Kepone-induced scoliosis and its histological consequences in fish.

Scoliosis in fish is caused by several diverse agents that possibly act on the central nervous system, neuromuscular junctions, or ionic metabolism. The organochlorine pesticide Kepone induces scoliosis in the sheepshead minnow. Some effects associated with Kepone-induced scoliosis in these fish are disruption of myotomal patterns, inter- and intramuscular hemorrhage, fractured centra of vertebrae, and death. The histological syndrome of Kepone poisoning in fish and the clinical syndrome in humans suggest that the nervous system is a primary target for Kepone and that scoliosis is a secondary effect of Kepone poisoning in fish.

Development of a methodology for successful multigeneration life-cycle testing of the estuarine sheepshead minnow, Cyprinodon variegatus.

Evaluation of effects on fish reproduction and development during chemical exposures lasting for multiple generations is sometimes limited by variable reproductive responses and the time required for the exposure. Established testing methods and the short life cycle of the sheepshead minnow, Cyprinodon variegatus, make this species particularly suitable for use in identifying potential impacts of contaminants in estuarine and marine environments. This study describes the refinement of life-cycle exposure methods that increased the reliability of reproduction in sheepshead minnows and reduced the time to maturation for larvae and juvenile fishes. A test of three spawning chamber designs, three sex ratios, and two photoperiods identified conditions that reduced the coefficient of variation in egg production from >100% to as little as 32%. The most reliable results were produced with groups of three female and two male fishes (all of similar size) when they were placed in a rectangular chamber and acclimated for 12 days. A test water temperature of 26.5 +/- 2 degrees C and a 14L:10D photoperiod resulted in fish producing a mean of 74 embryos per female per day, with a coefficient of variation of 31.8%. Egg fertility exceeded 90%, with a hatch rate of 95% for normal embryos (>or=80% yolk) and a hatch rate of or=2.7 cm standard length) was critical for spawning readiness. Adult fish were prepared for the spawning assessment by adding frozen brine shrimp to their diet. Results of these experiments provide methods that are of particular interest in assessment of endocrine-disrupting chemicals that are known to affect reproduction.

Delayed infection of the automatic implantable cardioverter-defibrillator. Current recognition and management.

Three cases of delayed infection of automatic implantable cardioverter-defibrillator devices without systemic manifestations are reported. Computed tomographic scan of the heart revealed fluid deep to the patch in each case. Sonication of explanted automatic implantable cardioverter-defibrillator patches facilitated the recovery of adherent microorganisms in one case. Management of this previously unrecognized problem is outlined.

Utility of CT scan evaluation for predicting pulmonary hypertension in patients with parenchymal lung disease. Medical College of Wisconsin Lung Transplant Group.

OBJECTIVE: To determine the utility of CT-determined main pulmonary artery diameter (MPAD) for predicting pulmonary hypertension (PH) in patients with parenchymal lung disease. DESIGN: Retrospective review of right-heart hemodynamic data and chest CT scans in 45 patients. SETTING: Tertiary-referral teaching hospital and VA hospital. PATIENTS: Between October 1990 and December 1995, 36 patients referred for evaluation of parenchymal lung disease or possible pulmonary vascular disease were found to have PH, as defined by mean pulmonary artery pressure (mPAP) > or =20 mm Hg. Nine control patients (mPAP <20 mm Hg) were also identified (4 from hospital records search, 5 after evaluation for possible PH). RESULTS: CT-determined MPAD was 35+/-6 mm in patients with PH and 27+/-2 mm in control subjects. In our group of patients, MPAD > or =29 mm had a sensitivity of 87%, specificity of 89%, positive predictive value (PPV) of 0.97, and positive likelihood ratio (LR) of 7.91 for predicting PH; in the subgroup of patients with parenchymal lung disease (n=28, PH and control subjects), MPAD > or =29 mm had a sensitivity of 84%, specificity of 75%, PPV of 0.95, and positive LR of 3.36 for predicting PH. The most specific findings for the presence of PH were both MPAD > or =29 mm and segmental artery-to-bronchus ratio > 1:1 in three or four lobes (specificity, 100%). There was no linear correlation between the degree of PH and MPAD (r=0.124). CONCLUSIONS: CT-determined MPAD has excellent diagnostic value for detection of PH in patients with advanced lung disease. Therefore, standard chest CT scans can be used to screen for PH as a cause of exertional limitation in patients with parenchymal lung disease. Because CT is commonly used to evaluate parenchymal lung disease, this information is readily available.

