Search PubMed⌕ Search

Biomedical subjects

W K Lam

Publications and source records attributed to W K Lam.

At least 163 records · Page 9Linked to original sources
PubMed1983

Bronchorrhea. A presenting feature of active endobronchial tuberculosis.

A 32-year-old woman presented with a one-month history of bronchorrhea (500 ml daily). She had normal findings on chest roentgenogram, and negative results for malignant cells and acid-fast bacilli in the sputum. Fiberoptic bronchoscopic examination, however, showed subtotal obliteration of left main bronchus due to active tuberculosis. The protean manifestations of endobronchial tuberculosis and its association with bronchorrhea are stressed.

Adult↗
PubMed1983

First report of asbestos-related diseases in Hong Kong.

There has been no report of malignant mesothelioma or asbestosis in Hong Kong despite the rapid growth of industry in the past few decades. Three patients with malignant pleural mesothelioma and one patient with asbestosis and small cell carcinoma of the lung are reported. All four patients were Chinese in Hong Kong and had a history of occupational exposure to asbestos. Although there is no mining of asbestos in Hong Kong, her rapid industrialization in the past few decades has led to a large population of asbestos-exposed workers in industry. The average annual consumption of crude asbestos (import minus re-export) has grown ten-fold in the past decade to 1.090 tonnes in 1978-79, and the number of workers handling asbestos products was estimated to be 20.000 in 1979. The problem of asbestos related diseases has however been little considered and further epidemiologic studies are warranted.

Adult↗
PubMed1983

Fibreoptic bronchoscopy in the diagnosis of bronchial cancer: comparison of washings, brushings and biopsies in central and peripheral tumours.

Fibreoptic bronchoscopic cytodiagnosis by washings and brushings and histodiagnosis by forceps biopsy were studied in 484 Chinese patients with bronchial carcinoma. When the tumour was bronchoscopically visible, the yields of the three procedures were: washings 76%, brushings 74% and biopsy 82%, giving a total yield of 94%. For peripheral bronchoscopically non-visible tumour, the yields were 52%, 52% and 61% respectively, making a total yield of 86%. Bronchial washings and brushings were important complementary procedures to biopsy and provided the exclusive diagnosis in 12% of the central and 25% of the peripheral tumours. The cytologic cell typing accuracy is 92% for epidermoid carcinoma, 87% for small cell carcinoma, 83% for adenocarcinoma and only 38% for large cell carcinoma. The accuracy of cell-typing of the two bronchial cytodiagnostic methods was comparable in central tumours, but higher with brushings in peripheral tumours.

Adult↗
PubMed1982

Rapid diagnosis of suspected pulmonary tuberculosis by fiberoptic bronchoscopy.

Fiberoptic bronchoscopy was performed on 65 patients suspected of having active pulmonary tuberculosis, who were either sputum smear-negative or had no sputum to test. Bronchial aspirate was smear positive in 25 of 65 patients (38%); postbronchoscopy sputum was smear positive in 15 of 60 (37%) and there was bronchial biopsy evidence of tuberculosis in 33 of 57 (58%). Biopsy was particularly useful; it provided the exclusive diagnosis in 12% of cases. When the 3 methods were combined, a diagnosis of tuberculosis was made within 3-4 days in 42 of 65 patients (65%). Taking culture results into consideration, we made a definitive diagnosis in 61 of 65 patients (94%). Thirteen patients had atypical radiographic shadows and 7 had unsuspected co-existing bronchogenic carcinoma. No major complication developed after bronchoscopy. Our results are compared with those of 3 other reported series.

Bronchi↗
PubMed1982

Effect of calcium antagonists on allergen-induced asthma.

The protective effect of inhaled verapamil (estimated dose 2 . 4 mg) and sub-lingual nifedipine (20 mg) against allergen-induced asthma were each assessed by the administration of calcium antagonists 30 min before bronchial provocation tests using Dermatophagoides pteronyssinus extracts on eight young perennial asthmatics. Neither drug changed the basal forced expiratory volume in one second (FEV1) or the provocation dose of allergen required to cause a 20% fall in FEV1 (PD20 . FEV1). That calcium antagonists are ineffective in preventing allergen-induced asthma suggest indirectly that mechanism other than mediator release from mast cells may also be involved.

