mTOR-dependent loss of PON1 secretion and antiphospholipid autoantibody production underlie autoimmunity-mediated cirrhosis in transaldolase deficiency.

Transaldolase deficiency predisposes to chronic liver disease progressing from cirrhosis to hepatocellular carcinoma (HCC). Transition from cirrhosis to hepatocarcinogenesis depends on mitochondrial oxidative stress, as controlled by cytosolic aldose metabolism through the pentose phosphate pathway (PPP). Progression to HCC is critically dependent on NADPH depletion and polyol buildup by aldose reductase (AR), while this enzyme protects from carbon trapping in the PPP and growth restriction in TAL deficiency. Although AR inactivation blocked susceptibility to hepatocarcinogenesis, it enhanced growth restriction, carbon trapping in the non-oxidative branch of the PPP and failed to reverse the depletion of glucose 6-phosphate (G6P) and liver cirrhosis. Here, we show that inactivation of the TAL-AR axis results in metabolic stress characterized by reduced mitophagy, enhanced overall autophagy, activation of the mechanistic target of rapamycin (mTOR), diminished glycosylation and secretion of paraoxonase 1 (PON1), production of antiphospholipid autoantibodies (aPL), loss of CD161+ NK cells, and expansion of CD38+ Ito cells, which are responsive to treatment with rapamycin in vivo. The present study thus identifies glycosylation and secretion of PON1 and aPL production as mTOR-dependent regulatory checkpoints of autoimmunity underlying liver cirrhosis in TAL deficiency.

A splicing-regulatory polymorphism in DRD2 disrupts ZRANB2 binding, impairs cognitive functioning and increases risk for schizophrenia in six Han Chinese samples.

The rs1076560 polymorphism of DRD2 (encoding dopamine receptor D2) is associated with alternative splicing and cognitive functioning; however, a mechanistic relationship to schizophrenia has not been shown. Here, we demonstrate that rs1076560(T) imparts a small but reliable risk for schizophrenia in a sample of 616 affected families and five independent replication samples totaling 4017 affected and 4704 unaffected individuals (odds ratio=1.1; P=0.004). rs1076560(T) was associated with impaired verbal fluency and comprehension in schizophrenia but improved performance among healthy comparison subjects. rs1076560(T) also associated with lower D2 short isoform expression in postmortem brain. rs1076560(T) disrupted a binding site for the splicing factor ZRANB2, diminished binding affinity between DRD2 pre-mRNA and ZRANB2 and abolished the ability of ZRANB2 to modulate short:long isoform-expression ratios of DRD2 minigenes in cell culture. Collectively, this work implicates rs1076560(T) as one possible risk factor for schizophrenia in the Han Chinese population, and suggests molecular mechanisms by which it may exert such influence.

Cytosolic aldose metabolism contributes to progression from cirrhosis to hepatocarcinogenesis.

Oxidative stress modulates carcinogenesis in the liver; however, direct evidence for metabolic control of oxidative stress during pathogenesis, particularly, of progression from cirrhosis to hepatocellular carcinoma (HCC), has been lacking. Deficiency of transaldolase (TAL), a rate-limiting enzyme of the non-oxidative branch of the pentose phosphate pathway (PPP), restricts growth and predisposes to cirrhosis and HCC in mice and humans. Here, we show that mitochondrial oxidative stress and progression from cirrhosis to HCC and acetaminophen-induced liver necrosis are critically dependent on NADPH depletion and polyol buildup by aldose reductase (AR), while this enzyme protects from carbon trapping in the PPP and growth restriction in TAL deficiency. Both TAL and AR are confined to the cytosol; however, their inactivation distorts mitochondrial redox homeostasis in opposite directions. The results suggest that AR acts as a rheostat of carbon recycling and NADPH output of the PPP with broad implications for disease progression from cirrhosis to HCC.

Early treatment with zoledronic acid prevents bone loss at the hip following acute spinal cord injury.