Use of computed tomography to assess mediastinal complications after median sternotomy.

Thirty computed tomographic (CT) scans from 27 patients who had undergone median sternotomy were reviewed. A control group of 15 asymptomatic patients was studied either early (within 21 days) or late (46 days to 22 years) after sternotomy. Twelve patients with symptoms ranging from sternal click to obvious mediastinitis also were studied within 30 days of sternotomy. The CT findings were correlated with the patient's clinical course. Imperfect sternal closure (sternal step-offs and gaps) was found in 10 of the 15 asymptomatic patients. Focal retrosternal fluid collections, air, and hematomas were seen in more than 75% of the asymptomatic patients. Retrosternal abscess, presternal abscess, and sternal disruption were noted in 3 symptomatic patients. Computed tomography correctly diagnosed the extent of mediastinal abscess in all patients. In the 3 patients in whom there was a discrepancy between the CT scan and the clinical findings, the scan ultimately was shown to be correct. These results indicate that computed tomography is a valuable tool in diagnosing wound problems after sternotomy because it accurately depicts the extent and depth of the wound infection.

Congestive heart failure and adult respiratory distress syndrome. New insights using computed tomography.

CT has brought new insights into our understanding of the patient with acute respiratory distress, pulmonary edema, and adult respiratory distress syndrome. This article documents some of the physiologic and imaging information gained from axial imaging of the critically ill.

Pulmonary edema and adult respiratory distress syndrome.

The pathophysiology and radiographic appearances of hydrostatic and increased permeability pulmonary edema are presented. Both typical and atypical appearances are discussed. The ability of the plain chest radiograph to differentiate between different types of edema is examined.

Computed tomography in acute cardiopulmonary disease.

This article reviews how CT will supplement or replace other diagnostic studies and evaluate patients with postoperative problems, posttraumatic problems, acute medical disorders, and iatrogenic complications.

Diagnostic imaging in acute cardiopulmonary disease.

Optimum use of portable radiography and the newer imaging modalities requires careful coordination between the radiologist and intensivist. This article discusses the current imaging approach to patients with acute pulmonary disease, acute cardiovascular disease, and postoperative and iatrogenic problems.

Spiral computed tomography in the evaluation of pulmonary embolism.

Determining the presence or absence of thromboembolic disease can often be problematic. Traditional diagnostic algorithms are reviewed and discussed. Spiral CT technology allows a relatively noninvasive visualization of the pulmonary vasculature and is a promising new diagnostic modality for acute and chronic thromboembolic disease. Its potential roles are discussed, and a new diagnostic algorithm is proposed.

Role of CT scanning in the superior vena cava syndrome.

The value of computerized tomographic (CT) studies was compared to other imaging procedures in 18 consecutive patients with the superior vena cava syndrome (SVCS) during a 47-month period. Sixteen of these cases had proved malignancy. In addition to tumor masses, CT findings included effacement, compression, and displacement of the great vessels and the presence of thrombi and collateral blood flow. Significantly, tumor was demonstrated in the region of the superior vena cava in five patients in whom a definite mass could not be diagnosed by other means. CT scanning in a sixth case revealed that although mediastinal tumor was present it was not located in the immediate region of the occluded vessels. CT was corroborative and helpful in planning therapy in all but one of the remaining patients. CT scans appear to be of most value in cases of SVCS in whom other modalities cannot demonstrate tumor and, particularly, in excluding recurrent tumor in previously treated patients.

Toxicological studies in tropical ecosystems: an ecotoxicological risk assessment of pesticide runoff in South Florida estuarine ecosystems.

