Estimation of transmission dynamics of the Ceratomyxa shasta actinospore to the salmonid host.

Transmission dynamics of the actinospore stage of Ceratomyxa shasta to the salmonid host were investigated under field and laboratory conditions. The number of parasites transmitted and the transmission rate were compared between 2 different exposure durations and also among different water velocities, by means of field exposures. Under laboratory conditions, the number of parasites transmitted and the transmission rates were compared across a broader range of water velocities and also at different water temperatures. Transmission rate was not constant over time as the number of parasites transmitted increased non-linearly between the 2 exposure durations. Transmission was also inversely related to water velocity and there was a threshold to transmission between 0.2-0.3 m s(-1). Lastly, transmission rate increased with water temperature up to 18 °C then decreased at 23 °C. These experiments provide a range of values of transmission that will be incorporated into an epidemiological model to simulate the effectiveness of different management strategies. Additionally, these experiments provided novel information on the effects of environmental conditions (i.e. water velocity and water temperature) on the transmission dynamics between the salmonid host and the actinospore stage.

Accurate demonstration of hepatic infarction in liver transplant recipients.

Serial HIDA scanning has proven to be a valuable tool in the postoperative management of liver transplant patients. Previous reports have documented its efficacy in detecting biliary leakage, abscess, and rejection. We have also found HIDA scanning to be a sensitive method for detecting early hepatic infarction before ultrasonographic changes occur. Two cases are presented to demonstrate the characteristic findings seen with hepatic infarctions.

The role of liver biopsy in evaluating acute allograft dysfunction following liver transplantation: a clinical histologic correlation of 34 liver transplants.

One hundred six liver biopsy specimens from 34 orthotopic liver transplant (OLT) patients were examined and the histologic findings correlated with the clinical course of the patients to determine if specific morphologic patterns were associated with specific causes of acute allograft dysfunction. The principle causes of allograft injury in these patients appeared to be acute rejection and ischemic injury, with rarer cases of viral infection and biliary obstruction. Graft rejection causing transient liver dysfunction was associated with a mixed inflammatory infiltrate in the portal tracts and involving the interlobular bile ducts. Rejection resulting in severe, persistent dysfunction was associated with destruction and loss of the interlobular bile ducts or portal inflammation, followed by acute centrilobular hepatocyte necrosis. Ischemic liver injury was characterized by hepatocyte ballooning and/or hepatocyte necrosis. Ischemic injury causing transient graft dysfunction demonstrated focal, limited areas of hepatocyte necrosis or transient centrilobular hepatocyte ballooning. Severe ischemic injury resulting in persistent dysfunction caused diffuse hepatocyte necrosis or centrilobular ballooning followed by centrilobular hepatocyte loss and severe cholestasis with evidence of bile duct epithelial injury. The histologic patterns observed were not pathognomonic; radiologic studies, bile cultures, and other laboratory tests were necessary to rule out biliary or vascular obstruction and bacterial cholangitis. However, liver biopsies, especially serial biopsies, were helpful in suggesting the probable cause of liver dysfunction and in predicting subsequent allograft recovery or failure.

Respiratory distress due to minocycline-induced pulmonary lupus.

Minoeycline, a semisynthetic tetracycline, is often used to treat acne and rheumatoid arthritis. It has been considered an unlikely drug to be associated with systemic lupus erythematosus; however, many cases of drug-induced lupus related to minocycline have been reported. Some of those reports included pulmonary lupus, but none of the patients described developed respiratory distress. We describe a patient treated with minocycline for 2 years who presented with progressive dyspnea, severe hypoxia, and pulmonary infiltrates necessitating hospitalization and oxygen supplementation.

Central pontine myelinolysis and pregnancy.

Central pontine myelinolysis, also known as osmotic demyelination syndrome, is an uncommon disorder associated with rapid correction of severe hyponatremia. We present the case of a healthy young pregnant woman with hyperemesis gravidarum who developed severe hyponatremia (serum sodium 103 mEq/L). After rapid correction of her serum sodium within 12-15 hours with a 0.9% saline solution, the patient became comatose and died of sepsis and respiratory failure. Examination of the brain showed extensive demyelination in both pontine and extrapontine areas.

Controversies in thyroid function testing.

Thyroid function tests can be abnormal in certain patients in the absence of thyroid dysfunction. All thyroid function tests can be affected in these patients, including the free thyroxine assays and free thyroxine index. Familiarity with the conditions affecting thyroid function tests is necessary to avoid incorrect diagnosis and unnecessary testing.

Triclonal gammopathy in a patient with plasma cell dyscrasia.

A triclonal gammopathy is an immunoglobulin abnormality in which three discrete monoclonal subpopulations of immunoglobulin molecules are present in a patient's serum. Monoclonal and biclonal gammopathies have been studied extensively, but relatively little is known about the much rarer triclonal gammopathies. The case described below illustrates some of the difficulties that this condition can present to the clinician and the clinical laboratory.

Cytogenetic evidence of clonality in a case of pigmented villonodular synovitis.

Pigmented villonodular synovitis is an uncommon benign lesion that is characterized by diffuse synovial proliferation. Based on animal models, this lesion has been conjectured previously to be reactive in nature. In this report, the authors present the histologic and cytogenetic findings for a pigmented villonodular synovitis that was excised from the right knee of a 47-year-old man. Trisomy 7 was observed in 24 of 75 (35%) metaphases obtained from short-term culture of cells from this tumor. These findings suggest that some cases of pigmented villonodular synovitis represent clonal, neoplastic proliferations.

The intracellular polymerase chain reaction for small CMV genomic sequences within heavily infected cellular sections.

The indirect intracellular polymerase chain reaction (in situ PCR) combines the potential sensitivity of the polymerase chain reaction (PCR) with the high specificity and morphological preservation of in situ hybridization (ISH). This study describes a method for the amplification of small, specific cytomegalovirus (CMV) genomic sequences [100 base pairs (bp)] within large formalin-fixed, paraffin-embedded tissue sections. A heat-resistant glue surrounds the section, creating a well which contains a relatively large volume of isotonic reaction solution without a covering mineral oil layer; this optimizes morphological preservation, permits the evaluation of large sections, and allows both denaturation steps and up to 40 cycles of in situ PCR to be performed, whilst progressively concentrating the reaction solution by evaporation during thermal cycling. ISH was performed using a non-isotopic DNA probe with specificity for CMV, with or without prior in situ PCR amplification, both for samples on slides (fibroblasts and lung) and in suspension (fibroblasts). Samples on slides were evaluated by both blinded studies and image analysis, comparing the intensity of signal (P < 0.003) and the numbers of positive cells detected (P < 0.007), with or without intracellular amplification. Cells in suspension were analysed by blinded studies on cytospins and by gel electrophoresis of cell lysates. Successful intracellular amplification was achieved in this high copy model.