Biomedical subjects

J S Sham

Publications and source records attributed to J S Sham.

At least 127 records · Page 7Linked to original sources

PubMed1990

Primary mediastinal seminoma.

The records and histopathology of 4 patients with primary mediastinal seminoma were reviewed. All of them were male and at presentation had one or more poor prognostic factors, namely superior vena cava obstruction, hilar lymphadenopathy, bulky tumor, and raised alpha-fetoprotein titers. Their treatment consisted partly or entirely of chemotherapy. Three of them survived free of disease 2-5 years off treatment, 1 of them died of pulmonary fibrosis with no tumor found at postmortem examination. The prognostic factors and treatment of this tumor and the risk of combined radiotherapy and chemotherapy containing bleomycin are discussed.

Adolescent↗

PubMed1990

Multiple malignant neoplasms in patients with nasopharyngeal carcinoma.

The records of 759 patients with nasopharyngeal carcinoma were reviewed. Fifteen of them also suffered from another malignant neoplasm. All patients had histological confirmation of the nasopharyngeal carcinoma and the other malignant neoplasm. There was no predilection for the second malignant neoplasms to arise from the bronchus. Although the observed number of second malignant neoplasms was not significantly different from the expected number (p greater than 0.05) computed by the patient-month approach, in 1 patient the second malignant neoplasm may be causally related to the previous treatment of nasopharyngeal carcinoma by radiotherapy.

Adult↗

PubMed1990

Prognostic factors of nasopharyngeal carcinoma: a review of 759 patients.

The records of 759 Stage I to IV nasopharyngeal carcinoma patients seen between January 1976 and December 1983 were reviewed. There were 72 (9.5%), 162 (21.3%), 317 (41.8%) and 208 (27.4%) patients with Stage I, II, III and IV disease, respectively. Ho's stage classification was found to give a reliable prognosis. The actuarial survival at 5 and 10 years for Stage I, II, III and IV disease was 80.8%, 71.5%, 40.7%, 17.7% and 33.4%, 48.4%, 30.0%, 9.5%, respectively. The significant factors affecting survival were found using Cox multivariate analysis, N and T stages, the size and degree of fixation of neck nodes, sex, age, the presence of cranial nerve palsy and ear symptoms at presentation. Bilateral neck node involvement, histology subtypes of tumour, headache and nasal symptoms at presentation, the difference in radiation dose to the primary tumour and the neck, the initial haemoglobin and white blood count were not significant factors in the present study. The N stage was found to be prognostically significant even among patient groups stratified for the size and degree of fixation of the neck nodes involved. Women had a better survival rate than men, and the survival of patients less than 40 years old was better than those who were older at 5 years, although by 10 years the survival for the two groups was comparable.

Adult↗

PubMed1990

Nasopharyngeal carcinoma: the significance of neck node involvement in relation to the pattern of distant failure.

The pattern of distant failure of 759 Stage I-IV cases of nasopharyngeal carcinoma was studied. The most common sites of distant metastasis were, in descending order, bone, lung and liver. The N stage, T stage and the characteristics (size and degree of fixation) of the neck nodes involved were found to be significant prognostic factors determining the development of distant metastasis. The bilaterality of neck node involvement, sex, age, haemoglobin and white blood count at diagnosis were not significant. The discriminating effect of N stage holds true in patient groups stratified for the node size and degree of fixation. The superiority of the Ho stage classification was confirmed. The high incidence of distant failure in patients with T3, N3, or bulky or fixed neck node involvement warrants further clinical trials to explore the role of adjuvant chemotherapy.

Adolescent↗

PubMed1990

Nasopharyngeal carcinoma: pattern of skeletal metastases.

The records of 153 nasopharyngeal carcinoma patients with skeletal metastases were reviewed. The skeletal system was the most common site of distant metastases. The patients who developed skeletal metastases were significantly younger than those without skeletal metastases, although there was no difference between sexes. The pattern of skeletal involvement conforms to the general pattern, the spine and pelvis being the common sites. The first region of involvement was lumbar spine (28.4%), then dorsal spine (27.7%), sacrum and pelvis (16.3%), femur (9.9%), rib and sternum (7.8%), humerus (5.0%), cervical spine (3.5%) and skull vault (1.4%). Radiologically, the lesions were lytic in 66.0%, mixed lytic and sclerotic in 12.8% and sclerotic in 21.2%. The time to development of symptomatic skeletal metastases of mixed or sclerotic nature was significantly longer than lytic lesions, and patients with mixed or sclerotic metastases also had better survival.

