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D Todd

Publications and source records attributed to D Todd.

At least 253 records · Page 14Linked to original sources

Gastrointestinal lymphoma in Chinese: a retrospective analysis.

Eighty-four Chinese patients with gastrointestinal lymphoma were reviewed. There were 45 gastric and 39 intestinal lymphomas. The median age was 45 years and the male to female ratio 1.14:1. Diffuse histiocytic (60 per cent) or diffuse large cell (53.5 per cent) lymphoma comprised a majority of the cases. A high incidence of gastrointestinal bleeding at presentation was observed in our patients. According to a modified staging classification, a larger proportion of patients with intestinal lymphoma had advanced disease (Stage III and IV) than those with gastric lymphoma (82 per cent versus 55 per cent, p less than 0.02) and gastric lymphoma carried a better prognosis. The modified staging classification used in this study appeared to stratify better the patients into 2 sub-groups of localized (Stage I and II) and advanced (Stage III and IV) disease, which correlated very well with the prognosis. Good treatment results were obtained following intensive therapy in our patients with localized disease (Stage I and II). The poorer treatment results of patients with advanced disease (Stage III and IV) call for better chemotherapy regimens and earlier diagnosis. Surgical resection of the primary gastrointestinal lesion is recommended to prevent haemorrhage and perforation following chemotherapy, which occurred in 38 per cent of our patients whose gastrointestinal lesions were not resected.

Adolescent↗

Management of stage I-II diffuse aggressive non-Hodgkin's lymphoma of the Waldeyer's ring: combined modality therapy versus radiotherapy alone.

Twenty five patients with stage I and II diffuse aggressive non-Hodgkin's lymphoma of the Waldeyer's ring were reviewed. There were 19 patients with diffuse histiocytic, 4 diffuse lymphocytic poorly differentiated and 2 diffuse mixed lymphoma. Their median age was 51 years. There were 12 males and 13 females. Eight patients had stage I, and 17 had stage II disease. There was a significantly higher incidence of involvement of the left side of the Waldeyer's ring compared to the right (p = 0.0251). Fifteen patients received radiotherapy alone, and ten had radiotherapy and chemotherapy. The median durations of follow-up were 42 (range 8-162) and 44 (range 8-97) months respectively. All patients had complete remission but 9 patients (36 per cent) subsequently had relapse of their lymphomas. Stomach was the commonest site of relapse (44 per cent). The disease free survival and overall survival at 5 years were 59 per cent and 57 per cent respectively. Higher relapse rate was observed in the radiotherapy alone group (60 per cent) as compared to the combined modality therapy group (0 per cent). Patients who received combined modality therapy had significantly superior 5 years disease free survival (100 per cent versus 32 per cent, p less than 0.01) and overall survival (81 per cent versus 40 per cent, p less than 0.05). After radiotherapy alone, patients with stage II disease appeared to have a high relapse rate than those with stage I disease (70 per cent versus 40 per cent) but the difference did not reach statistical significance due to small sample sizes. The histological subtypes did not appear to affect their prognosis. All patients with stage I and II diffuse aggressive non-Hodgkin's lymphoma of the Waldeyer's ring should have gastrointestinal barium studies at initial staging, and a prospective randomised study on these patients comparing radiotherapy alone and combined modality therapy should be performed.

Adolescent↗

Follicular non-Hodgkin's lymphoma in Hong Kong Chinese: a retrospective analysis.