A multiyear study in the C-111 canal system and associated sites in Florida Bay was undertaken to determine the potential pesticide risk that exists in South Florida. After the examination of extensive pesticide concentration data in surface water, tissues, and semipermeable membrane devices (SPMDs), canal contamination seems to be derived from the extensive agricultural production that drains into the C-111 canal. The results of this study indicate that runoff from agricultural processes led to quantifiable pesticide residues in both canal and bay surface water, which occasionally exceeded current water quality criteria. The major pesticide of concern was endosulfan, which was detected at 100% of the sites sampled. Endosulfan exposure did not cause any acute effects in fish and crustaceans deployed in field bioassays. Chronic effects were observed in copepods, clams, and oysters but could not be attributed to endosulfan exposure. The decision to alter the C-111 canal flow and allow increased freshwater flow into the adjacent Everglades National Park may result in discharges of pesticides into the Everglades. Continued monitoring in this area is needed during this change in flow regime.

Fast gradient echo magnetic resonance imaging of the normal diaphragm.

To determine the ability of fast gradient-recalled echo (GRE), breath-hold magnetic resonance imaging (MRI) to depict all regions of the diaphragm, 13 volunteers were scanned in coronal and sagittal planes. The central to anterior left hemidiaphragm and the posterior lumbar portions were each demonstrated in 12 subjects (92%). The crura were visible crossing anterior to the aorta in the sagittal plane in eight subjects (62%) and in the coronal plane in six subjects (46%). In the sagittal plane, the right crus was evident in eight subjects (62%). Muscular portions of the diaphragm in contact with the liver or body wall were less frequently discernible, and the central tendon could not be confidently resolved. Several artifacts occurred that interfered with visualization of the diaphragm. These observations indicate that many regions of the diaphragm can be seen with fast GRE, breath-hold MRI, but there are some limitations in depicting the diaphragm in its entirety.

Blastomycosis.

Blastomycosis is a relatively uncommon disease, even in its endemic region. The clinical course and symptoms are highly variable; patients may be asymptomatic or present with severe, fulminant disease. Antifungal agents are effective against pulmonary and disseminated disease, but relapses and reactivation can occur. The radiographic findings are nonspecific, and patients are often assumed to have bacterial pneumonia, malignancy, tuberculosis, or sarcoidosis before the correct diagnosis is made.

Effects of aerial thermal fog applications of fenthion on caged pink shrimp, mysids and sheepshead minnows.

Mosquito control applications of fenthion by aerial thermal fog equipment were studied at 2 sites in Collier County, FL, for sprays that occurred on June 20 and 23, 1984. Acute, lethal effects of fenthion deposited in these estuarine habitats were assessed for caged pink shrimp (Penaeus duorarum), mysids (Mysidopsis bahia) and sheepshead minnows (Cyprinodon variegatus). At Site 1, along a bay with substantial dilution and tidal mixing, fenthion concentrations of 1.5 and 0.29 micrograms/liter were measured in samples taken immediately after both sprays. Concentrations decreased to less than or equal to 0.020 microgram/liter 12 h postspray and no mortality was observed for caged pink shrimp and mysids. Site 2 was along a residential canal system that offered limited dilution and mixing. Maximum concentrations were 2.6 and 0.51 micrograms/liter and measurable concentrations (greater than 0.038 microgram/liter) of fenthion persisted at this site for 4 days. Fenthion concentrations in surface waters were toxic to caged pink shrimp and mysids after both sprays. No mortality occurred among caged sheepshead minnows at either site.

[Aortic traumatic lesion. Has tomodensitometry a role?]. / Lésion traumatique aortique. La tomodensitométrie a-t-elle un rôle?

The low positive yield from aortography in patients with suspected traumatic aortic rupture has prompted research into CT of the mediastinum as a screening investigation which could significantly reduce the number of negative angiograms performed. Much of the data published to date suggest a promising role for CT, but false negative scans have been reported and the precise false negative rate has yet to be determined. We propose an algorithm for the use of CT in suspected traumatic rupture but emphasise that continuous monitoring of outcomes and further large studies are required before CT can become an established screening technique.