Assessment of Osteoporosis at the Lumbar Spine Using Ultrashort Echo Time Magnetization Transfer (UTE-MT) MRI

BACKGROUND

Bone collagen-matrix contributes to the mechanical properties of bone by imparting tensile strength and elasticity, which can be indirectly quantified by ultrashort echo time magnetization transfer ratio (UTE-MTR) to assess osteoporosis.

PURPOSE

To evaluate osteoporosis at the human lumbar spine using UTE-MTR.

STUDY TYPE

Prospective.

POPULATION

One hundred forty-eight-volunteers (age-range, 50-85; females, N = 90), including 81-normal bone density, 35-osteopenic, and 32-osteoporotic subjects. Ten additional healthy volunteers were recruited to study the intrasession reproducibility of the UTE-MT.

FIELD STRENGTH/SEQUENCE

3T/UTE-MT, short repetition-time adiabatic inversion recovery prepared UTE (STAIR-UTE), and iterative decomposition of water-and-fat with echo-asymmetry and least-squares estimation (IDEAL-IQ).

ASSESSMENT

Fracture risk was calculated using Fracture-Risk-Assessment-Tool (FRAX). Region-of-interests (ROIs) were delineated on the trabecular area in the maps of bone-mineral-density, UTE-MTR, collagen-bound water proton-fraction (CBWPF), and bone-marrow fat fraction (BMFF).

STATISTICAL TESTS

Linear-regression and Bland-Altman analysis were performed to assess the reproducibility of UTE-MTR measurements in the different scans. UTE-MTR and BMFF were correlated with bone-mineral-density using Pearson's regression and with FRAX scores using nonlinear regression. The abilities of UTE-MTR, CBWPF, and BMFF to discriminate between the three patient subgroups were evaluated using receiver-operator-characteristic (ROC) analysis and area-under-the-curve (AUC). Decision-curve-analysis (DCA) and clinical-impact curves were used to evaluate the value of UTE-MTR in clinical diagnosis. The DeLong test was used to compare the ROC curves. P-value <0.05 was considered statistically significant.

RESULTS

Excellent reproducibility was obtained for the UTE-MT measurements. UTE-MTR strongly correlated with bone-mineral-density (r = 0.76) and FRAX scores (r = -0.77). UTE-MTR exhibited higher AUCs (≥0.723) than BMFF, indicating its superior ability to distinguish between the three patient subgroups. The DCA and clinical-impact curves confirmed the diagnostic value of UTE-MTR. UTE-MTR and CBWPF showed similar performance in correlation with bone-mineral-density and cohort classification.

DATA CONCLUSION

UTE-MTR strongly correlates with bone-mineral-density and FRAX and shows great potential in distinguishing between normal, osteopenic, and osteoporotic subjects.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

Rhegmatogenous retinal detachment in highly myopic eyes with implantable collamer lens

AIM

To investigate the clinical characteristics, treatment methods and outcomes of rhegmatogenous retinal detachment (RRD) in highly myopic eyes with implantable collamer lens (ICL).

METHODS

High myopia patients who received treatment for nontraumatic RRD after ICL implantation surgery at the Retinal Department of Zhongshan Ophthalmic Center from Jan 2018 to Dec 2022 were reviewed. Comprehensive ophthalmologic examinations including visual acuity measurement and digital fundus photography were performed in each patient.

RESULTS

A total of nine RRD eyes from nine patients who received V4c-ICL implantation were included. The mean time from ICL implantation surgery to the diagnosis of RRD was 32.44±22.56mo (range, 1-60mo). At the initial visit for RRD, giant retinal tear (GRT), horseshoe tear, simple round hole, and horseshoe tear combined with round hole were detected in 3, 3, 2, and 1 eye(s), respectively, with macula-off in eyes. Eight patients received surgical treatment, and one patient was treated by retinal laser photocoagulation alone. The ICL was preserved in 7 eyes. At the last follow-up, the mean best corrected visual acuity (BCVA) improved significantly from 1.76±1.06 logMAR at presentation to 0.81±1.01 logMAR (P=0.035), and no case of recurrent retinal detachment was found.

CONCLUSION

The morphological presentation of retinal breaks is diverse in this study. The ICL can be preserved in most cases during the course of retinal detachment repair surgery in our data, companied with acceptable visual and anatomical outcomes.

Histone deacetylase inhibitor pracinostat suppresses colorectal cancer by inducing CDK5-Drp1 signaling-mediated peripheral mitofission

Divisions at the periphery and midzone of mitochondria are two fission signatures that determine the fate of mitochondria and cells. Pharmacological induction of excessively asymmetric mitofission-associated cell death (MFAD) by switching the scission position from the mitochondrial midzone to the periphery represents a promising strategy for anticancer therapy. By screening a series of pan-inhibitors, we identified pracinostat, a pan-histone deacetylase (HDAC) inhibitor, as a novel MFAD inducer, that exhibited a significant anticancer effect on colorectal cancer (CRC) in vivo and in vitro. Pracinostat increased the expression of cyclin-dependent kinase 5 (CDK5) and induced its acetylation at residue lysine 33, accelerating the formation of complex CDK5/CDK5 regulatory subunit 1 and dynamin-related protein 1 (Drp1)-mediated mitochondrial peripheral fission. CRC cells with high level of CDK5 (CDK5-high) displayed midzone mitochondrial division that was associated with oncogenic phenotype, but treatment with pracinostat led to a lethal increase in the already-elevated level of CDK5 in the CRC cells. Mechanistically, pracinostat switched the scission position from the mitochondrial midzone to the periphery by improving the binding of Drp1 from mitochondrial fission factor (MFF) to mitochondrial fission 1 protein (FIS1). Thus, our results revealed the anticancer mechanism of HDACi pracinostat in CRC via activating CDK5-Drp1 signaling to cause selective MFAD of those CDK5-high tumor cells, which implicates a new paradigm to develop potential therapeutic strategies for CRC treatment.