Follicular lymphoma is relatively rare in Hong Kong Chinese. Fifty-two patients with follicular lymphoma were reviewed. The histology was nodular lymphocytic poorly differentiated (NLPD) in 75 per cent, nodular mixed (NM) in 21 per cent and nodular histiocytic (NH) in 4 per cent. Our patients appeared to have a higher proportion of NLPD and a lower proportion of NM lymphoma than the western series. Fifty patients were analysed excluding the two patients with NH lymphoma. They had a median age of 50 and a male to female ratio of 0.92. Seventy-two per cent of them presented with asymptomatic lymph node enlargement. Twenty per cent had B symptoms and 32 per cent bulky tumour. Twelve per cent had stage I disease, 2 per cent stage II, 30 per cent stage III and 56 per cent stage IV. A high incidence of bone marrow involvement (48 per cent of all patients) was found. All seven stage I-II patients responded to involved-field radiotherapy alone and none of them has relapsed. The 43 stage III-IV patients were treated with chemotherapy without deferral and a majority of them received CVP (51.1 per cent) or chlorambucil alone (34.9 per cent). The complete response rate of stage III-IV patients was 81 per cent and 26 per cent of the complete responders relapsed. The 5-years disease-free survival (DFS) and overall survival of all patients (stage III and IV) were 50 per cent and 65 per cent respectively. The DFS curve showed a pattern of continuous relapses. Stage III patients appeared to have a better complete response rate, a lower relapse rate and superior disease-free survival than stage IV patients but the differences did not reach statistical significance. However, the overall survival of stage III patients was significantly better than stage IV patients (p less than 0.02). Other factors including sex, age, presence of bulky tumour, B symptoms, histologic subtypes and the chemotherapeutic regimes did not significantly affect their prognosis.

Adolescent↗

Peripheral T-cell lymphoma presenting as hemophagocytic syndrome.

Three patients with peripheral T-cell lymphoma presenting with pyrexia, wasting, hepatosplenomegaly and pancytopenia in the absence of myelophthisic lymphomatous involvement are reported. Early in the course of the disease when there was no significant lymphadenopathy, these cases created enormous diagnostic confusion. Although the clinical features were suggestive of malignant histiocytosis (MH), marrow findings showed phagocytic histiocytes which did not appear atypical, and the criteria for diagnosis of MH could not be satisfied. Lymph node enlargement was detected only after 14, 5, and 8 weeks from the onset of symptoms, and the diagnosis of T-lymphoma was then made on lymph node biopsies. Treatment with multiple agent chemotherapy was attempted. Two patients died 3 days and 11 weeks after treatment was started and the third was lost to follow-up. In contrast with most of the cases reported in the literature, our cases show that a reactive hemophagocytic syndrome can be an early and prominent manifestation of an underlying T-cell lymphoma. Differentiation from other causes of hemophagocytic syndrome can be difficult and lack of histological proof of malignancy in the initial stage often delays definitive diagnosis and treatment.

Adult↗

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↗

Long-term follow-up of patients receiving salvage chemotherapy for intermediate and high grade non-Hodgkin's lymphomas.

This is an analysis of the long-term follow-up data of 99 patients receiving HOAP-Bleo, IMVP-16 and PAC as salvage chemotherapy for refractory or relapsed intermediate or high grade non-Hodgkin's lymphomas. Most of the patients received HOAP-Bleo or PAC following failure of initial chemotherapy and IMVP-16 was used mainly for HOAP-Bleo failures. The longest follow-up time of the surviving patients was 108 months. Twenty-two and 29 per cent of the patients survived beyond 2 years following HOAP-Bleo and PAC respectively. The treatment outcome following IMVP-16 was worst with a 2-year survival of only 5 per cent, as it was used mainly following HOAP-Bleo failures. Although the prognosis of these refractory or relapsed cases are poor, salvage treatment is still worthwhile as a small proportion of these patients may have long-lasting remissions and occasional patients may be cured. Newer approaches such as autologous bone marrow transplantation should be compared with current salvage chemotherapy regimens.

Adult↗

Management of advanced stage intermediate grade non-Hodgkin's lymphomas.

The treatment result of 271 cases of advanced stage intermediate grade lymphoma were reviewed. Ninety-four patients received CHOP chemotherapy, 45 BACOP and 17 m-BACOD. The clinical characteristics of the three groups of patients were comparable. Patients receiving CHOP had a complete response (CR) rate of 60 per cent, the disease-free survival of CR patients was 31 per cent at 5 years. The overall survival following CHOP chemotherapy was 38 per cent at 5 years. The use of the BACOP or m-BACOD regime did not appear to improve significantly the prognosis of these patients. Clinical staging, B symptoms, age and serum lactate dehydrogenase level were the most important independent prognostic factors.

Analysis of Variance↗

Hepatitis B infection in patients with lymphomas.

