Motivation Impairments of attention and memory are detectable in early psychosis, and often result in severe, longstanding functional impairments. Pharmacological interventions for cognitive impairments have been largely unsuccessful. The current study aims to explore the effects of aerobic exercise and mind-body exercise (yoga) on cognitive functioning and clinical symptoms in female patients with early psychosis. The potential neuromechanism underlying the clinical consequences was also investigated. Methods Female patients (n=120) diagnosed with schizophrenia spectrum disorders, brief psychosis, psychosis NOS, or delusional disorder (according to SCID) were recruited from three hospital/clinic sites. They were randomized into integrated yoga therapy group, aerobic exercise programme group, and waiting list as the control group. Both interventions were held three times weekly. At baseline and at 12 weeks, clinical symptoms, cognitive functions, quality of life and fitness levels were assessed in all participants, and completed structural MRI data were collected in 58 patients. Repeated measures ANOVA and ANCOVA analyses of the clinical, cognitive, quality of life and fitness data were compared between baseline and at 12 weeks among the three groups. Post-hoc Bonferroni test was used for comparing between two groups. Structural MRI data was analyzed by FreeSurfer V5.1 and Qdec V1.4 to calculate the brain volume and cortical thickness. Results Completed clinical and cognitive data were collected in 85 patients, and completed MRI imaging data of good quality were collected in 39 patients. No significant differences in age, education years, and duration of the illness at baseline were observed among the three groups. Both yoga and aerobic exercise groups demonstrated significant improvements in verbal encoding (p<0.01), short-term memory (p<0.05), long-term memory (p<0.01), and working memory (p<0.01) with moderate to large effect sizes compared to control groups. The yoga group showed significantly enhanced attention and concentration (p<0.05). Both yoga and aerobic exercise significantly improved overall clinical symptoms (p<0.05) and depressive symptoms (p<0.05) after 12 weeks. Significant increases were observed in the thickness of the left superior frontal gyrus and the right inferior frontal gyrus (pars triangularis) in the aerobic exercise group. Significant increases were observed in the volume of the postcentral gyrus and the posterior corpus callosum in the yoga group. There was a statistically significant correlation between improvements in working memory and changes in the postcentral gyrus (r=0.54, p<0.01) after controlling for the multiple comparisons with a Bonferroni adjusted alpha level. Discussion Both types of exercise improved memory in early psychosis patients, with yoga having a superior effect on attention than aerobic exercise. Observed increments in the cortical thicknesses and volume may indicate improved neurogenesis. Significance There have been few systematic clinical trial studying exercise and psychosis, and none of them has explored the effects of exercise in female patients with early stage psychosis. The present study indicates possible interventions for cognitive impairments in the patients with early psychosis, which are non-invasive and mostly safe. The application of yoga and aerobic exercise as adjunct treatments to treat psychosis in the clinical setting should be advocated. / published_or_final_version / Psychiatry / Doctoral / Doctor of Philosophy

Cancer is one of the leading causes of death worldwide. Monoclonal antibodies (mAbs) have been proved effective for cancer therapy. MAbs possess advantages over chemical drugs and small molecular drugs in cancer treatment, such as high specificity, low toxicity, effector function, long half-life in circulation system and less side effects. There are eight FDA-approved anti-cancer antibody drugs now, and many more are under development. Antibodies have two functional domains, the Fab region that is responsible for antigen recognition, and the Fc region that couples the antibody to immune effector pathways. Fab-mediated interference with cancer cell signalling may lead to growth inhibition and direct cell death, while Fc-mediated effector function through interactions with Fc-gamma receptors (FcrRs) expressed in immune cells or through complement cascades may lead to target cell cytotoxicity. Antibody engineering to increase the binding affinity and effector function may improve antibody in vivo efficacy. Anti-Her2 mAb herceptin (trastuzumab) is effective in treatment of Her2-overexpressing breast cancer patients. However, only 25–30% of patients with Her2-overexpressing tumors respond to single agent trastuzumab, and drug resistance develops even in responding patients. Accumulating evidence showed that cross-talk between Her2 and the insulin-like growth factor receptor type