Outcome analysis of intraventricular thrombolytic therapy for intraventricular haemorrhage

OBJECTIVES

To evaluate the outcome of intraventricular thrombolytic therapy for intraventricular haemorrhage and to formulate a safe and effective regimen.

DESIGN

Retrospective study.

SETTING

Regional neurosurgical centre, Hong Kong.

PATIENTS

Twenty-nine consecutive adult patients who presented from November 1995 to November 1998 with non-traumatic intraventricular haemorrhage (Graeb score, > or =7) with no active rebleeding risks from vascular abnormalities.

INTERVENTIONS

Fourteen consecutive patients received intraventricular streptokinase via the external ventricular drainage, and 15 consecutive patients received intraventricular urokinase treatment.

MAIN OUTCOME MEASURES

Patient demographics, Glasgow coma scale score, Graeb score, mortality rate, shunt rate, fever response, infection rate, catheter blockage rate, and local and systemic bleeding tendency.

RESULT

The mean age of the 16 men and 13 women was 59 years (range, 14-76 years). The median Graeb score for cases of intraventricular haemorrhage was 10 (range, 7-12). There was no significant difference in terms of the Graeb score distribution, total dosage, and duration of treatment between the streptokinase and urokinase groups. More cases of fever were observed in the streptokinase group, which could be due to its antigenicity. The infection rate of the central nervous system was 3%, and the shunt rate was 24%. The overall 1-month postoperative mortality was 10%, which was related to a low preoperative Glasgow coma scale score (< or =4). No local rebleeding, systemic coagulopathy, or catheter blockage occurred.

CONCLUSIONS

Intraventricular thrombolytic therapy is a safe and effective method of managing intraventricular haemorrhage. We suggest instilling 20 000 units urokinase intra-operatively, followed by 20 000 units daily for about 3 days, except in cases of vascular abnormality, bleeding tendency, and trauma.

Application of a toxicity identification evaluation for a sample of effluent discharged from a dyeing factory in Hong Kong

A first toxicity identification evaluation (TIE) was conducted in three phases using the Microtox test to identify the major toxicant(s) in effluent discharged from a dyeing plant in Hong Kong. In Phase I toxicity characterization indicated that anions were likely to be the major toxicants for the entire effluent. In Phase II concentrations of sulfite and other anions in the original and the anion exchange resin-treated effluent samples were determined by ion chromatography. Anions, which were found in the effluent at comparatively high concentrations and were suspected of being responsible for the toxicity to luminescent bacteria, were selected for further study in Phase III. Investigation in Phase III using the spiking and mass balance approaches confirmed that the sulfite ion was the major toxicant in the effluent.

Suppressive effect of combination treatment of leflunomide and methotrexate on chemokine expression in patients with rheumatoid arthritis

To study the immunosuppressive and anti-inflammatory effects of combined leflunomide and methotrexate (MTX) therapy on chemokine expression in patients with rheumatoid arthritis (RA), nine patients were enrolled for the combination therapy for 24 weeks. These patients have been on treatment with MTX 15 mg/week for not less than 3 months before entry to the study. A loading dose of l00 mg/day of leflunomide was given for 3 days, followed by 10 mg/day for the rest of the study period. Plasma concentrations of monocyte chemotactic protein-1 (MCP-1), thymus- and activation-regulated chemokine (TARC), and macrophage-derived chemokine (MDC) were assayed before and after combination treatment by ELISA. Gene expression of inflammatory cytokines and chemokines of peripheral blood mononuclear cells was analysed by cDNA expression array. Plasma MCP-1, TARC and MDC concentrations were significantly lower in patients after combination treatment [median (interquartile range) before versus after treatment: MCP-1 of 118.0 (64.0-515.2) versus 3.2 (0.0-22.8) pg/ml, P < 0.01; TARC of 126.1 (27.2-197.4) versus 0.0 (0.0-52.5) pg/ml, P < 0.05; MDC of 503.3 (446.2-600.9) versus 366.8 (337.4-393.4) pg/ml, P < 0.05]. Positive correlations among reductions in plasma chemokines and clinical outcome measures were also found. Expression of chemokine genes including MDC and TARC was suppressed after combination treatment [% suppression of 38.7 (54.3-13.0) and 53.7 (55.9-28.4), respectively]. Combination therapy with leflunomide and MTX exhibits anti-inflammatory activity in the suppression of chemokine expression and subsequent recruitment of inflammatory cells into the inflammatory sites in RA.

