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Biomedical subjects

B Ng

Publications and source records attributed to B Ng.

At least 37 records · Page 2Linked to original sources
PubMed1998

An audit of pancreatic pseudocyst management and the role of endoscopic pancreatography.

BACKGROUND: A rational algorithm for the management of symptomatic pancreatic pseudocysts is necessary with the increasing availability of radiological, surgical and endoscopic methods of treatment. METHODS: A retrospective audit of the management and outcome of all patients who presented with symptomatic pancreatic pseudocysts to the Auckland Hospital over a 9-year period (1988-96) was made. RESULTS: There were 44 patients (28 men, 16 women; median age 50; range 18-81) in this series. Initial management was not based on pseudocyst size, duration, location, wall thickness, the patients' symptoms and comorbidity, or the aetiology of pancreatitis. Of the 27 patients who had initial conservative management, 15 pseudocysts (56%) completely resolved. Of the 17 patients who were initially or subsequently treated with percutaneous catheter drainage (PCD), 10 pseudocysts (59%) completely resolved without additional treatment. Of the 13 patients initially or subsequently treated by surgery, all but one completely resolved after the first procedure. Two patients were successfully treated with endoscopic pancreatic stent placement. Complications arose in eight patients treated with PCD (47%) and four patients treated with surgery (31%). There was no mortality. The decision for active treatment was not preceded by delineation of the pancreatic duct by ERCP (endoscopic retrograde cholangiopancreatography) in 60% of patients. CONCLUSIONS: More than one-third of all patients with symptomatic pancreatic pseudocysts can be managed conservatively. Surgery yields excellent results but PCD has a high failure rate in patients with an underlying pancreatic duct stricture. A rational management algorithm is presented, based on pre-intervention ERCP, which should improve patient selection and outcome.

Adolescent↗
PubMed1998

Partial hepatectomy accelerates local tumor growth: potential roles of local cytokine activation.

BACKGROUND: Surgical excision of liver tumors represents the only curative treatment for primary and metastatic liver malignancies. It has been suspected that hepatectomy may stimulate growth of microscopic tumors. To determine whether local or systemic factors after hepatectomy are responsible for enhancement of tumor growth, the effects of hepatectomy on the experimental growth of liver or pulmonary tumors were examined. METHODS: One hour after injection of 10(6) Morris hepatoma cells into either the portal or femoral vein, which produces isolated liver and lung tumors, respectively, animals were randomized to undergo 0%, 30%, or 70% partial hepatectomy (PH). RESULTS: Animals that underwent portal injection of tumor had significantly increased liver tumor burden after PH (sham, 25 +/- 7 vs PH, 94 +/- 17; p < 0.01), whereas animals that underwent femoral injection had no change in lung tumor burden after PH. PH was associated with significantly increased levels of transforming growth factor-alpha, transforming growth factor-beta, and basic fibroblast growth factor in the liver but not in the lung. CONCLUSIONS: Changes in liver cytokine-growth factor activation may contribute to enhanced tumor growth in the liver after hepatectomy.

Animals↗
PubMed1998

Nightguard vital bleaching: a review and clinical study.

Based on current clinical experience and research, dentist-prescribed home bleaching, also referred to as nightguard vital bleaching, is a safe and effective technique for whitening teeth when a carbamide peroxide material (up to 10 percent) is used. The bleaching material should be produced by a recognised and reputable manufacturer and must be used under a dentist's supervision over a relatively short time. Mild thermal sensitivity is a common side effect; however, no long-term pulpal effects have been shown. The reduction in the bond strength of resin to freshly bleached enamel and dentine has been shown to be transient, and no clinically significant changes in surface morphology or physical properties have been shown to occur to teeth or dental restorative materials as a result of vital bleaching. As a consequence, vital bleaching has gained favour with patients and dentists alike. Significant benefit was obtained in 12 subjects using two nightguard bleaching systems which were equally effective.

Carbamide Peroxide↗
PubMed1997

Establishment of an experimental intrapulmonary tumor nodule model.

