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Biomedical subjects

E Chiu

Publications and source records attributed to E Chiu.

At least 73 records · Page 4Linked to original sources
PubMed1993

Drugs used for psychiatric disorders.

Psychiatric disorders are common in the elderly. Antidepressants are probably underprescribed. In recurrent depression, lifelong prophylaxis may be required. Benzodiazepines can aggravate cognitive impairment and cause falls; they should not be used for chronic insomnia. Antipsychotic drugs are useful for the treatment of delusions and hallucinations but are less effective for disturbed behaviour in dementia sufferers. There are no satisfactory drugs for treating dementia at present, but promising palliative treatments for Alzheimer's disease are under trial.

Aged↗
PubMed1993

Detection of immunoglobulin gene rearrangement in lymphoid malignancies of B-cell lineage by seminested polymerase chain reaction gene amplification.

Seminested polymerase chain reaction (PCR) was used to amplify the DNA fragments of the complementarity-determining region 3 of the immunoglobulin (Ig) gene heavy chain from the malignant cell specimens of patients with leukemias and lymphomas of B-cell lineage. Two different pairs of primers were used sequentially. Twenty of the 27 (74%) acute lymphoblastic leukemia (ALL) patients, 14 of 19 (74%) chronic lymphocytic leukemia (CLL) patients and eight of 20 (40%) non-Hodgkin's lymphoma (NHL) patients, who had rearrangement of the Ig gene heavy chain by Southern analysis, were positive by the seminested PCR. False-negative results appeared to occur more commonly in cases of lymphoma. The PCR analysis was also less likely to be positive if one-stage PCR studies with either pair of primers were both negative. The seminested PCR technique was found to have a high sensitivity of detecting malignant cells at the level of 0.02%. The clinical application of this assay needs to be investigated further.

Base Sequence↗
PubMed1993

Postnatal ocular expression of tyrosinase and related proteins: disruption by the pink-eyed unstable (p(un)) mutation.

Ocular pigmentation in the mouse occurs primarily postnatally as a result of the melanization of neural crest-derived melanocytes. Using immunologic and biochemical techniques, we demonstrate that in normal mice the expression of tyrosinase and the related proteins TRP-1 and TRP-2, rises during the first week of life, remains elevated for a week, and then steadily declines to low levels by adulthood. Sucrose gradient density centrifugation demonstrates that tyrosinase, TRP-1 and TRP-2 are present in high molecular weight forms in the eyes of wild-type mice. The normal time course is disrupted in mice carrying the pink-eyed unstable (p(un)) mutation at the P-locus, a model for tyrosinase-positive albinism in man. Tyrosinase and TRP-2 are present at wild-type levels in the eyes of p(un)/p(un) mice at birth, but, rather than rising, their levels rapidly decline over the first week of life. TRP-1 is almost undetectable, even at birth. High molecular weight complexes could not be detected in eyes of p(un)/p(un) mice. Our results suggest that postnatal ocular melanogenesis in the mouse presents an attractive model for the study of the orderly expression and action of the proteins involved in eumelanin synthesis, and that the p(un) mutation disrupts this temporally controlled process.

Albinism↗
PubMed1993

Motor functions of the basal ganglia.

A study of movement disorders such as Parkinson's disease and Huntington's disease can provide an indication of the motor functions of the basal ganglia. Basal-ganglia diseases affect voluntary movement and can cause involuntary movement. Deficits are often manifested during the coordination of fine multi-joint movements (e.g., handwriting). The disturbances of motor control (e.g. akinesia, bradykinesia) caused by basal-ganglia disorders are illustrated. Data suggest that the basal ganglia play an important role in the automatic execution of serially ordered complex movements.

Basal Ganglia↗
PubMed1993

Effective salvage therapy using all-trans retinoic acid for relapsed and resistant acute promyelocytic leukemia.

All-trans retinoic acid (ATRA) has been shown to be active against acute promyelocytic leukemia (APL). Six patients with APL, either in relapse or resistant to initial chemotherapy were reinduced with ATRA 100 g/m2/day for 6 weeks. Complete remission was achieved in all six of them. Side effects were seen in two of them. ATRA appears to provide a relatively safe and reliable means to induce a complete remission in patients with refractory or relapsed APL.