UNLABELLED: Osteoporosis after spinal cord injury is common. Reductions in bone density are rapid and fracture rates are higher after injury. Early treatment with 4 mg zoledronic acid significantly reduced bone loss at the hip compared to untreated individuals in the first year. Treatment appeared safe and well tolerated. INTRODUCTION: Bone mineral density (BMD) is lost rapidly following spinal cord injury (SCI), predominantly in the lower limbs. Bone turnover markers suggest an early increase in resorption. METHODS: A randomised, open-label study of 14 patients with acute SCI randomised to receive 4 mg IV zoledronic acid or standard treatment. BMD was measured by dual-X-ray absorptiometry at the lumbar spine and hip (femoral neck, total and trochanter) at baseline, 3, 6 and 12 months. Bone turnover markers (serum C-terminal telopeptide and Procollagen I N-terminal peptide and urinary N-terminal telopeptide/Cr ratio) were also measured. RESULTS: After 12 months, there was a significant difference in BMD between the groups at the total hip (12.4%, p = 0.005), trochanter (13.4%, p = 0.028) and lumbar spine (2.7%, p = 0.033). However, the difference between groups at the femoral neck was not significant (4.8%, p = 0.741). In the treated group, bone resorption was reduced and remained reduced up to 12 months. Other than flu-like symptoms immediately after the infusion, no adverse events were observed. CONCLUSION: IV zoledronic acid is an effective and well-tolerated treatment to prevent bone mineral density loss at the total hip and trochanter for up to 12 months following SCI.

Anatomical evidence for cerebellar and basal ganglia involvement in higher cognitive function.

The possibility that neurons in the basal ganglia and cerebellum innervate areas of the cerebral cortex that are involved in cognitive function has been a controversial subject. Here, retrograde transneuronal transport of herpes simplex virus type 1 (HSV1) was used to identify subcortical neurons that project via the thalamus to area 46 of the primate prefrontal cortex. This cortical area is known to be involved in spatial working memory. Many neurons in restricted regions of the dentate nucleus of the cerebellum and in the internal segment of the globus pallidus were labeled by transneuronal transport of virus from area 46. The location of these neurons was different from those labeled after HSV1 transport from motor areas of the cerebral cortex. These observations define an anatomical substrate for the involvement of basal ganglia and cerebellar output in higher cognitive function.

Relationship between gut-specific autonomic testing and bowel dysfunction in spinal cord injury patients.

STUDY DESIGN: Investigation of bowel function in 55 patients and 26 healthy volunteers using radiological, anorectal physiological and laser Doppler blood flow monitoring. OBJECTIVES: Bowel dysfunction is common after spinal cord injury (SCI). We aimed to determine whether hindgut testing of autonomic innervation provides insight into presence of symptoms, altered motor function (transit) and level of injury. SETTING: St Mark's Hospital, UK and The Spinal Injuries Unit, Royal National Orthopaedic Hospital, UK. METHODS: A total of 55 patients with chronic complete SCI and 26 healthy volunteers were studied. Twenty-four patients had lesions above T5 and 31 had lesions below T5. Thirty-five patients complained of constipation: 75% (18/24) of patients with lesions above T5 and 55% (17/31) of those with lesions below T5. Gut transit, rectal electrosensitivity and rectal blood flow were measured. RESULTS: Slow gut transit occurred in 65% of patients and in all the 35 patients complaining of constipation. Delay was pancolonic. All patients had an elevated sensory threshold. The threshold was significantly higher in those with subjective constipation (P<0.01), slow transit (P<0.04) and high SCI (P=0.046). Mucosal blood flow was lower in SCI patients with constipation (P<0.04) and slow transit (P<0.03). It was higher than normal in high-SCI volunteers (P=0.056), reflecting loss of sympathetic inhibition. CONCLUSIONS: In SCI, subjective constipation correlates closely with slow gut transit. Delay is pancolonic, regardless of the site of lesion. Sensory testing provides evidence for completeness of lesion, offering further evidence for pain transmission through sympathetic pathways. Studies in SCI patients provide further evidence of mucosal blood flow as a marker of altered autonomic innervation.

Molecular characterization of schizophrenia viewed by microarray analysis of gene expression in prefrontal cortex.

Microarray expression profiling of prefrontal cortex from matched pairs of schizophrenic and control subjects and hierarchical data analysis revealed that transcripts encoding proteins involved in the regulation of presynaptic function (PSYN) were decreased in all subjects with schizophrenia. Genes of the PSYN group showed a different combination of decreased expression across subjects. Over 250 other gene groups did not show altered expression. Selected PSYN microarray observations were verified by in situ hybridization. Two of the most consistently changed transcripts in the PSYN functional gene group, N-ethylmaleimide sensitive factor and synapsin II, were decreased in ten of ten and nine of ten subjects with schizophrenia, respectively. The combined data suggest that subjects with schizophrenia share a common abnormality in presynaptic function. We set forth a predictive, testable model.