I (IGF-IR), including receptor heterodimerization and transactivation, and elevated IGF-IR signalling have been associated with trastuzumab resistance. Therefore, we hypothesized that dual specific antibodies co-targeting both IGF-IR and Her2 may prevent or delay the emergence of resistance to mono-specific antibodies. Mouse monoclonal antibody, M590 showed very good binding activity to IGF-IR. By engineering the CH3 domain of human Fc in pDR12 plasmid, we developed a “knobs-into-holes” hybrid IgG expression system, and successfully produced M590-Herceptin bi-specific IgG, which showed high binding avidity for both antigens and preserved antibody-dependent cell-mediated cytotoxicity (ADCC), a main route of immune protections conferred by therapeutic antibodies in vivo. M590-Herceptin dual specific antibody inhibited breast cancer and ovarian cancer cell proliferation in vitro, and inhibited cancer growth in a SKOV-3 Her2- and IGF-IR-overexpressing ovarian cancer xenograft mouse model. M590-Herceptin hybrid showed better anti-cancer activity compared with M590 and Herceptin alone, or in combination. Meantime, I also constructed a phage display antibody Fab library using the mRNA of rabbits immunized by membrane proteins of SKOV-3 cells, and isolated a novel anti-Her2 mAb, designated as 1C6. Results from in vitro assays showed that 1C6 had anti-cancer activity which was comparable to that of herceptin. M590-1C6 hybrid IgG was also constructed, and the results from in vitro assays and mouse study showed that M590-1C6 hybrid IgG also possess better inhibitory activity of Her2 positive tumours compared with m590 or 1C6 alone. In summary, this study indicates that bi-specific antibodies co-targeting two elevated cancer receptors are more effective than mono-specific antibodies for cancer therapy. / published_or_final_version / Microbiology / Doctoral / Doctor of Philosophy

Glaucoma is a neurodegenerative disease and one of the major causes of blindness in the world. Secondary degeneration is involved in glaucoma. The retinal ganglion cells (RGCs) which are vulnerable to secondary degeneration in glaucoma are the promising target population for therapeutic intervention. Partial optic nerve transection (PONT) model has been established in the last decade. Primary and secondary degeneration can be separated in different regions of retinas in this model. Therefore, PONT is a good model for the study of mechanisms of secondary degeneration and the drug screening for secondary degeneration. Lycium barbarum (L. barbarum) has been shown to be neuroprotective for cortical neurons in vitro. It has also been shown that L. barbarum could delay RGCs death in a rat ocular hypertension model. In order to further investigate the effects of L. barbarum for RGCs, two models, complete optic nerve transaction (CONT) model and PONT model, were employed in my study. My results showed that the polysaccharide extract from L. barbarum (LBP) could partly prevent RGCs from death in the inferior retinas 4 weeks after PONT whereas it could not reduce the loss of RGCs after CONT. The1,1'-dioctadecyl-3, 3, 3’, 3’-tetramethylindocarbocyanine perchlorate(DiI) labeling of RGCs whose axons were transected showed that the majority of labeled cell bodies existed in the superior retinas. The result meant that more cell bodies in the superior retinas would die from primary degeneration than in the inferior retina after PONT. Therefore my results indicated that LBP protected RGCs which would die from secondary degeneration rather than primary degeneration. The results of Terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) staining showed that RGCs underwent apoptosis 1 week after PONT. Western-blot analysis demonstrated that oxidative stress was involved in the degeneration of RGCs after PONT. Furthermore, c-Jun N-terminal kinases (JNKs) pathway was activated which was indicated by an increase ofphospho-JNK2/3(p-JNK2/3)and phospho-c-jun(p-c-jun). Our results also revealed that orally feeding of LBP could increase the expression of manganese superoxide dismutase (MnSOD) and insulin growth factor-1 (IGF-1)and decrease the expression of p-JNK2/3 and p-c-jun. The results from optic nerve (ON) study showed that glial cells, including astrocytes and microglias/macrophages, were activated after PONT. Oxidative stress and inflammation were involved in the process. Secondary degeneration of ON was not obvious and LBP exerted no protective effects on the survival of axons in the ON. The multifocal electroretinography (mfERG) study showed that both the functions of inner retinas and outer retinas were damaged after PONT. The results indicated that other cell types or the synapses between different cell types were damaged in addition to RGCs. LBP could improve the function of the whole retinas, including both inner retinas and outer retinas after PONT. In conclusion, our results indicated that LBP protected RGCs from secondary degeneration via inhibiting oxidative stress and the activation of JNK pathway.LBP could also improve the function of both inner retinas and outer retinas after PONT. / published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