Adolescent↗
PubMed1982

Haemoptysis due to unsuspected foreign body penetration of the oesophagus.

A 42-year-old man presented with haemoptysis of undetermined cause for five months despite thorough investigation. Exploratory thoracotomy showed there had been "silent" penetration by a chicken bone through oesophagus into the lung. A retrospective review showed that the foreign body could be seen in only four out of 54 chest roentgenograms taken.

Adult↗
PubMed1982

Complications of intrapleural BCG in the treatment of operable non-small-cell bronchial carcinoma.

Seventy-eight patients entered a randomized study of postoperative intrapleural BCG in the treatment of bronchial carcinoma. 39 patients received BCG (Tice strain), of whom 17 took isoniazid, and there were 39 controls. There was a high rate of complications related to the use of intrapleural BCG, in both isoniazid and non-isoniazid treated groups. Postoperative infections occurred in eight BCG treated patients and one control; seven BCG treated patients but only one control developed prolonged postoperative chest pain. Empyema developed six months postoperatively in three of the BCG treated group. Furthermore BCG conferred no survival advantage at one year. We considered the complications to be of sufficient severity and incidence to discontinue the study.

Adult↗
PubMed1981

Immunohistochemistry of prostatic acid phosphatase.

The human prostatic acid phosphatase is a specific marker for the prostatic epithelial cells. By using an immunoperoxidase staining method for this enzyme, it is possible both to identify the prostatic epithelial cells and to recognize the prostatic origin of metastatic lesions of prostate cancer. Of the tissues containing prostatic epithelial cells from 120 patients, positive staining reaction was detected in 114 (95%), and negative in 6. In nonprostatic tissues from 242 patients, weak but positive staining reaction was detected in 8 (3.3%), including tissues from one renal cell carcinoma and 7 breast carcinomas. Of 27 patients in whom tumor tissues were tested at a time when tumor origin was unknown, the staining reaction was positive in 14 patients later found to have prostate cancer. It was negative in 6 patients with nonprostatic carcinoma and 7 patients with carcinoma of unknown primary. Although this immunohistochemical technique for prostatic acid phosphatase appears promising in diagnosing metastatic prostate cancer, its clinical significance and limitations remain unclear, and there are considerable technical problems yet to be solved. These problems are best approached by joint collaborative efforts of the various investigators interested in prostate cancer.

Acid Phosphatase↗
PubMed1981

Presence of "prostatic" acid phosphatase in human neutrophils.

The occurrence of natural substances with antigenic properties similar to those of the prostatic acid phosphatase was examined in one patient with neutrophilic leukemia and increased activity of serum acid phosphatase. The fraction responsible for the increased serum enzyme activity was tartrate sensitive and was identified as isoenzyme 2 by polyacrylamide gel electrophoresis. This isoenzyme originated from the leukocytes but had similar electromobility to that of the prostatic acid phosphatase isoenzyme 2. Immunohistochemical and counterimmunoelectrophoretic studies indicated that this leukocytic isoenzyme was present in the neutrophils and shared antigenic properties with the prostatic isoenzyme 2. Leukocytes from one patient with acute granulocytic leukemia, two patients with polycythemia vera with neutrophilia, and five normal subjects also contained this prostatic acid phosphatase like isoenzyme. Elevated serum "prostatic" acid phosphatase activity, therefore, may be found not only in prostatic cancer but also in granulocytic leukemia and perhaps other diseases.

Acid Phosphatase↗
PubMed1980

Immunohistochemical diagnosis of prostatic cancer with metastasis.

