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Biomedical subjects

S T Ho

Publications and source records attributed to S T Ho.

At least 163 records · Page 9Linked to original sources
PubMed1985

Effects of 4-aminopyridine on cat blood pressure in relation to the sympathetic nervous system.

The pressor effect of 4-aminopyridine (4-AP) was studied in anesthetized cats and in isolated cat aortic ring preparations. A significant increase in blood pressure (38.9 +/- 11.4 mmHg) was observed following intravenous administration of 4-AP (0.3 mg/kg). The elevated blood pressure lasted for 1.3 h and returned to the control level after 1.5 h. The pressor effect of 4-AP was not blocked by prior administration of phentolamine (2 mg/kg i.v.) or by pretreatment with reserpine (2 mg/kg i.m., once a day for two consecutive days). In vitro, a dose-dependent tonic contraction of aortic ring was noted after addition of 4-AP into the bathing fluid. The ED50 of 4-AP was significantly greater than that of norepinephrine (NE) (8 X 10(-4) M vs. 10(-7) M). Phentolamine (10(-6) M) antagonized the contractile response to NE but not that to 4-AP, whereas verapamil (10(-5) M) attenuated the 4-AP induced contractile response. A diminished contractile effect was also obtained when aortic ring preparations were bathed in calcium-free solution. These data suggest that the sympathetic nervous system plays a minor role in the pressor effect of 4-AP and that the increased calcium influx may account, at least partially, for the vasoconstricting effect of 4-AP.

4-Aminopyridine↗
PubMed1985

An unusual case of sacrococcygeal teratoma and a short review.

While sacrococcygeal teratoma presents typically at birth as a mass lesion, we had a case of late presentation with the classical triad of urinary retention, constipation and weakness of legs. Interesting enough, a tuft of hair together with a small lump was noted at birth and an associated small meningocoele was found at operation. We review the literature with regard to pathogenesis, clinical features, differential diagnosis, malignant change and treatment of the tumour.

Constipation↗
PubMed1980

Adriamycin in the treatment of resectible and irresectible primary hepatocellular carcinoma.

The treatment of 205 patients with primary hepatocellular carcinoma in Singapore from 1975 to 1980 is reviewed. Adriamycin given at a dose of 40 mg/m(2) intravenously every 4 weeks for irresectible tumours achieved a response rate of 32% alone and has significantly prolonged the median survival time to 4 1/2 months (135 days) in these individuals. Despite this response only 1/34 (3%) patient showed complete remission and is alive at 2 1/2 years. Use of other combinations with Adriamycin e.g. 5 Fluorouracil and Vincristine produced a significant response in the first 16 weeks (p < 0.005) but not thereafter, when completed with the historical group. To improve the response and to consolidate this response, split doses of total hepatic irradiation (to a maximum of 3,150 rads) and alternate day administration of intravenous Adriamycin 10 mg (to a maximum of 90 mg) were given. 12/23 patients (50%) responded. This was followed by a four weekly Adriamycin, 5 F.U. and Vincristine. Median survival time was 5 1/2 months (165 days). Relapse occurred in all patients. Similarly in 5 patients who had resections, early recurrences occurred in 3/5 (60%) within 3 months, inspite of postoperative chemotherapy with Adriamycin, 5 F.U., Vincristine and Cyclophosphamide given every four weeks. In view of the high recurrence rate following effective treatment, further studies on the biological behaviour of these abnormal livers is required.

Antineoplastic Agents↗
PubMed1979

The management of gastroschisis.

A review of gastroschisis treated at the Royal Alexandra Hospital for Children, Sydney, in the ten years between 1967 and 1976, was carried out. Early postoperative deaths occurred in those with poor general condition before and immediately after the operation. The presence of a gastrostomy appears to be most effective in the immediate postoperative period to assist in decreasing intraabdominal pressure. The results of three initial operative methods are discussed. The three procedures are the Gross method; prosthetic closure; and the Savage and Davey method of transverse incision and closure. The purpose of this paper is to suggest that the procedure described by Savage and Davey has been a most successful procedure in providing reliable and safe method of closure of gastroschisis, avoiding the complications and morbidity of staged closure using prosthetic material.