Haematological manifestations in patients with severe acute respiratory syndrome: retrospective analysis

OBJECTIVES

To evaluate the haematological findings of patients with severe acute respiratory syndrome (SARS).

DESIGN

Analysis of the demographic, clinical, and laboratory characteristics of patients with SARS.

SETTING

Prince of Wales Hospital, Hong Kong. Subjects All patients with a diagnosis of SARS between 11 March and 29 March 2003 who had no pre-existing haematological disorders.

MAIN OUTCOME MEASURES

Clinical end points included the need for intensive care and death. Univariate and multivariate analyses were performed to examine factors associated with adverse outcome.

RESULTS

64 male and 93 female patients were included in this study. The most common findings included lymphopenia in 153 (98%) of the 157 patients, neutrophilia in 129 (82%), thrombocytopenia in 87 patients (55%), followed by thrombocytosis in 77 (49%), and isolated prolonged activated partial thromboplastin time in 96 patients (63%). The haemoglobin count dropped by more than 20 g/l from baseline in 95 (61%) patients. Four patients (2.5%) developed disseminated intravascular coagulation. Lymphopenia was shown in haemato-lymphoid organs at postmortem examination. Multivariate analysis showed that advanced age and a high concentration of lactate dehydrogenase at presentation were independent predictors of an adverse outcome. Subsets of peripheral blood lymphocytes were analysed in 31 patients. The counts of CD4 positive and CD8 positive T cells fell early in the course of illness. Low counts of CD4 and CD8 cells at presentation were associated with adverse outcomes.

CONCLUSIONS

Abnormal haematological variables were common among patients with SARS. Lymphopenia and the depletion of T lymphocyte subsets may be associated with disease activity.

Plasma TARC concentration may be a useful marker for asthmatic exacerbation in children

Recent studies suggested the T-helper cells type-2 lymphocytes-specific thymus and activation-regulated chemokine (TARC) and monocyte-derived chemokine (MDC) are useful inflammatory markers for chronic asthma. However, their roles in assessing the severity of acute asthma are unknown. This study aims to evaluate the serial changes of plasma TARC and MDC concentrations in children with asthmatic exacerbation. All patients with acute asthma were treated with systemic corticosteroid for 5 days. The severity of asthmatic exacerbation was classified according to the Global Initiative for Asthma guidelines. Plasma TARC and MDC concentrations were measured by sandwich enzyme immunoassays. Sixteen children, with a median (interquartile range) age of 9.3 (7.2-10.6) yrs and asthmatic exacerbation, were recruited. Plasma TARC concentration showed inverse correlation with peak expiratory flow rate at presentation. The median plasma TARC concentration was highest during the acute attacks (46 pg x mL(-1)) as compared to those levels at 1 (31 pg x mL(-1)) and 5 weeks (32 pg x mL(-1)) following treatment. The median plasma MDC level similarly decreased from 698 pg x mL(-1) at baseline to 261 pg x mL(-1) 1 week later, but increased back to 574 pg x mL(-1) at 5 weeks. These results suggest that plasma T-helper cells type-2 lymphocytes-specific thymus and activation-regulated chemokine but not monocyte-derived chemokine concentration may be a useful inflammatory marker in assessing asthmatic exacerbation in children.

A study of candidate genes for psoriasis near HLA-C in Chinese patients with psoriasis

BACKGROUND

Genetic analyses have identified the HLA-Cw6 allele as the major risk allele for psoriasis in many racial groups. However, by serological typing, HLA-Cw6 is not considered a risk factor in Chinese psoriatics. There are several susceptibility genes for psoriasis residing in chromosome 6p near the HLA-C locus, including the corneodesmosin (CDSN) gene, the octamer transcription factor-3 (POU5F1) gene, the major histocompatibility complex class I chain-related gene A (MICA), and the gene for tumour necrosis factor (TNF)-alpha. However, the information about their role in psoriasis in Chinese patients is limited.

