Search PubMed⌕ Search

Biomedical subjects

S L Loke

Publications and source records attributed to S L Loke.

72 records · Page 4Linked to original sources

Disseminated zygomycosis masquerading as cerebral lupus erythematosus.

Zygomycosis often occurs in patients with an underlying disease, e.g., diabetes mellitus, leukemia, and lymphoma, or an immunocompromised state. This report discusses a case of a 21-year-old woman with systemic lupus erythematosus complicated by uremia, acidosis, steroid therapy, prolonged antimicrobial therapy, and disseminated zygomycosis.

Adult↗

Immunohistological subtypes of non-Hodgkin's lymphoma in Hong Kong Chinese.

One hundred and four unselected cases of non-Hodgkin's lymphoma (NHL) in adult Chinese patients in Hong Kong were typed, using monoclonal and conventional antibodies, by immunoenzymatic labelling methods on cryostat sections or cell smears. The total included 69 cases (66%) of B-cell and 26 (25%) of T-cell tumours. The diffuse large cell (centroblastic or immunoblastic) types formed the largest proportion (44.9%) of B lymphomas. Of 26 cases of T-cell lymphoma 25 were of peripheral type; of these 25, the most frequent subtype (42.3%) was the immunoblastic lymphadenopathy-like lesion. Although there were 9 pleomorphic T-cell lymphomas, none of the patients presented with the adult T-cell leukemia/lymphoma syndrome. The incidence of T-cell lymphomas in our population is not markedly higher than that of western countries, but there are some interesting differences in the types of T-cell lymphomas that are commonly seen.

Adult↗

Clinical and histopathological predictors of progressive disease in IgA nephropathy.

The clinical course and biopsy findings of twenty-one patients with IgA nephropathy, followed up for a mean period of 37.4 mth (range 24-54 mth) after diagnosis, were reviewed retrospectively to determine whether the clinical presentations, the laboratory findings or histopathologic changes have prognostic implications. An age of 24 yr or above and a serum creatinine of 0.18 mmol/l or above at diagnosis correlated significantly with renal insufficiency at the end of the follow-up (P = 0.023 & 0.03). Proteinuria of 1.5 g/d or more and hypertension (systolic greater than 150 mmHg or diastolic greater than 100 mmHg) when well controlled, were not found to be significant. Asymptomatic proteinuria and gross hematuria, on the other hand, correlated negatively with renal insufficiency at the end of the follow up (P = 0.034). With respect to histopathological changes, greater than 30% global glomerular sclerosis and moderate or marked tubular atrophy correlated significantly with renal insufficiency (P = 0.005 and 0.005). However, less than 10% glomerular crescents, small amounts of mesangial electron dense deposits or absent ultrastructural peripheral glomerular capillary wall abnormalities correlated negatively with renal insufficiency (P = 0.017, 0.03 & 0.03).

Adolescent↗

Pulmonary scar cancer. A pathologic reappraisal.

A total of 49 consecutive specimens of lung cancer were collected prospectively at surgical resection or autopsy from 40 men and nine women, aged 40-74 years. Of the 49 tumors, the gross appearance of 22 fitted the description of a scar cancer, i.e., a tumor with pleural puckering and central pigmentation. Nineteen of the "scar cancers" were peripheral (17 adenocarcinomas and two squamous cell carcinomas); three were central (one squamous cell carcinoma and two adenocarcinomas). In the 19 peripheral "scar cancers," elastic stains demonstrated the presence of collapsed, unfibrosed lung tissue at the center with traction of the overlying pleura toward it. Elsewhere in the tumor, the elastic framework was either destroyed or expanded by tumor filling the alveolar spaces. None of the "scar cancers" had a significant desmoplastic reaction that might otherwise explain the scarred appearance. It appeared that local atelectasis was solely responsible for the pleural puckering and central pigmentation. On the other hand, atelectatic lung tissue was not seen in the 27 cancers that did not have the appearance of a scar cancer. Tuberculosis was found in 10 of the 49 lung specimens. In only one specimen was the tuberculous lesion anatomically associated with the tumor. There was no evidence of pulmonary infarct in any of the specimens. The term "scar cancer" was considered inappropriate as there was no preformed fibrous tissue. The scarred appearance was thought to be the result of localized pulmonary atelectasis owing to small airways obstruction by tumor. Association with tuberculosis was considered incidental.