This paper reviewed the clinical characteristics and treatment outcome of 484 lymphoma patients with known hepatitis B status. Comparisons were made between the hepatitis B surface antigen positive and negative patients. Also, the effect of treatment for lymphomas, including cytotoxic chemotherapy, in the hepatitis B antigen positive patients were analysed. The hepatitis B status was determined in 484 Chinese lymphoma patients at the time of initial diagnosis. Hepatic complications occurring during therapy for lymphomas were analysed. Although our lymphoma patients had a similar prevalence of hepatitis B markers of 42 per cent, they had a strikingly higher positive rate of 22 per cent for hepatitis B surface antigen and a relatively lower positive rate of 20 per cent for antibody, as compared to the respective figures of 9.5 per cent and 33 per cent in the control population. The hepatitis B surface antigen positive patients were younger than the negative patients but their treatment outcomes were similar despite the higher incidence of hepatic complications (21 per cent) in the hepatitis B surface antigen positive patients during therapy for lymphomas. None of the clinical parameters analysed appeared to be useful in predicting the development of these complications which included fatal liver failure (5.7 per cent), icteric hepatitis (5.7 per cent) and anicteric hepatitis (9.5 per cent). The high prevalence of hepatitis B surface antigen in our lymphoma patients may be related to the immunosuppressive effect of lymphomas. There is no definite evidence to suggest that hepatitis B infection has an aetiological or promoting role in the pathogenesis of lymphomas. Hepatitis B infection has contributed to the high incidence of hepatic complications during therapy for lymphomas and possible ways of prevention need to be investigated.

Adolescent↗

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↗

Detection of immunoglobulin gene rearrangement in B-cell lymphomas by polymerase chain reaction gene amplification.

This is a report on our attempt to use polymerase chain reaction (PCR) to detect rearrangement of the immunoglobulin gene in the tissue specimens obtained from 30 patients with non-Hodgkin's lymphomas. There were 20 B-cell lymphomas and 10 T-cell. All 20 B-cell lymphomas but none of the 10 T-cell lymphomas had JH rearrangement by Southern analysis. Two pairs of primers (V670/OL-4 and VH26/OL-4) were designed to amplify the CDR3 region of the immunoglobulin gene heavy chain. The PCR analysis was positive using either one or both pairs of primers in 11 of the the 20 cases (55 per cent) of B-cell lymphomas which all had positive rearrangement by Southern analysis. The two pairs of primers seemed to produce complementary results as the specimens may be positive to one pair but negative to the other. The false negative rate of 45 per cent is however much higher than the respective figures of 18 per cent and 0 per cent observed in our patients with acute lymphoblastic leukemia and chronic lymphocytic leukemia in a previous study. Peripheral blood and bone marrow biopsy specimens obtained at the time of initial diagnosis were available from 10 patients with B-cell lymphomas whose lymph node biopsy specimens at the time of diagnosis were positive by both Southern analysis and PCR. All these peripheral blood and marrow specimens had no microscopic evidence of involvement by lymphoma cells and JH rearrangement was not detected by Southern analysis. However, rearranged bands identical to that of the lymph node biopsy specimen were detected by PCR in the peripheral and marrow blood of one of them. This PCR technique has been shown to have a sensitivity of 0.1 per cent in our previous report and may be more useful than morphology alone or Southern analysis in detecting minimal lymphomatous involvement in the peripheral blood and bone marrow at the time of initial diagnosis. Further clinical correlation is required to confirm the finding.

Base Sequence↗

Intensive chemotherapy for peripheral T-cell lymphomas.