OBJECTIVES

We aimed to determine whether Cw6 and the genetic polymorphism of the CDSN gene, POU5F1 gene, MICA gene and the gene for TNF-alpha promoter region were associated with an increased risk of psoriasis in Chinese patients.

METHODS

We conducted a case-control association study in 105 Chinese patients with psoriasis vulgaris and 160 control subjects of similar ages. Genotypes of Cw6, the CDSN gene, the POU5F1 gene, and the gene for the TNF-alpha promoter region were determined by polymerase chain reaction (PCR) followed by restriction enzyme digestion. Genotyping of MICA was determined by PCR combined with fluorescent-based automated fragment detection technology. Results The allele frequencies showed no differences between patients and controls for the POU5F1 gene, MICA gene and the gene for TNF-alpha promoter region. The frequency of the HLA-Cw6 allele in the psoriasis group was significantly higher than that in the control group (18.6% vs. 6.56%, P < 0.00005). For the CDSN gene, patients were more likely to have C allele at position +619 (P = 0.006) and C allele at position +1243 (P = 0.007), but the significance disappeared after correction for multiple testing (Pc > 0.05).

CONCLUSIONS

HLA-Cw6 remains the most significant susceptibility gene in Chinese patients with psoriasis. However, the role of the CDSN gene in the pathogenesis of psoriasis deserves further scrutiny.

Tumour necrosis factor-alpha-induced expression of intercellular adhesion molecule-1 on human eosinophilic leukaemia EoL-1 cells is mediated by the activation of nuclear factor-kappaB pathway

BACKGROUND

Intercellular adhesion molecule-1 (ICAM-1) has been shown to mediate the adhesion and migration of eosinophils to the site of allergic inflammation. However, molecular mechanisms regulating the expression of ICAM-1 in eosinophils are still being elucidated. We investigated the effect of tumour necrosis factor-alpha (TNF-alpha) on ICAM-1 expression of eosinophils.

METHODS

The surface expression of ICAM-1 on a human eosinophilic leukaemic cell line, EoL-1, was assessed by immunocytochemical staining. The phosphorylation of inhibitor kappa B-alpha (IkappaB-alpha) and p38 mitogen-activated protein kinase (MAPK) was detected by Western blot. Nuclear factor kappa-B (NF-kappaB) pathway-related genes were evaluated by the cDNA expression array system, whereas the activity of NF-kappaB was measured by electrophoretic mobility shift assay (EMSA).

RESULTS

TNF-alpha was found to induce the cell surface expression of ICAM-1. A specific proteasome inhibitor N-cbz-Leu-Leu-leucinal (MG-132), but not a p38 MAPK inhibitor (SB 203580), was found to suppress the TNF-alpha-induced expression of ICAM-1 on EoL-1 cells. The gene expressions of ICAM-1, NF-kappaB and IkappaBalpha were up-regulated after the stimulation with TNF-alpha. Further, TNF-alpha was shown to induce IkappaB-alpha phosphorylation and degradation, thereby indicating the activation of NF-kappaB. In EMSA, there was a shifted NF-kappaB band on TNF-alpha-treated cells with or without SB 203580, but no shifted band was observed on MG-132-treated cells.

CONCLUSION

In vitro studies of EoL-1 cells, an eosinophilic leukaemic cell line, confirmed that NF-kappaB plays an important role in the expression of ICAM-1 and recruitment of eosinophils in allergic inflammation.

Tuberculous meningitis with spinal tuberculous arachnoiditis

This report is of a 36-year-old woman who initially presented with confusion and fever. Subsequent investigations showed tuberculous meningitis with acute hydrocephalus. Ventriculoperitoneal shunt was performed and anti-tuberculosis therapy was given. The patient was later noticed to have weakness of both lower limbs and urinary retention. Magnetic resonance imaging of the thoracic spine showed radiological features of tuberculous arachnoiditis with cord compression. Decompressive laminectomy was performed and high-dose systemic corticosteroid was given. A high level of awareness is required when diagnosing tuberculous arachnoiditis and the importance of high-dose corticosteroid in the treatment regimen is emphasised.

