H bond is weakened by formation of the NH-S hydrogen bond. The results are indicative of the existence of the NH-S hydrogen bond in the complex.

Structure, hormonal regulation, and chromosomal location of genes encoding barley (1-->4)-beta-xylan endohydrolases

A gene encoding (1-->4)-beta-xylan xylanohydrolase (EC 3.2.1.8) isoenzyme X-I has been isolated from a barley genomic library and the nucleotide sequence of a 2704-bp fragment defined. The gene contains a single intron of 91 bp in the coding region of the mature enzyme and additional introns may be present in the 5'-untranslated region. Expression of the xylanase gene is restricted to the aleurone layer of germinated grain, where the phytohormone gibberellic acid induces both transcriptional activity of the gene and the secretion of active enzyme from the layers. Abscisic acid abolishes the gibberellic acid induction of xylanase gene expression. The hormonal responses are consistent with the presence of promoter sequences, all of which are within 150 bp of the putative transcription start site, that have been implicated as cis-acting elements within gibberellic acid response complexes in plant genes. The elements include a pyrimidine box, CTCTTTCC, together with TAACGAC and TATCCAT boxes. Three genes encode (1-->4)-beta-xylanase isoenzymes in barley and these have been mapped on the barley genome using two doubled haploid populations and seven wheat-barley addition lines. The three xylanase genes are closely linked on the long arm of chromosome 7 (5H). No recombination was detected between the genes in 234 doubled haploid lines. The genes are flanked by the RFLP markers CDO506 on the proximal side and PSR370 at the distal end.

Seven members of the (1→3)-β-glucanase gene family in barley (Hordeum vulgare) are clustered on the long arm of chromosome 3 (3HL)

Members of the (1→3)-β-glucan glucanohydrolase (EC 3.2.1.39) gene family have been mapped on the barley genome using three doubled haploid populations and seven wheat-barley addition lines. Specific probes or polymerase chain reaction (PCR) primers were generated for the seven barley (1→3)-β-glucanase genes for which cDNA or genomic clones are currently available. The seven genes are all located on the long arm of chromosome 3 (3HL), and genes encoding isoenzymes GI, GII, GIII, GIV, GV and GVII (ABG2) are clustered in a region less than 20 cM in length. The region is flanked by the RFLP marker MWG2099 on the proximal side and the Barley Yellow Mosaic Virus (BYMV) resistance gene ym4 at the distal end. The gene encoding isoenzyme GVI lies approximately 50 cM outside this cluster, towards the centromere. With the exception of the gene encoding isoenzyme GIV, all of the (1→3)-β-glucanase genes are represented by single copies on the barley genome. The probe for the isoenzyme GIV gene hybridized with four DNA bands during Southern blot analysis, only one of which could be incorporated into the consensus linkage map.

Detection of loss of heterozygosity of p53 gene in paraffin-embedded breast cancers by non-isotopic PCR-SSCP

A rapid non-isotopic PCR-SSCP (polymerase chain reaction-single-stranded conformation polymorphism) method was developed in this study to detect polymorphism and loss of heterozygosity (LOH) of p53 in formalin-fixed and paraffin-embedded samples of normal breast tissue and of breast cancer. p53 expression was also examined by immunohistochemistry. In 35 paired samples, heterozygosity in exon 4 of p53 was detected in 17 cases (49 per cent) and LOH of the p53 gene in breast cancer tissues was observed in 7 out of 15 informative cases (47 per cent). The correlation of LOH of p53 with positive p53 immunostaining did not reach statistical significance, but all immunostaining-positive tumours among informative cases had LOH of p53. The results support the hypothesis that in most cases the allelic deletion of p53 may uncover the 'recessive mutation' in the remaining allele. However, LOH of p53 was more frequent than positive immunostaining and was significantly associated with poor differentiation of breast cancer (P < 0.05). The results suggest that the allelic deletion of p53 may also contribute to the development and progression of breast cancer by reducing the amount of normal p53 protein. These results show that non-isotopic PCR-SSCP is a simple, fast, and effective method for detecting polymorphism and LOH of the p53 gene, which is especially useful for retrospective studies.

[A comparison of proliferating cell nuclear antigen immunostaining, nucleolar organizer region staining in lung cancer]

Seventy-three cases of lung cancer were studied using two different methods, immunostaining for the proliferating cell nuclear antigen (PCNA) and nucleolar organizer region staining (AgNORs), to assess the degree of cell proliferation. Both PCNA immunostaining and AgNOR staining were found to be significantly correlated with histological grade of lung cancer. The mean number of AgNOR per nucleus was found to be associated with LI of PCNA (r = 0.70, P < 0.01). The results suggest that the two proliferation-associated factors may be used as the additional diagnostic parameters in the grading of lung cancer.

Solitary adrenal metastasis from hepatocellular carcinoma: a case report of simultaneous successful resections

The case is presented of a 64-year-old male with a left adrenal mass and multiple liver lesions. Preoperative image work-ups included ultrasonography, computed tomography, selective liver and adrenal angiographies, and magnetic resonance imaging. Serial serum alpha-fetoprotein monitoring and the adrenal hormone profile were within the normal ranges. A left adrenalectomy and a right lobectomy of the liver were performed, and the pathology revealed hepatocellular carcinoma with left adrenal metastasis. The clinical significance of the present case, together with the diagnosis and management of the disease is discussed.

Spinal cord substance P mediates carbachol-induced cardiovascular responses from the rostral ventrolateral medulla

Intrathecal (i.t.) infusion of substance P (SP) antagonist, (D-Pro2, D-Trp7,9)-substance P (20 micrograms), lowered blood pressure profoundly without any significant change of heart rate. The hypertensive and tachycardic responses elicited by microinjection of carbachol (25 ng/site) into the bilateral rostral ventrolateral medulla (rVLM) were blocked by i.t. infusion of SP antagonist. These data provided evidence that an excitatory cardiovascular effect induced by cholinergic system in rVLM may be mediated mainly by the SP receptors in spinal cord.

Solubilization of murine melanoma xylosyltransferase and galactosyltransferase activities and their inactivation by dialdehyde nucleosides

The enzymes involved in the initial steps in the biosynthesis of glycosaminoglycans were examined in the murine B16 melanoma. Approximately 60% of the melanoma xylosyltransferase activity and nearly all of the galactosyltransferase activity were membrane-bound; these enzymatic activities were solubilized by treatment with Nonidet P-40 and potassium chloride, and the Michaelis constants for the substrates and acceptor molecules were determined and found to be comparable to those reported for these enzymes from the chick embryo and a rat chondrosarcoma. Dialdehyde nucleosides, which have been reported to alter the activity of several enzymes involved in nucleic acid synthesis, inhibited both xylosyltransferase and galactosyltransferase activities, with galactosyltransferase being considerably less sensitive than xylosyltransferase. The inhibition of xylosyltransferase by dialdehyde nucleosides was irreversible, with no apparent specificity for the base moiety of the dialdehyde nucleosides.