Management of deep sacral and ischial pressure injuries with free-style local perforator flaps: A D+P+DPD model

BACKGROUND

Previous reports on the treatment of sacral and ischial pressure injuries have not provided clear algorithms for surgical therapies. The objective of this study was to establish a reconstruction algorithm to guide the selection of an ideal free-style perforator flap that can be tailored to the defect in question.

METHODS

We used 23 perforator flaps to reconstruct 14 sacral and 8 ischial defects in 22 patients over 5 years. A reconstruction algorithm system was developed based on the anatomical features of the perforator vessels (diameter, D; pulsatility [++∼+++], P) and their position in the skin island (DPD) (ie, D+P+DPD). A perforator-based propeller flap was applied as the first-line choice; if this plan was not feasible, we applied an altered V-Y advancement model or another second-choice technique.

RESULTS

All flaps survived, and only 1 patient experienced partial wound dehiscence, which healed by secondary intention. After an average follow-up period of 11.2 months, no patient experienced recurrence or infection.

CONCLUSIONS

Free-style perforator flap selection is determined by pressure injury and the desired advantage of a specific approach. The use of free-style perforator-based propeller flaps allows a surgeon to transfer healthy tissue into the defect, shifts the suture line away from the bony prominence, and preserves additional future donor sites. In cases where unexpected variations are encountered, the V-Y advancement model or another technique can be used. The simplified surgical algorithm (D+P+DPD) can provide versatility and reliability, achieve a durable, natural esthetic outcome, and minimize injuries to future donor sites.

Association between Systolic Blood Pressure and Diabetic Retinopathy in Both Hypertensive and Normotensive Patients with Type 2 Diabetes: Risk Factors and Healthcare Implications

A common diabetes-related microvascular complication is diabetic retinopathy (DR), yet associations between blood pressure (BP) and risks for DR in diabetic patients with normal BP received inadequate attention. This may lead to 'clinical inertia' in early DR prevention. We aimed to assess whether the extent to which systolic BP levels were associated with DR in patients with type 2 diabetes (T2DM) and normal BP were similar to that in those with concurrent hypertension. Data were collected from patients with T2DM attending ophthalmic check-up with primary care referral (n = 2510). BP measurements, clinical laboratory tests, and dilated fundus examination were conducted according to gold standard of diagnosis and routine clinical procedure. Of all subjects, over 40% were normotensive and one fifth were clinically diagnosed with DR. Systolic BP levels increased across DR categories of escalated severity irrespective of the coexistence of hypertension. Ordinal logistic regression analysis showed that an increased systolic BP was independently and significantly associated with DR (adjusted odds ratio [aOR] = 1.020, p < 0.001 for hypertensives; aOR = 1.019, p = 0.018 for normotensives), after adjusting for diabetes duration, sex, lifestyles, and haemoglobin A1c levels. Regular monitoring of systolic BP should not be neglected in routine diabetes management even when BP falls within the normal range. (200 words).

Comparative Proteome Identifies Complement Component 3-Mediated Immune Response as Key Difference of Colon Adenocarcinoma and Rectal Adenocarcinoma

Colorectal cancer (CRC) is one of the most lethal diseases with high morbidity and mortality worldwide. Clinically, tumors located in colon and rectum have diverse prognosis and therapeutic outcome. Here, we performed data mining derived from 20 CRC patient samples to compare proteomic difference between colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ). We found that differential expressed proteins (DEPs) upregulated in COAD were mainly enriched in immune response, moreover, higher immune scores were found in COAD than READ, as calculated by The Cancer Genome Atlas (TCGA) data. To identify the core protein of DEPs with high prognostic value for COAD, we performed topological overlap matrix (TOM) to investigate the hub proteins using 77 immune-relevant DEPs, and identified complement component 3 (C3) as the core protein in the immune-relevant DEPs matrix between the COAD and READ. Moreover, we found that C3 was up-regulated in COAD, and its expression was negatively associated with overall survival of COAD patients but not READ. In conclusion, we identified C3-mediated immune response as key feature to distinguish COAD and READ, and highlighted C3 as potential biomarker with high prognostic value for clinical application, which provided new clue for precise treatment of COAD.

[Clinical characteristics of patients with delayed hepatolenticular degeneration]

