Hodgkin disease relapse discovered at the time of liver transplant for acute liver failure.

Lymphoma is a recognized cause of liver damage and in rare instances presents as ALF. In such cases, the underlying malignancy is often difficult to detect. Historically, the prognosis has been poor. Cure has occasionally been achieved with chemotherapy alone. LT in this setting is controversial, but has contributed to successful outcomes, as in the case of the five-yr-old girl reported here.

Immersive Learning Design for Technology Education: A Soft Systems Methodology.

Science, technology, engineering and mathematics (STEM) education is a globalized trend of equipping students to facilitate technological and scientific developments. Among STEM education, technology education (TE) plays a significant role in teaching applied knowledge and skills to create and add value to systems and products. In higher education, the learning effectiveness of the TE assisted by the immersive technologies is an active research area to enhance the teaching quality and learning performance. In this study, a taught subject of radio frequency identification (RFID) assisted by using mixed reality technologies in a higher education institution was examined, while the soft systems methodology (SSM) was incorporated to evaluate the changes in learning performance. Under the framework of SSM, stakeholders' perceptions toward immersive learning and RFID education are structured. Thus, a rich picture for teaching activities is established for subject control, monitoring, and evaluation. Subsequently, the design of TE does not only satisfy the students' needs but also requirements from teachers, industries, and market trends. Finally, it is found that SSM is an effective approach in designing courses regarding hands-on technologies, and the use of immersive technologies improves the learning performance for acquiring fundamental knowledge and application know-how.

The architectural transcription factor high mobility group I(Y) participates in photoreceptor-specific gene expression.

The nonhistone chromosomal proteins high mobility group I(Y) [HMG I(Y)] have been shown to function as architectural transcription factors facilitating enhanceosome formation on a variety of mammalian promoters. Specifically, they have been shown to act as a "molecular glue" mediating protein-protein and protein-DNA contacts within the enhanceosome complex. HMG I(Y) proteins are expressed at high levels in embryonic and transformed cells and have been implicated in transcriptional regulation in these cells. Terminally differentiated cells, however, have been reported to express only minimal, if any, HMG I(Y). In contrast to these observations, we show here that adult mouse retinal photoreceptors, which are terminally differentiated cells, express high levels of these proteins. Using retinoblastoma cells as an approximate model, we further demonstrate in transiently transfected cells that inhibition of HMG I(Y) expression and mutation of HMG I(Y) binding sites significantly reduce rhodopsin promoter activity. DNase I footprint analysis indicates that HMG I protein interacts with a discrete site within the rhodopsin proximal promoter. This site overlaps with the binding site for Crx, a paired-like homeodomain transcription factor that is essential for photoreceptor functioning and that when mutated causes several forms of human photoreceptor degeneration. Both biochemical and functional experiments demonstrate that HMG I(Y) physically associate with Crx and that their interaction with DNA is required for high-level transcription of the rhodopsin gene. These data provide the first demonstration that HMG I(Y) can be important for gene activation in terminally differentiated cells.

The HMG I proteins: dynamic roles in gene activation, development, and tumorigenesis.

The high mobility group I, Y, and I-C proteins are low-molecular-weight, nonhistone chromosomal proteins that play a general role modulating gene expression during development and the immune response. Consistent with their role in early development, all three proteins are expressed at high levels during embryogenesis, and their expression is markedly diminished in differentiated cells. Exceptions to the general repression of these genes in adult tissues involve (1) A burst of synthesis of the HMG I protein during the immune response (during lymphocyte activation and preceding cytokine/adhesion molecule gene expression), (2) A constitutive expression of the HMG I and Y proteins in photoreceptor cells, and (3) Derepression of HMG I, Y, and often I-C expression in neoplastic cells. Work from several laboratories has now uncovered how these proteins participate in gene activation: (1) By altering the chromatin structure around an inducible gene-and thus influencing accessibility of the locus to regulatory proteins-(2) By facilitating the loading of transcription factors onto the promoters, and (3) By bridging adjacent transcription factors on a promoter via protein/protein interactions. Despite the similar structures and biochemical properties of the three proteins, the work has also provided clues to a division of labor between these proteins. HMG I and Y have demonstrable roles in enhanceosome formation, whereas HMG I-C has a specific role in adipogenesis. C-terminal truncations of HMG I-C and wild-type HMG Y appear to function in a manner analogous to oncogenes, as assessed by cellular transforation assays and transgenic mice. Future work should clearly define the similarities and differences in the biological roles of the three proteins, and should evolve to include attempts at pharmaceutical intervention in disease, based upon structural information concerning HMG I interactions with DNA and with regulatory proteins.

