Biomedical subjects
Publications and source records attributed to H M Ross.
Tracheal laceration is a rare but potentially devastating complication of endotracheal intubation. Traditional management of intubation-related tracheal laceration is operative. Nonoperative management of a woman noted to have a tracheal laceration during intubation is described. Criteria by which nonoperative treatment can be considered are outlined.
BACKGROUND: A model of isolated single-lung perfusion in the rat has been established in our laboratory to study the chemotherapeutic treatment of pulmonary metastases. A sequential bilateral isolated lung perfusion model was designed to investigate the feasibility of staged perfusions in the rat. METHODS: Twenty-four Fischer rats were randomized into three experimental groups of 8 rats each. All rats underwent left isolated lung perfusion. One, 2, or 3 weeks later, the rats in groups I, II, and III, respectively, underwent contralateral (right) perfusion. Five control animals (group IV) underwent sequential bilateral sham thoracotomies 1 week apart. Arterial blood gas analysis was performed 1 week after the second operation in the rats in groups I and IV. RESULTS: All animals survived the first operation, with 100% (8/8), 75% (6/8), and 100% (8/8) of the animals in perfusion groups I, II, and III, respectively, surviving the second operation. All control animals (group IV) survived the second sham thoracotomy. Arterial blood gas analysis did not show a significant difference in the oxygen or carbon dioxide partial pressure or the pH between group I and IV (p = 0.32, 0.96, and 0.76, respectively). CONCLUSIONS: Our experiments demonstrate that sequential bilateral isolated lung perfusion is safe in and well tolerated by the rat. This model can be used to investigate the safety and efficacy of staged perfusions with chemotherapeutic agents in the treatment of bilateral pulmonary metastases in the rat.
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.
Phenotypic and phylogenetic studies were performed with three strains of a catalase-positive, gram-positive, coccus-shaped bacterium isolated from otters. The results of a 16S rRNA gene sequence analysis demonstrated that these strains represent a hitherto unknown subline within the genus Staphylococcus. Based on the results of the phylogenetic analysis and phenotypic criteria, we propose that these bacteria should be classified as members of a new species, Staphylococcus lutrae. The type strain of S. lutrae is DSM 10244.
BACKGROUND: Nationally, the results of pancreaticoduodenectomy for adenocarcinoma of the pancreas have improved. Therefore, we examined our experience with this operation. METHODS: A retrospective review of tumor registry data from four greater Hartford, Connecticut, hospitals identified 51 patients who underwent pancreaticoduodenectomy for adenocarcinoma of the head of the pancreas between 1982 and 1992. RESULTS: The 30-day operative mortality rate for the group was 4%. Life table survival analysis revealed a five-year survival rate of 15% and a median survival of 15 months. Twelve patients had postoperative radiation therapy and chemotherapy. The median survival in this group was 36 months, significantly longer than that of the nonadjuvant therapy group (13 months, P < .02). No difference in operative mortality or ultimate survival was seen between the hospital with the largest experience and the three other hospitals. CONCLUSIONS: Pancreaticoduodenectomy can be performed safely at hospitals with relatively low pancreaticoduodenectomy volume. Survival rates are longer than in past reviews.
DNA immunization has been shown to elicit both antibody and CTL responses against antigens expressed by infectious organisms. Because CTL responses have been implicated in rejection of cancer, we investigated whether DNA immunization by particle bombardment using a gene gun could induce CTL responses that were capable of rejecting tumors in mice. DNA immunization by particle bombardment using genes encoding beta-galactosidase and ovalbumin primed mice to generate CTLs in two genetic backgrounds (DBA/2 and C57BL/6 strains, respectively). DNA immunization was more potent in inducing CTLs than immunization with an optimized regimen of ovalbumin peptide plus immune adjuvant. Immunity induced by DNA immunization protected mice against s.c. challenge with tumors expressing the beta-galactosidase antigen. Tumors were rejected even when DNA immunization was started 3 or 7 days after tumor challenge as tumors were becoming established. Tumor rejection required CD8(+) T cells, confirming a role for CTLs in vivo. These studies show that DNA immunization by particle bombardment can efficiently induce CTL responses that are capable of rejecting even established tumors.