Objective: To evaluate the clinical manifestations, metal metabolism, imaging characteristics and treatment response in patients with delayed Wilson disease (WD). Methods: Patients with untreated WD (40 with delayed onset and 40 with non-delayed onset) were enrolled. Twenty healthy people were included as normal controls. All patients were evaluated with modified Young scale neural symptom scores, grade of Child liver function and mental symptoms rating scale, magnetic resonance imaging (MRI) scan, magnetic sensitive imaging (susceptibility weighted imaging, SWI), metal metabolism. Corrected phase (CP) was measured at SWI. After 2 week treatment, neurologic symptoms, liver function, and metal metabolism were reviewed. Results: The total score of neurological symptoms in WD patients with delayed onset was lower than that of non-delayed onset (13.00±6.87 vs. 21.13±5.53, P=0.033). The scores of SCL-90 and HAMA depression scales in patients with delayed onset were lower than those of non-delayed onset. On T(2) weighted imaging, areas including substantia nigra and thalamus, the caudate nucleus, globus pallidus, putamen presented high signal rate in patients with delated onset than those with non-delayed (P=0.022, 0.037, 0.022, 0.037, 0.029 respectively). The SWI CP values of cangbai sphere and shell nucleus in patients with delayed onset were lower than those with non-delayed onset. Patients with delayed onset had higher urinary copper than those with non-delayed onset before and after treatment (P=0.040, 0.036). After treatment, the score of abnormal tremor and gait in patients with delayed onset was decreased (P=0.037, 0.044), while as the occurrence of neurological symptoms was increased by 10%, and the liver function level in patients with delayed WD was decreased in 3 cases. Conclusions: The brain of WD patients with delayed onset is mainly composed of metal deposits, however the cell damage is not apparent. Clinical symptoms are characterized by significant liver injury, but relatively mild neurological and psychiatric symptoms. Patients with delayed WD have higher urinary copper excretion than those with non-delayed WD. Chelating agents improves the neurological symptoms in patients with delayed onset.

[Clinical characteristics of the Wilson disease carrier]

Objective: To study the clinical symptoms, copper metabolism and imaging characteristics of Wilson disease (WD) carriers and to explore the treatment strategy of WD carriers. Methods: Forty WD carriers, 40 WD patients and 20 normal controls from the First Affiliated Hospital of Sun Yat-sen University from July 2007 to May 2018 were included. The modified Young scale was used for neural symptom scoring, and Child grading of liver function, mental symptoms rating scale, magnetic resonance imaging (MRI) scan, susceptibility weighted imaging (SWI) inspection, metal metabolism tests were also applied to all the included subjects. Corrected phase (CP) was measured by SWI. WD carriers were divided into symptomatic group and asymptomatic group. Symptomatic WD carriers were treated with penicillamine for 2 weeks and zinc gluconate for 3 months, then their neurological symptoms, liver function grade, metal metabolism index were rechecked. Results: Six WD carriers presented with some clinical symptoms, including 5 with neurological symptoms and 4 with liver dysfunction. The score of Hamilton anxiety (HAMA) scale of symptomatic WD carriers was higher than that of normal control group (P=0.021). 85% of carriers had ceruloplasmin level less than 0.26 g/L. 80% of carriers had serum copper between normal controls and WD patients. The free copper level of WD carriers was lower than that of WD patients (P=0.012, 0.019). Urinary copper in symptomatic WD carriers was higher than normal controls (P=0.047). The CP values of thalamus, globus pallidus and putamen in symptomatic WD carriers were lower than those in normal control group. After treatment with penicillamine in symptomatic WD carriers, urinary copper was higher than that before treatment (P=0.036). After treatment, the liver enzymes of symptomatic WD carriers returned to normal, and the score of modified Young scale was lower than before treatment (P=0.031). Conclusions: Mild copper metabolism abnormality is seen in WD carriers. A few carriers have neurological symptoms such as limb tremors, or liver symptoms such as abnormal liver enzymes. Abnormal copper metabolism is more serious in symptomatic WD carriers than in asymptomatic WD carriers. Symptomatic WD carriers can be treated with zinc gluconate.

Correlations between the optic nerve head morphology and ocular biometrics in highly myopic eyes

AIM

To analyze peripapillary atrophy β/γ zone (PPA-β/γ) and the optic disc ovality index, and to assess their associations with the axial length (AL), refractive error, best corrected visual acuity (BCVA), choroidal thickness (CT), and age in highly myopic eyes.

METHODS

This was a retrospective observational case series. The study included 667 patients consecutively examined for highly myopic eyes [spherical equivalent ≤-6.0 diopters (D) and AL≥26 mm] with or without myopic retinopathy. Each patient went through a comprehensive ophthalmological examination that included spectral domain optical coherence tomography (SD-OCT) of the macula, A-mode ultrasonography, and a cycloplegic refraction test. The ovality index and PPA-β/γ area were measured from optic disc photographs.

RESULTS

A significant association was seen between PPA-β/γ area and the ovality index (P=0.000, r=-0.232). The PPA-β/γ area increased significantly with a longer AL, older age, worse BCVA, higher refractive error, and thinner choroid (P<0.01). The oval disc was significantly correlated with a longer AL, older age, worse BCVA, higher refractive error, larger PPA-β/γ area, and thinner choroid (P<0.01).

CONCLUSION

The PPA-β/γ zone and ovality index in highly myopic eyes show distinct associations with the AL, refractive error, BCVA, age, and CT.

Immunotolerant indoleamine-2,3-dioxygenase is increased in condyloma acuminata

BACKGROUND

The tryptophan-depleting enzyme indoleamine-2,3-dioxygenase (IDO) is critical for the regulation of immunotolerance and plays an important role in immune-associated skin diseases.

OBJECTIVES

To analyse the level of IDO in condyloma acuminata (CA) and its role in this condition.

METHODS

IDO expression was assessed in the skin and peripheral blood of healthy controls and patients with CA. To assess the role of skin IDO in immunity, the ability of isolated epidermal cells to metabolize tryptophan and the influence on polyclonal T-cell mitogen (PHA)-stimulated T-cell proliferation were explored.