Seasonal variation in the necropsy incidence of pulmonary thromboembolism in Hong Kong.

The seasonal variation in the necropsy incidence of significant pulmonary thromboembolism in Hong Kong was investigated. A total of 3446 adult Chinese necropsies carried out in Queen Mary Hospital, Hong Kong, from 1987 to 1992 showed an overall rate of 3.77% for significant pulmonary thromboembolism. The rates for individual months were calculated and compared. The pattern of seasonal variation showed that there are two troughs in early summer (June, July) and early winter (November, December), with rates between 1.6% and 2.4%. The rates in the months for the rest of the year were between 4.0% and 5.5%. The overall pattern was similar to that of the temperate zone although the climate was quite different.

Myofibroblasts in hepatitis B related cirrhosis and hepatocellular carcinoma.

Peritoneal liver biopsy specimens from eight patients with hepatitis B associated cirrhosis, complicated by hepatocellular carcinoma, were studied for identification and localisation of myofibroblasts. The avidin-biotin peroxidase complex technique was used on paraffin wax sections, using monoclonal antibodies for actin and desmin, and ultrastructural examination was performed. Myofibroblasts were found in seven of the eight cirrhotic specimens and in all eight tumour specimens. They were identified in the fibrotic areas by the immunohistochemical technique, but ultrastructural examination disclosed their presence in the perisinusoidal space and between tumour cells.

Mesenchymal hamartoma of liver in a man: comparison with cases in infants.

A 53 year old man with a large mesenchymal hamartoma is reported. Only a few bile ducts could be found in the periphery of the lesion and no hepatocytes were identified within the lesion. As far as is known, this is the only adult male patient reported to date. On the basis of the reported findings of mesenchymal hamartoma in other adults, it is suggested that there could be changes in the morphology of this lesion with age: progressive loss of hepatocytes; degeneration of bile duct epithelium; and cystic change of the mesenchymal component. The haematopoietic element is considered to be part of the fetal hepatic haematopoiesis that occurs in the hamartoma.

Clinicopathological pattern of pulmonary thromboembolism in Chinese autopsy patients: comparison with Caucasian series.

The clinicopathological data of adult Chinese patients identified to have 'significant pulmonary thromboembolism (PTE)' at autopsy in Queen Mary Hospital (QMH) Hong Kong, from 1990 to 1994 inclusive, were analysed retrospectively. The prevalence of PTE was documented and data were compared with published series of Caucasian patients. The parameters studied included sex-age distribution, associated diseases, symptomatology, site of venous thrombosis, duration of admission and intervals between surgery and death. The rate of PTE was 4.7% (4.5% in males and 5.2% in females). The mean age of PTE patients was significantly higher than that of non-PTE patients (p < 0.001). Two clinicopathological features worthy of note are: (1) as in Caucasian patients, most Chinese patients with 'significant PTE' do not present with leg symptoms although many of them are found to have deep vein thrombosis (DVT) at postmortem; and (2) DVT in these patients is found in the calf veins rather than in the more proximal deep veins. The recently identified racial differences in hemostasis that may contribute to the differences between Chinese and Caucasian people are discussed.

Conjunctival melanotic lesions in Chinese: comparison with Caucasian series.