Adenocarcinoma↗

Clinico-pathological features of malignant lymphomas in 294 Hong Kong Chinese patients, retrospective study covering an eight-year period.

The clinical records and histological material from 294 adult Chinese patients with malignant lymphoma were examined. These patients were first seen at the Queen Mary Hospital, Hong Kong, during the 8-year period 1975-82. There were 27 patients (9.2%) with Hodgkin's disease (HD) and 267 with non-Hodgkin's lymphoma (NHL). The median age at presentation was younger for HD (45 years) and the male: female ratio was higher (2:1) than the corresponding figures for NHL of 51 years and 1.4:1. In 76 patients (28.5% of NHL), the disease was thought to have originated in an extra-nodal site, 48 of these cases being gastrointestinal lymphomas. It was possible to reclassify 234 NHL according to the Rappaport and Kiel classifications, and the Working Formulation (WF) proposed by the US National Cancer Institute Study; for HD, the Rye classification was used in 26 cases where suitable material was available. Nodular/follicular lymphomas made up 17.1% of nodal NHL and 5.3% of extra-nodal NHL. The "histiocytic" (Rappaport) or large-cell (WF) subtype was the commonest amongst diffuse NHL. There were only four cases of Burkitt's lymphoma. For HD, the nodular sclerosing subtype was commonest in females (5 out of 8 cases) and for males, the commonest was mixed cellularity (10 out of 18 cases). Of patients with nodal NHL 64.7%, presented with Stage IV disease. For HD, there were about equal numbers of patients presenting with Stage II and Stage IV disease (10 and 9 respectively). The low incidence of Hodgkin's disease and of follicular lymphomas is comparable to figures from other "oriental" countries such as Japan.

Adolescent↗

Coronary atherosclerosis among Hong Kong Chinese--a histological and morphometric study using electronic digitizer.

In order to document the prevalence of atherosclerosis of the major coronary arteries among Hong Kong Chinese, a study on material from autopsies done during the year 1981 in Queen Mary Hospital was carried out. The narrowest part of the proximal coronary arteries was studied by light microscopy and morphometrically by electronic digitizer. We found an onset of atherosclerosis in young adult males and a linear progression with age. Females had a delayed onset with a sharp rise after menopause. We were surprised to find an incidence of atherosclerosis among Hong Kong Chinese comparable with that in western populations, as distinct from Chinese in Mainland China. However, mortality due to ischemic heart disease remained relatively low. Racial factors may contribute to this partial dissociation between coronary atherosclerosis and ischemic heart disease.

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↗

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↗

Secondary central nervous system involvement by non-Hodgkin's lymphoma: the risk factors.

The risk of secondary central nervous system (CNS) was estimated in 833 cases of non-Hodgkin's lymphoma diagnosed between January 1975 and December 1988. Fifty-one of them had CNS disease (51/833, 6.1 per cent). No case of low grade lymphoma developed CNS disease. However, 6.5 per cent and 16.7 per cent of patients with intermediate and high grade lymphomas, respectively, had secondary CNS involvement. Stage IV disease and the presence of B symptoms were also associated with an increased risk of CNS disease. Significantly higher incidence of CNS disease was seen in patients with lymphoma involving orbit (43 per cent), testis (40 per cent), peripheral blood (33 per cent), bone (29 per cent), nasal/paranasal sinuses region (23 per cent) and bone marrow (20 per cent). CNS prophylaxis is recommended to patients with an increased risk of CNS disease.

Brain Neoplasms↗

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↗

Presence of Epstein-Barr virus DNA in nasal lymphomas of B and 'T' cell type.

