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Biomedical subjects

J F Bale

Publications and source records attributed to J F Bale.

At least 73 records · Page 4Linked to original sources
PubMed1986

Aberrant activation and regulation of the oxidative burst in neutrophils with Mol glycoprotein deficiency.

Patients whose cells are deficient in the glycoproteins LFA-1, Mol, and p150,95 have recurrent infections and pronounced abnormalities in neutrophil adherence, aggregation, chemotaxis, and phagocytosis. We characterized activation and regulation of oxidative metabolism of Mol-deficient neutrophils. These cells failed to depolarize or to produce O2- or H2O2 normally when stimulated by opsonized zymosan. The chemotactic peptide formyl methionyl-leucyl-phenylalanine depolarized Mol-deficient neutrophils normally but caused supernormal production of O2- and H2O2, a result of a prolonged burst in oxidative metabolism. Phorbol myristate acetate depolarized Mol-deficient neutrophils at a nearly normal rate but evoked release of significantly less O2- and H2O2 than from normal PMN. The aberrant activation and regulation of the oxidative burst in Mol-deficient neutrophils are considered in light of recently emerging concepts in the cell biology of this process, and the possibility that these abnormalities reflect a defect in the cytoskeleton-membrane interaction is discussed.

Cell Adhesion↗
PubMed1986

Magnetic resonance imaging of the spine in children.

We reviewed the magnetic resonance imaging (MRI) scans of the spine of 42 children who had neurologic signs compatible with lesions of the spinal cord. Twenty-three of the children had abnormalities identified by MRI. The spectrum of abnormalities included posttraumatic lesions, tumor, tethered cord, and syringohydromyelia. Tethered cord with or without lipoma and syringohydromyelia were the most common findings, affecting six and four children, respectively. Thirteen children studied by MRI also underwent conventional metrizamide myelography and/or computed tomography. In 12 cases, the findings of MRI were comparable to those of myelography and computed tomography. These observations indicate that MRI effectively detects lesions of the spinal cord in children. Because MRI can be performed on an outpatient basis and avoids the risks of metrizamide myelography, we conclude that MRI should be considered to be the preferred screening technique for children with suspected spinal cord disorders.

Adolescent↗
PubMed1986

Cerebral infarction complicating Fontan surgery for cyanotic congenital heart disease.

We report on four children who had cerebral vascular events in the first three months after the Fontan procedure for complex cyanotic congenital heart disease. Potential risk factors in these children included congestive heart failure, postoperative thrombocytosis, and cardiac arrhythmias. These cases suggest that children who undergo Fontan surgery may be at increased risk for cerebral infarction.

Adolescent↗
PubMed1986

MRI in children with postinfectious disseminated encephalomyelitis.

Acute disseminated encephalomyelitis, an inflammatory and demyelinating disorder of central nervous system white matter, typically occurs following childhood viral infections. Although CT may demonstrate abnormalities, many children have normal CT studies in spite of widespread neurologic abnormalities. We report a series of five patients with the typical clinical presentation of disseminated encephalomyelitis who were studied using magnetic resonance imaging (MRI). In each case the children presented with progressive subacute neurologic abnormalities including headache, diplopia, ataxia, hemiparesis, seizures, dysarthria, and/or coma. CT was nondiagnostic. MRI clearly demonstrated multifocal white matter lesions of the cerebrum, brainstem, and cerebellum which corresponded to clinical signs. The patients improved dramatically with corticosteroid therapy. MRI showed progressive resolution of multifocal lesions in conjunction with clinical improvement.

Acute Disease↗
PubMed1986

Cytomegalovirus transmission in a Midwest day care center: possible relationship to child care practices.

The epidemiology of cytomegalovirus (CMV) infection and transmission in a large Iowa day care center was studied. Over the 9 months of the study the overall CMV prevalence rates were 21% to 22%, with rates as high as 71% in toddlers. Titers of CMV in the urine or saliva of infected children were as high as 3 X 10(4) plaque-forming units of CMV per milliliter, similar to titers of CMV observed in some congenitally infected infants. Restriction enzyme analysis of CMV isolates from children in the center demonstrated two major clusters with similar patterns, one among 2- and 3-year-old children and another among infants. The clustering of similar CMV isolates among nonambulatory infants suggests that child care or hygienic practices may contribute to the spread of CMV infection in day care centers. Furthermore, the relatively high prevalence of CMV excretion in this center and the low seropositivity rates to CMV among adults in Iowa suggest that adults in the Midwest who have contact with children in day care centers may be at risk for primary CMV infection.