Integrating genetic, functional genomic, and bioinformatics data in a systems biology approach to complex diseases: application to schizophrenia.

The search for DNA alterations that cause human disease has been an area of active research for more than 50 years, since the time that the genetic code was first solved. In the absence of data implicating chromosomal aberrations, researchers historically have performed whole genome linkage analysis or candidate gene association analysis to develop hypotheses about the genes that most likely cause a specific phenotype or disease. Whereas whole genome linkage analysis examines all chromosomal locations without a priori predictions regarding what genes underlie susceptibility, candidate gene association studies require a researcher to know in advance the genes that he or she wishes to test (based on their knowledge of a disease). To date, very few whole genome linkage studies and candidate gene studies have produced results that lead to generalizable findings about common diseases. One factor contributing to this lack of results has certainly been the previously limited resolution of the techniques. Recent technological advances, however, have made it possible to perform highly informative whole genome linkage and association analyses, as well as whole genome transcription (transcriptome) analysis. In addition, for the first time we can detect structural DNA aberrations throughout the genome on a fine scale. Each of these four approaches has its own strengths and weaknesses, but taken together, the results from an integrated analysis can implicate highly promising novel candidate genes. Here, we provide an overview of the integrated methodology that we have used to combine high-throughput genetic and functional genomic data with bioinformatics data that have produced new insights into the potential biological basis for schizophrenia. We believe that the potential of this combined approach is greater than that of a single mode of discovery, particularly for complex genetic diseases.

The cerebellum: an overview.

Life has been compared to a beautiful tapestry, woven in intricate design of many threads and colors. By means of physics, chemistry, physiology, anatomy, embryology and genetics we unravel this texture, separate its constituent threads and colors, but lose the pattern as a whole. These analytical sciences have enormously increased our knowledge of life's constituent elements and processes, but the pattern of the tapestry is usually neglected or ignored.

Analysis of complex brain disorders with gene expression microarrays: schizophrenia as a disease of the synapse.

The level of cellular and molecular complexity of the nervous system creates unique problems for the neuroscientist in the design and implementation of functional genomic studies. Microarray technologies can be powerful, with limitations, when applied to the analysis of human brain disorders. Recently, using cDNA microarrays, altered gene expression patterns between subjects with schizophrenia and controls were shown. Functional data mining led to two novel discoveries: a consistent decrease in the group of transcripts encoding proteins that regulate presynaptic function; and the most changed gene, which has never been previously associated with schizophrenia, regulator of G-protein signaling 4. From these and other findings, a hypothesis has been formulated to suggest that schizophrenia is a disease of the synapse. In the context of a neurodevelopmental model, it is proposed that impaired mechanics of synaptic transmission in specific neural circuits during childhood and adolescence ultimately results in altered synapse formation or pruning, or both, which manifest in the clinical onset of the disease.

A benign psoas mass following metal-on-metal resurfacing of the hip.

As metal-on-metal arthroplasty becomes more widespread, concerns are being raised about the potential dangers of metal particulate debris. We present the case of a benign psoas mass secondary to the presence of such particles. The mass was excised and the hip resurfacing subsequently revised to a total hip replacement.

The efficacy of intra-articular bupivacaine for relief of pain following arthroscopy of the ankle.

The intra-articular injection of local anaesthetic is frequently used for pain relief after arthroscopy. There is, however, no published evidence of the analgesic effect of bupivacaine in the ankle. In a randomised, double-blind study, 35 patients undergoing arthroscopy of the ankle were allocated to receive intra-articular saline or bupivacaine. Pain was assessed using pain scores and additional analgesic requirements. Intra-articular bupivacaine had a significant analgesic effect in the immediate post-operative period, reducing pain scores and the need for additional analgesics. We recommend the use of intra-articular bupivacaine for post-operative analgesia in ankle surgery.

Cerebellar projections to the prefrontal cortex of the primate.