Conjunctival melanotic lesions in Chinese were studied and compared with those of Caucasians. These lesions were diagnosed in Chinese patients over a two-year period. They were excised under the clinical diagnoses of nevi, primary acquired melanosis (PAM) and malignant melanoma. For the cases included, the histology slides and clinical information were reviewed. Eighteen cases of nevi and nine non-nevoid lesions were identified. Among the non-nevoid lesions, there were eight cases of basal cell hyperpigmentation (one congenital, five acquired, two unknown) and one malignant melanoma. Benign or atypical melanocytic hyperplasias (MH) were not seen. This pattern is very different from that of Caucasian series. Acquired hyperpigmentation is almost only seen in Chinese and seldom in Caucasians. On the other hand, atypical MH is only seen in Caucasians, and not in Chinese. We conclude that conjunctival hyperpigmentation is associated with ethnicity and does not progress to MH, whether benign or atypical. It should be recognised as a distinct entity of no malignant potential that is part of the PAM clinical spectrum.

An autopsy study of pulmonary thromboembolism in Hong Kong Chinese.

A retrospective study of autopsied material in the last 15 yrs is documented an increasing incidence of pulmonary thromboembolism (PTE) in Hong Kong Chinese. The incidence of significant PTE increased from 0.58% in the first 5 yr period to 2.08% in recent years. The topographic features and characteristics of these PTE patients are analysed and the factors contributing to the changes are discussed.

Myospherulosis in renal cell carcinoma.

OBJECTIVE: To study retrospectively the identification, characteristics, and localization of myospherulosis in different types of renal cell carcinomas. DESIGN: Twenty-seven consecutive renal cell carcinomas treated by radical nephrectomy in 1 year were studied. All the tumor and nontumor slides were examined for myospherulosis. The demographic data, histological type of renal cell carcinoma, Robson stage, and Fuhrman grades were recorded. RESULTS: Myospherules were found in 10 cases. They were associated with the clear cell type and a higher nuclear grade. The cell type remained the only significant factor when these 2 factors were tested together with the tumor stage by logistic regression. Myospherulosis tended to be found in younger patients but was not associated with the sex or the side of the tumor. They were scattered within tumor cystic spaces or among sheets of tumor cells. Some of the myospherules might arise from histiocytes or even tumor cells. Compared with previous reports of myospherulosis associated with exogenous or endogenous lipid, the myospherules associated with renal cell carcinoma were smaller and more uniform in size. There is no associated fibrosis or foreign body giant cell reaction. CONCLUSION: As far as we know, this is the first report of myospherulosis occurring in malignant tumors in human, and their associated features are different from those previously described for myospherulosis related to exogenous or endogenous lipid.

Desmoplastic variant of ameloblastoma in Chinese patients.

Desmoplastic ameloblastoma is a rare tumour, and we know of only 43 previously reported cases. We report seven Chinese patients (five men and two women) with the desmoplastic variant of ameloblastoma, which makes up 9% of all ameloblastomas diagnosed during the years 1981-1995. The age ranged from 18 to 68 years (mean 43). Five of the tumours were in the maxilla and two were in the mandible. Five of them were situated anteriorly, the remaining two cases involving both anterior and posterior maxilla. The features of the 42 cases previously reported were reviewed and were compared with those in the present study. Our results differ in that we found a male predominance, wider age range and more tumours in the maxilla. Histologically, this variant of ameloblastoma is characterized by abundant collagenous stroma. Because the epithelial clusters may show prominent squamous metaplasia or may be compressed into thin strands in most areas, the appearance may mimic a squamous odontogenic tumour or odontogenic fibroma. The behaviour of this variant of ameloblastoma is likely to be the same as that of the classic ameloblastoma.

Smoking cessation among Hong Kong Chinese smokers attending hospital as outpatients: impact of doctors' advice, successful quitting and intention to quit.