RESULTS

IDO median fluorescence intensities in peripheral blood mononuclear cells from patients with CA were similar to those from healthy controls. Immunohistochemistry showed that IDO⁺ cells were rare in normal skin and the control skin of patients with CA, but were greatly accumulated in wart tissue. Most fluorescence signals of IDO⁺ cells did not overlap with those of CD1a⁺ Langerhans cells. Human papillomavirus (HPV) DNA probe in situ hybridization showed a large number of IDO⁺ cells in the HPV^- site. Keratinocytes in the skin of healthy controls and the circumcised skin of patients with CA could minimally transform tryptophan into kynurenine, but IDO-competent epidermal cells from warts could transform tryptophan. In addition, these IDO-competent epidermal cells could inhibit PHA-stimulated T-cell proliferation. The addition of an IDO inhibitor, 1-methyl-d-tryptophan, restored the inhibited T-cell proliferation.

CONCLUSIONS

Abnormally localized high IDO expression might be involved in the formation of a local immunotolerant microenvironment.

[Difference in imaging and metal metabolism between hepatic and cerebral type Wilson disease]

Objective: To evaluate the difference of metal metabolism, damage to structure and functional activity in brains between hepatic and cerebral type Wilson disease (WD). Methods: Forty patients with WD, including 20 with cerebral type and 20 with hepatic type, and 20 age-matched healthy controls in the First Affiliated Hospital, Sun Yat-sen University between Jul 2013 and May 2016 were enrolled.All study subjects underwent diffusion tensor imaging (DTI), resting state functional MRI (rs-fMRI) and susceptibility weighted imaging (SWI) of the brain.Six regions of interest (ROIs) were chosen.The values of fractional anisotropy (FA), λ in ROIs were determined on DTI, FA and fiber volumes between ROIs were also determined on DTI.The values of amplitude of low frequency fluctuation (ALFF) and regional homogeneity (REHO) in ROIs were determined on rs-fMRI.The values of corrected phase (CP) were calculated on SWI.The copper and iron content were measured.The difference of imaging and metal metrics between cerebral type and hepatic type WD were evaluated. Results: DTI metrics differed between patients with the cerebral and hepatic types of WD.ALFF values in the caudate nucleus, and thalamus were lower (P=0.037, 0.040), and REHO values in the caudate nucleus were lower (P=0.029), in patients of cerebral type than in hepatic type patients.CP values of the right caudate nucleus and left putamen in cerebral type WD patients were lower than in hepatic type patients (P=0.020, 0.23). The serum iron content of hepatic type WD patients was higher than the normal (P=0.013), and the urine copper content was higher than the cerebral type patients (P=0.021). Conclusions: Metal deposition and damage to the structure and functional activity in the brain may occur in hepatic type WD patients.The structural and functional activity damage of the brain in hepatic type is less severe than that in cerebral type patients, while the metal deposition is not significant different between hepatic and cerebral type.

Epigenetic mechanism of maternal post-traumatic stress disorder in delayed rat offspring development: dysregulation of methylation and gene expression

Maternal post-traumatic stress disorder (PTSD) increases the risk of adverse neurodevelopmental outcomes in the child. Epigenetic alternations may play an essential role in the negative effects of PTSD. This study was aimed to investigate the possible epigenetic alterations of maternal PTSD, which underpins the developmental and behavioral impact. 24 pregnant Sprague-Dawley (SD) rats were randomly grouped into PTSD and control groups. Open-field tests (OFTs), elevated pull maze (EPM) assays, gene expression profile chip tests, and methylated DNA immunoprecipitation sequencing (MeDIP-Seq) were performed on the offsprings 30 days after birth. The results showed that PTSD offsprings had lower body weights and OFT scores than control offsprings. Enzyme-linked immunosorbent assays showed that serotonin receptor (5-HT) and dopamine levels were significantly lower in PTSD offsprings than in control offsprings. In contrast, corticosterone levels were higher in the PTSD group than in the control group. In a comparison of the PTSD group versus the control group, 4,160 significantly differentially methylated loci containing 30,657 CpGs were identified; 2,487 genes, including 13 dysmethylated genes, were validated by gene expression profiling, showing a negative correlation between methylation and gene expression (R = -0.617, P = 0.043). In conclusion, maternal PTSD could delay the physical and behavioral development of offsprings, and the underlying mechanism could contribute to changes in neurotransmitters and gene expression, owing to dysregulation of whole-genome methylation. These findings could support further clinical research on appropriate interventions for maternal PTSD to prevent methylation dysregulation and developmental retardation.

Models of logistic regression analysis, support vector machine, and back-propagation neural network based on serum tumor markers in colorectal cancer diagnosis

We evaluated the application of three machine learning algorithms, including logistic regression, support vector machine and back-propagation neural network, for diagnosing congenital heart disease and colorectal cancer. By inspecting related serum tumor marker levels in colorectal cancer patients and healthy subjects, early diagnosis models for colorectal cancer were built using three machine learning algorithms to assess their corresponding diagnostic values. Except for serum alpha-fetoprotein, the levels of 11 other serum markers of patients in the colorectal cancer group were higher than those in the benign colorectal cancer group (P < 0.05). The results of logistic regression analysis indicted that individual detection of serum carcinoembryonic antigens, CA199, CA242, CA125, and CA153 and their combined detection was effective for diagnosing colorectal cancer. Combined detection had a better diagnostic effect with a sensitivity of 94.2% and specificity of 97.7%; combining serum carcinoembryonic antigens, CA199, CA242, CA125, and CA153, with the support vector machine diagnosis model and back-propagation, a neural network diagnosis model was built with diagnostic accuracies of 82 and 75%, sensitivities of 85 and 80%, and specificities of 80 and 70%, respectively. Colorectal cancer diagnosis models based on the three machine learning algorithms showed high diagnostic value and can help obtain evidence for the early diagnosis of colorectal cancer.

