A reliable, efficient, microinjection apparatus and methodology for the in vivo exposure of rainbow trout and salmon embryos to chemical carcinogens.

A modular apparatus and technique for the injection of salmonid fish embryos with chemical carcinogens are described. A key feature of the methodology is the relative ease of routine through-the-eggshell injection, into the yolk sac of living salmonid fish embryos, inside the "eyed-stage" egg. The procedure is sufficiently rapid that 2 persons working as a team can give injections to 200 embryos per hour. The injection per se induces low mortality, i.e., optimal net survival rates (controls given an injection of dimethyl sulfoxide vs. those not given an injection) in the range of 70-90%. Because only small amounts of chemical are handled in relatively dilute form, the exposure method poses low risks to both the experimentalist and the environment. Preliminary results in a test of 4 carcinogens that differed widely in their structures and requirements for metabolic activation indicated that hepatocellular neoplasms were induced in rainbow trout (Salmo gairdneri) in response to 100 ng aflatoxin B1 (CAS: 1162-65-8)/egg, 1 microgram N-methyl-N'-nitro-N-nitrosoguanidine (CAS: 70-25-7)/egg, and 10 micrograms benzo[a]pyrene (CAS: 50-32-8)/egg. Nine months after exposure, liver neoplasms were observed in 25, 21, and 9%, respectively, of the rainbow trout, but no neoplasms were observed in rainbow trout exposed to 100 micrograms dimethylnitrosamine (CAS: 62-75-9)/egg. Liver neoplasms were also induced in 17% of coho salmon (Oncorhynchus kisutch) given an injection as embryos of 90 ng aflatoxin B1/egg or 5 micrograms N-methyl-N'-nitro-N-nitrosoguanidine/egg.

Epizootic neoplasms in fishes from a lake polluted by copper mining wastes.

Examination of fishes from Torch Lake, Houghton County, Mich., revealed epizootic neoplasms of several types in two closely related species. Saugers, Stizostedion canadense, and walleyes, Stizostedion vitreum, were commonly affected with hepatocellular carcinomas, dermal ossifying fibromas, and perivisceral masses resembling mesotheliomas that were usually associated with the mesenteric capsule of the spleen. Saugers were 100% affected with liver neoplasms. Histopathologic and ultrastructural aspects of the neoplasms are described. Torch Lake has been used as a repository for copper mining waste to the extent that an estimated 20% of the original volume has been filled in by these materials. Several direct and indirect etiologic roles for the mine waste as causative agents of the fish tumors are discussed.

32P-postlabeling analysis of aromatic DNA adducts in fish from polluted areas.

Brown bullheads (Ictalurus nebulosus) were sampled from sites in the Buffalo and Detroit Rivers where fish are exposed to high levels of sediment bound polycyclic aromatic hydrocarbons, and suffer from an elevated frequency of liver cancer. DNA was isolated from the livers of these wild fish and from control specimens which were raised in clean aquariums. DNA was enzymatically digested to normal and adducted nucleotides, and hydrophobic/bulky adducts were enriched in the digests either by preparative reverse-phase high-pressure liquid chromatography, or selective nuclease P1 dephosphorylation of normal nucleotides. Aromatic DNA-carcinogen adducts were then quantitated using 32P-postlabeling analysis. Using both adduct enrichment procedures, chromatograms derived from DNA of fish from polluted areas showed a diffuse diagonal radioactive zone not present in DNA from aquarium raised fish. The diagonal zone appeared to consist at least in part of multiple overlapping discrete adduct spots which could be partially separated by gradient high-pressure liquid chromatography prior to 32P-postlabeling analysis, and most of which were more strongly retained on a reverse-phase column than the major benzo(a)pyrene-DNA adduct. The behavior of the adducts in the diagonal radioactive zone and of their unlabeled precursors is consistent with their identification as nucleotide adducts of a variety of bulky hydrophobic aromatic environmental compounds. Total pollution-related adduct levels as analyzed by HPLC adduct enrichment and 32P-postlabeling were 70.1 +/- 29 (SD) nmol/mol normal nucleotide in fish from the Buffalo River, and 52 and 56 nmol/mol for two specimens from the Detroit River.

Attendances at a field hospital emergency department during operations in Iraq November 2003 to March 2004 (Operation Telic III).

OBJECTIVE: This study investigated the types of presentations; time lines and disposal of patients from the international, local and military community in Southern Iraq. METHODS: All presentations to the Emergency Department (ED) were clinically and demographically coded and entered onto an electronic database. RESULTS: During the period studied the emergency department dealt with 1455 new presentations of which 75% were UK Armed Forces personnel. CONCLUSIONS: This represented a busy period in the field hospitals time in Iraq and offered valuable training to emergency medicine trainees in an unusual environment.