BACKGROUND: A pulmonary tumor model is necessary to study the biology and therapy of lung cancer. Methods to establish a solitary intrapulmonary nodule are not well defined. Two methods for solitary intrapulmonary tumor nodule development in the Fischer rat are described. METHODS: Methylcholanthrene-induced sarcoma cell suspensions were introduced into lung parenchyma of Fischer rats via limited thoracotomy and lung puncture, or instilled into a distal airway after tracheal puncture and catheterization. Intrapulmonary tumor location, implantation mortality, procedure length, and animal survival were recorded. RESULTS: Single pulmonary nodules developed at the implanted position in 100% (n = 320) and 95% (62/65) of animals after direct injection into the pulmonary parenchyma or via tracheal puncture and instillation. Operative mortality was 2% and 5% via lung or tracheal implantation, respectively. Less than 5 minutes was required for each implantation. Mean survival time was 24 +/- 2 and 26 +/- 6 days after lung or tracheal implantation in animals allowed to survive until tumor-induced death. CONCLUSIONS: These easily performed, reproducible methods of establishing solitary intrapulmonary tumors are useful tools for lung cancer research.

Animals↗
PubMed1996

The role of general practitioners in mental health care: a survey of needs and problems.

OBJECTIVE: To assess the attitudes of general practitioners to central Auckland mental health service provision, and their perceived role and educational needs for clinical management of patients with mental disorders. METHOD: A postal questionnaire survey of all general practitioners within the Auckland Healthcare (Central Auckland CHE) area. RESULTS: 140 (49%) valid responses were returned from 287 sampled. 94% supported a shared care role with mental health services; 57% considered their role as main case manager to be important. 79% of the general practitioners considered they had insufficient time to manage patients with mental disorders. 69% of respondents reported difficulties receiving information about changes to treatment; 65% were unsure whether patients had a case manager, and 64% reported general difficulties with liaison with the mental health services. Education about a range of mental health issues was sought by three quarters of the group. CONCLUSION: This survey suggested that liaison between general practice and specialist mental health services in central Auckland is poor, but that general practitioners are eager to seek ways to improve the care of people suffering mental disorders.

Adult↗
PubMed1996

Interferon gamma protects against hepatic tumor growth in rats by increasing Kupffer cell tumoricidal activity.

An increasing number of hepatic resections are being performed as potentially curative surgery for malignant liver neoplasms. Hepatectomy and subsequent liver regeneration produce a local environment that enhances growth of microscopic residual tumor. To determine if pretreatment with murine interferon gamma (IFN-gamma) can protect against such enhanced tumor growth, Buffalo rats were randomized to receive a 3-day treatment of IFN-gamma (50,000 U/qD intraperitoneally) or saline. Groups then underwent intrasplenic injection of 10(6) Morris hepatoma cells, followed 1 hour later by sham (control) or partial hepatectomy (PH) of 70%. PH significantly enhanced tumor growth within the liver (control, 8 +/- 3 nodules per liver; PH, 73 +/- 12 nodules per liver; P < .001). This enhancement was attenuated by prior administration of IFN-gamma IFN-gamma/PH, 16 +/- 3; P < .001 vs. PH). Growth factor release and liver regeneration were not affected significantly by pretreatment with IFN-gamma. The effect of IFN-gamma on tumor growth is associated with a significant enhancement of Kupffer cell (KC)-mediated tumoricidal activity (percentage of specific lysis, 55 +/- 10% control, 78 +/- 11% IFN-gamma, P < .01) but not lymphocyte-mediated tumoricidal activity. Because microscopic residual disease may be present after hepatectomies for cancer, IFN-gamma may be useful agent in retarding growth of residual tumors.

Animals↗
PubMed1996

Effect of human growth hormone on human pancreatic carcinoma growth, protein, and cell cycle kinetics.

