Arterial occlusions in neonates: use of fibrinolytic therapy

For neonates with ischemia of an extremity or extensive thrombosis of the aorta after umbilical artery catheterization, prompt recognition and management decisions are necessary. The cases of eight infants with symptomatic thrombosis who were treated with fibrinolytic agents were retrospectively reviewed to study means of diagnosis and response to therapy. Peripheral thrombosis was seen in two otherwise healthy infants; fibrinolytic therapy produced complete lysis in one and partial lysis in the other. The six infants with central thrombosis presented with low Apgar scores and multiple clinical problems; umbilical catheters were already in place. To assess the clot, real-time sonography was performed in all six patients, and umbilical arteriograms were obtained in five. Fibrinolytic therapy produced complete lysis of clot in five of the six infants. The one death occurred in a premature infant in whom a large intracranial hemorrhage developed 6 hours after institution of therapy.     

Gastric adenocarcinoma: CT versus surgical staging

Seventy-five patients with gastric carcinoma underwent preoperative staging with computed tomography (CT). In 14 patients, CT failed to demonstrate lymphadenopathy despite the presence of malignant lymph nodes at surgery. In 13 patients, CT demonstrated enlarged nodes, but no malignant involvement was found at surgery. Although spread to the pancreas was correctly predicted in three patients with lack of fat plane between tumor and pancreas, five patients lacking a fat plane had no invasion, whereas eight patients with an intact fat plane had invasion. Thirty-five patients (47%) were incorrectly staged with CT:23 (31%) were understaged and 12 (16%) were overstaged. CT does not accurately display the true extent of disease in patients with gastric carcinoma and therefore should not be used routinely for staging.     

Epstein-Barr virus-associated hemophagocytic syndrome: virological and immunopathological studies

The virus-associated hemophagocytic syndrome (VAHS) is a disorder characterized by a benign, generalized histiocytic proliferation, with marked hemophagocytosis associated with systemic viral infections. We have studied the virological and immunopathological events occurring in two children experiencing Epstein-Barr VAHS. Neither of the patients had an underlying immunodeficiency and both recovered from their disease and are completely well one year after follow-up. In each patient, evidence for primary Epstein-Barr virus (EBV) infection was documented with a typical humoral immune response, including IgM antibody directed against virus capsid antigen. EBV was demonstrated in lymphoreticular tissues by electron microscopy and molecular hybridization studies. Permissive EBV infection was suggested by the finding of mature virus particles and linear viral DNA in lymphoreticular tissues. Immunopathological studies demonstrated complete effacement of lymph node architecture by a marked proliferation of immunoblasts in patient 1 and infiltration and effacement of the lymph node architecture with benign-appearing histiocytes in patient 2. Atypical lymphocytes characteristic of acute EBV infection were notably absent in the peripheral blood of both patients and cytotoxic T cells, which normally lyse EBV-infected B cells, were also absent from the peripheral circulation. Our observations suggest that EBV-induced VAHS may be the result of an increased virus burden in the face of immunoregulatory cell imbalances.     

Real-time magnetic resonance with physiologic monitoring for improved scan localization.

Imaging of the coronary arteries at diagnostic resolutions is made difficult due to cardiac and respiratory motion during data acquisition. Cardiac gating and respiratory gating or breath holding are effective ways to reduce the effects of motion. The optimal cardiac and respiratory timings vary widely across individuals. This work presents a real-time magnetic resonance imaging approach with physiologic monitoring that can be used to predict the optimal timings on a subject-by-subject basis during a brief real-time prescan. The feasibility of this approach at determining the optimal cardiac trigger delay and respiratory phase is demonstrated.     

Characteristics and responses of EBV immortalized B cells from periodontal disease patients

OBJECTIVE: This study was designed to examine human B cell responses to Actinobacillus actinomycetemcomitans (Aa). The general hypothesis to be tested was that Epstein-Barr virus (EBV) immortalized B cells could be used to investigate variations in B cell responsiveness of periodontitis patients to periodontal pathogens, and that B cells derived from the peripheral blood of periodontal disease patients infected with Aa demonstrate differences in in vitro activities compared to periodontally healthy subjects. DESIGN: EBV-transformed B celt lines were used to analyze immunoglobulin and Aa-specific antibody responses, as well as to determine the frequencies of cells producing immunoglobulin (Ig) of a specific isotype and detect clones secreting antibodies specific for Aa. Lymphoblastoid cells lines (LCL) were derived by clonal transformation of peripheral blood lymphocytes from 10 Aa-infected patients with adult periodontitis (Aa-AP) and seven normal subjects. METHODS: The B cells were incubated in Aa-coated polystyrene plates to separate adherent and non-adherent cells, and stimulate the cells with the whole bacteria. In addition, the B cells were stimulated with Aa LPS, E.coli LPS, or the polyclonal B cell activators (PBAs), poke weed mitogen (PWM) and Staphylococcus aureus protein A (SpA). Both adherent and non-adherent cell populations were cultured for up to 15 days. MAIN OUTCOME MEASURE: Total immunoglobulins (Igs) and antibody (IgG, IgA, IgM) levels to Aa in the culture supernatants were assessed using an ELISA. The distribution of IgG, IgA, IgM and Aa-specific antibody producing cells was analyzed by a double immunoenzymatic staining technique. RESULTS: IgM levels produced by the LCLs were significantly increased vs IgG and IgA (P < 0.001). Three days after Aa stimulation, a marked increase in the level of total Igs and Aa-specific antibody was observed in adherent cells from Aa-AP (P < 0.05-0.03).Aa-specific antibody levels were significantly higher in the supernatants from Aa-AP vs normals throughout the culture interval (P < 0.03). There was also a significant increase in Aa-specific antibody levels after stimulation with Aa LPS or E.coli LPS (P < 0.05), whereas PWM and SpA had no significant effect on antibody to Aa. There was a predominance of IgM cells compared to IgG and IgA isotypes (P < 0.04) in LCLs from Aa-infected patientS. After stimulation with Aa, a significant increase in the number of IgA (111%) and IgG (48%) secreting cells was observed, concomitant with a 74% decrease in the Ig-negative cell population. Total Aa⁺ cells increased significantly after stimulation (P < 0.001), predominated by Aa-specific IgG and IgM antibody producing cells. CONCLUSIONS: These results showed that LCLs from Aa-infected patients were polyclonal with respect to isotype distribution. Further stimulation with Aa revealed a shift to cytoplasmic IgG and IgA expression, as well as increases in the Aa-specific B cell population. In contrast, the PBAs stimulated the LCLs to synthesize primarily IgM.Additionally, the findings indicated that: (I) without T cells, polyclonal activation of B cells may lead to elevated Aa-specific B cell populations; and (2) the presence of previously sensitized B cells is required to exert an antigen specific antibody response in the LCL.We conclude that secondary activation of primed B cells by oral bacteria or their products in advanced periodontal lesions may contribute to the local accumulation of significant numbers of Ig-producing cells. This report also suggested that EBV-mediated transformation can be used to probe B cell-bacterial interactions in studies of periodontitis.     