Substituted ferrocenes and iodine as synergistic thermoelectrochemical heat harvesting redox couples in ionic liquids.

Combining ferrocene and iodine results in enhanced thermoelectrochemical (or thermogalvanic) waste heat harvesting abilities, for both the Seebeck coefficient and the overall power output. All systems displayed a mixture of ferrocene, ferrocenium, iodine and triiodide. The observed enhancement correlates with lower electron-density on the ferrocene; the synergistic improvement observed for mixtures of substituted ferrocenes and iodine is attributed to the formation of charge-transfer complexes. Combining dibutanoylferrocene and iodine resulted in the highest Seebeck coefficient of 1.67 mV K(-1).

Facile, room-temperature pre-treatment of rice husks with tetrabutylphosphonium hydroxide: Enhanced enzymatic and acid hydrolysis yields.

Aqueous solutions of tetrabutylphosphonium hydroxide have been evaluated as pretreatment media for rice husks, prior to sulphuric acid hydrolysis or cellulase enzymatic hydrolysis. Varying the water:tetrabutylphosphonium hydroxide ratio varied the rate of delignification, as well as silica, lignin and cellulose solubility. Pre-treatment with 60wt% hydroxide dissolved the rice husk and the regenerated material was thus heavily disrupted. Sulphuric acid hydrolysis of 60wt%-treated samples yielded the highest amount of glucose per gram of rice husk. Solutions with good lignin and silica solubility but only moderate to negligible cellulose solubility (10-40wt% hydroxide) were equally effective as pre-treatment media for both acid and enzymatic hydrolysis. However, pre-treatment with 60wt% hydroxide solutions was incompatible with downstream enzymatic hydrolysis. This was due to significant incorporation of phosphonium species in the regenerated biomass, which significantly inhibited the activity of the cellulase enzymes.

Carcinogens and cancers in freshwater fishes.

Epizootics of neoplasms in freshwater fish species are considered in relation to circumstantial and experimental evidence that suggest that some epizootics of neoplasia of hepatocellular, cholangiocellular, epidermal, and oral epithelial origin may be causally related to contaminant exposure. Although there is concern for the safety of consuming fish affected with neoplasms, this concern may be misdirected as direct transmission of cancer by ingesting cancerous tissue would seem unlikely. Of greater concern is the matter of toxic and cancer-causing chemicals present in edible fish that exhibit neoplasia as a symptom of past exposure via residence in a polluted waterway. There is ample evidence to suggest that contaminant chemicals ingested via contaminated Great Lakes fish may already be affecting both human and ecosystem health, but these effects are subtle and may require new approaches to the study of the affected systems.

Computed tomography-assisted management of splenic trauma.

BACKGROUND: In patients who have suffered an injury to the spleen, preservation of the organ is of the utmost importance. To assist in management, contrast-enhanced computed tomography (CT) has been used. We reviewed our experience with a protocol for nonoperative management of splenic trauma based on CT grading of the injury. METHODS: During the initial period of the study, 50 CT examinations for blunt abdominal trauma in adults were reviewed by staff radiologists for evidence of splenic injury. The radiologists, blinded to clinical management decisions, graded the CT studies as "A" if there was a subcapsular hematoma or capsular disruption, "B" if there was a parenchymal injury not extending into the hilum, or "C" if there was deep laceration of fracture of the hilum. Following confirmation of the accuracy and reproducibility of the grading scale, the splenic trauma management protocol was instituted, in which nonhilar injuries were managed nonoperatively. RESULTS: In the initial assessment, patients managed nonoperatively had shorter hospital stays and received fewer blood transfusions than those undergoing operation. Among 30 patients subsequently enrolled in the protocol, those treated nonoperatively remained in the hospital for fewer days than those treated surgically. Again, fewer units of blood and platelets were used in the nonoperative group. Institution of the protocol decreased the incidence of celiotomy. CONCLUSIONS: The severity of splenic trauma evident on CT staging guides safe nonoperative management. Patients not suffering injury to the splenic hilum (A and B scores) can be managed without operation, resulting in shorter hospital stays and fewer blood products used.

The significance of needle placement site in acupuncture.