Elevated plasma concentrations of nitric oxide, soluble thrombomodulin and soluble vascular cell adhesion molecule-1 in patients with systemic lupus erythematosus

OBJECTIVE

To investigate the correlations among plasma concentrations of nitric oxide (NO), soluble thrombomodulin (sTM) and vascular cell adhesion molecule (sVCAM-1), and whether these three molecules are associated with renal involvement in patients with systemic lupus erythematosus (SLE).

METHODS

Plasma NO concentrations of 73 SLE patients (35 with renal disease, RSLE patients; 38 without renal disease, SLE patients) and 28 age- and sex-matched healthy control subjects were measured by the non-enzymatic Griess assay, and sTM and sVCAM-1 by enzyme-linked immunosorbent assay.

RESULTS

In RSLE patients, plasma nitrite concentrations were significantly higher than in control subjects (P=0.009) and correlated positively with plasma sTM, plasma creatinine and urea (all P<0.05). Plasma sTM and sVCAM-1 concentrations were significantly elevated in RSLE and SLE patients (both P<0.0001) compared with controls. Plasma sTM was significantly correlated with plasma sVCAM-1, and both were correlated with plasma creatinine and urea and the SLE Disease Activity Index (all P<0.05).

CONCLUSION

Elevated plasma NO, sTM, and sVCAM-1 concentrations have significant intercorrelations and are strongly associated with renal involvement in SLE.

Anti-proliferative and differentiation-inducing activities of the green tea catechin epigallocatechin-3-gallate (EGCG) on the human eosinophilic leukemia EoL-1 cell line

A novel approach for the treatment of leukemia is the differentiation therapy in which immature leukemia cells are induced to attain a mature phenotype when exposed to differentiation inducers, either alone or in combinations with other chemotherapeutic or chemopreventive drugs. Over the past decade, numerous studies indicated that green tea catechins (GTC) could suppress the growth and induce apoptosis on a number of human cancer cell lines. However, the differentiation-inducing activity of GTC on human tumors remains poorly understood. In the present study, the effect of the major GTC epigallocatechin-3-gallate (EGCG) on the proliferation and differentiation of a human eosinophilc leukemic cell line, EoL-1, was examined. Our results showed that EGCG suppressed the proliferation of the EoL-1 cells in a dose-dependent manner, with an estimated IC(50) value of 31.5 microM. On the other hand, EGCG at a concentration of 40 microM could trigger the EoL-1 cells to undergo morphological differentiation into mature eosinophil-like cells. Using RT-PCR and flow cytometry, it was found that EGCG upregulated the gene and protein expression of two eosinophil-specific granule proteins, the major basic protein (MBP) and eosinophil peroxidase (EPO), in EoL-1 cells. Taken together, our findings suggest that EGCG can exhibit anti-leukemic activity on a human eosinophilic cell line EoL-1 by suppressing the proliferation and by inducing the differentiation of the leukemia cells.

Expression of FHL2 and cytokine messenger RNAs in human myocardium after cardiopulmonary bypass

BACKGROUND

Proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, and IL-8 have been implicated in myocardial injury following cardiopulmonary bypass (CPB). However, little evidence is currently available to directly confirm such a relationship. We have previously documented that a newly discovered 'four and a half LIM-only protein 2' (FHL2) is exclusively expressed in myofibres. We hypothesized that the upregulation of FHL2 is proportional to the degree of myocardial injury and investigated the myocardial expression of FHL2 together with these cytokine messenger RNAs (mRNAs) during clinical CPB.

METHODS

Intermittent hypothermic blood cardioplegia was used in all patients. Atrial myocardial biopsies were obtained immediately at the onset and at the end of CPB in 33 consecutive patients undergoing valvular or coronary artery surgery. TNF-alpha, IL-6, and IL-8 mRNA expressions in these myocardial samples were determined by semi-quantitative reverse transcription-polymerase chain reaction. Myocardial FHL2 expression was determined by Western blot analysis. Serum levels of the MB isoenzyme of creatine kinase (CK-MB) and cardiac troponin-I (cTnI) before surgery and 24 h after the end of CPB were also measured.