Abdominal Muscles↗
PubMedDate not supplied

Comparison of intravenous nalbuphine infusion versus naloxone in the prevention of epidural morphine-related side effects.

BACKGROUND AND OBJECTIVES: Epidural morphine is accepted as an efficient means of postoperative pain management. However, development of side effects such as nausea and vomiting and pruritus has been reported. This study compared the efficacy of intravenous infusions of nalbuphine or naloxone in the prevention of epidural morphine-related side effects. METHODS: Seventy-five female patients undergoing epidural anesthesia for total hysterectomy were enrolled in a randomized, double-blind study. At the end of the surgery, all patients received epidural 3 mg morphine (every 12 hours) for postoperative pain. Meanwhile, patients in group 1 received an adjuvant intravenous infusion of nalbuphine 60 microg/kg/h, patients in group 2 received intravenous infusion of naloxone 2 microg/kg/h, and patients in group 3 received intravenous saline infusion only. A rescue analgesic of intramuscular 50 mg meperidine (every 4 hours) was available for each patient. Patients were observed for 24 hours. RESULTS: All patients had adequate postoperative pain relief. However, the proportion of patients requiring rescue analgesia and the total consumption of rescue analgesic were higher in group 2 than in the other two groups. The incidence of nausea and vomiting and pruritus was higher in group 3 than in the other two groups. CONCLUSIONS: We found that coadministration of either nalbuphine or naloxone with epidural morphine reduces the incidence of morphine-related side effects. However, unlike naloxone, nalbuphine did not attenuate the analgesic effect of epidural morphine.

Adult↗
PubMedDate not supplied

Epidural fentanyl speeds the onset of sensory block during epidural lidocaine anesthesia.

BACKGROUND AND OBJECTIVES: Shortening the onset time of sensory block is a practical goal to improve the quality of epidural anesthesia. The addition of fentanyl to a local anesthetic solution is widely used during epidural anesthesia. This randomized double-blind study examined the onset time of sensory block during epidural lidocaine anesthesia with and without added fentanyl to the epidural solution. METHODS: Thirty-six young male patients undergoing knee arthroscopy were randomly allocated into 3 groups of 12 patients each: epidural fentanyl (EF, epidural administration of 17 mL of 2% lidocaine plus 100 microg fentanyl and followed by intravenous (IV) injection of 2 mL of normal saline); IV fentanyl (IF, epidural administration of 17 mL of 2% lidocaine plus 2 mL of normal saline and followed by IV injection of 100 microg of fentanyl); and control (C, epidural administration of 17 mL of 2% lidocaine plus 2 mL of normal saline and followed by IV injection of 2 mL of normal saline). The sensory block was assessed by pinprick method. The hemodynamic changes, postepidural shivering, and side effects of epidural fentanyl were also recorded. RESULTS: There was no difference in the distribution of age, weight, and height among the 3 groups. The onset time of sensory block up to T(10) dermatome was significantly more rapid in the EF group (8.3 +/- 3.7 minutes) than that of the IF group (13.1 +/- 4.2 minutes, P <.05) or C group (14.2 +/- 5.4 minutes, P <.05). The upper level of sensory block was also significantly higher in the EF group. Although the incidence of shivering was lower in the EF group, this did not reach statistical significance. Postepidural arterial blood pressures and heart rates were no different among the 3 groups. No nausea, vomiting, pruritus, respiratory depression, urinary retention, or hypotension were observed in any patients. CONCLUSION: Epidural injection of the mixture of 100 microg fentanyl and 2% lidocaine solution accelerated the onset of sensory block during epidural lidocaine anesthesia without increased side effects.