An immunohistochemical method for detecting prostatic acid phosphatase is described for the diagnosis of metastatic prostatic carcinoma. The specific antiserum against prostatic acid phosphatase was prepared from rabbit by injection of acid phosphatase purified from seminal fluid. This method gives a selective staining of the cytoplasm of the glandular epithelial cells of prostatic tissue specimens on paraffin section. Most of the non-prostatic tissues were negative except for occasional weak staining in granulocytes, islet cells of pancreas, parietal cells of stomach, tubular epithelial cells of kidney, and liver cells. Also examined were 50 consecutive cases of metastatic tumor involving the bone marrow and 5 cases of metastatic prostatic carcinoma involving the lymph node or lung. All 20 cases with prostatic primary lesion showed positive staining. All other cases were negative, except 5 of the 14 cases of metastatic breast carcinoma in women showing weakly positive results. The method is fairly specific for identification of metastatic prostatic carcinoma. Occasional positive staining in breast tumor needs further study to establish whether the staining is due to the same isoenzyme or to certain cross immunoreactivity.

Acid Phosphatase↗
PubMed1979

Albumin-bound bilirubin in subchoroidal fluid.

The most unique property of subchoroidal fluid was found to be the high bilirubin level. One distinct yellow band in the same position as albumin was observed when it was subjected to electrophoresis on agarose film. The yellow compound was very soluble in chloroform. Its identity to bilirubin was confirmed by its absorption maximum at 445 nm, and a positive reaction with Ehrlich's diazo reagent. Subretinal fluid and liquid vitreous often had a yellowish appearance after ocular hemorrhage. However, their bilirubin level was not elevated above that of serum. Our data indicated that the degradation of RBCs may be an important causative factor of persistant detachment.

Aged↗
PubMed1979

Significance of "high" acid phosphatase activity in the serum of normal children.

Serum acid phosphatase activity in normal children (newborn to 18 years) is several fold that in normal adults. Activity is age-related but not sex-related. The isoenzyme pattern in children is similar to that in adults and contains no prostatic fraction. Quantitatively, most of the enzyme activity in the serum of children is tartrate-resistant and correlates well with heat-labile fractions of alkaline phosphatase activity in serum, suggesting that the source of the higher acid phosphatase activity in children is bone. Significant tartrate-resistant acid phosphatase activity was demonstrated in the giant cells in three patients with giant-cell tumors, but not in the "osteoblasts" in six patients with osteogenic sarcomas and many other normal or abnormal tissues. This work suggests that the higher enzyme activity in the serum of children represents a normal physiological phenomenon resulting from their greater osteoclastic activity.

Acid Phosphatase↗
PubMed1979

Comparison of acid phosphatase isoenzymes of human seminal fluid, prostate, and leukocytes.

We used ion-exchange column chromatography and electrophoresis on polyacrylamide gel to compare the acid phosphatase isoenzymes of prostate and leukocytes. The major isoenzyme of the prostate is band 2A; only a trace of band 2B was observed. However, the major isoenzymes of leukocytes are band 4 and band 2B, and only a small amount of band 2A was observed. The three isoenzymes isolated from leukocytes or prostate gland react to the antiserum prepared against the aicd phosphatase isoenzyme of seminal fluid. Acid phosphatases of leukocytes other than the three isoenzymes mentioned above did not interact with the antiserum.

Acid Phosphatase↗
PubMed1978

Biochemical properties of tartrate-resistant acid phosphatase in serum of adults and children.

Spectrophotometry of total acid phosphatase activity in children's sera showed an average value of 22.4 +/- 2.9 and 7.4 +/- 0.8 U/liter, for the hydrolysis of p-nitrophenyl phosphate and alpha-naphthyl phosphate, respectively. Analyses of "band 5b", after electrophoresis on acrylamide gel, gave even higher values. The values for children's sera were much higher than those for sera from adults. The multiplicity of acid phosphatases in sera of children and adults was studied by electrophoresis on acrylamide gel and by chromatography on CM-Sepharose. Both methods showed the major acid phosphatase in children's sera to be an acid pyrophosphatase, band 5b. Its catalytic properties are indistinguishable from the enzyme previously isolated from the spleen of leukemic reticuloendotheliosis.

4-Nitrophenylphosphatase↗