The cerebellum is known to project via the thalamus to multiple motor areas of the cerebral cortex. In this study, we examined the extent and anatomical organization of cerebellar input to multiple regions of prefrontal cortex. We first used conventional retrograde tracers to map the origin of thalamic projections to five prefrontal regions: medial area 9 (9m), lateral area 9 (9l), dorsal area 46 (46d), ventral area 46, and lateral area 12. Only areas 46d, 9m, and 9l received substantial input from thalamic regions included within the zone of termination of cerebellar efferents. This suggested that these cortical areas were the target of cerebellar output. We tested this possibility using retrograde transneuronal transport of the McIntyre-B strain of herpes simplex virus type 1 from areas of prefrontal cortex. Neurons labeled by retrograde transneuronal transport of virus were found in the dentate nucleus only after injections into areas 46d, 9m, and 9l. The precise location of labeled neurons in the dentate varied with the prefrontal area injected. In addition, the dentate neurons labeled after virus injections into prefrontal areas were located in regions spatially separate from those labeled after virus injections into motor areas of the cerebral cortex. Our observations indicate that the cerebellum influences several areas of prefrontal cortex via the thalamus. Furthermore, separate output channels exist in the dentate to influence motor and cognitive operations. These results provide an anatomical substrate for the cerebellum to be involved in cognitive functions such as planning, working memory, and rule-based learning.

Cerebellar output: motor and cognitive channels.

The input to the cerebellum has long been known to originate from widespread regions of the cerebral cortex including the frontal, parietal and temporal lobes. The output of the cerebellum, however, was thought to project mainly to the primary motor cortex. Recent anatomical observations have challenged this view. It is now apparent that cerebellar output goes to multiple cortical areas, including not only the primary motor cortex, but also areas of premotor and prefrontal cortex. In fact, there is growing evidence that each of the areas of cerebral cortex that project to the cerebellum is also the target of cerebellar output. The cerebellar output to individual cortical areas originates from distinct clusters of neurons in the deep nuclei which we have termed `output channels'. The individual output channels to the cortical areas we have examined display little or no overlap. Physiological recordings in awake trained primates indicate that neurons in different output channels appear to be involved in distinct aspects of behavior, and in both motor and cognitive functions. These observations indicate that the cerebellar influence on the cerebral cortex is more extensive than previously recognized.

Brain abscess caused by Cladosporium trichoides.

In 17 previously reported cases of cladosporiosis, no reliable therapy was described, and death occurred usually within one year of diagnosis. Pretreatment isolates from our two patients were inhibited by 6.2 mug/ml and 3.1mug/ml of flucytosine, respectively. Although both patients died, postmortem examination results showed that in one patient, the fungus had been eradicated. In the other patient, C trichoides that was isolated at postmortem examination was resistant to flucytosine treatment.

Cold injury amputees--a psychosocial problem?

The rehabilitation of 8 cold injury lower limb amputees is described, 7 of whom were alcoholic and had significant personality disorders. Delayed wound healing was the only common physical problem but the psychosocial difficulties were substantial and were the principal determinant of outcome following rehabilitation.

Does cyclical loading affect the elution of antibiotics from articulating cement knee spacers?

Two-stage revision surgery for infected total knee replacement offers the highest rate of success for the elimination of infection. The use of articulating antibiotic-laden cement spacers during the first stage to eradicate infection also allows protection of the soft tissues against excessive scarring and stiffness. We have investigated the effect of cyclical loading of cement spacers on the elution of antibiotics. Femoral and tibial spacers containing vancomycin at a constant concentration and tobramycin of varying concentrations were studied in vitro. The specimens were immersed and loaded cyclically to 250 N, with a flexion excursion of 45°, for 35 000 cycles. The buffered solution was sampled at set intervals and the antibiotic concentration was established so that the elution could be calculated. Unloaded samples were used as a control group for statistical comparison. The elution of tobramycin increased proportionately with its concentration in cement and was significantly higher at all sampling times from five minutes to 1680 minutes in loaded components compared with the control group (p = 0.021 and p = 0.003, respectively). A similar trend was observed with elution of vancomycin, but this failed to reach statistical significance at five, 1320 and 1560 minutes (p = 0.0508, p = 0.067 and p = 0.347, respectively). However, cyclically loaded and control components showed an increased elution of vancomycin with increasing tobramycin concentration in the specimens, despite all components having the same vancomycin concentration. The concentration of tobramycin influences both tobramycin and vancomycin elution from bone cement. Cyclical loading of the cement spacers enhanced the elution of vancomycin and tobramycin.