Forty-two patients with previously untreated peripheral T-cell lymphomas (PTCL) were treated with an intensive chemotherapy protocol. Either the BACOP or the m-BACOD regimen was used for induction. Patients achieving complete clinical remission after three courses were given intensive consolidation and maintenance chemotherapy similar to the L10/L17M protocol designed by the Memorial Sloan-Kettering Group for acute lymphoblastic leukemia and lymphoblastic lymphoma. There were 27 (64 per cent) males and 15 (36 per cent) females. The median age was 54 years (mean 53, range 15 to 68). Seven of them (17 per cent) had stage I disease, four (10 per cent) stage II, seven (17 per cent) stage III and 24 (57 per cent) stage IV. Eighteen patients (43 per cent) had B symptoms and four (10 per cent) had bulky disease. According to the Working Formulation, the histology was diffuse mixed in 16 patients (38 per cent), diffuse large cell in 18 (43 per cent), diffuse immunoblastic in four (10 per cent) and unclassifiable in four (10 per cent). According to a modified Japanese Lymphoma Study Group's classification, the histology in 24 patients (57 per cent) was the pleomorphic type, in 13 (31 per cent) immunoblastic-lymphadenopathy-like (IBL-like), and in five (12 per cent) unclassifiable. The overall complete remission rate was 67 per cent. Twenty-five per cent of the complete responders relapsed and the DFS of the CR patients was 62 per cent at three years. The overall survival of all patients at three years was 52 per cent. Patients with stage I, II and III disease had significantly better CR rate (100 per cent versus 42 per cent, p = 0.001) and overall survival (82 per cent versus 35 per cent at three years, p = 0.01) than those with stage IV disease but the relapse rate and DFS of CR patients were similar. This study shows that the prognosis of patients with PTCL can be improved by intensive therapy.

Adolescent↗

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↗

Prognostic factors for primary gastrointestinal lymphoma.

The gastrointestinal tract is a common primary extranodal site for non-Hodgkin's lymphoma. There is however no uniform consensus on its pathological classification, clinical staging system and management. This paper reports the experience in the management of 425 Chinese patients with primary gastrointestinal lymphoma in Hong Kong from January 1975 to June 1993. There were 230 (54 per cent) males and 195 (46 per cent) females. Their median age was 53 years. The primary sites were: the esophagus in three (1 per cent), stomach in 238 (56 per cent), small intestine in 131 (31 per cent) and large intestine in 53 (12 per cent). According to the Working Formulation, there were 20 (4.7 per cent) small lymphocytic, 10 (2.4 per cent) follicular small cleaved cell, 15 (3.5 per cent) follicular mixed, five (1.2 per cent) follicular large cell, 40 (9.4 per cent) diffuse small cleaved cell, 50 (12 per cent) diffuse mixed, 181 (43 per cent) diffuse large cell, 30 (7.1 per cent) immunoblastic, five (1.2 per cent) lymphoblastic, 10 (2.4 per cent) diffuse small non-cleaved cell and 50 (14 per cent) unclassifiable lymphoma. Immunophenotyping was performed in 199 (47 per cent) patients: 90 per cent B-cell, 7 per cent T-cell and 3 per cent uncertain. According to a Manchester system, 81 (19 per cent) patients had stage I disease, 44 (10 per cent) stage II, 85 (20 per cent) stage III and 215 (51 per cent) stage IV. B symptoms were present in 275 (65 per cent) patients and bulky disease in 104 (25 per cent). Surgery followed by chemotherapy was the mainstay of treatment. Of the 408 patients treated, 63 per cent had a complete remission with relapse rate of 42 per cent. For those with complete remission, 47 per cent were free from disease at 5 years. The overall median survival of all patients was 45 per cent at 5 years. Multivariate analysis revealed that significant independent prognostic factors predicting better survival were young age of < 60 years, low grade histology, stage I and II disease and absence of bulky tumour. For gastric lymphoma, aggressive surgery did not significantly improve their outcome. Chemotherapy appears to play an important role in the management of gastrointestinal lymphoma. Better classification of the primary gastrointestinal lymphoma and more refined stratification of the patients according to the prognostic variables may allow individualization of treatment. Prospective randomized studies are essential to define the relative roles of surgery, chemotherapy and radiotherapy.

Adult↗

Is there conscious choice in directed mutation, phenocopies, and related phenomena? An answer based on quantum measurement theory.

In a previous article (Goswami, 1997), it was suggested that an application of quantum measurement theory under the auspices of a monistic idealist ontology (that consciousness is the ground of being) can solve many difficult problems of neo-Darwinism, e.g., alternating rapid creativity and homeostasis observed in evolution and the directionality, origin, and nature of life. In this article, we propose an epigenetic quantum mechanism to explain the connection of developmental processes and evolution, as has been evidenced in such controversial phenomena as directed mutation and phenocopies.

Animals↗