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Brucella organisms which differed from the recognised species of the genus, were isolated from nine seals, eight cetaceans and one otter. A method is described for the isolation of Brucella species from sea mammals and the first isolations of Brucella species are recorded from an Atlantic white-sided dolphin (Lagenorhynchus acutus), two striped dolphins (Stenella coeuleoalba), a hooded seal (Cystophora cristata), a grey seal (Halichoerus grypus) and a European otter (Lutra lutra). There were differences in the culture media required for the primary isolation of the organisms and in their dependency on carbon dioxide, Subcutaneous lesions, when present, always yielded a confluent growth. The organisms were isolated from seven of 14 spleen samples and also from the mammary glands, uterus, testes and blood and the mandibular, gastric, iliac, sub-lumbar and colorectal lymph nodes.
OBJECTIVE: Isolated lung perfusion allows the delivery of high-dose chemotherapy to the perfused lung and is an efficacious modality in the treatment of pulmonary metastases in the rat. Melphalan activity in this model was investigated. METHODS: TOXICITY STUDY: Maximum tolerated dose of melphalan delivered by means of isolated lung perfusion was determined by survival after contralateral pneumonectomy. PHARMACOKINETICS STUDY: Nineteen rats were treated with melphalan administered either by isolated lung perfusion (2 mg) or intravenously (2 mg or 1 mg). Lung, pulmonary effluent, and serum melphalan were analyzed by high-pressure liquid chromatography. EFFICACY STUDY: On day 0, 41 rats received an intravenous injection of 5 x 10(6) methylcholanthrene induced sarcoma cells. On day 7, rats either received intravenous melphalan (2 mg [n = 10]; 1 mg [n = 8]) or underwent left isolated lung perfusion with 2 mg of melphalan (n = 12). Isolated lung perfusion with buffered hetastarch in sodium chloride (Hespan, n = 11) was used as control. On day 14, pulmonary nodules were counted. RESULTS TOXICITY: Maximum tolerated dose of melphalan delivered buy means of isolated lung perfusion was 2 mg. PHARMACOKINETICS: Left lung melphalan level was significantly higher in the isolated lung perfusion group (62.2 +/- 34.3 microg/gm lung) than in the intravenous treatment groups (6.9 +/- 1.9 microg/gm lung and 3.3 +/- 0.9 microg/gm lung, respectively) (p = 0.0002). EFFICACY: Significantly fewer left lung nodules were found in animals receiving melphalan by means of isolated lung perfusion (7 +/- 10) than in the groups receiving intravenous melphalan (60 +/- 21) or buffered hetastarch by isolated lung perfusion (84 +/- 52) (p = 0.01 and p = 0.0001, respectively). CONCLUSION: Isolated lung perfusion with melphalan is safe and effective in the treatment of pulmonary sarcoma metastases in the rat.
OBJECTIVES: Body weight is regulated by the balance between energy intake and energy expenditure, but the influence of HIV infection on energy balance has not been fully examined. The main objectives of this study were (1) to assess the effect of HIV on energy balance, (2) to examine the relationship of parameters of immunodeficiency to energy balance, and (3) to examine the interrelationship of different components of energy balance in asymptomatic HIV-seropositive men. DESIGN: A cross-sectional study of nutrition and metabolism in asymptomatic HIV-seropositive men METHODS: Components of energy balance were examined in 104 asymptomatic HIV-seropositive men (CD4 count 4-482 x 10(6)/l) and 57 age-matched HIV-seronegative male controls. Energy and protein intake were measured using 5-day diaries, and small bowel absorption and permeability was assessed using four sugar probes. Resting energy expenditure was calculated from indirect calorimetry and nitrogen loss estimated from 24 h urine collection. Four methods were used to assess the effect of HIV infection on body composition (anthropometry, dual energy X-ray absorptiometry, bioelectrical impedance and 24 h urine creatinine). RESULTS: Resting energy expenditure per kilogram of fat-free mass was raised (P < 0.0001), fat mass was decreased (P = 0.001), fat-free mass was increased (P = 0.05), energy intake was higher (P = 0.05), absorption of L-rhamnose (P = 0.01) and 3-O-methyl-D-glucose was decreased (P = 0.003), and small bowel permeability was increased (P < 0.0001) in HIV-seropositive men compared with HIV-seronegative controls. HIV-seropositive subjects with a CD4 count less than 100 x 10(6)/l had decreased absorption of L-rhamnose (P < 0.05), D-xylose (P < 0.05) and 3-O-methyl-D glucose (P < 0.05) compared with HIV-seropositive subjects at higher CD4 counts, and had a similar resting energy expenditure to HIV-seronegative controls. Protein intake, carbohydrate, fat and protein oxidation. 24 h nitrogen excretion and appendicular muscle mass were similar in HIV-seropositive men and controls. CONCLUSION: HIV infection exerts a direct effect on parameters of energy balance that varies with the severity of immunosuppression.
