Biomedical subjects

F Ho

Publications and source records attributed to F Ho.

13 recordsLinked to original sources

PubMed1992

Clonal Epstein-Barr virus genome in T-cell-rich lymphomas of B or probable B lineage.

Seventeen nodal lymphomas (originally diagnosed as T-cell lymphomas based on histological features and immunohistochemical staining results) were studied for the presence of Epstein-Barr virus (EBV) genome, and the results correlated with immunoglobulin and T-cell receptor gene rearrangement analyses performed on the same tissue samples. All four EBV positive cases had clonal rearrangement of the joining region of the immunoglobulin heavy chain (IgJH) gene without clonal T-cell receptor beta-chain (TCR beta) gene rearrangement. Of these, two cases also showed clonally rearranged light chain gene, and they were reclassified as T-cell rich B-cell lymphomas (TRBL). The other two cases lacked clonal kappa or lambda light chain rearrangement and they were reclassified as T-cell rich lymphomas of probable B lineage, based on their isolated IgJH clonal rearrangement. These B-cell lymphomas may be easily misdiagnosed as T-cell lymphomas owing to the presence of an abundant reactive T-cell infiltrate masking the tumor population. The florid T-cell reaction may represent an unusual host response towards a clonal proliferation of EBV bearing B cells.

Blotting, Southern↗

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↗

PubMed1990

Klinefelter's syndrome and primary central nervous system lymphoma.

Klinefelter's syndrome is known to be associated with various malignancies including male breast cancer and germ cell tumour. We report a patient with Klinefelter's syndrome who developed a primary B-cell lymphoma of the central nervous system (CNS). To the best of our knowledge, this is the first case of primary CNS lymphoma in Klinefelter's syndrome.

Adult↗

PubMed1990

Immunoglobulin gene rearrangement in the peripheral blood and bone marrow of patients with lymphomas of the mucosa-associated lymphoid tissues.

The theory of 'homing' mechanism has been proposed to explain the association of malignant lymphoma involving multiple sites of mucosa-associated lymphoid tissue (MALT). DNA rearrangement in the peripheral blood and bone marrow specimens of 20 patients with MALT lymphoma were studied utilizing JH and C beta gene probes, aiming to detect circulating lymphoma cells and unrecognized bone marrow involvement. Our search for malignant cells in the peripheral blood was unrewarding and the 'homing' theory remained unproven. However, the study of DNA rearrangement showed to be useful in determining the malignant nature of abnormal lymphoid aggregates found in the bone marrow of these patients.

Adult↗

PubMed1988

Choledochal fungal ball. An unusual cause of biliary obstruction.

A 31-year-old patient with sickle-cell disease who had previous cholecystectomy developed acute onset of jaundice and abdominal pain. An endoscopic retrograde cholangiography demonstrated multiple filling defects within the bile ducts. Microscopic examination of "calculi" removed at surgery revealed that a fungal ball composed of Candida was the cause of biliary obstruction in this case. The patient eventually recovered after removal of the fungal masses and intrabiliary instillation of amphotericin.

Adult↗

PubMed1987

Peripheral T cell lymphoma.

Thirty-one Chinese patients with peripheral T cell lymphoma (PTCL) were reviewed. Using the modified Japanese Lymphoma Group classification, there were nine (29%) of the pleomorphic type, 16 (52%) immunoblastic lymphadenopathy (IBL)-like, two (7%) T-zone lymphoma, and one (3%) Lennert's lymphoepithelioid type. Three (9%) were not classifiable. All were positive for T11 (E rosette receptor antigen). Fifty-four percent (15 of 28) were positive predominantly for T4 (helper T cell) and 46% (13/28) for T8 (suppressor T cell). The median age of the patients was 57 years. They usually presented with advanced disease, and while extranodal involvement was common, CNS disease was not seen. The IBL-like type was associated with a positive Coombs' test and polyclonal hypergammaglobulinemia. Five of the nine pleomorphic type were checked for antibody to HTLV-I virus and all were negative. PTCL was associated with poor prognosis, which was not influenced by the histologic subtypes and the T4/T8 phenotypes. The complete response rate of 13 consecutive patients who received the BACOP (bleomycin, doxorubicin, cyclophosphamide, vincristine, and prednisone) L17M regimen was significantly better than the 16 historic controls who received other less-intensive regiments, 84% v 19% (P less than .01). The relapse rate was also significantly lower, 9% v 100% (P less than .001). There appeared to be an improvement in the disease-free survival (DFS) (80% v 0% at 18 months), as well as the overall survival (60% v 36% at 18 months), but the differences did not reach statistical significance due to small sample sizes.