To identify factors affecting current smokers' intention to quit smoking and factors associated with successful quitting among ex-smokers in Hong Kong. A cross-sectional survey of Chinese patients attending medical and surgical Specialist Outpatient Clinics (SOPCs) of public hospitals in Hong Kong, using a structured questionnaire. Results of the 642 respondents, 21% were current smokers, 9% were ex-smokers and 69% were non-smokers. 74% of the smokers reportedly received quitting advice from doctors. Among the current smokers, past quitting attempts, receiving information from sources other than doctors, believing that doctor's advice was useful, believing that all smokers should quit smoking and a positive attitude towards quitting were associated with intention to quit. Among those who had attempted to quit, being older (aged 50 or above), being retired/unemployed and consuming more than 10 cigarettes per day were associated with successful quitting. We found that advice from doctors on quitting smoking did not have any impact on Chinese smokers quitting or future intention to quit and reflect the inadequacy of advice given by Hong Kong doctors. The predictors of intention to quit and successful quitting identified in the study could be used to design future smoking cessation services.

Rasagiline protects against alpha-synuclein induced sensitivity to oxidative stress in dopaminergic cells.

Rasagiline is a propargylamine and irreversible monoamine oxidase (MAO) B inhibitor used for the treatment of Parkinson's disease (PD). It has demonstrated neuroprotective properties in laboratory studies. Current concepts of PD aetiopathogenesis include the role of alpha-synuclein, protein aggregation, free radical metabolism and mitochondrial dysfunction in contributing to cell death. We have used a combination of alpha-synuclein and free radical mediated toxicity in a dopaminergic cell line to provide a model of nigral toxicity in order to investigate the potential molecular mechanisms that mediate rasagiline protection. We demonstrate that rasagiline protects against cell death induced by the combination of free radicals generated by paraquat and either wild-type or A53T mutant alpha-synuclein over-expression. This protection was associated with a reduction in caspase 3 activation, a reduction in superoxide generation and a trend to ameliorate the fall in mitochondrial membrane potential. Rasagiline induced an increase in cellular glutathione levels. The results support a role for rasagiline in protecting dopaminergic cells against free radical mediated damage and apoptosis in the presence of alpha-synuclein over-expression. The data are of relevance to the interpretation of the potential mechanisms of action of rasagiline in explaining the results of disease modification trials in PD.

Plasma levels of matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) in age-related macular degeneration.

BACKGROUND: Several studies indicate that age-related macular degeneration (AMD) and atherosclerosis may share common pathogenetic pathways. The aim of this study was to determine the role of systemic matrix metalloproteinases (MMPs) in AMD, given that MMPs are implicated in the pathogenesis of atherosclerosis. METHODS: This study determined the plasma matrix metalloproteinases (MMP-2 and MMP-9) levels in three groups of subjects: group 1 included subjects with age-related maculopathy (ARM), group 2 included subjects with choroidal neovascularization (CNV) owing to AMD and group 3 consisted of age-matched controls. RESULTS: The mean plasma levels of MMP-2 were not significantly different in the three groups. In contrast, the mean plasma MMP-9 levels were significantly higher in ARM and CNV groups compared to that of the control group. However, there was no significant difference in MMP-9 levels between ARM and CNV groups. CONCLUSION: This is the first study that reveals a link between raised plasma MMP-9 levels with AMD. Further studies are required to identify the factors that contribute to this association.

Plasma levels of matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) in age-related macular degeneration.

BACKGROUND: Several studies indicate that age-related macular degeneration (AMD) and atherosclerosis may share common pathogenetic pathways. The aim of this study was to determine the role of systemic matrix metalloproteinases (MMPs) in AMD, given that MMPs are implicated in the pathogenesis of atherosclerosis. METHODS: This study determined the plasma matrix metalloproteinases (MMP-2 and MMP-9) levels in three groups of subjects: group 1 included subjects with age-related maculopathy (ARM), group 2 included subjects with choroidal neovascularization (CNV) owing to AMD and group 3 consisted of age-matched controls. RESULTS: The mean plasma levels of MMP-2 were not significantly different in the three groups. In contrast, the mean plasma MMP-9 levels were significantly higher in ARM and CNV groups compared to that of the control group. However, there was no significant difference in MMP-9 levels between ARM and CNV groups. CONCLUSION: This is the first study that reveals a link between raised plasma MMP-9 levels with AMD. Further studies are required to identify the factors that contribute to this association.