Adolescent↗

PubMed1990

Seminoma of normally-descended and cryptorchid testis.

The records of 40 patients with seminoma of testis were reviewed; nine had cryptorchidism. The incidence of cryptorchidism among the 36 Chinese patients was 22% (8/36). All Stage I and four Stage II patients were treated by orchidectomy followed by radiotherapy of 30 Gy or more to the pelvic and para-aortic lymphatics, while another seven Stage II patients received pelvic and para-aortic lymphatics plus mediastinal irradiation. For patients with normally-descended testis, the 2-year survival for Stage I was 94% and Stage II, with small and clinically unpalpable abdominal nodal metastases, 86%. For patients with Stage I and II seminoma arising from cryptorchid testis, comparable survival can be achieved by giving similar doses of radiation and adjusting the size of the para-aortic and pelvic radiation fields to cover the known extent of the disease. The prognosis of patients with seminoma arising from cryptorchid testis depends more on the stage and extent of disease than the status of cryptorchid testis. Painful groin mass or abdominal pain were the presenting symptoms in more than half of the patients with cryptorchid testes. The changed symptomatology in this group of patients can result in diagnosis delay.

Abdominal Pain↗

PubMed1989

Fiberoptic endoscopic examination and biopsy in determining the extent of nasopharyngeal carcinoma.

This is a prospective study on the use of flexible endoscope and multiple biopsies in the assessment of nasopharyngeal carcinoma in 72 patients. This study confirmed the presence of submucosal growth pattern in nasopharyngeal carcinoma in 72 patients. This study confirmed the presence of submucosal growth pattern in nasopharyngeal carcinoma and this occurred in 13.8% of patients. Occult microscopic extension of tumor not detectable by fiberoptic endoscopy occurred in another 51.4% of patients. It has also been shown that multiple biopsy is superior to clinical examination in evaluating the extent of disease in nasopharyngeal carcinoma. Multiple biopsies are suggested for the early detection of nasopharyngeal carcinoma in high-risk cases. Although the better-defined tumor extent do not currently influence the treatment policy of nasopharyngeal carcinoma, and it is too early to assess its prognostic significance, it betters our understanding of the behavior of this tumor. Future analysis in correlation with long-term follow-up data may help to improve the stage classification systems and treatment strategy.

Biopsy↗

PubMed1989

Experience with the management of primary endodermal sinus tumor of the mediastinum.

Ten male patients with extensive primary endodermal sinus tumor of the mediastinum were treated with chemotherapy (with or without surgical excision and radiation therapy) between 1977 and 1985. Three patients, treated with cyclophosphamide-vincristine-based chemotherapy, died 1.5, 2.5, and 6.0 months, respectively, after initial diagnosis. Of the seven patients treated with cisplatin-based chemotherapy, one patient died of septicemia at 2.5 months after diagnosis and was disease-free at autopsy examination. Three other patients died of progressive disease at 7.0, 13.0, and 14.0 months, respectively. The three survivors remain alive at 17.0, 31.0, and 40.0 months from diagnosis; all are without evidence of disease. Of the three patients who underwent excision of the residual mediastinal tumor after cisplatin-based chemotherapy, persistent local disease was found in two patients. One of these two patients died of recurrent disease. All surviving patients had surgical resection of the tumor either before or after cisplatin-based chemotherapy, with or without radiotherapy and the timing of therapeutic interventions was guided by changes in the serum alpha-fetoprotein concentrations after initial therapy and during follow-up. Our experience suggests that the optimal management of patients with primary mediastinal endodermal sinus tumor requires an aggressive multidisciplinary approach guided by the extent of the tumor and the serum tumor marker levels.

Adolescent↗

PubMed1989

4-epidoxorubicin in recurrent cervical cancer.

Thirty-eight patients with histologically proven recurrent cervical cancer were treated with epirubicin, an analogue of anthracycline. There were eight complete responders and ten partial responders. The overall response rate was 47.8%. The survival duration of the responders was significantly longer than that of the nonresponders. The optimal dose of epirubicin has yet to be determined. The dosage of 120 mg/m2 was well tolerated. The role of epirubicin as an adjuvant chemotherapeutic agent in the treatment of cervical cancer was discussed.