Adult↗

PubMed1986

Distinct short-lived and long-lived antibody-producing cell populations.

This report analyzes the life span of Ig-containing cells (IgCC) in different sites of antibody production. The experimental approach was based upon the observations that most IgCC are derived from proliferating precursors while IgCC themselves are mainly nondividing end cells. Rats were given a continuous infusion of [3H] thymidine via an osmotic pump inserted in the peritoneal cavity. At intervals of 1, 3, 5 or 10 days after starting infusions, tissues were taken and analyzed by a combination of immunohistology and autoradiography to identify the proportions of IgCC which had gone through S phase of the cell cycle during the period of infusion. After 3 days infusion the median and (range) percent-labeled IgCC in the medullary cords of mesenteric and cervical lymph nodes and the red pulp of the spleen were, respectively, 88 (81-90), 75 (66-77) and 88 (82-93). Conversely that for IgCC in bone marrow was only 13 (11-17) and that in the lamina propria of the jejunum 47 (33-68). The rate of increase in labeling of bone marrow IgCC with length of infusion was approximately linear. Extrapolation of this slope suggests that bone marrow IgCC have a life span in excess of 3 weeks. The slopes of increase in IgCC labeled with time for lymph nodes and spleen were clearly biphasic suggesting that while most IgCC in these tissues have a life span of less than 3 days, there is also a minor population of long-lived IgCC. The lamina propria appears to have approximately equal proportions of long and short-lived IgCC. The life span of IgCC, with the exception of IgMCC, appears to be a feature of the site of antibody production rather than the Ig class produced. Almost all IgM-containing cells were found to be short lived.

Animals↗

PubMed1986

Purpura fulminans in a Chinese boy with congenital protein C deficiency.

Severe and recurrent purpura fulminans developed in a Chinese boy at one day of age. Results of coagulation studies performed on the patient during attacks were compatible with the diagnosis of disseminated intravascular coagulation. Subsequent investigations have revealed that the patient is homozygous and that his parents are heterozygous for protein C deficiency. Cryoprecipitate and fresh frozen plasma induced a remission, and administration of warfarin has been successful in preventing recurrence of attacks for as long as 8 months without infusion of any plasma components. None of the family members who are heterozygous for protein C deficiency have had thrombotic episodes.

Combined Modality Therapy↗

PubMed1979

Construction and mapping of recombinant plasmids used for the preparation of DNA fragments containing the Escherichia coli lactose operator and promoter.

Three DNA restriction fragments of established sequence containing the Escherichia coli lac genetic controlling regions were cloned. In each case a recombinant plasmid was constructed which was suitable for the subsequent large scale purification of the lac fragment. A 789-base pair HindII fragment, containing the lac operator, promoter, and cyclic AMP receptor protein binding site, was ligated into the single HindII site of the amplifiable plasmid minicolicin E1 DNA (pVH51). A 203-base pair Hae III fragment containing the same genetic sites was ligated into the single Eco RI site of pVH51 which had been "filled in" by the Micrococcus luteus DNA polymerase. Thus, the lac fragment was inserted between two Eco RI sites. Plasmids containing multiple copies of this Eco RI fragment were then constructed. A 95-base pair Alu I fragment containing the lac promoter and operator was cloned similarly. Also, the 203-base pair fragment was cloned into the Eco RI site of pVH51 using a 300-base pair linker fragment (isolated by RPC-5 column chromatography) which permitted retention of its Hae III ends. Mapping studies on pVH51 DNA with a number of DNA restriction endonucleases, including Alu I, Taq I, and Hpa II, are described.

DNA Restriction Enzymes↗

PubMed1979

Gastrointestinal lymphomas in Hong Kong Chinese.

Forty-six Chinese patients with primary gastrointestinal lymphoma were analyzed. The most common presentations were with abdominal pain, bleeding or a palpable mass. Only one case resembled the pattern of the so-called "Mediterranean lymphoma." The most common primary sites were the stomach and the ileum. One case of colonic lymphoma was associated with schistosomiasis but was probably not etiologically related. The pattern of primary gastrointestinal lymphoma in Chinese corresponds in general to the pattern observed in western countries.

Adolescent↗

PubMedDate not supplied

Hodgkin's disease in Hong Kong Chinese.