Traditional acupuncturists claim that correct needling of classical acupuncture loci is associated with a characteristic set of sensations usually referred to as 'Teh Chi'. The studies reported here examine this claim. In the first a multiple adjective sensation rating scale was developed and administered to 125 patients receiving acupuncture treatment. The results were subjected to principal components analysis and the first factor to emerge provided some support for the constellation of sensations corresponding to Teh Chi. In the second study the scale was used in a randomised controlled mixed single/double blind experiment in which 65 volunteers were stimulated at three classical and three non-classical (sham) needling sites by either a trained acupuncturist (single blind) or an anaesthetist (double blind). The results of the second study did not support the contention that the sensations of Teh Chi occur more frequently at classical acupuncture needling sites. The implications of the results for the practice of acupuncture are discussed.

The use of Foley balloon catheters in cardiac surgery.

Situations may arise during elective and emergency surgery when vascular control is required but conventional vascular clamps cannot be used. We have found the Foley catheter useful for the control of inadvertent perforation of the heart especially in "redo" operations. We describe the use of the Foley catheter for the control of the difficult aorta and illustrate its potential versatility in a variety of uncommon situations. As Foley catheters are present in every operating theatre we hope that our experience will be of benefit to other surgeons who encounter similar problems.

Subcapsular hematoma as a predictor of delayed splenic rupture.

Over the past 46 months at a level I trauma center, 966 computed tomography (CT) scans were performed for blunt abdominal trauma. Eighty-three (8.6%) demonstrated splenic injury, and 31 (3.2%) of these showed a subcapsular hematoma with or without associated parenchymal damage. Of the 31 patients, 23 were managed conservatively, based initially upon surgeons' preference (14 patients) and after March 1990 to conform to the authors' splenic trauma protocol (nine patients). The eight patients operated upon were hemodynamically stable and all underwent splenectomy. Subcapsular hematoma, as diagnosed by preoperative CT scan, was confirmed in each of the eight celiotomies. Parenchymal involvement, which had also been identified in these eight patients by CT, was evident at operation in all, and hilar involvement occurred in three. None of the 23 observed patients developed delayed splenic rupture. All were discharged home with outpatient follow-up in surgical clinic to at least 1 month without further complication. The authors came to the following conclusions: 1) Subcapsular hematoma is neither a predictor for delayed splenic rupture, nor by itself an indication for operative management of the injured spleen in the hemodynamically stable patient; 2) Degree of parenchymal injury based on CT morphology, specifically hilar involvement, signifies the need for laparotomy with splenectomy; 3) Splenorrhaphy has a reduced role in splenic trauma because most injuries now operated upon are severe.

32P-postlabeling detection of DNA adducts in fish from chemically contaminated waterways.

Fish were collected from sites in the chemically-contaminated Buffalo River, New York, and the Detroit River, Michigan. The sediments of these rivers have high levels of chemical contaminants, including polycyclic aromatic hydrocarbons (PAHs), and fish from these locations have high prevalences of liver cancer. To determine chemical-DNA interactions and a possible role for chemicals as a cause of the observed tumors, DNA was isolated from livers and was enzymatically digested to normal and adducted nucleotides. The DNA digests were enriched for hydrophobic, bulky adducts, either by preparative reverse phase high pressure liquid chromatography, or by selective nuclease P1 dephosphorylation of normal nucleotides. DNA-chemical adducts were then quantitated by 32P-postlabeling analysis. Regardless of the adduct enrichment procedure, the chromatograms derived from DNA of fish from polluted areas showed a diffuse, diagonal radioactive zone consisting, at least in part, of multiple overlapping discrete adduct spots. The behavior of the adducts in the diagonal radioactive zone and of their unlabeled precursors is consistent with their identification as nucleotide adducts of a variety of bulky, hydrophobic, aromatic genotoxic compounds. Analysis of bile demonstrated recent exposure to multi-ringed aromatic compounds.

Appropriate use of helicopters to transport trauma patients from incident scene to hospital in the United Kingdom: an algorithm.

A simple algorithm has been produced to assist front line ground ambulance personnel, air ambulance crews, and immediate care doctors attending trauma patients in selecting the most appropriate mode of transport from the incident scene to hospital.

Combined coronary artery bypass surgery and abdominal aortic aneurysm repair.

The proper management of patients with asymptomatic abdominal aortic aneurysms and significant coexistent coronary artery disease is still debatable. The most common approach has been to perform the coronary artery bypass surgery some weeks before the abdominal aortic aneurysm repair in the hope of reducing the cardiac morbidity and mortality. We report our initial experience of three consecutive elective cases where the coronary artery bypass surgery and the abdominal aortic aneurysm repair were performed at one operation by the same operating surgeon.