Clonidine but not propranolol decreases plasma neuropeptide Y (NPY) levels

The effects of acute administration of two antihypertensive drugs, clonidine and propranolol, on plasma NPY and catecholamine levels were compared in sinoaortic denervated (a model associated with a marked increase in sympathetic tone and a rise in blood pressure) and normal conscious dogs. Clonidine decreased plasma noradrenaline and NPY concentrations in both groups of animals. Propranolol failed to change plasma noradrenaline and NPY levels in sinoaortic denervated dogs but elicited a decrease in plasma noradrenaline with no change in NPY levels in normotensive animals. The present experiments show that changes in plasma noradrenaline and NPY concentrations are not always simultaneous. The decrease in plasma NPY concentrations could contribute to the sympatholytic effect of clonidine.     

Prevalence of latex sensitization among hospital physicians occupationally exposed to latex gloves.

Patients undergoing surgery who have a history of occupational exposure to latex gloves may be predisposed to intraoperative anaphylaxis caused by latex allergy. Thus, medical personnel who routinely wear latex gloves may be at higher risk than the general population. The prevalence of latex sensitization has not been reported previously among physicians using latex gloves in a North American hospital setting. Using a latex skin prick test (SPT), we determined the prevalence of latex sensitization among 101 staff anesthesiologists, radiologists, and surgeons who regularly use latex gloves and among 100 atopic controls who were not occupationally exposed to latex gloves. Latex SPT was positive in 10 of 101 physicians (rho = 0.099; 95% confidence interval [CI] 0.041, 0.157) and 3 of 100 controls. Subgroup analysis showed that 9 of 38 atopic physicians were SPT-positive (rho = 0.237; 95% CI 0.102, 0.372). Atopic physicians were more likely to be latex SPT-positive than either nonatopic physicians or atopic controls (atopic vs. nonatopic physicians: P = 0.0006, odds ratio = 19.2, 95% CI 15.4, 23.1; atopic physicians vs. atopic controls: P = 0.0005, odds ratio = 9.1, 95% CI 7.5, 11.6). We conclude that compared to nonatopic physicians exposed to latex, or nonexposed atopic controls, atopic physicians who wear latex gloves are at increased risk of latex allergy.     

Ocular and cerebral metastases in the VX2 rabbit tumor model: contrast- enhanced MR imaging

Ocular and cerebral metastases developed after the inoculation of a VX2 tumor cell suspension into the internal carotid artery of 15 rabbits. The hematogenous spread of tumor cells resulted in ocular metastases in 13 of 15 animals (86.7%) and cerebral system metastases in 14 of 15 animals (93%). Magnetic resonance (MR) imaging with Gd-DTPA demonstrated early disruption of the blood-ocular barrier and blood-brain barrier 5-7 days after infusion of tumor cells. Quantitative assessment of contrast enhancement revealed a mean increase in signal intensity of 145% +/- 51% in the anterior chambers, 102% +/- 70% for choroidal metastases, and 51% +/- 29% for central nervous system (CNS) metastases. These results indicate that contrast-enhanced MR imaging can be used to demonstrate a loss of blood-ocular barrier integrity that is similar to the breakdown of the blood-brain barrier associated with metastatic tumors to the CNS and eye.     

Improved Liver Function Following Treatment with an Extracorporeal Liver Assist Device

Abstract: A 68-year-old woman with fulminant hepatic failure of unknown etiology was treated with a bioartificial liver assist device. Prior to treatment, she had a number of clinical and laboratory features that suggested a hopeless outcome. Treatment was associated with a dramatic change in her mental status, and her clinical picture improved progressively during 6 days of continuous therapy. Evidence of recovery of native liver function allowed the discontinuation of treatment, and she continued to improve for a further 3½ days before her demise from septic shock. We propose that a metabolically active liver assist device is a logical and practical method for treating the critical phase of fulminant hepatic failure.