Adjuvants, Anesthesia↗
PubMedDate not supplied

Predicting chemotherapy response to paclitaxel-based therapy in advanced non-small-cell lung cancer with P-glycoprotein expression.

BACKGROUND: It was reported that multidrug resistance gene 1 (MDR1) encoding human P-glycoprotein (Pgp) may play an important role in multidrug resistance of lung cancer. Therefore, before initiating chemotherapy, it is important to accurately determine the presence of Pgp in lung cancer, to achieve a satisfactory chemotherapy response. OBJECTIVES: The aim of this study was to compare immunohistochemical analyses of Pgp expression and response to paclitaxel in non-small-cell lung cancer (NSCLC). METHODS: Before chemotherapy with paclitaxel, 50 patients with stage IIIb or IV NSCLC were enrolled in this study. Immunohistochemical analyses were performed on multiple nonconsecutive sections of the biopsy specimens to determine Pgp expression. Chemotherapy response was evaluated in the 3rd month after completion of treatment by clinical and radiological methods. RESULTS: All of the 28 (100%) cases with good response had negative Pgp expression and 15 of the 22 (68%) cases with poor response had positive Pgp expression (p < 0.05). No significant differences were found for other prognostic factors (age, sex, body weight loss, performance status, tumor cell type, and tumor stage) between good response and poor response groups. CONCLUSIONS: Although Pgp expression in NSCLC does not fully predict chemotherapy response to paclitaxel-based therapy, detection of Pgp expression will aid in planning paclitaxel-based therapy for patients with advanced NSCLC. Further studies with a larger number of patients and a longer time of follow-up are necessary to confirm our findings.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Technetium-99m-tetrofosmin scintigraphy in the prediction of chemotherapy response of untreated malignant lymphomas and comparison with other prognostic factors.

The aim of this study was to retrospectively predict the chemotherapy response of untreated malignant lymphomas using technetium-99m tetrofosmin (Tc-TF) scintigraphy and to compare the technique with other prognostic factors. In this study, before any chemotherapy, 25 patients with malignant lymphomas (ML) underwent Tc-TF scintigraphy. Scintigraphy was performed 10 minutes after intravenous injection of 20 mCi Tc-TF to calculate the tumor-to-normal (T/N) uptake ratio. In the first 1-2 years after complete chemotherapy, the response was evaluated by clinical and radiological methods. Compared with the 10 ML patients with poor chemotherapy response, the 15 ML patients with good response had a significantly higher mean T/N uptake ratio (3.23 +/- 0.56) versus 1.18 +/- 0.11). All of the 15 patients with good response had positive scintigraphic results whilst the 10 patients with poor response had negative scintigraphic results. When compared with other prognostic factors, Tc-TF scintigraphy was the tool to predict the chemotherapy response of ML patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Detection of cervical lymph node metastases of nasopharyngeal carcinomas with technetium-99m tetrofosmin single photon emission computed tomography and comparison with computed tomography.

The purpose of this study was to evaluate the usefulness of technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) in the detection of cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC), and to compare Tc-99m TF SPECT results with computed tomography (CT) findings. Fifty patients with biopsy-proven NPC and suspected cervical LN metastases underwent head and neck Tc-99m TF SPECT and CT to detect cervical LN metastases. Cervical LN metastases of 40 patients were confirmed by histopathological examination of biopsy samples. For 22 LN lesions with discordant results between Tc-99m TF SPECT and CT, Tc-99m TF SPECT could correctly detect 4 metastatic and 7 benign LN lesions while CT could correctly detect 5 metastatic and 6 benign LN lesions. Agreement positive results of Tc-99m TF SPECT and CT could correctly detect all of the 18 metastatic LN lesions. Tc-99m TF SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with CT. The combined use of Tc-99m TF SPECT and CT could significantly increase the accuracy of detect cervical LN metastases in NPC compared with the single use of either Tc-99m TF SPECT or CT.

Adult↗