Extrafascial excision of the rectum: surgical anatomy of the fascia propria.

PURPOSE: It is now agreed that it is of vital importance to maintain the fascia propria as an intact envelope around the mesorectum to prevent tumor spillage while performing rectal excision for cancer. There are several surgical techniques described to achieve an intact fascial envelope, each arising from differing descriptions of the fascia propria of the rectum. The aim of this study was to describe the detailed surgical anatomy of the fascia propria. METHODS: Thirteen rectal specimens surgically removed by the technique of extrafascial excision were subjected to gross inspection, dissection, and histologic and electron microscopic examination. The attachments, thickness, and composition of the fascia propria were determined. RESULTS: The fascia propria is a continuous fascial sleeve surrounding the rectum and mesorectum that can be dissected as a complete "sock" off a fresh extrafascial specimen. It is 154 (+/- 1 standard deviation = 61-391) microm thick, is thinner anteriorly than posteriorly (P < 0.05), and is composed predominantly of collagen. It can be identified surgically at the pelvic brim as a shiny membrane and lies inside the hypogastric nerves and the pelvic plexuses. CONCLUSION: The fascia propria forms a sleeve around the mesorectum, offering a surface against which to dissect, enabling safe removal of the rectum with its intact mesorectum while preserving the autonomic nerves of the pelvis. The term "extrafascial excision" highlights the importance of the fascia propria in this operation.

Estrogen treatment induces elevated expression of HMG1 in MCF-7 cells.

The high mobility group (HMG) 1 protein is a highly conserved and ubiquitous chromosomal protein found enriched in active chromatin. In this study, we have investigated the effect of estrogen on the expression of the human high mobility group protein HMG1 gene and found that the HMG1 mRNA level in MCF-7 cells was sharply increased 2.5-fold after 30 min of estrogen treatment. Under continuous estrogen treatment, the HMG1 mRNA level decreased to a 1.5 times that of the basal level at 90 min and remained at this elevated level under estrogen treatment for up to 24 h. These results support the recent finding by Verrier et al. (C.S. Verrier, 1997, Mol. Endocrinol. 11, 1009-1019) that HMG1 promotes the binding of the estrogen receptor to the estrogen response element and further reinforce our believe that HMG1 plays a significant role in estrogen-induced gene expression.

Functional domains of the cone-rod homeobox (CRX) transcription factor.

The paired-like homeodomain transcription factor CRX (cone-rod homeobox) is involved in regulating photoreceptor gene expression and rod outer segment development. Mutations in CRX have been associated with several retinal degenerative diseases. These conditions range from Leber congenital amaurosis (a severe cone and rod degeneration of childhood onset) to adult onset cone-rod dystrophy and retinitis pigmentosa (an adult onset condition that primarily affects rods). The goal of this study is to better understand the molecular basis of CRX function and to provide insight into how mutations in CRX cause such a variety of clinical phenotypes. We performed deletion analysis in conjunction with DNA binding and transient transfection-based transactivation studies to identify the functional domains within CRX. DNA binding requires a complete homeodomain. Furthermore, truncated proteins that did not contain an intact homeodomain failed to demonstrate detectable expression in tissue culture upon transfection. Transactivation analysis indicated that both the OTX tail and the WSP domain are important for controlling positive regulatory activity of CRX. Interestingly, the mapped CRX transactivation domains were also critical when coexpressed with NRL. Specifically, the synergy between CRX and NRL was constant regardless of which CRX variant was used.