Adolescent↗
PubMed1993

Bone marrow transplantation for thalassemia in Hong Kong: the early experience.

The first experience of bone marrow transplantation (BMT) for thalassemia in Hong Kong is reported. Of the three children transplanted using a matched allogeneic donor, two have been surviving disease free 291 and 256 days post-BMT respectively. The other child rejected the graft and remained transfusion dependent. Mild graft versus host disease occurred in one of the children which subsided on cyclosporin A alone. The regimen-related toxicities were mild and easily manageable. Thus the result is encouraging and the procedure is now accepted as an option of treatment for good risk patients in Hong Kong.

Bone Marrow Transplantation↗
PubMed1992

Non-aggressive therapy for chronic myeloid leukaemia in blastic transformation.

A total of 40 patients presenting with chronic myeloid leukaemia in blastic transformation were treated with a non-aggressive chemotherapy regimen consisting of vincristine, cytosine arabinoside and thioguanine. Remissions were achieved by 3/10 (30%) patients displaying lymphoid transformation (remission duration, 2, 3, and 5 months, respectively) and by 5/30 (17%) subjects exhibiting myeloid changes (duration 2+, 4, 4, 5 and 7 months, respectively). Myelosuppression was the major toxicity and non-haematological toxicities were mild and acceptable. The median survival of patients exhibiting lymphoid and myeloid blastic transformation as measured from the time of transformation was 6 and 3 months, respectively, but the difference was not statistically significant. Three subjects displaying lymphoid transformation and five showing myeloid changes survived for greater than 12 months after the time of transformation.

Acute Disease↗
PubMed1992

Initiation and execution of movement sequences in those suffering from and at-risk of developing Huntington's disease.

Recent research has shown that Huntington's disease (HD) causes problems in the initiation and execution of movement (akinesia, bradykinesia): information which is useful in documenting the functional progression of the disease. The present experiment used a sequential movement task to characterize such impairments. Eighteen patients diagnosed as suffering from HD, and a similar number of matched At-Risk (AR) and Normal control subjects, performed sequential button pressing tasks, under varying amounts of visual advance information. Specific dimensions of motor control were examined (hand, direction). Movement initiation and in particular movement duration were useful indicators of the functional progression of the disease, and also detected anomalies of performance in some AR individuals. Impaired motor programming was indicated by patients' difficulty in initiating movements in the absence of external visual cues, and their problems in utilizing advance information to control movement. Patients had specific deficits in initiating movements with the nonpreferred hand, and directional movement asymmetries were accentuated. The results suggest that HD causes difficulties at three discrete levels: in utilizing advance information, in the initiation and in the spatial representation of movement.

Adult↗
PubMed1992

The pattern of psychiatric morbidity in a Victorian urban aboriginal general practice population.

Victorian Aboriginal people, most of whom live an urban lifestyle, form a distinct cultural group within the wider Victorian community. This paper describes a unique psychosocial study of urban Aboriginal adults attending a general practitioner at the Victorian Aboriginal Health Service in Fitzroy. The frequency and nature of psychiatric disorders among survey respondents is reported, together with a discussion of the association between this morbidity and certain sociodemographic variables.

Adolescent↗
PubMed1991

Detection of immunoglobulin gene rearrangement in acute and chronic lymphoid leukemias of B-cell lineage by polymerase chain reaction gene amplification.

Polymerase chain reaction (PCR) was used to amplify the DNA fragments of the complementarity determining region 3 of the immunoglobulin (Ig) gene heavy chain from the leukemic cell specimens of patients with acute and chronic lymphoid leukemias of B-cell lineage. Two different pairs of primers were tested. Fourteen of the 17 (82%) cases of acute lymphoblastic leukemia (ALL), and all 15 cases (100%) of B-cell chronic lymphocytic leukemia, who had rearrangement of the Ig gene heavy chain by Southern analysis, were positive by PCR with either one or both pairs of primers. This technique was able to detect leukemic cells at the level of 0.1%. Applying it to study the remission marrow specimens following induction chemotherapy was more useful than morphology alone in predicting early relapse of the leukemia.

