Effect of age on the acute lethal response of the beagle to cobalt-60 gamma radiation.
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Biomedical subjects
Publications and source records attributed to A C Lee.
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Microvillous membrane fractions from human term placentae were prepared by differential centrifugation. Extration of membranes with PBS-EDTA or KCI removed soluble cytoplasmic components and serum proteins excepting trace amounts of albumin and transferrin. PAGE-SDS revealed 11 components in the Triton solubilized crude fraction after PBS-EDTA extraction. Membrane components solubilized with Triton were not fractionated by gel filtration on Bio-Gel A-50 m but DEAE-cellulose chromatography partially resolved these components. Three fractions were obtained by stepwise elution of absorbed materials using increasing concentrations of NaCl in the equilibrating buffer. These fractions were characterized using SDS-PAGE. The material unabsorbed to the DEAE contained two components of small molecular weight and one of them showed a positive PAS stain. The first eluted protein peak showed nine components, seven of which stained with PAS. The bulk of glycoproteins with molecular weights greater than 130 000 daltons were found in this fraction. The second eluted peak from DEAE was rich in components with molecular weights less than 42 000 daltons. Four components in this fraction were not identified in the other two ion-exchange fractions. Bands representing mobilities of albumin, transferrin and alkaline phosphatase were observed in DEAE-cellulose fractions; however, 12 components of unknown structure were revealed.
BACKGROUND: The danger of bacteremia due to contaminated platelets is not well known. There are also no established guidelines for the management of febrile reactions after platelet transfusion. STUDY DESIGN AND METHODS: To determine the risk of symptomatic bacteremia after platelet transfusion, 3584 platelet transfusions given to 161 patients after bone marrow transplantation were prospectively studied. Platelet bags were routinely refrigerated for 24 hours after transfusion. Septic work-up was initiated for a temperature rise of more than 2 degrees C above the pretransfusion value within 24 hours of platelet transfusion or a temperature rise of more than 1 degree C that was associated with chills and rigor. Diagnosis of bacteremia after platelet transfusion was made only when the pairs of isolates from the blood and the platelet bags were identical with respect to their biochemical profile, antibiotic sensitivity, serotyping, or ribotyping. RESULTS: Thirty-seven febrile reactions, as defined above, occurred. Bacteremia subsequent to platelet transfusion was diagnosed in 10 cases. There was a 27-percent chance (95% CI, 15-43%) that these febrile reactions represented bacteremia that resulted from platelet transfusion. For a subgroup of 19 patients with a temperature rise of more than 2 degrees C, the risk of bacteremia was 42 percent (95% CI, 23-64%). Septic shock occurred in 4 of the 10 bacteremic patients. A rapid diagnosis was possible because the involved bacteria were demonstrated by direct Gram stain of the samples taken from the platelet bags of all 10 patients. CONCLUSION: Significant febrile reactions after platelet transfusion are highly likely to be indicative of bacteremia. Routine retention of platelet bags for subsequent microbiologic study was useful in the investigation of these febrile reactions. Empiric antibiotic therapy is indicated.
The article describes two Chinese boys ages 2 and 3 years with unilateral Wilms' tumors complicated by intracaval and intracardiac extension. In contrast to the previously recommended treatment with surgery followed by chemotherapy and radiation therapy, the children were managed primarily with combination chemotherapy before definitive operation. Reduction of tumor size on serial imaging was documented, and no viable tumor cells were found when the involved kidney and right atrium were explored. Both patients remained alive without evidence of disease more than 5 years after initial diagnosis. A literature search revealed case reports and retrospective analyses of 70 patients with Wilms' tumors and intracardiac involvement, and a tendency toward preoperative chemotherapy with or without the addition of radiation therapy was observed. The overall outcome of this group of patients parallels the outcome of those without intracardiac extension by histology and stage. Wilms' tumor presenting with extension into the inferior vena cava and right atrium is thus rare and renders the affected child with additional cardiovascular complications and operative risks. As a result of the uncommon occurrence, a consensus on management based on prospective study would be difficult. The present report and the literature are supportive of the use of preoperative chemotherapy in the initial management of advanced Wilms' tumor extending into the right atrium.