Ischemic stroke is a leading cause of disability and death around the world. Higher concentration of glutamate following ischemic stroke is a factor leading to cell death, including neural stem cell death. Up to now no effective treatments of ischemic stroke are available. Notoginsenoside R1 (Noto R1) is the main component of Panax notoginseng, which is a traditional Chinese medicine for the treatment of cardiovascular disease. Its protective effects on the neural cell were noted recently. The main purpose of this experimental study was to investigate the mechanism of Noto R1 against glutamate neurotoxicity on primary cultured mouse cortical neural stem cells in vitro, and its effects on ischemic stroke on mice brain in vivo. In the in vitro part, primary culture of neural stem cells was prepared from 12.5-day-old C57BL/6N mice embryos cortex. Neural stem cells were confirmed by nestin-staining and differentiation study afterwards. Then neural stem cells were incubated with Noto R1 and glutamate for 24 hours. Cells were fixed for TUNEL staining and caspase-3 staining. Protein was collected for western blot for Bax, Bcl-2, phos-AKT, JNK/SAPK, and phospho-p38 MAPK. Results showed that glutamate has cytotoxicity in a dose-dependent manner on neural stem cells. Noto R1 showed remarkable neuro-protective effects on neural stem cells exposed to excessive glutamate by higher viability. Noto R1 significantly reduced caspase-3 expression and TUNEL-positive cells. Furthermore, Noto R1 increased the protein expression of Bcl-2 and phospho-AKT, and reduced Bax expression. Moreover apoptosis pathway study showed phospho-p38 expression was suppressed in the Noto R1 group. In the in vivo part, Noto R1 was administrated systemically to mice of MCAo followed by reperfusion. Behavior score and viability rate were assessed before sacrifice. TTC staining was performed for evaluating infarct area, volume and edema. H&E staining was applied for histological examination. TUNEL staining, IHC staining of Nestin, AQP4 and GFAP were performed. In the first part of Noto R1 of 40 mg/kg or PBS was injected into venous at the onset of blood vessel occlusion for 2 hours, and then followed by 22 hours of reperfusion. Results were all negative. In the second part, Noto R1 was injected intra-peritoneum for 10 days prior to MCAo which lasted for 1 hour 50 minutes, then reperfusion was allowed for 22 hours. Results showed Noto R1 improved behavior score and viability rate. Meanwhile Noto R1 significantly reduced ischemic area, volume and edema percentage. Moreover TUNEL-positive cells in the affected cortex were significantly decreased. Nestin-positive cell in the striatum were significantly increased in the Noto R1 group, and immunoactivity of AQP4 and GFAP was apparently decrease with Noto R1 treatment. In conclusion, this study showed that Noto R1 protected cultured neural stem cells against glutamate neurotoxicity in vitro via p38 MAPK pathway by inhibiting Bax protein expression and enhancing protein expression of Bcl-2 and phospho-AKT. Moreover, it also demonstrated significant preventive effects against ischemic stroke with mice model in vivo. In a word Noto R1 presents a highly potential candidate preventing ischemic stroke clinically in the future. / published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

Background Dementia is a leading cause of disability and dependency in elderly people, generating significant physical, psychological, and financial challenges for patients, caregivers, and healthcare systems worldwide. For Alzheimer’s disease (AD), the most common form of dementia, established treatments such as Acetyl-Cholinesterase Inhibitors (AChE) have proven to be marginally beneficial, but side effects remain. Alternatively, a standardized preparation of Ginkgo Biloba Extract (EGb-761) is a popular herbal medicine used globally and widely available in Hong Kong. This paper reviews and synthesizes the effectiveness of EGb-761 in the treatment of AD compared to placebo and AChE treatments. Methods A systematic search was performed using PubMed, ProQuest, and Google Scholar to identify all relevant randomized controlled studies in English that examined the effectiveness of EGb-761 on individuals with AD. The studies, based on expert consensus, had to have a minimum duration of 22 weeks and one of two primary outcome measures: 1. cognitive functioning, 2. functional ability in activities-of-daily-living (ADL). A secondary outcome measure, safety (drop-out rate from adverse events), was also evaluated. Quality was assessed based on indicators derived from the CONSORT 2010 checklist. Findings Ten randomized controlled trials