Burkitt Lymphoma↗
PubMed1991

Salvage chemotherapy containing moderate-dose cytosine arabinoside and mitoxantrone for relapsed and resistant acute myeloid leukaemia.

A total of 29 evaluable patients with acute myeloid leukaemia (AML) either in relapse or resistant to initial induction daunorubicin-containing chemotherapy were given a salvage regimen consisting of moderate-dose cytosine arabinoside and mitoxantrone. There were 8 (28%) complete responders (CRs), 4 (14%) partial responders (PRs), and 17 (52%) nonresponders. The duration of CRs was 2+, 2+, 3+, 3, 4+, 4, 5 and 6 months respectively. Two of the eight CR patients were refractory to initial daunorubicin-containing induction therapy and another two had achieved a previous CR lasting less than 6 months. Four of the eight CR patients had received an amsacrine-containing salvage regimen (ATA) prior to administration of the present moderate-dose cytosine arabinoside and mitoxantrone regimen; this indicates the lack of absolute clinical cross-resistance between the present combination and the daunorubicin- or amsacrine-containing regimens. However, the duration of CRs achieved by these patients remains very short and should, if possible, be followed by allogeneic or autologous bone marrow transplantation.

Acute Disease↗
PubMed1991

Intensive chemotherapy for adult lymphoblastic lymphomas.

A total of 20 adults patients presenting with previously untreated lymphoblastic lymphoma underwent an intensive chemotherapy protocol. Either the BACOP or the m-BACOD regimen was used for induction. If the patients achieved a complete clinical remission (CR) after three courses, they were given intensive consolidation and maintenance chemotherapy based on a protocol that was modified from the L10/L17M regimen of the Memorial Sloan-Kettering group for acute lymphoblastic leukaemia and lymphoblastic lymphoma. Patients exhibiting localised areas of bulky disease were given additional involved-field radiotherapy. In all, 15 (75%) men and 5 (25%) women were entered in this study. Their median age was 28 years (mean, 30 years; range, 12-64 years). Overall, 3 (15%) had stage II disease, 3 (15%) had stage III disease and 14 (70%) had stage IV disease; 7 (35%) patients exhibited B symptoms and 4 (20%) had bulky disease. The overall (CR) rate was 10/20 (20%), and that following BACOP and m-BACOD therapy was 4/8 (50%) and 6/12 (50%), respectively. In all, 7 of the 10 complete responders (70%) relapsed. The disease-free survival of the ten who achieved a CR was 23% at 3 years. The overall survival of all 20 patients at 3 years was only 37%, and there were very few long-term survivors. More effective treatment for adult lymphoblastic lymphoma is required.

Adult↗
PubMed1991

Chemotherapy for early-stage gastrointestinal lymphoma.

A total of 176 patients with gastrointestinal lymphomas were reviewed. According to a modified staging classification, 51 of them had stage I/II disease and the remaining 125 had stage III/IV disease. In most cases (68%), the histology was intermediate-grade according to the NIH working formulation, and the B-cell immunophenotype was involved in 89% of the 45 cases with a known immunophenotype. The primary site was the stomach in 56% of cases and the bowel in 44%. A significantly higher proportion (P = 0.001) of those with bowel lymphomas had stage III/IV disease (88% vs 57%). The primary gastrointestinal lesion was resected in 122 patients, including all 51 cases of stage I/II disease. In all, 8 stage I/II patients were given radiotherapy alone following surgery and the other 43 underwent chemotherapy; of the latter, 19 received additional radiotherapy following chemotherapy. Chemotherapy was also given to 112 stage III/IV patients, 42 of whom underwent additional radiotherapy. Factors associated with a poorer prognosis included advanced disease, bowel lymphoma and advanced age. Although the complete response (CR) rate according to disease stage was similar, stage I/II patients receiving chemotherapy showed a significantly lower relapse rate, better disease-free survival following CR and improved survival as compared with those receiving radiotherapy alone. However, additional radiotherapy following chemotherapy did not further improve the clinical outcome.

Adolescent↗
PubMed1991

m-BACOD chemotherapy for intermediate- and high-grade non-Hodgkin's lymphoma.