Adult↗

PubMed1989

Long-term follow-up of potentiation of radiotherapy by cis-platinum in advanced cervical cancer.

Between January 1982 and January 1983 all patients with advanced cervical cancer were randomized into three groups: radiotherapy only (group I), radiotherapy plus weekly cis-platinum (group II), and radiation plus twice-weekly cis-platinum (group III). Better initial central control was observed in group III patients. Long-term survival was similar in the three groups. Potentiation of radiotherapy with cis-platinum failed to show any significant improvement in long-term survival.

Cisplatin↗

PubMed1989

Treatment of stage I nasopharyngeal carcinoma: analysis of the patterns of relapse and the results of withholding elective neck irradiation.

This is a retrospective analysis of 196 patients with nasopharyngeal carcinoma Stage I (Ho's classification) treated by megavoltage radiation during 1980-1984. The primary target volume included all potential sites of local invasion and the first station lymph nodes at retropharyngeal spaces. Two different dose schedules were used, both gave a total tumor dose biologically equivalent to 65 Gy by conventional fractionation, and both achieved a 5-year actuarial local-recurrence-free survival of 88%. Elective neck irradiation was withheld in all except seven patients. The overall 7-year actuarial survival was 85%, but the relapse-free survival was only 62%. The patterns of relapse, prognostic factors, and treatment complications were analyzed. Eighteen patients (9%) recurred locally. Radical retreatment with radiation achieved complete remission in seven out of fifteen cases. Distant failure occurred in 17 patients (9%). Although 57 (30%) of the 189 patients without elective neck irradiation subsequently showed lymph node involvement, none of the seven regionally-treated patients relapsed. The successful regional salvage rate was 81% overall (46 out of 57 patients), but 90% (44 of 49) for those properly treated with whole neck irradiation. However, the 7-year actuarial survival was lower in patients with nodal relapse than those without (70% versus 87%) because of the associated higher incidence of hematogenous dissemination. The various aspects of treatment, the value of elective neck irradiation in particular, are discussed.

Adult↗

PubMed1989

Primary mediastinal endodermal sinus tumors: CT evaluation.

Five patients with primary mediastinal endodermal sinus tumor have been evaluated by computed tomography (CT). The tumors were all located in the anterior mediastinum. Prechemotherapy CT demonstrated large, irregularly enhancing inhomogeneous masses without fat components. Calcification was visualized in two tumors. Some parts of the pleura-lung interface were irregular in four cases. Obliteration of fat planes to pericardium and chest wall was evident in all cases, and there was infiltration of intercostal muscles in four. Postchemotherapy CT in two patients who responded to chemotherapy showed either newly developed cystic lesions or cystic change of the original mediastinal mass. The cystic masses had more regular borders, a homogeneous hypodense center, and a smooth peripheral rim of contrast-enhancing tissue.

Adolescent↗

PubMed1989

Radiotherapy of brain metastases from carcinoma of the bronchus.

A retrospective study of 68 patients suffering from carcinoma of the bronchus with brain metastases is presented. They were treated in the Radiotherapy Department, Queen Elizabeth Hospital over a 5-year period (1982 to 1986). There were 42 male and 26 female patients. The age range was 30 to 78 years (median 58.5). All patients were treated with whole-brain photon irradiation using lateral opposing fields. The dosage could be divided into two groups: 30 Gy given in 10 to 15 daily fractions (30 patients), or 22.5 Gy given in five daily fractions (38 patients). There was no significant difference in the actuarial survival of the two groups (P = 0.37), the median survival being 7 and 6 weeks respectively. There was no difference in survival between the groups with different histological subtypes (P = 0.43). The 5-day short fractionation is the preferred treatment as it gives patients more time away from hospital. In 80.4% of patients there was progression of neurological symptoms before death. Increasing the dose of radiotherapy to the main bulk of tumour may improve the symptom-free survival or overall survival.

Adenocarcinoma↗

PubMed1989

Direct cardiac stimulation by arginine vasotocin in bullfrogs (Rana catesbeiana).