The role of human growth hormone (hGH) as a nutritional adjunct for cancer patients is controversial because of its potential mitogenic effects on tumor growth. No studies to date have examined the effect of hGH on human tumor response in vivo. In Vitro: Athymic mice were injected (s.c.) daily with hGH (GH, n=14) or saline (CTL, n=14). On Day 10, serum was collected and added to human pancreatic carcinoma cells in culture. In Vivo: Athymic mice were inoculated (s.c.) with human pancreatic carcinoma cells. On Day 14, mice were randomized to receive daily either hGH (GH, n=14) or saline (CTL, n=12). On Day 29, animals received [3H]phenylalanine for tissue protein fractional synthetic rate (FSR) measurement. Tumors were excised and cell cycle kinetics analyzed. Data are expressed as mean +/- SEM. Statistical analysis was performed by unpaired t test and/or ANOVA where appropriate. In Vitro: Serum from GH-treated animals had elevated IGF-1 levels (287 +/- 34 ng/ml vs 157 +/- 53 ng/ml, P<0.001) and significantly stimulated cell growth (No. cells x 10(3)/well) compared with CTL serum (925 +/- 31 vs 747 +/- 38, P<0.001). In Vivo: Serum for GH-treated animals had elevated IGF-1 levels (287 +/- 34 ng/ml vs 157 +/- 53 ng/ml, P<0.001) and significantly stimulated cell growth (No. cells x 10(3)/well) compared with CTL serum (925 +/- 31 vs 747 +/- 38, P<0.001). In Vivo: Growth hormone had no significant effect on tumor growth rate (mm3/day) (1.45 +/- 0.47 CTL vs 1.57 +/- 0.66 GH), final tumor weight (mg) (0.19 +/- 0.15 CTL vs 0.17+/- 0.06 GH), DNA Index (1.5 +/- 0.1 CTL vs 1.5 +/- 0.1 GH), percent S phase (20.3 +/- 3.3 CTL vs 22.1 +/- 3.0 GH), or tumor FSR (%/day) (51.1 +/- 17.8 CTL vs 70.2 +/- 61.1 GH). Growth hormone significantly elevated serum IGF-1 levels (ng/ml) (176 +/- 48 CTL vs 222 +/- 53 GH, P<0.005) and liver FSR (%/day) (62.8 +/- 17.8 CTL vs 79.7 +/- 12.7 GH, P<0.005). Serum of GH-treated mice increased human pancreatic cell growth in vitro. In vivo, GH administration raised serum IGF-1 levels and increased liver protein FSR, without tumor growth, cell cycle kinetics, or protein FSR.

Animals↗
PubMed1996

Isolated lung perfusion with doxorubicin reduces cardiac and host toxicities associated with systemic administration.

BACKGROUND: For patients with malignant neoplasms metastatic to lung, systemic chemotherapy in doses high enough to achieve significant survival improvement is often limited by host toxicity. Isolated single-lung perfusion offers the advantage of delivering high-dose organ-specific chemotherapy while minimizing systemic toxicity. We compared the cardiac and systemic toxicities associated with intravenous administration versus isolated single-lung perfusion with doxorubicin. METHODS: Thirty-three male Fischer 344 rats weighing 275 to 300 g were randomized into three groups: normal control rats (n = 11), intravenous doxorubicin (7/mg/kg) (n = 11), and isolated left lung perfusion with 320 micrograms doxorubicin/mL (n = 11). Animals undergoing isolated single-lung perfusion were anesthetized with pentobarbital, intubated, and ventilated, and then had left thoracotomy with cannulation of the pulmonary artery and a pulmonary venotomy; pulmonary artery and vein were clamped proximally. Animals were perfused for 10 minutes at a rate of 0.5 mL/min, followed by a 5 minute rinse with buffered hespan solution. Arteriotomy and venotomy were repaired and circulation was restored. Daily weights were recorded. On day 24, cardiac output was determined in all groups by injection of radiolabeled chromium 51 microspheres. RESULTS: Animals treated with 7 mg/kg intravenous doxorubicin had a significant weight loss as compared with those treated with isolated lung perfusion (209.2 +/- 29.9 g versus 302.3 +/- 10.1 g; p < 0.01). Animals treated with isolated single-lung perfusion, after recovering from surgical stress, resumed normal growth pattern. Significant cardiac toxicities were seen in intravenously treated animals; cardiac index (27.4 +/- 6.9 versus 39.4 +/1 6.3 mL/min/100g body weight and heart weights (0.56 +/- 0.04 versus 0.88 +/- 0.09 g) were reduced in the intravenously treated group as compared with the group treated with isolated single-lung perfusion. In addition, severe hematologic toxicities are associated with intravenous doxorubicin administration. CONCLUSIONS: Intravenous administration of doxorubicin is associated with severe host toxicities, which include weight loss, decreased cardiac function, and hematologic toxicity. Isolated lung perfusion with high-dose doxorubicin is well tolerated and is associated with minimal host toxicity.

