Images in cardiovascular medicine. Diffuse infiltration of lymphoma of the myocardium mimicking clinical hypertrophic cardiomyopathy.
Explore the source record for details and available documents.
Autopsy↗
Biomedical subjects
H K Ng
Publications and source records attributed to H K Ng.
Specific epitopes of the structural and hypothetical proteins elicit variable humoral responses in SARS patients.
BACKGROUND: Severe acute respiratory syndrome (SARS) is an infectious disease which was caused by a novel coronavirus (SARS-CoV). SARS has caused an outbreak in the world during 2003 and 2004, with 8098 individuals being infected and a death toll of 774 in 28 regions around the world. Specific humoral responses to viral infection remain unclear. OBJECTIVE: To analyse the antigenicity of the SARS-CoV genome and identify potential antigenic epitopes in the structural proteins. METHODS: Potential antigenic epitopes were identified in the structural proteins (nucleocapsid, membrane, spike, and small envelope proteins) and hypothetical proteins (SARS3a, 3b, 6, 7a, and 9b) that are specific for SARS-CoV. A peptide chip platform was created and the profiles of antibodies to these epitopes were investigated in 59 different SARS patients' sera obtained 6-103 days after the onset of the illness. Serial sera from five additional patients were also studied. RESULTS: Epitopes at the N-terminus of the membrane protein and the C-terminus of nucleocapsid protein elicited strong antibody responses. Epitopes on the spike protein were only moderately immunogenic but the effects were persistent. Antibodies were also detected for some putative proteins, noticeably the C-termini of SARS3a and SARS6. CONCLUSIONS: Important epitopes of the SARS-CoV genome that may serve as potential markers for the viral infection are identified. These specific antigenic sites may also be important for vaccine development against this new fatal infectious disease.
Antibodies, Viral↗
Klebsiella meningitis mimicking clinical deterioration from hemorrhage of a complex posterior fossa arteriovenous malformation.
We report a case of a 33-year-old male with a history of complex posterior fossa arteriovenous malformation (AVM) with partial resection done in China; at follow-up in our unit, he presented with a 1-day history of acute deterioration of consciousness level after minor head injury. The clinical and radiologic features were compatible with spontaneous hemorrhage from the AVM, and the patient died 1 day after admission. However, postmortem examination revealed the direct cause of death was due to Klebsiella meningitis. The clinical catch is highlighted, and the importance of early and prompt detection of this condition is emphasized.
Adult↗
Apolipoprotein E epsilon4 allele is associated with the volume of white matter changes in patients with lacunar infarcts.
The relationship between the apolipoprotein E (APOE) exon 4 polymorphism and white matter changes (WMC) in elderly subjects or patients with Alzheimer's disease is controversial. To investigate this polymorphism in relation to WMC in patients with lacunar infarcts, we prospectively observed 67 patients with acute lacunar infarct and 134 age- and sex-matched controls. Genotypes were determined using a nested polymerase chain reaction. WMC were measured quantitatively and were divided into two groups, severe and mild, with the mean volume of WMC as the cut point. Twenty-two patients (33%) had severe WMC. There was a significant difference in the distribution of APOE epsilon2, epsilon3, and epsilon4 alleles between severe and mild WMC groups (P = 0.002). The frequency of epsilon4 alleles was higher in patients with severe WMC than in those with mild WMC (25% vs. 7%, P = 0.003). These results suggest that APOE epsilon4 may exacerbate WMC in patients with lacunar infarcts. Further studies are required to confirm this finding.
Aged↗
Surgical treatment of a neonate with refractory seizures secondary to congenital giant cell astrocytoma: case report and literature review.
Congenital brain tumours are rare. They account for 0.5% to 1.9% of intracranial tumours in childhood and have an incidence of 0.34 per million live births. Most congenital brain tumours are neuro-ectodermal tumours and medulloblastomas; giant cell astrocytoma and other tuberous sclerosis-related tumours are rare. We report on a neonate who developed seizures that were refractory to medical treatment. Imaging studies revealed a right frontal calcified tumour. Surgical resection was performed successfully and pathology revealed the tumour to be a giant cell astrocytoma. The child was seizure-free afterwards.
Anticonvulsants↗
Differential role of hydrogen peroxide and staurosporine in induction of cell death in glioblastoma cells lacking DNA-dependent protein kinase.