OBJECTIVE: The metabolic response to AIDS-defining opportunistic infections was examined to provide a logical basis for the management of associated weight loss. DESIGN: A prospective study of metabolism in AIDS. SETTING: HIV outpatients' department and wards at the Chelsea and Westminster Hospital, London. PATIENTS: Ten asymptomatic Centers for Disease Control and Prevention stage II HIV-seropositive control subjects and 36 HIV-seropositive patients with a single newly diagnosed and untreated opportunistic infection [10 with microsporidial or cryptosporidial diarrhoea, 10 with Pneumocystis carinii pneumonia, nine with cytomegalovirus enteritis and seven with systemic Mycobacterium avium-intracellulare]. MAIN OUTCOME MEASUREMENTS: Subjects had measurements of resting energy expenditure using indirect calorimetry and of body composition using dual energy X-ray absorptiometry. RESULTS: Subjects with protozoal diarrhoea had a decreased resting energy expenditure (P < 0.05) and decreased body fat (P < 0.01). Subjects with P. carinii pneumonia had an elevated resting energy expenditure (P < 0.05). Subjects with systemic M. avium-intracellulare had an elevated resting energy expenditure (P < 0.05) and decreased skeletal muscle mass (P < 0.05). Subjects with cytomegalovirus enteritis had a non-significant elevation of resting energy expenditure with a non-significant loss of both fat and lean tissue. CONCLUSION: Subjects with protozoal diarrhoea show a starvation response to infection and subjects with systemic M. avium-intracellulare show a cachectic response. Since there is a variation in the metabolic response to opportunistic infection in AIDS patients, nutritional management should be directed according to the specific cause.
We performed phenotypic and phylogenetic studies of a gram-negative, rod-shaped bacterium isolated from cetaceans. The results of a 16S rRNA gene sequence analysis demonstrated that this bacterium represents a previously unknown line of descent in the family Pasteurellaceae. On the basis of the results of our phylogenetic analysis and phenotypic criteria, we propose that this organism should be classified as a new species, Actinobacillus delphinicola sp. nov. The type strain of A. delphinicola sp. nov. is strain NCTC 12870.
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Phenotypic and phylogenetic studies were performed on a Gram-negative obligately anaerobic rod-shaped bacterium isolated from two sea mammals. 16S rRNA gene sequence analysis demonstrated the bacterium represents a hitherto unknown line of descent peripherally associated to the fusobacteria and low G+C relatives. Based on the result of the phylogenetic analysis and phenotypic criteria, it is proposed that the bacterium should be assigned to a new genus, Cetobacterium ceti gen. nov., sp. nov. The type strain of Cetobacterium ceti sp. nov. is NCFB 3026.
The organochlorine (OC) residues, chlorobiphenyls (CBs), DDT and its metabolites, dieldrin, hexachlorobenzene and technical chlordane mixtures have been determined in the blubber of harbour porpoise and bottlenose dolphins from around the north and east coasts of Scotland as a result of strandings and bycatches between 1988 and 1991. The concentrations of OCs range from some of the lowest values reported at 280 micrograms kg-1 for t-CBs, 145 micrograms kg-1 for t-DDT and 71 micrograms kg-1 for dieldrin to some of the highest values, 23,000 micrograms kg-1 for t-CBs, and 10,200 micrograms kg-1 for t-DDT. OC levels were correlated with the age and sex of the sample of harbour porpoise and bottlenose dolphins from the Moray Firth area. The study confirms that the concentration of these compounds is highly dependent on co-factors of age and sex, and that data from single or small numbers of animals may be of limited value in comparing information on organochlorine residues in mammals within or between regions.
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