Animals↗
PubMed1996

Isolated lung perfusion with FUDR in the rat: pharmacokinetics and survival.

BACKGROUND: Although surgical resection remains the mainstay of treatment for metastatic pulmonary colorectal cancer, 5-year survival approaches only 30% to 40%. We have developed a model of isolated left lung perfusion (ILP) with FUDR (2'-deoxy-5-fluorouridine) for the treatment of pulmonary colorectal metastases. FUDR ILP toxicity and pharmacokinetics were evaluated and compared with continuous intravenous infusion in the rat. METHODS: Toxicity was first evaluated in F344 rats (n = 17) after left ILP (20-minute perfusion at 0.5 mL/min) with 21 mg/mL (n = 11), 28 mg/mL (n = 2), 35 mg/mL (n = 2), and 70 mg/mL (n = 2) of FUDR. Animals were followed up and weights recorded for 14 days postoperatively before a right pneumonectomy was performed to evaluate the effect of FUDR perfusion on left lung function. In the second study, 32 rats (n = 8/group) underwent: systemic FUDR (intravenous), or ILP with 7, 14, and 21 mg/mL respectively (ILP 7, ILP 14, and ILP 21 groups). Left lungs and serum were analyzed for FUDR and 5-fluorouracil by high-performance liquid chromatography. RESULTS: Rats perfused with doses of FUDR greater than 21 mg/mL died perioperatively. All animals perfused at 21 mg/mL survived until day 14, and 8/11 survived a right pneumonectomy. Rats that survived ILP resumed normal weight gain and grooming habits within 1 week. Pharmacokinetic evaluation demonstrated that ILP at 21 mg/mL maximally elevated total lung FUDR and 5-fluorouracil levels (508.5 +/- 96.4 micrograms/g lung) in comparison with the ILP 14, ILP 7, and intravenous groups (299.1 +/- 44.8, 116.0 +/- 21.1, and 7.5 +/- 4.1 micrograms/g lung, respectively) (p < 0.05). Serum FUDR levels were 10.5 +/- 6.8, 1.3 +/- 0.5, 2.31 +/- 1.1, and 1.2 +/- 0.4 microgram/g lung (p = not significant) for intravenous, ILP 7, ILP 14, and ILP 21 groups, respectively. CONCLUSIONS: Isolated left lung perfusion with FUDR is well tolerated to a maximum dose of 21 mg/mL and results in significantly higher FUDR and 5-fluorouracil lung levels with low serum levels compared with intravenous treatment. These higher pulmonary levels may offer advantages in the treatment of pulmonary colorectal metastases.

Animals↗
PubMed1995

Isolated lung perfusion with FUDR is an effective treatment for colorectal adenocarcinoma lung metastases in rats.