A total of 92 patients with previously untreated intermediate- or high-grade non-Hodgkin's lymphoma attending the University Department of Medicine, Queen Mary Hospital, Hong Kong, were treated with the m-BACOD chemotherapy regimen (methotrexate, bleomycin, doxorubicin, cyclophosphamide, vincristine and dexamethasone). Additional involved-field radiotherapy was given to 32 (35%) patients. Myelosuppression was the major toxicity, and 5 (5%) treatment-related deaths occurred due to pneumonia, bleomycin sensitivity, doxorubicin cardiotoxicity and reactivation of hepatitis B infection. The overall complete response (CR) rate was 65/92 (71%) and the relapse rate was 22/65 (34%). The disease-free survival of the 65 CR patients at 2 years was 52% and the overall survival of all 92 patients at 3 years was 56%. The CR rate of stage I and II patients was significantly better than that of those with stage III and IV disease (87% vs 59%; P = 0.01), and the CR rate of stage III patients was superior to that of those with stage IV disease (86% vs 50%; P = 0.05). The overall survival of stage III and IV patients was significantly worse than that of subjects with stage I and II disease (31% vs 73%; P = 0.02). Multivariate analysis revealed that the independent prognostic variables significantly determining the CR rate and survival included the clinical stage and the serum lactate dehydrogenase level. From this study, the results of treatment with the m-BACOD regimen in patients with advance disease appeared to be similar to those obtained using the conventional CHOP regimen (cyclophosphamide, doxorubicin, vincristine and prednisone).

Adolescent↗
PubMed1991

Rearrangement of immunoglobulin and T cell receptor genes in acute and chronic leukaemias.

The pattern of immunoglobulin (Ig) and T cell receptor (TCR) gene rearrangements was determined in 87 patients with acute and chronic leukaemias and myelodysplastic syndromes by Southern blot hybridisation. All 31 cases of common, B cell and null cell acute lymphoblastic leukaemia, and B cell chronic lymphocytic leukaemia showed Ig heavy chain (JH) rearrangement, and TCR (beta-chain) rearrangement was seen in all 5 cases of T cell acute lymphoblastic leukaemia. Inappropriate JH and TCR (beta) rearrangements were present in some cases of T-ALL (60%) and common acute lymphoblastic leukaemia (18%), respectively. For the 19 patients with acute leukaemias following chronic myeloid leukaemia, blastic transformation, all 4 with lymphoid transformation and 3 of the 15 with myeloid transformation had JH rearrangement, and 3 CD10-positive lymphoid transformation and 2 myeloid transformation had their TCR (beta) genes rearranged. In conclusion, the pattern of Ig and TCR gene rearrangements correlated well with the cell lineage. However, cross-lineage rearrangements were more commonly seen in patients with acute leukaemias following chronic myeloid leukaemia blastic transformation, as compared to the de novo cases.

Adolescent↗
PubMed1991

Direct comparison of peripheral T-cell lymphomas with their B-cell counterpart.

The aim of this study was to determine the effect of immunophenotype on the clinical characteristics and prognosis of 144 adult Chinese patients with non-Hodgkin's lymphomas. Those entities with well-recognised immunophenotype and clinical characteristics were excluded. Significantly more patients with T-cell lymphomas had B symptoms (52 vs. 30%, p = 0.05) and fewer had bulky disease (7 vs. 25%, p = 0.04). Extranodal involvements of liver, spleen, marrow, nasal region and skin were significantly more common in T-cell lymphomas. On the other hand, gastro-intestinal involvement was more commonly seen in B-cell tumours. Induction chemotherapy of comparable intensity was used in treating these patients. The immunophenotype did not appear to affect significantly their prognosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Management of low-grade lymphomas in Hong Kong Chinese.

During a 14-year period, 122 of 840 (14.5) Hong Kong patients with non-Hodgkin's lymphomas were diagnosed to have low-grade lymphomas according to the Working Formulation. Only 28 (23%) of them had stage I and II disease and local radiotherapy appeared to be curative in some of them. Although remissions were achieved with chemotherapy in a majority of the stage III and IV patients, a pattern of continuous relapses was noted in their disease-free survival curve. Multivariate analysis revealed that clinical stage and presence of B symptoms were significant independent prognostic factors.

Adolescent↗