We studied 12 tumours from 11 Chinese patients with primary nasal lymphoma for presence of Epstein-Barr Virus (EBV) DNA, using Southern-blot analysis. These results were correlated with immunophenotype and T-cell receptor (TcR) or immunoglobulin gene rearrangement patterns. EBV DNA was detected in all nine tumours with a 'T' phenotype, in both primary and secondary sites. When the structure of the viral genomic termini was studied using the EcoRI-Dhet probe, a single clonal episomal band was demonstrated in five tumour samples, with one other case showing a biclonal pattern. However, none of these cases showed clonal rearrangement of TcR beta chain gene, and TcR gamma rearrangement was found only in one. The lineage of these phenotypic 'T' lymphomas therefore require further studies for confirmation. Two out of three B-lymphomas were also EBV DNA+; clonal EBV DNA was found in one. Their B-lineage was confirmed by detection of clonal immunoglobulin gene rearrangements. The association of EBV with an increasing number of lymphomas of different types highlights the need for continued study into its role in oncogenesis.

Blotting, Southern↗

Non-Hodgkin's lymphomas involving the female genital tract.

Thirteen female patients with lymphomas involving the genital tract were studied. Their median age was 50 years. There were three cases of stage I disease, one stage II and nine stage IV. The gastrointestinal tract was commonly involved in patients with disease in the ovary. The histology was mostly intermediate or high grade according to the Working Formulation. Immunophenotyping was performed in six patients and they were all B-cell tumours. There appeared to have a strong association between gastrointestinal involvement and ovarian disease. All patients received combination chemotherapy with or without additional radiotherapy and the survival of patients with stage I and II disease appeared to be superior to those with stage IV disease. However, the difference observed did not reach statistical significance because of small patient number. It remains uncertain whether lymphomas of the female genital tract by itself carries a poorer prognosis than the nodal lymphomas of comparable stage and histology.

Adult↗

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↗

The prognostic factors for peripheral T-cell lymphomas.

The peripheral T-cell lymphomas of 50 patients were classified by histological type and tumour cell size, the latter as described by the Nebraska Group. There was no difference in the pattern of their clinical features among the various histological subtypes and their clinical outcome was similar. Cell size and other factors including sex, age, presence of B symptoms, sites of primary disease, histological subtypes according to the Japanese classification, lactate dehydrogenase level and presence of bulky disease did not appear to correlate with clinical outcome. However, patients with stage IV disease had significantly lower CR rate (9/29 versus 16/21, p = 0.01) and poorer survival at 3 years (p = 0.05) than those with stage I, II and III disease. Patients receiving COPP, the less intensive chemotherapy regimen, appeared to have poorer clinical outcome but the difference observed was not statistically significant because of the number of patients in each subgroup.

Age Factors↗

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↗

A c-myc antisense oligodeoxynucleotide inhibits entry into S phase but not progress from G0 to G1.

Initiation of T-lymphocyte proliferation by mitogen or antigen involves a cascade of gene activation events. Thus, by the time mitogen-activated T cells have reached the G1/S interface, many genes that are transcriptionally silent in G0, like the c-myc, IL-2, IL-2 receptor (IL-2R) and transferrin receptor (TfR) genes, have been transcriptionally activated. To understand the role of the individual genes in the activation process, one must be able to interfere specifically with the expression or function of each particular gene product. In this way, by blocking the IL-2R with an antibody, it has been demonstrated that IL-2/IL-2R interaction is required to induce TfR expression in activated T cells. When the function or expression of intracellular proteins is to be blocked, however, the need to introduce antibodies into the cytoplasm of viable cells, although possible, is a limiting factor. We have taken another approach, namely the exogenous addition to bulk cell cultures of small antisense oligomers. Sequence-specific antisense oligodeoxyribonucleotides have been reported to inhibit intracellular viral replication without interfering with cellular protein synthesis. Similarly, rabbit globin mRNA translation in a cell-free system and in rabbit reticulocytes has been inhibited by oligomers complementary to the globin mRNA initiation codon region. Recently, a pentadecadeoxyribonucleotide complementary to the initiation codon and four downstream codons of human c-myc mRNA was reported to inhibit the proliferation of the human leukaemic cell line HL-60 specifically. We report here that the same c-myc complementary oligonucleotide inhibits mitogen-induced c-myc protein expression in human T lymphocytes and prevents S phase entry. Interestingly, c-myc antisense treatment did not inhibit G0 to G1 traversal as assessed by morphologic blast transformation, transcriptional activation of the IL-2R and TfR genes, or induction of 3H-uridine incorporation.

Cell Division↗