from eight countries, with participants ranging from mild to severe AD were included. Of the ten studies, eight compared EGb-761 with placebo, three compared EGb-761 head-to-head with an AChE (two with Donepezil, one with Rivastigmine), and one compared EGb-761 and AChE stand-alone treatment with combined treatments (EGb-761 + AChE). Overall results on cognitive and functional improvements were mixed. Of the studies that demonstrated a positive association, the clinical significance is questionable. Conclusions Although results were inconsistent, EGb-761’s safety appears to be acceptable. In Hong Kong, given the widespread availability, popularity and perceived safety of EGb-761, the population needs appropriate guidance and support from the government to safeguard quality and increase awareness of potential drug-herb interactions. Concurrently, with AChE becoming an increasingly established treatment for AD, more head-to-head studies on EGb-761 and AChE on the local population are needed to increase understanding and public awareness. / published_or_final_version / Public Health / Master / Master of Public Health

Matrix metalloproteinase (MMP) induced extra cellular matrix (ECM) degradation is a crucial process involved in the development of many chronic inflammatory diseases, including cardiac remodeling and cancer metastasis. In cardiac remodeling, the presence of pathological stimuli leads to elevated MMP-9 expression and impairment of cardiac performance, which subsequently develops into heart failure. While in tumorgenesis, MMP-9 has been found to play key roles in metastasis, as it can break physical barriers for the tumor. Therefore, searching for agents targeting MMP-9 is a new direction for the treatment of cardiac remodeling and cancer metastasis. Chinese herbal medicine is becoming increasingly used worldwide in recent decades. In the past twenty years, as many highly selective and sensitive bioassays were introduced into the bioactive compounds screening from herbal medicine, more than one hundred new drug candidates have been identified. Therefore, herbal medicine is a potential source of bioactive compounds. Panax notoginseng (PNG) is one of the most common traditional Chinese medicines to treat cardiovascular diseases, and it was also reported to have anti-cancer effect. We hypothesized that it contains bioactive compounds that could inhibit MMP-9 activity in cardiomyocytes and cancer cells. In order to examine the effect of PNG on cardiac remodeling and cancer metastasis, we employed TNF-α induced MMP-9 in H9c2 cell (a rat cardiomyocyte) and HepG-2 cell (a human hepatoma cell) as an in vitro assay, respectively. PNG was first extracted by four different extraction methods according to the polarity of the solvent. The most effective fraction in suppressing MMP-9 activity in TNF-α induced H9c2 cell was chosen for further separation by silica gel column chromatography and high performance liquid chromatography (HPLC) until a single compound was isolated. According to the result of spectroscopic analysis by NMR, the compound was identified as ginsenoside Rb1. For the bioactivity assays, real-time quantitative polymerase chain reaction (QPCR) and Enzyme-linked immunosorbent assay (ELISA) were used to measure the mRNA and protein expression of MMP-9, respectively. We also examined the MMP-9 activity by gelatin zymography. The results showed that both of the PNG extract obtained from 10% ethanol extraction method (PNG-3) and purified Compound P (ginsenoside Rb1) showed significant inhibitory effect on MMP-9 expression and activity in H9c2 cells and HepG-2 cells. We further examined the molecular mechanisms of the inhibitory effect of PNG-3. H9c2 and HepG-2 cells were pretreated with different kinase inhibitors followed by the activation by TNF-α. The results showed the protein kinase R (PKR) inhibitor could inhibit TNF-α induced MMP-9 in both of the two cell lines. Furthermore, the results of Western blot showed the PNG-3 suppressed the phosphorylation of eIF-2α which is a down-stream effector of PKR in TNF-α stimulated H9c2 and HepG-2 cells, respectively. Therefore, PNG-3 may act through PKR to regulate TNF-α induced MMP-9 activity. In summary, bioactivity guided fractionation is an effective way of isolating bioactive compounds from medicinal herbs. In addition, PNG containing ginsenoside Rb1 may be a potential candidate of MMP-9 inhibition for the treatment of cardiac remodeling and cancer metastasis. / published_or_final_version / Paediatrics and Adolescent Medicine / Master / Master of Philosophy