Child↗
PubMed1985

Kaposi's sarcoma metastatic to the CNS.

Metastatic lesions of the CNS developed in two male patients with disseminated Kaposi's sarcoma. One patient was a homosexual, but the second patient had no apparent risk factors for disseminated Kaposi's sarcoma. These cases indicate that CNS involvement by tumor should be suspected in patients with Kaposi's sarcoma who exhibit abnormal neurologic signs or symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1985

The interaction of murine cytomegalovirus with murine neutrophils: effect on migratory and phagocytic activities.

To investigate the interaction of cytomegalovirus (CMV) with neutrophils, we studied the effects of in vitro incubation of murine neutrophils with murine CMV (MCMV). Neutrophils incubated with MCMV for 4 h had depressed chemotactic activity, mean chemotactic index of 1.34 +/- 1.43 for MCMV-treated neutrophils vs 3.22 +/- 2.11 for controls. Engulfment of latex spheres by MCMV-treated neutrophils was also reduced. These differences were not attributable to loss of cell viability. UV-inactivation of MCMV pools abolished the inhibitory effects of MCMV, indicating that these effects were related to infectivity of the virus. Electron microscopic studies at 4 h demonstrated virus particles within the phagosomes of occasional neutrophils. These studies demonstrate that neutrophil functions can be altered by an in vitro interaction with infectious CMV and suggest that a direct effect of CMV on neutrophils could account for the abnormal neutrophil functions observed during animal CMV infections.

Adsorption↗
PubMed1985

Murine neutrophils collected from subcutaneously implanted sponges.

Polyvinyl sponges implanted subcutaneously in mice were used as a source of murine neutrophils (PMNs). Yield of PMNs from sponges averaged 6.3 X 10(5) PMNs per mouse and viability of sponge PMNs was 96.5%. These results were comparable to the yield and viability of PMNs harvested from peripheral blood. The chemotactic activity of sponge PMNs was significantly greater than the chemotactic activity of peripheral blood PMNs (chemotactic index of 4.78 +/- 1.66 in sponge PMNs versus 2.16 +/- 1.08 in peripheral blood PMNs, P less than 0.001). The difference in chemotactic activity was not attributable to hypotonic injury of PMNs nor the presence of soluble factors in sponge fluids. Phagocytic activity of sponge PMNs was comparable to the activity of blood PMNs (mean of 31.3 +/- 16.4% phagocytic cells for sponge PMNs versus 33.0 +/- 23.9% for blood PMNs). In addition, the number of fluorescent spheres ingested by sponge PMNs was not different (mean of 2.81 +/- 0.86 in sponge PMNs versus 2.65 +/- 0.68 spheres per cell for blood PMNs). These studies indicate that subcutaneously implanted sponges can be used as a source of functioning murine PMNs.

Animals↗
PubMed1985

T-lymphocyte subpopulations and function during murine cytomegalovirus infection.

To study the effects of cytomegalovirus infection on T-lymphocyte subpopulations, we determined helper (Lyt 1.2) and suppressor (Lyt 2.2) T-lymphocyte subset numbers using monoclonal antibodies and measured lymphocyte responsiveness to mitogen during sublethal murine cytomegalovirus (MCMV) infection of 3-wk-old Balb/c mice. MCMV-infected mice had reduced Lyt 1.2 to Lyt 2.2 T-lymphocyte ratios on days 1, 3, 5, and 9 of infection. Alterations in T-lymphocyte subsets were accompanied by diminished lymphocyte response to concanavalin A. Lymphocyte responsiveness and Lyt 1.2 to Lyt 2.2 ratios were maximally reduced on day 5 of MCMV infection and correlated strongly with peak virus recovery from spleen, bone marrow, and peripheral blood leukocytes. These results indicate that acute MCMV infection of mice causes abnormalities in T-lymphocyte subset ratios and responsiveness to mitogen similar to the abnormalities observed in human cytomegalovirus infections. MCMV infection of mice is a useful model to study the mechanism by which cytomegalovirus infections induce altered T-lymphocyte subpopulations.