RESULTS

The duration of aortic crossclamping and CPB was 70+/-33 and 99+/-37 min, respectively. No elevated myocardial TNF-alpha mRNA expression was found after CPB. IL-6 mRNA expressions were detected in 14 pairs of the myocardial biopsies and were elevated in 11 (33%) post-CPB biopsies. Similarly, IL-8 mRNA expressions were detected in 19 pairs of samples and were elevated in 14 (42%) post-CPB biopsies. Among the 17 pairs of biopsies with positive FHL2 expression, FHL2 levels were increased in 11 (33%) post-CPB samples. Moreover, the elevated FHL2 expression was associated with an increase in IL-6 (P=0.018) and IL-8 (P=0.024) mRNA expression after CPB. Postoperative CK-MB and cTnI levels were significantly higher in patients with myocardial FHL2 expressions than those without (CK-MB, 13.5+/-2.3 vs. 6.5+/-0.8 ng/ml, P=0.022; cTnI, 10.7+/-2.0 vs. 3.5+/-0.6 ng/ml, P=0.0013).

CONCLUSIONS

Our findings demonstrate for the first time that both IL-6 and IL-8 mRNAs are upregulated in human cardiac myocytes following CPB and these cytokines may be involved in myocardial ischemia-reperfusion injury, as reflected by their association with an increased expression of FHL2.

Elevated production of interleukin-18 is associated with renal disease in patients with systemic lupus erythematosus

To investigate the production mechanism and proinflammatory role of the cytokine interleukin (IL-18) in lupus nephritis, we investigated the plasma concentrations of IL-18 and nitric oxide (NO) and the release of IL-18 and NO from mitogen-activated peripheral blood monomuclear cells (PBMC), in 35 SLE patients with renal disease (RSLE), 37 patients without renal disease (SLE) and 28 sex- and age-matched healthy control subjects (NC). IL-18 and NO concentrations were measured by ELISA and colourimetric non-enzymatic assay, respectively. Gene expressions of IL-18 and IL-18 receptor were analysed by RT-PCR. Plasma IL-18 and NO concentrations were significantly higher in RSLE than NC (both P < 0.01). Elevation of plasma IL-18 in RSLE correlated positively and significantly with SLE -disease activity index and plasma NO concentration (r = 0.623, P < 0.0001 and r = 0.455, P = 0.017, respectively), and the latter also showed a positive and significant correlation with plasma creatinine (r = 0.410, P = 0.034) and urea (r = 0.685, P < 0.0001). There was no significant difference in gene expressions of IL-18 and IL-18 receptor in PBMC among RSLE, SLE and NC. Percentage increase in culture supernatant IL-18 concentration was significantly higher in RSLE than SLE and NC (both P < 0.05). The basal NO release was significantly higher in RSLE than that in SLE and NC (both P < 0.005). IL-18 is therefore suggested to play a crucial role in the inflammatory processes of renal disease in SLE.

Activation of p38 mitogen-activated protein kinase and nuclear factor-kappaB in tumour necrosis factor-induced eotaxin release of human eosinophils

The CC chemokine eotaxin is a potent eosinophil-specific chemoattractant that is crucial for allergic inflammation. Allergen-induced tumour necrosis factor (TNF) has been shown to induce eotaxin synthesis in eosinophils. Nuclear factor-kappaB (NF-kappaB) and mitogen-activated protein kinases (MAPK) have been found to play an essential role for the eotaxin-mediated eosinophilia. We investigated the modulation of NF-kappaB and MAPK activation in TNF-induced eotaxin release of human eosinophils. Human blood eosinophils were purified from fresh buffy coat using magnetic cell sorting. NF-kappaB pathway-related genes were evaluated by cDNA expression array system. Degradation of IkappaBalpha and phosphorylation of MAPK were detected by Western blot. Activation of NF-kappaB was determined by electrophoretic mobility shift assay. Eotaxin released into the eosinophil culture medium was measured by ELISA. TNF was found to up-regulate the gene expression of NF-kappaB and IkappaBalpha in eosinophils. TNF-induced IkappaBalpha degradation was inhibited by the proteasome inhibitor N-cbz-Leu-Leu-leucinal (MG-132) and a non-steroidal anti-inflammatory drug sodium salicylate (NaSal). Using EMSA, both MG-132 and NaSal were found to suppress the TNF-induced NF-kappaB activation in eosinophils. Furthermore, TNF was shown to induce phosphorylation of p38 MAPK time-dependently but not extracellular signal-regulated kinases (ERK). Inhibition of NF-kappaB activation and p38 MAPK activity decreased the TNF-induced release of eotaxin from eosinophils. These results indicate that NF-kappaB and p38 MAPK play an important role in TNF-activated signalling pathway regulating eotaxin release by eosinophils. They have also provided a biochemical basis for the potential of using specific inhibitors of NF-kappaB and p38 MAPK for treating allergic inflammation.