Various DNA double-strand break repair mechanisms, in which DNA-dependent protein kinase (DNA-PK) has a major role, are involved both in the development and treatment of glioblastoma. The aim of the present study was to investigate how glioblastoma cells responded to hydrogen peroxide and staurosporine (STS) and how such a response is related to DNA-PK. Two human glioblastoma cell lines, M059J cells that lack DNA-PK activity, and M059K cells that express a normal level of DNA-PK, were exposed to hydrogen peroxide or STS. The response of the cells to hydrogen peroxide or STS was recorded by measuring cell death, which was detected by three different methods-MTT, annexin-V and propidium iodide staining, and JC-1 mitochondrial probe. The result showed that both hydrogen peroxide and STS were able to induce cell death of the glioblastoma cells and that the former was mainly associated with necrosis and the latter with apoptosis. Glioblastoma cells lacking DNA-PK were less sensitive to STS treatment than those containing DNA-PK. However, DNA-PK had no significant influence on hydrogen peroxide treatment. We further found that catalase, an antioxidant enzyme, could prevent cell death induced by hydrogen peroxide but not by STS, suggesting that the pathways leading to cell death by hydrogen peroxide and STS are different. We conclude that hydrogen peroxide and STS have differential effects on cell death of glioblastoma cells lacking DNA-dependent protein kinase. Such differential roles in the induction of glioblastoma cell death can be of significant value in selecting and/or optimizing the treatment for this malignant brain tumor.
Apoptosis↗
Temozolomide in the treatment of recurrent malignant glioma in Chinese patients.
OBJECTIVE: To determine the anti-tumour efficacy and safety profile of temozolomide in local Chinese patients with recurrent malignant glioma. DESIGN. Open-label trial. SETTING: University teaching hospital, Hong Kong. PATIENTS: Twenty-two patients had been enrolled in the study since 2001. Patients had to show unequivocal evidence of tumour recurrence or progression on gadolinium-enhanced magnetic resonance imaging after failing conventional radiotherapy and surgery for initial disease. Histology reviewed by a neuropathologist was required to show anaplastic glioma (anaplastic astrocytoma, anaplastic oligodendroglioma, or mixed anaplastic oligoastrocytoma) or glioblastoma multiforme. INTERVENTIONS: Patients were treated with temozolomide (200 mg/m(2) per day for the first 5 days of a 28-day cycle for four cycles) and monitored clinically every month and radiologically (gadolinium magnetic resonance imaging) at 6 months. MAIN OUTCOME MEASURES: Six-month progression-free survival and objective response rate. RESULTS: Twenty-two patients with recurrent malignant glioma were recruited between January 2001 and July 2004. Progression-free survival at 6 months was 54.5%. The mean progression-free survival for all patients was 7.2 months. The objective response rate, determined by gadolinium magnetic resonance imaging, was 9% for patients demonstrating a complete or partial response and a further 45% for patients demonstrating stable disease. Temozolomide was well tolerated orally with minimal adverse events. CONCLUSION. Preliminary results showed that temozolomide had an acceptable safety profile and anti-tumour activity in recurrent malignant glioma in local Chinese population. The results were comparable with those of western studies.
Adolescent↗
Tissue and cellular tropism of the coronavirus associated with severe acute respiratory syndrome: an in-situ hybridization study of fatal cases.
Severe acute respiratory syndrome (SARS) is a new human infectious disease with significant morbidity and mortality. The disease has been shown to be associated with a new coronavirus (SARS-CoV). The clinical and epidemiological aspects of SARS have been described. Moreover, the viral genome of SARS-CoV has been fully sequenced. However, much of the biological behaviour of the virus is not known and data on the tissue and cellular tropism of SARS-CoV are limited. In this study, six fatal cases of SARS were investigated for the tissue and cellular tropism of SARS-CoV using an in-situ hybridization (ISH) technique. Among all the tissues studied, positive signals were seen in pneumocytes in the lungs and surface enterocytes in the small bowel. Infected pneumocytes were further confirmed by immunofluorescence-fluorescence in-situ hybridization (FISH) analysis. These results provide important information concerning the tissue tropism of SARS-CoV, which is distinct from previously identified human coronaviruses, and suggest the possible involvement of novel receptors in this infection. Whereas the lung pathology was dominated by diffuse alveolar damage, the gut was relatively intact. These findings indicated that tissue responses to SARS-CoV infection are distinct in different organs.
Animals↗
The use of autologous serum tears in persistent corneal epithelial defects.
PURPOSE: Persistent corneal epithelial defects (PED) present a very challenging problem to anterior segment surgeons. Autologous serum tears had been demonstrated to be beneficial in the treatment of PED. The current study was conducted to review the local spectrum of indications and to examine the outcome of autologous serum tear usage. METHODS: All cases of PED treated with autologous serum tears at a tertiary referral centre for the period August 1999 - July 2001 were identified and reviewed. RESULTS: A total of 10 eyes from 10 patients were identified (5OD : 5OS). The gender ratio was 7M : 3F and the mean age was 36.8 (range 17-73) years old. The mean duration of PED before the usage of autologous serum tears was 22.4+/-69.6 days. Six eyes healed within 2 weeks, but two eyes failed to heal after 1 month of treatment and two patients defaulted follow-up. No adverse effects were observed with the addition of autoserum tears. CONCLUSIONS: The results of the current study correlated well with previous reported studies. Autologous serum tears may be considered as a valuable adjunct in the management of recalcitrant cases of PED.