Valproic acid attenuates the suppression of acetyl histone H3 and CREB activity in an inducible cell model of Machado-Joseph disease

Machado-Joseph disease (MJD) is caused by a (CAG)n trinucleotide repeat expansion that is translated into an abnormally long polyglutamine tract. This disease is considered the most common form of spinocerebellar ataxia (SCA). In the present study, we developed stable inducible cell lines (PC12Tet-On-Ataxin-3-Q28/84) expressing ataxin-3 with either normal or abnormal CAG repeats under doxycycline control. The expression of acetyl histone H3 and the induction of c-Fos in response to cAMP were strongly suppressed in cells expressing the protein with the expanded polyglutamine tract. Treatment with valproic acid, a histone deacetylase inhibitor (HDACi), attenuated mutant ataxin-3-induced cell toxicity and suppression of acetyl histone H3, phosphorylated cAMP-responsive element binding protein (p-CREB) as well as c-Fos expression. These results indicate that VPA can stimulate the up-regulation of gene transcription through hyperacetylation. Thus, VPA might have a therapeutic effect on MJD.

Relationships between biochemical and physiological changes induced by exercise in postmyocardial infarction patients

AIM

AIM of the study was to examine the relationships between biochemical and physiological changes induced by exercise in postmyocardial infarction patients (PMIP) during the early stages of cardiac rehabilitation.

METHODS

Forty-nine male non-blockade recent PMIP, aged 63.8 ± 4.7 years, performed a graded exercise test on a motorised treadmill until volitional cessation or reaching any of the American College of Sports Medicine criteria. Blood pressure and rate-pressure product (RPP) were recorded every three minutes. A 12-lead electrocardiogram was monitored continuously and heart rate (HR) was taken from this. Blood samples were obtained by two methods; those used for testing blood lactate (BL) were taken from an already warmed finger tip before and during exercise, and the others used for enzymatic analysis based on lactate dehydrogenase (LDH), lactate dehydrogenase isoenzyme 1 (LDH-1), creatine kinase (CK) and creatine kinase polypeptide sub-unit MB (CK-MB) were collected by venipuncture from the antecubital vein pre and immediate post exercise test.

RESULTS

Highly significant correlations existed between exercise-induced changes in HR, RPP, BL and ST segment level with increased enzymes activity in serum, and 73.1% to 90.1% of the variance in percentage increase of the enzyme activity could be predicted from the variance in percentage increase of HR during exercise. However, the mechanism of these relationships may differ.

CONCLUSION

Since the rise in serum enzymes during submaximal exercise is primarily attributed to changes in membrane permeability in fatigued muscle, these relationships provide useful guidance to health professionals obtaining biochemical information about muscle fatigue.

A comparing study of quantitative staining techniques for retinal neovascularization in a mouse model of oxygen-induced retinopathy

AIM

To explore an efficient, practical and objective quantitative method to evaluate the retinal neovascularization in mouse model of oxygen induced retinopathy (OIR).

METHODS

Thirty C57BL/6J mice were explored in OIR model procedure. Eyes were removed for different staining methods including: (1) HE staining; (2) immunohistochemistry with Griffonia Simplicifolia Lectin(GSL); (3) Immunofluorescence with FITC labeled CD31 antibody; (4) Two-step immunofluorescence with purified-CD31 antibody; (5) FITC-Dextran perfusion combined with two-step purified-CD31immunofluorescence. Images of the retinal vasculature were analyzed by imaging software.

RESULTS

GSL immunohistochemistry could clearly demonstrate the deep and superficial capillary beds. FITC labeled CD31 Immunofluorescence was blurring with high fluorescence background which was hard to distinguish retinal neovascularization in some area. Excellent detail of neovascularization and preexistent retinal vessels was provided in two-step Purified-CD31 immunofluorescence group.

CONCLUSION

GSL immunohistochemistry can clearly demonstrate neovascularization tufts in deep and superficial capillary beds. Immunofluorescence of specific antigen CD31 on vascular endothelium can selectively label the neovascularization of mouse retina. When combined with computer analysis software, it is an effective and objective quantitative method to evaluate the retinal neovascularization in OIR mouse model.

[A preliminary study on intravitreal injection of bevacizumab for treatment of neovascular age-related macular degeneration]

OBJECTIVE

To evaluate the short-term safety of intravitreous bevacizumab (Avastin) and its effects on visual acuity (VA) and subfoveal choroidal neovascularization (CNV) in patients with neovascular age-related macular degeneration (ARMD).

METHODS

Single-center, uncontrolled clinical study. Five ARMD patients (5 eyes) with subfoveal CNV and best-corrected VA (BCVA) less than 0.1 were participated. Patients were treated with an intravitreous injection of bevacizumab (1.5 mg, 0.06 ml). Ophthalmologic evaluations included BCVA test, ocular examination, intraocular pressure (IOP) measurement, optical coherence tomography (OCT) imaging and fluorescein angiography (FFA).

RESULTS

There were no ocular or systemic adverse events observed, except a mild elevation of IOP [26 mm Hg (1 mm Hg = 0.133 kPa)] in 1 case on the 3rd day after injection, which was controlled by topical medication. One out of 5 eyes had a significant improvement of BCVA (from 0.1 improved to 0.4) in one week after injection. By 2 months, the BCVA increased in 4 cases (increased 1 to 6 lines) and 3 of them remained stable for 4 to 6 months and 1 decreased at the 4 th month post injection. The thickness of central retina reduced 5.9% to 41.4% and FFA revealed a remarkable reduction or an absence of leakage from CNV in 3 eyes by the 4th month.