The antidiuretic and vasopressor effects of arginine vasotocin (AVT) in bullfrogs have been well documented. However, the direct cardiac stimulatory effects of AVT have not been previously reported. We found that AVT stimulates significant increases in heart rate, pulse pressure, and the maximal time derivative of ventricular pressure in anesthetized bullfrogs after the beta-adrenergic and muscarinic receptors in the heart were blocked by atropine and propranolol. In spontaneously beating isolated frog atria, AVT increased the beating rate by 20% and the contractile force by 100%. The inotropic effect of AVT was also demonstrated in electrically driven atria and ventricles. Propranolol was ineffective in blocking these cardiac responses in vitro. The Hill coefficients of the concentration-response curves did not differ from unity. In conclusion, AVT possesses both positive chronotropic and inotropic effects in bullfrogs, Rana catesbeiana, probably by direct stimulation of its specific receptors in the heart.

Animals↗

PubMed1989

Treatment of persistent and recurrent nasopharyngeal carcinoma by brachytherapy.

The early results of brachytherapy for persistent and recurrent nasopharyngeal carcinoma in 30 patients is presented. Fifteen patients were treated by intracavitary caesium, 12 patients were treated by interstitial gold grain implant using the split-palate approach and three patients were treated by both intracavitary caesium and interstitial gold grain implant for the first and second relapse in the nasopharynx, respectively. The overall tumour control rate for intracavitary caesium was 5/18 (28%) with median follow-up of 25.2 months, and for interstitial gold grain implant it was 9/14 (64%) with median follow-up of 16.5 months. Interstitial gold grain implantation appears to be effective in the treatment of persistent and recurrent nasopharyngeal carcinoma.

Adult↗

PubMed1988

Parathyroid hormone and calcium entry blockade in a vascular tissue.

The mechanism of the vasorelaxing action of a synthetic parathyroid hormone fragment, bPTH-(1-34), was studied. Rat tail artery helical strips were constricted in vitro with potassium chloride (6 x 10(-2) M), arginine vasopressin (2 mU/ml) or BAY-K-8644 (3 x 10(-7) M in the presence of 1.5 x 10(-2) M KCl). bPTH-(1-34) was able to relax the constricted tissue or to inhibit the constriction. All three constricting agents increased calcium uptake by the vascular tissue as determined by the measurement of the low-affinity lanthanum-resistant pool of calcium. Such increases in calcium uptake were significantly reduced by bPTH-(1-34). These data suggest that PTH may be a natural circulating hormone or chemical capable of inhibiting calcium entry in a vascular tissue.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1988

Brainstem auditory evoked potentials after irradiation of nasopharyngeal carcinoma--report on two cases with myelopathy of the brainstem.

Brainstem auditory evoked potentials (BAEP) were recorded in two patients with nasopharyngeal carcinoma (NPC) irradiated 14 and three years ago respectively and compared with 15 healthy controls. The patients had features of post-irradiation myelopathy of the brainstem with reduced gag reflex, unilateral vocal cord paralysis and fasciculation of the tongue. The first patient had a blind left eye. The second patient had quadriparesis. All ears revealed post-irradiation otitis media changes and mixed deafness. BAEP was not recognizable in the left ear of the first patient and was normal in the left ear of the second patient. Simultaneous electrocochleogram and BAEP were recorded from the right ear of the first case. The wave I-V latency interval were prolonged in both right ears. In the absence of local recurrence and brain secondaries, these BAEP changes are attributed to the post-irradiation myelopathy of brainstem.

Brain Stem↗

PubMed1986

Calcium-dependent chronotropic action of bovine parathyroid hormone (1-34) in isolated atria of Japanese quail, Coturnix coturnix japonica.

The involvement of extracellular calcium in the chronotropic action of parathyroid hormone (PTH) in isolated quail atria was studied. Bovine (b) PTH-(1-34) caused dose-dependent increases in the atrial beating rate. The PTH-induced positive chronotropism was significantly attenuated by lowering the extracellular calcium concentration or by using the calcium channel antagonists verapamil and D600. This suggests the importance of calcium influx in the cardiac action of PTH. beta-Adrenergic blockade with propranolol did not affect the responses to bPTH-(1-34). This further substantiates the previous findings that the PTH action is independent of cardiac beta-adrenoceptor stimulation.

Animals↗