Adolescent↗
Intravenous cyclophosphamide improves cardiac dysfunction in lupus myocarditis.
We describe a Chinese woman who developed severe heart failure 3 years from the onset of systemic lupus erythematosus (SLE). Endomyocardial biopsy confirmed lupus myocarditis, with focal infiltrates of small lymphocytes and some polymorphic neutrophils. The conventional treatment for cardiac failure plus oral prednisolone failed to bring clinical and echocardiographical improvement until the addition of intravenous (i.v.) 'pulse' cyclophosphamide. Three weeks after i.v. cyclophosphamide treatment, there was significant improvement of her heart failure symptoms with improvement in the ejection fraction from 19% to 63%.
Adult↗
T cell infiltration and chemokine expression: relevance to the disease localization in murine graft-versus-host disease.
Acute graft-versus-host disease (GVHD) involves mainly skin, liver and intestines. Other organs such as heart, muscle and central nervous system are seldom affected, although their parenchymal cells also express alloantigens, such as MHC class I antigens. The mechanism of this selective involvement of distinct organs in acute GVHD is not well understood. We postulated that it might be related to the selective migration of activated alloreactive T cells. Indeed, T cell infiltration, revealed by examination of serial samples using flow cytometry and immunohistology, occurred early and continuously in the target organs such as the liver, but not in a non-target organ, the heart, in a murine acute GVHD model. Since T cell migration is largely controlled by the expression of chemokine and chemokine receptors, we investigated the chemokine spectrum in target/non-target organs of mice with acute GVHD. We found that in the spleen and liver MIP-1alpha, MIP-2 and Mig were the predominant chemokines expressed. In another target organ, the skin, MIP-1alpha, MIP-2, MCP-1 and MCP-3 were all highly expressed. In a non-target organ of acute GVHD, the heart, the predominant chemokines expressed were MCP-1 and MCP-3. This distinct pattern of chemokine expression in these organs may contribute to the preferential recruitment of inflammatory cells into the liver and skin, but not into the heart, in acute GVHD.
Acute Disease↗
Apolipoprotein e genotype and outcome in aneurysmal subarachnoid hemorrhage.
BACKGROUND AND PURPOSE: Active management of ruptured intracranial aneurysm in subarachnoid hemorrhage is indicated in patients with favorable prognosis. Outcome prediction is based on patient characteristics and clinical and radiological factors. Current clinical grading scales are imprecise, with low interobserver reproducibility. Therefore, outcome prediction remains inconsistent and decision making becomes difficult, especially for patients with poor clinical grade. METHODS: The possible relationship between apolipoprotein E genotype and the outcome of patients suffering spontaneous subarachnoid hemorrhage was investigated. A prospective study was conducted on all patients with spontaneous aneurysmal subarachnoid hemorrhage admitted to our unit during a 2-year period. All patients were managed according to standard protocol, and treatments were given according to their clinical grading. Patient characteristics, clinical grade, radiological grade, and apolipoprotein E genotype were documented. The focus of the study was the 6-month neurological outcome for this group of patients after they were discharged. RESULTS: Seventy-two patients with aneurysmal subarachnoid hemorrhage were admitted to the Prince of Wales Hospital in Shatin, Hong Kong, China, from February 1998 to February 2000. Their ages ranged from 24 to 95 years of age, with a mean (SD) age of 58.3 (15.0) years. Apolipoprotein E epsilon4 was found in 15 patients (21%). At 6 months, Glasgow Outcome Scale score < or = 3 was found in 29 patients (40%). Univariate analysis showed that older patients (odds ratio [OR], 1.03; 95% CI, 1.00 to 1.07; P=0.07) and patients with poor Fisher's grade (OR, 4.5; 95% CI, 1.3 to 15.2; P=0.01), poor World Federation of Neurological Surgeons grade (OR, 5.8; 95% CI, 1.9 to 17.8; P=0.002), or apolipoprotein E epsilon4 (OR, 6.0; 95% CI, 1.7 to 21.3; P=0.006) were more likely to attain unfavorable outcome at 6 months. The additional effect of apolipoprotein E epsilon4 remained significant in the multiple logistic regression model (OR, 11.3; 95% CI, 2.2 to 57.0; P=0.003); the gain in predictive performance was not significant (P=0.26). CONCLUSIONS: Apolipoprotein E epsilon4 genotype is related to poor outcome in patients with subarachnoid hemorrhage.
Adult↗
Lytic skull metastasis secondary to thyroid carcinoma in an adolescent.