CONCLUSION

Our preliminary results are promising, showing that intravitreous bevacizumab therapy is well tolerated with an improvement in VA, OCT, and FFA outcomes. A multi-center randomized controlled clinical trial is needed to evaluate the long-term safety and effectiveness of intravitreous bevacizumab therapy on neovascular ARMD.

Pars Plana Vitrectomy and Internal Limiting Membrane Peeling for Macular Oedema Secondary to Retinal Vein Occlusion: a Pilot Study

Introduction: Macular oedema is the main cause of visual impairment following retinal vein occlusion. The purpose of this study was to evaluate the anatomical and functional outcome of pars plana vitrectomy and internal limited membrane (ILM) peeling for macular oedema secondary to retinal vein occlusion. Clinical Picture: This pilot study is a prospective non-randomised series of 11 eyes of 11 patients with macular oedema secondary to retinal vein occlusion. The best-corrected visual acuity (BCVA), foveal thickness on optical coherence tomography, fundus fluorescein angiography (FFA) and multifocal electroretinography were evaluated. Treatment and Outcome: All 11 patients underwent pars plana vitrectomy with ILM peeling. The mean postoperative follow-up was 13.5 months (range, 1.5 to 24). The mean thickness at the foveal centre decreased from 794 ± 276m preoperatively to 373 ± 150m, 302 ±119m, 249 ± 203m and 185 ± 66m at 1 week, 1 month, 3 months and the final visit postoperatively, respectively (all P <0.001, paired t- test, compared to preoperative thickness). Postoperative FFA demonstrated markedly reduced leakage in the macular region. At the final visit, BCVA improved 2 lines or more in 72.7% (8/11) of patients and was unchanged in 27.3% (3/11) patients. Complications included cataract in 7 patients and vitreous haemorrhage, recurrence of macular oedema and visual field defect in 1 case each. Conclusion: Pars plana vitrectomy and ILM peeling rapidly reduced the macular oedema caused by retinal vein occlusion, with improvement in BCVA. Key words: Foveal thickness, Internal limiting membrane peeling, Macular oedema, Retinal vein occlusion, Visual acuity

Pars plana vitrectomy and internal limiting membrane peeling for macular oedema secondary to retinal vein occlusion: a pilot study

INTRODUCTION

Macular oedema is the main cause of visual impairment following retinal vein occlusion. The purpose of this study was to evaluate the anatomical and functional outcome of pars plana vitrectomy and internal limited membrane (ILM) peeling for macular oedema secondary to retinal vein occlusion.

CLINICAL PICTURE

This pilot study is a prospective nonrandomised series of 11 eyes of 11 patients with macular oedema secondary to retinal vein occlusion. The best-corrected visual acuity (BCVA), foveal thickness on optical coherence tomography, fundus fluorescein angiography (FFA) and multifocal electroretinography were evaluated.

TREATMENT AND OUTCOME

All 11 patients underwent pars plana vitrectomy with ILM peeling. The mean postoperative follow-up was 13.5 months (range, 1.5 to 24). The mean thickness at the foveal centre decreased from 794 +/- 276 microm preoperatively to 373 +/- 150 microm, 302 +/- 119 microm, 249 +/- 203 microm and 185 +/- 66 microm at 1 week, 1 month, 3 months and the final visit postoperatively, respectively (all P <0.001, paired t- test, compared to preoperative thickness). Postoperative FFA demonstrated markedly reduced leakage in the macular region. At the final visit, BCVA improved 2 lines or more in 72.7% (8/11) of patients and was unchanged in 27.3% (3/11) patients. Complications included cataract in 7 patients and vitreous haemorrhage, recurrence of macular oedema and visual field defect in 1 case each.

CONCLUSION

Pars plana vitrectomy and ILM peeling rapidly reduced the macular oedema caused by retinal vein occlusion, with improvement in BCVA.

A comparative study on SWCNT and DWCNT field-effect transistors

Field-effect transistors have been fabricated using single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs), and their electrical transport properties have been studied comparatively. While a semiconducting SWCNT exhibits better field-effect characteristics than a DWCNT counterpart, the DWCNT shows more complicated response to external gate modulation. Depending on the nature of the two shells of a DWCNT, i.e., whether the shell is semiconducting (S) or metallic (M), a DWCNT device can be described as either S-S, or S-M, or M-S, or M-M. It was found that the S-S and M-M or M-S devices show similar field-effect characteristics to those found in SWCNT devices. But for S-M DWCNT devices, distinct field-effect characteristic was found and attributed to the combined effects of intershell interactions and screening by free carriers of the inner metallic shell. The S-M DWCNT devices thus provide a perfect system for studying the important intershell interaction, and information on the effect of this interaction on the electrical properties of a multi-walled carbon nanotube can be obtained by a comparative study of S-M DWCNT and S-SWCNT devices.

Effect of H2 on the Electrical Transport Properties of Single Bi2S3 Nanowires

Field effect transistors have been fabricated using Bi2S3 nanowires. Whether the contact is ohmic or non-ohmic, the current of Bi2S3 nanowires was found to increase remarkably in H2 compared to that in a vacuum. Carrier density and mobility within the nanowires and the contact barriers between the nanowires and the electrodes have been extracted using field effect and two-probe current-voltage curves. It was found that H2 enhances electronic mobility and carrier density within the nanowires dramatically. The effect of H2 on the contact barriers was observed to be negligible compared to the other two effects.