Infection with Listeria monocytogenes is uncommon in patients receiving cytotoxic chemotherapy, and is even rarer among recipients of bone marrow transplantation. Hemosiderosis, either idiopathic or caused by transfusion, appears to be another risk factor. We report a 3-year-old Chinese girl with transfusion-dependent Diamond-Blackfan syndrome who had L. monocytogenes septicemia when she received an allogeneic bone marrow transplantation. She was treated successfully with intravenous ampicillin. Our case adds to the clinical evidence that patients with iron overload are susceptible to listeriosis, particularly when they are immunocompromised and do not receive iron-chelation treatment.
A 13-year-old girl with Plesiomonas shigelloides septicemia is reported. The infection occurred while she was receiving an allogeneic bone marrow transplantation for acute promyelocytic leukemia. Treatment with ciprofloxacin was successful. Twenty-one cases of Plesiomonas septicemia have been reported in the literature. Immunocompromised hosts, especially neonates, are commonly affected. The case mortality rate is high, with 13 of the reported patients dying of the infection. Successful treatment relies on the early identification of the organism and implementation of effective antibiotics.
A 19-year-old girl with thalassemia intermedia presented with signs of thoracic spinal cord compression secondary to extramedullary hematopoiesis. She was started on a transfusion regimen to maintain a hemoglobin level of more than 12.5 g/dL. Clinical signs disappeared within the first week and circulating erythroblastemia was completely suppressed by the second week. Magnetic resonance imaging 4 weeks after diagnosis revealed near-complete resolution of the extradural mass, followed by gradual improvement in the posterior tibial somatosensory evoked potentials. Transfusion therapy may be diagnostically and therapeutically useful in spinal cord compression secondary to extramedullary hematopoiesis, obviating the need for surgery or radiotherapy.
The thalassemias are common in Hong Kong. One of the severe forms, beta-thalassemia major, has been preventable locally by antenatal screening since 1983. Yet new patients are still being diagnosed. In this retrospective study, 34 children with severe beta-thalassemia syndromes were diagnosed in two major public hospitals between 1990 and 1996. They included one pair of identical twins and two pairs of siblings. Twenty-seven (79%) had homozygous beta-thalassemia and seven (21%) had beta E thalassemia. All but four (12%) were transfusion dependent. Fifty-five (89%) parents had been evaluated for their thalassemia status. Forty-eight had beta-thalassemia traits and seven were hemoglobin E carriers. The reasons for the birth of these children with severe beta-thalassemia syndromes were (1) late or no antenatal visit (n = 8, 24.2%), including three cross-border deliveries in which the pregnant mothers came from mainland China to Hong Kong for confinement, (2) lack of maternal screening (n = 13, 39.4%), (3) lack of paternal screening (n = 7, 21.2%), (4) parental refusal (n = 3, 9.1%), and (5) unknown (n = 2, 6.1%). These findings suggest that several factors undermine the effectiveness of antenatal screening for prevention of thalassemias. Many medical practitioners and the general public are still not aware of the screening procedures. The migration of population from mainland China to Hong Kong may result in the birth of many more children with beta-thalassemia major.
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BACKGROUND AND OBJECTIVES: A commonly used test dose in parturients receiving continuous lumbar epidural analgesia for labor consists of 3 mL of dextrose-free 1.5% lidocaine with 1:200,000 epinephrine. METHODS: of 1,962 obstetric epidural anesthetics administered over a 17-month period, unintentional subarachnoid placement of the epidural catheter was detected by injection of the test dose in five laboring patients. The characteristics of the resulting subarachnoid blocks were studied. RESULTS: After negative aspiration for cerebrospinal fluid in each case, test dose injection resulted in the rapid onset of high sensory block with associated motor and sympathetic block, accompanied by significant hypotension requiring aggressive treatment. CONCLUSIONS: While this test dose appears to be a sensitive indicator of an unexpected subarachnoid catheter, the resulting excessive spinal blocks in these laboring patients raise the question of its safety.