Intracellular signal transduction in eosinophils and its clinical significance

The incidence and prevalence of allergic diseases such as asthma and allergic rhinitis have recently been increasing worldwide. Eosinophils are the principal effector cells for the pathogenesis of allergic inflammation via the secretion of highly cytotoxic granular proteins including eosinophil cationic protein, major basic protein and eosinophil protein X. Blood and tissue eosinophilia is a common manifestation of late-phase allergic inflammation causing tissue damage. The development of eosinophilia correlates with the production of haematopoietic cytokines including interleukin (IL)-3. IL-5 and granulocyte macrophage colony stimulating factor (GM-CSF), and eosinophil-specific chemoattractant, eotaxin, from T-lymphocytes and the epithelium respectively. Elucidation of intracellular mechanisms that control the activation, apoptosis and recruitment of eosinophils to tissues is therefore fundamental in understanding these disease processes and provides targets for novel drug therapy. Over the past decade, there has been intensive investigation for the intracellular signal transduction regulating various biological functions of eosinophils and their roles in the pathogenesis of eosinophil-related diseases. This review will emphasize on the cytokine and chemokine-mediated signal transductions including the RAS-RAF-mitogen-activated protein kinases (MAPK), Janus kinases (JAK)-signal transducers and activators of transcription (STAT), phosphatidylinositol 3-kinase (PI3K) and nuclear factor-kappa B (NF-kappaB), and various antagonists of receptors and inhibitors of intracellular signaling molecules as potential therapeutic agents of allergic diseases.

Bounded-depth threshold circuits for computer-assisted CT image classification

We present a stochastic algorithm that computes threshold circuits designed to discriminate between two classes of computed tomography (CT) images. The algorithm employs a partition of training examples into several classes according to the average grey scale value of images. For each class, a sub-circuit is computed, where the first layer of the sub-circuit is calculated by a new combination of the Perceptron algorithm with a special type of simulated annealing. The algorithm is evaluated for the case of liver tissue classification. A depth-five threshold circuit (with pre-processing: depth-seven) is calculated from 400 positive (abnormal findings) and 400 negative (normal liver tissue) examples. The examples are of size n=14,161 (119 x 119) with an 8 bit grey scale. On test sets of 100 positive and 100 negative examples (all different from the learning set) we obtain a correct classification close to 99%. The total sequential run-time to compute a depth-five circuit is about 75h up to 230h on a SUN Ultra 5/360 workstation, depending on the width of the threshold circuit at depth-three. In our computational experiments, the depth-five circuits were calculated from three simultaneous runs for depth-four circuits. The classification of a single image is performed within a few seconds.

Brain tuberculoma in Hong Kong

We report two cases of brain tuberculoma occurring in patients residing in Hong Kong. Both patients presented with headache and had space-occupying lesions evident on computed tomography scans of the brain. The patients had no history of tuberculosis and no symptoms of concurrent extracranial tuberculosis were evident. The diagnosis of tuberculoma was made at the time of surgical excision. Delayed diagnosis of brain tuberculoma is likely to occur in industrialised countries where tuberculosis is rare. In Hong Kong, however, with a constant influx of foreign domestic workers from endemic regions, a high index of suspicion should be maintained. Imaging studies support, but do not confirm, the diagnosis of brain tuberculoma. We recommend obtaining a definitive histological diagnosis, with computed tomography-guided stereotactic biopsy, before starting antituberculous therapy. Surgical excision is necessary in patients with raised intracranial pressure secondary to the lesion, who are not responding to medical therapy.