Currently, the only treatment capable of significantly prolonging survival in patients with isolated pulmonary metastases from colorectal adenocarcinoma is complete resection. Systemic chemotherapy has been shown to provide little benefit. We evaluated the efficacy of highdose, organ-specific 2'-deoxy-5-fluorouridine (FUDR) using a model of isolated single-lung perfusion (ILP) in the rat. On day 0, 28 BDIX rats were inoculated intravenously with 10(6) viable Sp-5 colorectal adenocarcinoma cells. On day 10 after-tumor inoculation, animals were randomized into five treatment groups. Group I received a continuous intravenous infusion of FUDR (1 mg.kg-1.d-1) for 7 days administered by an osmotic minipump. Group II underwent isolated left lung perfusion with a buffered Hespan solution, groups III to V underwent ILP with 3.5, 7, and 14 mg of FUDR per milliliter of the buffered Hespan solution, respectively. Animals undergoing ILP were anesthetized with pentobarbital, intubated, and ventilated, and then underwent left thoracotomy with cannulation of the pulmonary artery; the pulmonary artery and vein were clamped proximally. Groups II to V were perfused for 20 minutes at a rate of 1 mL/min, followed by a 5-minute washout with FUDR-free buffered Hespan solution. On day 26 after tumor inoculation, the animals in all groups were sacrificed and their lungs were stained and counted. Animals that underwent ILP with 14 mg of FUDR per milliliter of the buffered Hespan solution showed a significant decrease in the number of tumor nodules on the treated side versus the number on the untreated side (455.2 +/- 87.3 versus 11 +/- 6.4; p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1995

Isolated single-lung perfusion: a study of the optimal perfusate and other pharmacokinetic factors.

BACKGROUND: Isolated single-lung perfusion with doxorubicin hydrochloride was shown to be effective in clearing experimental sarcoma lung metastases in the rat. The best perfusate to be used for isolated lung perfusion and factors affecting the final lung concentration of doxorubicin are the subject of the present study. METHODS: In experiment 1, 60 animals were randomized to undergo isolated left lung perfusion with doxorubicin with six different perfusates (n = 10 per group): saline, low-potassium-dextran, 5% albumin, 6% hetastarch, 5% buffered albumin, and 6% buffered hetastarch. Five animals served as negative controls. After perfusion, the lung wet to dry ratio and final lung doxorubicin concentration were determined. In experiment 2, 60 animals underwent isolated left lung perfusion with either 80 micrograms/mL or 320 micrograms/mL of doxorubicin. Animals were perfused at either 0.5 mL/min or 1 mL/min and for 2, 6, or 10 minutes. At the end of the perfusion period, the left lung doxorubicin concentration was measured. Statistical analysis included analysis of variance, the Duncan test for multiple comparisons, and multiple linear regression analysis. Significance was defined as a p value of less than 0.05. RESULTS: In experiment 1, perfusion with 6% buffered hetastarch resulted in the lowest lung wet to dry ratio, significantly different from all groups except the controls. Perfusion with low-potassium-dextran solution led to the highest final lung concentration of doxorubicin. In experiment 2, a model to predict final lung doxorubicin concentration was constructed: Log (final lung concentration) = 1.9 + 0.0071.P + 0.186.T, where P is the measured perfusate concentration of doxorubicin, and T is the time of perfusion in minutes. The R2 was 0.91 and p, less than 0.001. The dose of doxorubicin per kilogram of animal body weight, the dose of doxorubicin per square meter of body surface area, the total amount of doxorubicin delivered, and the rate of perfusion did not meet the criteria to enter the equation. CONCLUSIONS: Isolated lung perfusion experiments should use 6% buffered hetastarch as the perfusate. The perfusate doxorubicin concentration and the duration of perfusion are the only factors determining the final lung concentration of doxorubicin. In lung perfusion experiments, the dose of chemotherapy is not as important as the perfusate concentration and the duration of the perfusion. Animals should be perfused at a lower rate so the lungs are exposed to less doxorubicin without changing the final lung concentration.

Albumins↗
PubMed1995

Pulmonary artery perfusion of doxorubicin with blood flow occlusion: pharmacokinetics and treatment in a metastatic sarcoma model.