Skeletal system plays a crucial role in our life. Skeletal diseases and disorders unlike cancer, are not fatal, but affect the quality of our life. Cell-based therapeutic strategies to generate targeted desired cell types for repair or replacement of damaged skeletal tissues are ideal regenerative medicines. Because of the heterogeneous cell types generated from embryonic and mesenchymal stem cells, the ability of progenitor population to differentiate into a target cell type appear to be a better alternative for tissue regeneration. Osteo-chondroprogenitors uniquely co-expressing Sox9 and Runx2 with dual differentiation potential to become chondrocytes and osteoblasts is a progenitor cell which is suitable for cell based therapy of bone disease. Therefore, developing effective strategies to generate sufficient quantities of osteo-chondroprogenitors are essential. Toward this, we took advantage of two lineage conversion approaches. The first strategy was to interrogate the ability of osteoblasts to be reprogrammed into induced pluripotent stem (iPS) cells and another one was to use defined transcription factors to induce chondrocyte lineage from skin fibroblasts. The selection of osteoblasts is based on the fact that it is originally derived from osteo-chondroprogenitor lineage and the stochastic events of iPS induction might revert osteoblasts first to their progenitor state before becoming pluripotent. The second approach is based on a previous report using three transcription factors (Sox9, Klf4 and c-Myc) to reprogramme skin fibroblasts into chondrocyte lineage. Our aim is to examine whether osteo-chondroprogenitors would be formed during the two reprogramming processes using Sox9-EGFP knock-in mice as a reporter. We reasoned that osteoblasts can be reprogrammed into iPS cells by four Yamanaka’s factors with pluripotency as shown by their ability to form teratomas and contribute to chimeric embryos. However base on the limitation of selector marker of osteo-chondroprogenitor we still cannot capture this progenitor during iPS reprogramming. And because of the pluripotency potential, pluripotent reprogramming approach also brings high risk of teratoma formation. Therefore our second objective was performed to examine whether osteo-chondroprogenitors would be formed during lineage reprogramming. Transient appearance of Sox9-EGFP/Runx2+ve cells was observed in the intermediate stage of over 14 days of chondrocyte lineage induction from skin fibroblasts by Sox9, klf4 and c-Myc. Cells expressing Sox9-EGFP/Runx2+ve showed typical molecular markers of osteo-chondroprogenitors. In vitro and in vivo differentiation assays demonstrated that Sox9-EGFP/Runx2+ve cells can differentiate predominantly into osteoblasts and chondrocytes. Taken together our data indicate that cells with osteo-chondrogenic potential could be generated by defined transcription factors-mediated reprogramming processes. / published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy

Chronic heart failure is one of the commonest fatal diseases in the world. Much work has been done to reveal its complicated pathogenesis and develop effective therapy. Xinmailong (XML), a compound extracted from Periplaneta americana, has been launched on the market in Mainland China as a proprietary medication for treating patients with chronic heart failure. Although it is highly effective, its mechanism of action is still not completely understood. In this study, the results of calcium (〖Ca〗^(2+)) imaging demonstrated that XML increased electrical impulse-induced intracellular calcium ([〖Ca〗^(2+)]i), in H9c2 cells, an rat embryonic cardiomyocytes cell line. This effect was dependent on extracellular 〖Ca〗^(2+) but not the 〖Ca〗^(2+) store from sarcoplasmic reticulum because XML had no effect on thapsigargin -induced 〖Ca〗^(2+) release. The effect of XML was inhibited by ML218-HCl but not nimodipine, indicating that XML interacted with T-type 〖Ca〗^(2+) channels but not L-type 〖Ca〗^(2+) channels. Unlike KB-R7943, which is a sodium calcium exchanger inhibitor, XML did not affect [〖Ca〗^(2+)]i in the absence of electric stimulation, implying that XML did not work on sodium calcium exchanger. Ouabain, a sodium-potassium ATPase inhibitor, increased the electrical impulse-induced [〖Ca〗^(2+)]i and the effect of ouabain and XML were not additive, suggesting that the site of action of ouabain and XML was overlapped. Biochemical assay on phosphate concentration showed that XML was able to inhibit the activity of sodium-potassium ATPase. Our study also demonstrated that XML reduced the production of reactive oxygen species in H9c2 cells. Western blotting showed that such antioxidant properties mechanism might involve the increased expressions of antioxidant enzymes including superoxide dismutase 1, superoxide dismutase 2 and heme oxygenase 1. In conclusion, our study has provided evidence that XML increases [〖Ca〗^(2+)]i level by activating T-type 〖Ca〗^(2+) channels and inhibiting sodium-potassium ATPase. The antioxidant effect of XML may also contribute to the cardioprotective effect of XML but further investigation is required. / published_or_final_version / Pharmacology and Pharmacy / Master / Master of Philosophy

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