A lower incidence of Hodgkin's disease in Orientals has been recognized. Although most Hong Kong Chinese came from the Guandong province of China, the incidence of Hodgkin's disease in Hong Kong Chinese is 9.2 per cent which is more comparable to the low figure of 6 per cent in Japan than the 32 per cent incidence in Guangdong. If this discrepancy in the ethnically similar populations is confirmed, other etiological or promoting factors must be considered. Ninety-two Hong Kong Chinese patients (54 males and 38 females) with Hodgkin's disease were reviewed. The median age was 34 years (range 5-79 years). The histology was lymphocyte predominant in nine (10 per cent), nodular sclerosing in 34 (37 per cent), mixed cellularity in 29 (31 per cent), lymphocyte depleted in nine (10 per cent) and unclassified in 11 (12 per cent). Seventeen per cent had stage Ia disease, 2 per cent Ib, 15 per cent IIa, 11 per cent IIb, 11 per cent IIIa, 9 per cent IIIb, 11 per cent IVa and 24 per cent IVb. Twenty-five of them (27 per cent) were staged by laparotomy. Twelve patients (13 per cent) had bulky disease. Identical to the pattern observed in Caucasians, our patients had an apparent biomodal age distribution, a male predominance and similar distribution of histological subtypes according to the Rye classification. The absence of an early peak in young adulthood and the lower incidence of the nodular sclerosing subtype reported in the Japanese was not observed in our patients. A variety of treatments were given to the 92 patients. Most of the patients with stage I-II disease received radiotherapy except for those with B symptoms, bulky disease or lymphocyte depleted histology, who received chemotherapy with or without radiotherapy. All patients with stage III-IV disease received chemotherapy with or without radiotherapy except for two patients with stage IIIa disease who had total nodal irradiation only. The multivariate analysis revealed that Ann Arbor staging was a significant independent factor determining the disease-free survival of patients in complete remission and the overall survival of all patients. Age was the other independent variable significantly determining the overall survival.

Adolescent↗

PubMedDate not supplied

Primary and secondary cutaneous lymphomas in Hong Kong Chinese.

Sixty-eight Hong Kong Chinese patients with cutaneous lymphomas were studied. There were 38 males and 30 females and their median age was 52 years. According to a staging system as proposed by the Mycosis Fungoides Cooperative Group, 48 (71 per cent) of the patients had disseminated stage IV disease. There were nine (13 per cent) cases of mycosis fungoides. The remaining cases were mostly intermediate or high grade non-Hodgkin's lymphomas according to the Working Formulation. Immunophenotyping was performed in 23 cases and in 17 cases (74 per cent), T-cell tumours were identified. Many of these T-cell lymphomas were unclassifiable according to the Working Formulation and were either pleomorphic or immunoblastic-lymphadenopathy-like T-cell lymphoma according to a modified system of the Japanese Lymphoma Study Group. A variety of therapies were given to these patients and those with stage IV disease had a significantly poorer survival. On the other hand, the histology, and immunophenotype did not appear to be useful in predicting prognosis.

Adolescent↗

PubMedDate not supplied

COPP chemotherapy for elderly patients with intermediate and high grade non-Hodgkin's lymphoma.

One hundred and forty-one consecutive patients above and 231 below the age of 60 years with previously untreated intermediate or high grade non-Hodgkin's lymphoma were included in this study. Patients above the age of 60 years were treated with the COPP chemotherapy regimen. The younger patients, at or below the age of 60, received a doxorubicin-containing regimen (119 had CHOP, 65 had BACOP and 47 had m-BACOD). For stage I patients, the clinical results were similar but for stage II, III or IV disease, those receiving COPP had significantly worse CR rate and survival than those who had a doxorubicin-containing regimen. Multivariate analysis on patients receiving the COPP chemotherapy revealed that the independent prognostic variables significantly determining CR rate and survival included clinical stage (p = 0.04) and serum lactate dehydrogenase level (p = 0.001). Myelosuppression was the major toxicity following COPP chemotherapy in this group of patients. There were 10 (7 per cent) treatment-related deaths. Compared to the reported results using doxorubicin-containing regimens to treat elderly patients with aggressive NHL in the literature, the more aggressive treatment does not appear to improve significantly the clinical outcome of this group of patients and seems to produce treatment results very much similar to COPP. However, accurate comparison is difficult because of the variation in the patient characteristics. Further prospective controlled randomized trials will be necessary to determine the optimal therapy for these patients.

Adolescent↗