BACKGROUND: We compared pharmacokinetics, toxicity, and treatment efficacy of pulmonary artery perfusion of low-dose doxorubicin with blood flow occlusion to intravenous doxorubicin injection in a metastatic sarcoma model in the rat. METHODS: Animals received left pulmonary artery perfusion with 0.1, 0.2, or 0.5 mg/kg doxorubicin at a rate of 0.1 mL/min for 1 minute with 20 minutes of blood flow occlusion. Doxorubicin levels of the lung, heart, and serum were assayed. Body weights after treatment were recorded and right pneumonectomy was performed. The results were compared with those in rats that received 5 mg/kg doxorubicin by intravenous injection or the saline group. Pulmonary sarcoma metastases were treated with 0.5 mg/kg doxorubicin through lung perfusion or intravenously, or with saline solution. RESULTS: Doxorubicin levels in the lung, heart, and serum were 112.1 +/- 9.2 micrograms/g, 1.7 +/- 0.2 microgram/g, and 0.3 +/- 0.1 microgram/mL in the group with 0.5 mg/kg doxorubicin perfusion, versus 24.8 +/- 1.9 microgram/g, 10.1 +/- 1.3 microgram/g, and 0.7 +/- 0.2 microgram/mL in the intravenous group (p < 0.05). Animals had normal growth patterns and survived after right pneumonectomy in the perfused group, whereas the intravenous group failed to thrive. No tumors were found or a significant reduction in nodules was noted in the lungs treated with perfusion as compared with untreated right lungs or the intravenous and saline groups. CONCLUSION: This chemotherapy model has important pharmacokinetic advantages and causes an increased treatment response for pulmonary metastatic sarcoma with minimal systemic and local toxicity as compared with systemic doxorubicin administration.

Animals↗
PubMed1995

The measurement of ionic conductivities and mobilities of certain less common organic ions needed for junction potential corrections in electrophysiology.

Junction potential corrections are often required in electrophysiological measurements, particularly when using the patch-clamp technique. The ionic conductivities and mobilities of certain less common organic ions were measured for use in junction potential corrections in electrophysiological measurements. The mobilities of these ions relative to K+ were: aspartate (0.30), choline (0.51), gluconate (0.33), glutamate (0.26), HEPES (0.30), isethionate (0.52), MES (0.37), MOPS (0.35), N-methyl-D-glucamine (0.33), and Tris (0.40). In addition, junction potentials were directly measured for a number of typical simplified patch-clamp solutions containing these ions. The measured junction potentials generally agreed well with the values calculated using the Generalized Henderson Equation with the appropriate ionic mobility. The accuracy of the measurements is discussed.

Electric Conductivity↗
PubMed1994

Unilateral pulmonary artery occlusion inhibits growth of metastatic sarcoma in the rat lung.

Tumors depend on their blood supply for growth. The blood supply to metastatic neoplasia of lung is usually from the pulmonary circulation or both the pulmonary and systemic circulation. The antineoplastic effect of pulmonary artery occlusion was investigated in a rat model of methylcholanthrene-induced metastatic pulmonary sarcoma. Left pulmonary artery ligation was performed on day 7 after tumor inoculation, and animals were sacrificed on day 14. The tumor burden of the left lung decreased 44% when compared with the control group. The survival of non-tumor-bearing rats undergoing left pulmonary artery ligation for 24 hours followed by right pneumonectomy after 2 weeks was also studied. No significant lung damage after a period of left pulmonary artery ligation was seen, as evidenced by both survival after contralateral right pneumonectomy and histology. Balloon occlusion of pulmonary artery, together with regional chemotherapy for patients with lung metastases, may warrant investigation.

Animals↗
PubMed1994

Effect of growth hormone on tumor and host in an animal model.