Field-Effect Characteristics and Screening in Double-Walled Carbon Nanotube Field-Effect Transistors

Field-effect transistors (FETs) have been fabricated using double-walled carbon nanotubes (DWCNTs), and electrical transport measurements have been carried out on 125 DWCNT FETs. Among these devices, 52 were found to show basically semiconducting field-effect characteristics, 44 show metallic characteristics, and 29 show neither pure semiconducting nor metallic characteristics. These 3 distinct types of field-effect characteristics were identified as resulting from the semiconducting (S)-S, metallic (M)-M or M-S, and S-M combinations of the two shells of the DWCNT. While the S-S and M-M or M-S DWCNT devices exhibit similar field-effect characteristics to those by single-walled carbon nanotube (SWCNT) devices, the S-M device responds uniquely to the external gate voltage. In particular, it was found that free charges in the inner metallic shell may screen the outer semiconducting shell from the gate effect and that the screening is directly related to the intershell interaction, which increases with increasing temperature and tube diameter. The screening is disadvantageous to the performance of DWCNT FETs, and a similar effect is expected to occur in MWCNTs.

Performing probe experiments in the SEM

A four nanoprobe system has been installed inside a FEI XL30 F scanning electron microscope (SEM), and shown to be fully compatible with the normal functions of the SEM and also a Gatan cold stage (model C1003, -185-400 degrees C). With some selected examples of applications, we have shown that this nanoprobe system may be used effectively for gripping, moving and manipulating nanoobjects, e.g. carbon nanotubes, setting up electric contacts for electronic measurements, tailoring the structure of the nanoobject by cutting, etc. and even for making unexpected nanostructures, e.g. a nanohook. Applications in other areas have also been speculated, limitations or disadvantages of the current design of the probe system were discussed, and methods for possible improvement were suggested.

Copper transportion of WD protein in hepatocytes from Wilson disease patients in vitro

AIM

To study the effect of copper transporting P-type ATPase in copper metabolism of hepatocyte and pathogenesis of Wilson disease (WD).

METHODS

WD copper transporting properties in some organelles of the cultured hepatocytes were studied from WD patients and normal controls.These cultured hepatocytes were incubated in the media of copper 15 mg x L(-1) only, copper 15 mg x L(-1) with vincristine (agonist of P-type ATPase) 0.5mg x L(-1), or copper 15 mg x L(-1) with vanadate (antagonist of P-type ATPase) 18.39 mg x L(-1) separately. Microsome (endoplasmic reticulum and Golgi apparatus), lysosome, mitochondria, and cytosol were isolated by differential centrifugation. Copper contents in these organelles were measured with atomic absorption spectrophotometer, and the influence in copper transportion of these organelles by vanadate and vincristine were comparatively analyzed between WD patients and controls. WD copper transporting P-type ATPase was detected by SDS-PAGE in conjunction with Western blot in liver samples of WD patients and controls.

RESULTS

The specific WD proteins (M(r)155,000 lanes) were expressed in human hepatocytes, including the control and WD patients. After incubation with medium containing copper for 2 h or 24 h, the microsome copper concentration in WD patients was obviously lower than that of controls, and the addition of vanadate or vincristine would change the copper transporting of microsomes obviously. When incubated with vincristine, levels of copper in microsome were significantly increased, while incubated with vanadate, the copper concentrations in microsome were obviously decreased. The results indicated that there were WD proteins, the copper transportion P-type ATPase in the microsome of hepatocytes. WD patients possessed abnormal copper transporting function of WD protein in the microsome, and the agonist might correct the defect of copper transportion by promoting the activity of copper transportion P-type ATPase.

CONCLUSION

Copper transportion P-type ATPase plays an important role in hepatocytic copper metabolism. Dysfunction of hepatocytic WD protein copper transportion might be one of the most important factors for WD.

[Study on syndrome pattern in insulin resistant model rats]

OBJECTIVE

To explore the Syndrome pattern in insulin resistant model rats.

METHODS

Eight Sprague-Dawley (SD) rats were induced to insulin resistance (IR) by 60% high-sucrose forage.

RESULTS

The correlative co-efficient of some biological and internal changes were clusterly analyzed and divided into 3 groups, which was closely related with phleg tubidity, blood stasis and internal toxin types respectively. The phlegm turbidity type was characterized by high content of blood lipid (triglyceride, total cholesterol) and high concentration of glycated serum protein; the blood stasis type was characterized by tendency of high viscosity and high coagulant state, the blood pressure increased, prothrombin time shortened, fibrinogen content raised and RBC and platelet count increased; while the internal toxin type was characterized by high content of glucose, insulin and the elevation of tumor necrosis factor.

CONCLUSION

The combined Syndrome of phlegm turbidity, blood stasis and internal toxin is the Syndrome-pattern in insulin resistant model rat. This observation provides theoretic basis for clinical and experimental studies of TCM.

[Effect of stilbene polymer (Gn-3) on experimental liver injuries in mice]

AIM

To study the protective effect of Gn-3 (a stilbene polymer isolated from Gnetum parvifolium) against liver injury induced by CCl4, N-acetyl-p-aminophenol (APAP) and Bacillus Calmette-Guerin (BCG) plus bacterial lipopolysaccharide (LPS) in mice.