Long-term changes in water quality and phytoplankton characteristics in port shelter, Hong Kong, from 1988-1998

This study analysed monthly physico-chemical and phytoplankton data collected from 10 marine monitoring stations in Port Shelter Hong Kong, from 1988 to 1998. Cluster analysis based on all water quality parameters measured shows that the 10 monitoring stations can be grouped into three clusters: Cluster I consists of stations located in Outer Port Shelter; Cluster II consists of stations located in Inner Port Shelter and Cluster III consists of a single station in Hebe Heaven, a well-sheltered Bay in Inner Port Shelter. Factor analysis shows high positive loadings for nutrients and nutrient ratios in the first two factors of the three clusters, which indicates that the stations of the three clusters were primarily grouped according to their respective nutrient conditions. In Inner Port Shelter, and particularly Station PM5 in the sheltered Hebe Haven, the influence of surface runoff and pollution loading from the surrounding catchment area was apparent. Five stations located along a transect from Inner to Outer Port Shelter were selected for trend analysis. An increasing trend for temperature and a decreasing trend for pH are observed in all Stations except PM10 which is at the mouth of Port Shelter. The results of canonical analysis revealed that temperature and pH could also play an important role in determining the density and biovolume of the minor algal groups in Port Shelter.

Modulation of the gene expression of N-methyl-D-aspartate receptor NR2B subunit in the rat neostriatum by a single dose of specific antisense oligodeoxynucleotide

N-methyl-D-aspartate receptors (NRs) are a group of ionotropic glutamate receptors in the brain and they are composed of heteromeric subunits (NR1, NR2A-D and NR3). In the neostriatum, a brain region that is associated with movement in animals, NMDA channels are known to involve in the motor control. Our previous report (Lai et al., 2000, Neuroscience 98, 493-500) has shown that a single dose of antisense oligodeoxynucleotides that are specific to NR1 subunit results in blockage of the gene expression of NR1 as well as NR2A subunits in the neostriatum. In the present study, antisense oligodeoxynucleotides that are specific to NR2B (ANR2B) were then employed as molecular tools to further investigate the molecular interactions of NMDA receptor subunits in the neostriatum. A single dose of ANR2B was injected unilaterally into the rat neostriatum. After one day of injection, no modification of motor behavior was found in the ANR2B-injected rats. The mRNA level of NR2B in the ANR2B-injected neostriatum was found to be decreased (-20.4%) by reverse transcriptase polymerase chain reaction (RT-PCR). However, the mRNA levels of NR1, NR2A, NR2C and NR2D in the ANR2B-treated neostriatum were found to be unchanged. After two days of injection, NR2B immunoreactivity was found to decrease in the ANR2B-treated neostriatum by immunofluorescence (-35.1%). At higher magnification, NR2B immunoreactivity was found to decrease in presumed spiny neurons of the neostriatum (-23.4%). No change in NR1 immunoreactivity was observed. These results indicate that a single dose of ANR2B can successfully block the gene expression of NR2B in neurons of the neostriatum and there is less effect on NR1 and other NR2 subunits. The blockage of the gene expression of NR2B is therefore specific and the present results may provide important implications in applications of antisense in research and in clinical therapy of neurological diseases.

Specific expression of cytochrome P4501A1 gene in gill, intestine and liver of tilapia exposed to coastal sediments