BACKGROUND: The relative effects of growth hormone on tumor versus host growth and protein metabolism are not known. This study examines the influence of recombinant rat growth hormone (r-rGH) on host and tumor growth, host body composition, and protein synthesis of tumor and host in tumor-bearing rats. METHODS: After left flank implantation of methylcholanthrene-induced sarcoma, 28 Fischer rats with palpable tumor were treated with s.c. saline or 1 mg/kg/day r-rGH for 11 days. At death, fractional protein synthetic rates (FSRs) of tumor, liver, and gastrocnemius muscle were determined. In a separate experiment, 27 tumor-bearing rats received saline or 1 mg/kg/day r-rGH for 2 weeks. Tumor and host growth and host body composition were analyzed. RESULTS: Animals treated with r-rGH had significantly higher liver FSR than did controls (233 +/- 27%/day vs. 110 +/- 4%/day, respectively). No significant differences were associated with growth hormone administration with respect to tumor growth, host composition, or FSR of tumor or muscle. CONCLUSIONS: Growth hormone stimulates liver protein synthesis, without changing tumor growth, protein synthesis, or host composition in this rat sarcoma model. Further investigation of growth hormone as an anticachectic agent is warranted.

Animals↗
PubMed1994

Isolated single-lung perfusion with TNF-alpha in a rat sarcoma lung metastases model.

We conducted a trial of isolated lung perfusion using tumor necrosis factor (TNF) in an experimental sarcoma lung metastasis model. In an in vitro experiment, methylcholanthrene-induced sarcoma cells were incubated for 48 hours with 42 micrograms/mL of either human or murine TNF. Controls were incubated with Hank's balanced salt solution. In an in vivo experiment, 23 F344 rats were injected with 10(7) methylcholanthrene-induced sarcoma cells. On day 7, 4 animals were perfused with 210 micrograms of murine TNF, 5 animals were perfused with 420 micrograms of murine TNF, 10 animals underwent isolated lung perfusion with 420 micrograms of human TNF, and 4 animals were injected systemically with 420 micrograms of human TNF. Animals were sacrificed on day 14 and the lung nodules counted. The cells incubated with murine TNF exhibited a 21% decrease in growth (p = 0.07); cells incubated with human TNF showed a 37% decrease in growth (p < 0.05). Animals perfused with 210 micrograms/mL of murine TNF and animals treated by systemically administered human TNF showed no tumor response. Animals perfused with 420 micrograms/mL of murine TNF had 7.8 +/- 14.2 nodules on the left lung and 58.5 +/- 66.0 nodules on the right lung (p = 0.07). Animals perfused with 420 micrograms/mL of human TNF had 21.7 +/- 18.3 nodules on the left lung and 91.7 +/- 66.2 nodules on the right lung (p < 0.01). On the basis of these findings, we conclude that isolated lung perfusion with TNF can be done safely in the rat and is effective in decreasing the growth of sarcoma lung metastases.

Animals↗
PubMed1994

A simplified method for endotracheal intubation in the rat.

Endotracheal intubation in small laboratory animals is often necessary for survival experiments. Methods of airway control have included tracheostomy, blind intubation, and intubation under direct vision. Most of these methods are unsatisfactory and associated with high failure and complication rate. We developed an easy method of endotracheal intubation in the rat that requires simple material that is easily available to any research facility. The animals were anesthetized with pentobarbital sodium, the tongue was pulled out, and an otoscope was introduced into the oropharynx. By direct vision, a guide wire was inserted into the trachea and a 16-gauge intravenous catheter was glided over the wire. The first group of 70 rats underwent left thoracotomy with endotracheal intubation and mechanical ventilation at our laboratory as part of a study on isolated lung perfusion. The second group of five rats was anesthetized with pentobarbital, and a left carotid catheter and an endotracheal tube were inserted. Animals were ventilated with 100% O2. Arterial blood gases were sampled before intubation, 30 min after ventilation, and 60 min after extubation. In the first group, 94.3% (66 of 70) of the animals survived surgery and mortality was not directly related to the intubation and/or ventilation. All five animals of the second group survived the procedure to be extubated. Arterial PO2 before intubation, 30 min after intubation and ventilation, and 60 min after extubation was 77.1 +/- 8.5, 465.0 +/- 55.6, and 98.9 +/- 12.8 Torr, respectively. PCO2 at the same time points was 42.5 +/- 10.1, 35.1 +/- 6.3, and 32.7 +/- 6.5 Torr, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