METHODS

The experimental model of liver injury were induced by 0.1% CCl4 i.p. (10 mL.kg-1.d-1 for 3d), APAP i.p. (150 mg.kg-1) or BCG (5 mg) plus LPS (7.5 micrograms) in mice. The levels of ALT in serum, MDA and GSH in liver tissues were detected. The histopathologic changes were observed by light microscope.

RESULTS

Gn-3 was shown to markedly reduce the elevated serum ALT levels, liver tissue MDA and improve the histopathological changes in all the three experimental liver injury models. No effect of Gn-3 was observed on the liver GSH level in liver injury mice.

CONCLUSION

Gn-3 was found to inhibit the development of liver injury caused by CCl4, APAP, or BCG plus LPS. This means that Gn-3 has liver protective effects.

Embryonic hemoglobins are expressed in definitive cells

Human embryonic zeta and epsilon globin chains are synthesized in yolk sac-derived primitive erythroid cells, and decrease rapidly during definitive erythropoiesis. Examination of zeta and epsilon globin expression at the cellular level using dual-color immunofluorescence staining with specific monoclonal antibodies showed that embryonic globin proteins are present in definitive erythroid cells. More than half of fetal erythrocytes were positive for zeta and approximately 5% for epsilon globin. Approximately one third of newborn red blood cells were zeta-positive and less than 1% epsilon-positive. Adult erythrocytes did not have embryonic globins. Erythroblasts that developed in liquid cultures also contained embryonic globin in amounts which declined with ontogenic age, and the proportion of positive cells in vitro was less than in the comparable erythrocytes that developed in vivo. Thus, embryonic globin chains are synthesized in definitive erythroid cells and decrease with ontogeny. Modulation of embryonic globin gene expression is not solely due to a switch from primitive to definitive erythropoiesis.

Cloning and characterization of the mouse alpha globin cluster and a new hypervariable marker

A 95-kb region of the mouse genome spanning the entire alpha-globin gene cluster was isolated as overlapping cosmid clones and characterized. In addition to the embryonic (zeta) and adult (alpha) genes, the cloned contig contains the complete N-methylpurine-DNA glycosylase (MPG) gene, the alpha-globin-positive regulatory element (mHS-26), and a previously unidentified hypervariable region (named the mouse alpha-HVR). In mice, the distance between the MPG gene and mHS-26 is approximately 18 kb; between the mHS-26 and the zeta-gene, approximately 26 kb; from the zeta-gene to the 5' end of the alpha-gene, approximately 16 kb; and the two alpha-genes are separated by approximately 12 kb. In human, the corresponding distances are approximately 27 kb, approximately 40 kb, approximately 19 kb, and approximately 3 kb respectively. The alpha-HVR is located approximately 18 kb upstream of the mouse zeta-globin gene transcription start site and contains a variable copy number tandem repeat (VNTR) array of a 35-bp sequence rich in (G+C) content. The unit sequence of the HVR shares the short core sequence with the HVRs identified in the human alpha-gene cluster. Thus, this HVR may be a valuable evolutionary marker, as well as a useful genetic marker for the mouse.

Environmental factors in the etiology of Parkinson's disease

Parkinson's disease (PD) has been proposed to result from the interaction of aging and environment in susceptible individuals. Defective metabolism of debrisoquine, inherited as an autosomal recessive, has been associated with this susceptibility. In 35 PD patients and 19 age-matched controls, no significant differences in debrisoquine metabolism were found, although a trend to impaired metabolism was noted in patients with disease onset less than or equal to 40. Foci of PD patients were associated with rural living and well water drinking, or rural living coupled with market gardening or wood pulp mills. In a questionnaire survey, patients with PD onset less than or equal to age 47 were significantly more likely to have lived in rural areas and to have drunk well water than those with onset greater than or equal to age 54 (p less than or equal to 0.01). Because of population mobility in North America, a case-control study designed to test environmental, occupational, dietary and other proposed risk factors for PD was conducted in China, where the population is more stationary and the environment more stable. No significant differences in incidences of head trauma, smoking or childhood measles were found between patients and controls.

[Serum beta 2-microglobulin and carcinoembryonic antigen in patients with bronchogenic carcinoma]

In patients with bronchogenic carcinoma of various types and stages, serum beta 2-microglobulin (beta 2-M) and carcinoembryonic antigen (CEA) were assayed simultaneously. The concentrations of serum beta 2-M and CEA were found to be statistically related to complete remission of the tumor (P less than 0.01). But it was also found that there was no correlation between the levels of beta 2-M and CEA (r = 0.0621). In follow-up, the CEA was found to be increasing incessantly as the disease progressed. For the level of serum beta 2-M, as the patients' condition got worse, it first rose, then dropped and became markedly lower before the patient died. The serum beta 2-M was often elevated 3-5 months earlier than CEA, and frequently resumed the normal level later than CEA after the carcinoma had a complete remission. With the progression of the bronchogenic carcinoma, elevation of beta 2-M was not necessarily a sign of poor prognosis. In contrast, with the serum beta 2-M markedly lowered after an initial elevation, the serum CEA became elevated, the prognosis was usually poor. The authors believe that, in patients with lung cancer, CEA produced from the lung cancer cells would give a level fluctuating with the size of the primary focus and the extent of the metastasis. But its positive rate is rather low. The serum beta 2-M is produced indirectly by certain immunologic function against bronchogenic carcinoma or its metabolites and not by the cancer cells directly. The positive rate of beta 2-M is high, so slightly is its false positive rate.(ABSTRACT TRUNCATED AT 250 WORDS)