We report an unusual case of skull metastasis secondary to thyroid carcinoma in an adolescent girl. The 18-year-old presented with an occipital scalp swelling of 5 years' duration. She reported having thyroid surgery in mainland China 10 years previously. Radiological investigations on presentation demonstrated a lytic hypervascular skull lesion. Preoperative angiography and embolisation was followed by surgical excision. Pathological examination showed the lesion to be a thyroid carcinoma with a predominantly follicular pattern and a completion hemithyroidectomy was subsequently performed. Computed tomography of the thorax showed small micronodules in both lung fields compatible with metastases. The patient was given whole body iodine-131 internal radiation treatment and subsequently commenced thyroid-stimulating hormone-suppressive treatment with thyroxine. The management of thyroid carcinoma and subsequent skull metastasis in children and adolescents is reviewed and controversial points are highlighted.
Adenocarcinoma, Follicular↗
(31)phosphorous and single voxel proton MR spectroscopy and diffusion-weighted imaging in a case of star fruit poisoning.
We herein describe the case of a patient with chronic renal failure complicated by star fruit poisoning. T2-weighted and diffusion-weighted MR imaging showed hyperintense lesions at the thalami and right temporo-occipital cortex. Single voxel proton MR spectroscopy revealed elevation of lactate and (31)phosphorous MR spectroscopy revealed elevation of inorganic phosphate and decrease of phosphocreatine and nucleoside triphosphates. The imaging and metabolic changes indicated energy deprivation, with subsequent cortical necrosis proved at autopsy.
Aspartic Acid↗
Heterogeneous responses of aquaporin-4 in oedema formation in a replicated severe traumatic brain injury model in rats.
Aquaporin-4 (AQP4) is the most abundant water channel in the rat brain. In this study, the distribution pattern and mRNA expression levels of AQP4 were examined in a severe traumatic brain injury model by immunohistochemistry and reverse transcription-polymerase chain reaction. Oedema formation and blood-brain barrier (BBB) integrity were assessed by wet-dry weight measurements and immunostaining of endogenous IgG respectively. In the oedematous contusional cortex with impaired BBB integrity, negative immunostaining of AQP4 and down-regulation of its mRNA level were identified (P<0.05) at 1 day post-injury, while in other oedematous regions of the injured brain where BBB was intact, there was no significant change in the AQP4 expression level. This heterogeneous pattern of AQP4 responses can be interpreted as follows: focal brain injury (such as a contusion) with impaired BBB resulting in vasogenic oedema is associated with reduction of AQP4 expression, whereas, in cytotoxic oedema, associated with diffuse brain injury with intact BBB, changes in AQP4 expression are not significant. This study provides basic information for investigating new treatments for traumatic brain oedema.
Animals↗
Prevalence and distribution of human herpesvirus 6 variants A and B in adult human brain.
The presence of human herpesvirus 6 (HHV-6) in brain tissues of 40 consecutive post-mortem cases was examined. For each case, autopsy samples were collected from the cerebellum, frontal, temporal, parietal and occipital lobes of both sides of the brain. HHV-6 DNA was detected by nested polymerase chain reaction and characterised into variants A and B. Overall, 97/400 (24.3%) samples were positive for HHV-6 DNA with 16 being variant A and 81 being variant B, but none of the samples harboured both variants. When analysed by patient, 34/40 (85%) had HHV-6 DNA detected in the brain. The viral DNA positivity did not show significant variation with gender and age. Four patients harboured variant A, 23 harboured variant B, and seven had both variants at different positions. The results indicate that both HHV-6A and HHV-6B are neurotropic and human brain may be another site for latency. HHV-6B was detected in brain tissues of a majority (75%) of the studied population and with a widespread distribution within the brain. Although the observed prevalence of HHV-6A in brain is lower (27.5%), in view of its lower seroprevalence, the neuroinvasive potential of variant A may be comparable to that of variant B. Although both variants are potential pathogens for the nervous system, the fact that they can exist, probably for most of the time, as commensals in human brain needs to be considered when interpreting their roles in neuropathology.
Adult↗
Epithelioid haemangioendothelioma of the brain: a case report.
We report a rare epithelioid haemangioendothelioma in the frontal lobe. The CT and MRI findings are characteristic and correspond to histological features intermediate between those a cavernous haemangioma and an aggressive vascular tumour.
Adult↗
Sellar and suprasellar medulloepithelioma.
Medulloepithelioma is a rare tumour with a very poor prognosis. The most frequent site in the central nervous system is the cerebral hemispheres. Appearances on MRI are very variable, possibly reflecting the divergent forms of differentiation seen at histological examination. We report a rare case of sellar and suprasellar medulloepithelioma in a 2-year-old boy and discuss the imaging, differential diagnosis and pathologic findings.
Brain Neoplasms↗