Toxicological effects of persistent organic pollutants (POPs) in aquatic ecosystems lead to the deterioration of water quality and adversely affect fish and human health. The highly lipophilic nature of these pollutants may enter fish through the diet or by water-borne exposure. In monitoring contamination in aquatic systems, induction of the cytochrome P450 1A1 (CYP1A1) gene of fish has been evaluated as a sensitive, "early warning" method. The objective of the present study was to characterize the induction of the gene in fish upon exposure to coastal sediments and to determine its specific expression in liver and extrahepatic organs (i.e. gill and intestine) in which the toxicological effects to the corresponding tissues could be addressed. Sediment samples were collected from different sites, including Victoria Harbour (VS), Ma Wan (MW), Tsim Bei Tsui (TBT) and Mai Po (MP). The samples were analyzed for polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). CYP1A1 mRNA expression was measured in juvenile tilapia exposed experimentally to coastal sediment for 3 and 7 days. A negative control group of fish maintained in seawater was used. Using the primer dropping polymerase chain reaction technique, gill, intestinal and hepatic CYP1A1 mRNAs were quantified. Chemical analysis shows that the samples from VS contaminated with the highest concentration of PCBs (45.24 p.p.b.) and PAHs (1663.7 p.p.b.), followed by MW (16.01 and 347.7 p.p.b.), TBT (14.48 and 235.2 p.p.b.) and MP (14.60 and 242.2 p.p.b.). Fish exposed to sediments were contaminated with various levels of PCBs (VS, 64.14-72.06 p.p.b.; MP, 27.06-31.62 p.p.b.; TBT, 27.29-33.92 p.p.b.; MW, 16.05-17.76 p.p.b.) and PAHs (VS, 124.7-304.9 p.p.b.; MP, 97.57-164.1 p.p.b.; TBT, 25.38-98 p.p.b.; MW, 24.07-68.13 p.p.b.). The control fish displayed moderate expression of CYP1A1 mRNA in liver (1.45 arbitrary units), gill (1.21 arbitrary units) and intestine (0.56 arbitrary units). Following sediment exposure, there was a large increase in CYP1A1 mRNA in intestine and liver but no significant changes in gill tissues. In the first 3 days, there was anywhere from 34-96 and 69-156% induction of the CYP1A1 transcripts in intestine and liver, respectively. Following 7 days of exposure, a continued induction of high level of CYP1A1 mRNA in intestine (73-157%) was observed. The induction of CYP1A1 in liver and intestine provided a defensive mechanism against POPs entering from the external environment.

A study of apolipoproteins E and A-I in cutaneous amyloids

BACKGROUND

Apolipoprotein E (apoE) is present in a variety of biochemically different amyloid deposits, including Alzheimer's disease, systemic amyloidosis and primary cutaneous amyloidosis (PCA). Among the three closely related alleleic forms of apoE, the epsilon4 allele is linked to Alzheimer's disease. Apolipoprotein A-I (apoA-I), another apolipoprotein, is also found in senile plaques of Alzheimer's disease and in amyloid of aortic atherosclerotic plaques. Furthermore, apoA-I has recently been found to be associated with hereditary cutaneous and cardiac amyloidosis.

OBJECTIVES

To determine whether the apoE epsilon4 allele is associated with increased risk of PCA and whether apoE and apoA-I are present in PCA and common secondary cutaneous amyloidosis (SCA) (i.e. basal cell carcinoma, Bowen's disease and seborrhoeic keratosis).

METHODS

We examined the apoE genotype in 57 Chinese patients with PCA and 58 normal healthy control subjects of similar age. In addition, immunohistochemical staining was performed to determine the localization of apoE and apoA-I in skin tissues from 15 patients with SCA and 15 with PCA.

RESULTS

The frequency of the epsilon4 allele in the PCA group was not significantly higher than that in the control group (8.8% vs. 6.9%, P > 0.05). ApoE was present in amyloid deposits in both PCA and SCA, but apoA-I was not detected in these cutaneous amyloid deposits.

CONCLUSIONS

ApoE is also a component of amyloid deposits in SCA. Although the genetic susceptibility of certain apoE isoforms may not be a crucial factor in the development of PCA and, although apoA-I is not associated with amyloid deposits of PCA and SCA, the role of apolipoproteins in amyloidogenesis deserves further scrutiny.

Odontogenic subperiosteal abscess of orbit: a case report

Subperiosteal abscess of orbit is an uncommon but serious complication of orbital infection. We report a case of a 78 year old gentleman who presented with bilateral periorbital oedema and proptosis. Computerised tomography of orbit revealed bilateral dilated superior ophthalmic veins. Bilateral carotid-cavernous fistula was initially suspected. Serial imaging showed an increasing bilateral subperiosteal lesion of the orbit. Fine needle aspiration confirmed subperiosteal abscess. A high level of awareness is necessary in diagnosing subperiosteal abscess.