Animals↗
PubMed1985

Reye syndrome associated with aspirin therapy for systemic lupus erythematosus.

A 14-year-old girl in whom Reye syndrome developed during aspirin therapy for an inflammatory disorder proven to be systemic lupus erythematosus is reported. This case and similar cases of Reye syndrome in patients with juvenile rheumatoid arthritis suggest that an etiologic relationship exists between salicylate therapy and Reye syndrome in children with collagen vascular disorders.

Adolescent↗
PubMed1984

Human cytomegalovirus infection and disorders of the nervous system.

Infection with human cytomegalovirus (CMV) occurs in nearly 1% of live-born infants, and from 60% to 80% of the inhabitants of the United States acquire CMV infection by mid adulthood. While neurologic disorders do not develop in the majority of congenitally infected infants, congenital CMV infection can severely damage the developing nervous system, causing microcephaly, psychomotor retardation, seizures, and deafness. Furthermore, approximately 10% of infants who are asymptomatic at birth subsequently exhibit sensorineural hearing loss. In the adult, CMV infection has been associated with the Guillain-Barré syndrome, meningoencephalitis, and retinitis. Although Guillain-Barré syndrome can accompany CMV infections in previously healthy adults, meningoencephalitis and retinitis occur more commonly in immunosuppressed patients, particularly among organ transplant recipients. In total, at least 7,000 persons in the United States each year have neurologic disorders attributable to CMV infection.

Adolescent↗
PubMed1984

Experimental murine cytomegalovirus infection of ocular structures.

To study experimental cytomegalovirus (CMV) infection of ocular structures, 3-week-old Swiss-Webster mice were inoculated intraperitoneally with a 0% to 20% lethal inoculum of murine CMV (MCMV). Murine cytomegalovirus was recovered from homogenates of eye tissues on days 3, 5, and 7 after inoculation. Peak virus titers, mean of 2.93 +/- 0.67 log plaque-forming units of MCMV per gram of ocular tissue occurred on day 5. Urine cytomegalovirus was recovered from explant cultures of eye and optic nerve 14, 21, 60, 90, and 120 days after MCMV inoculation. Murine cytomegalovirus also persisted in intraocular fluids for as long as 90 days. Murine cytomegalovirus infection was confirmed by immunofluorescence antibody staining and transmission electron microscopy. These experiments indicate that MCMV infects the ocular tissues of mice during systemic MCMV infection, and persists in ocular tissues for as long as 120 days after infection. These studies may be directly relevant to ocular disorders that occur during acquired CMV infections of humans, and suggest that ocular tissues may be a site of CMV persistence or latency.

Animals↗
PubMed1984

Phenylpropanolamine-associated CNS complications in children and adolescents.

Hypertension, severe headache, and grand mal seizures developed in a 13-year-old girl after ingestion of one nonprescription diet pill containing phenylpropanolamine and caffeine. This case is at least the sixth report of seizures with phenylpropanolamine use in children or adolescents. Phenylpropanolamine ingestion must be included in the differential diagnosis of young patients, particularly adolescents, in whom acute neurological symptoms develop.

Adolescent↗
PubMed1983

Impaired migratory and chemotactic activity of neutrophils during murine cytomegalovirus infection.

Mice have been shown to have increased susceptibility to bacterial and fungal superinfections between days 1 and 5 of acute murine cytomegalovirus (MCMV) infection. The current study demonstrated that, during the same period of the MCMV infection, migration of neutrophils into a subcutaneous sponge was impaired (1,300-2,000 cells/mm3 in MCMV-infected animals vs 6,000-7,000 cells in controls; P less than 0.01) and chemotaxis of neutrophils harvested from the sponge was decreased (chemotactic index of 1.5-2.1 in infected animals vs 5.4-5.7 in controls; P less than 0.01). The number of neutrophils in peripheral blood was not altered. Infectious MCMV was present in the neutrophil-rich fraction of peripheral white blood cells, suggesting that direct viral infection of neutrophils may contribute to altered function. These studies suggest that abnormalities in neutrophil function during acute cytomegalovirus infection may contribute to the enhanced susceptibility to bacterial and fungal infections that occurs in both experimental animals and humans.

Animals↗
PubMed1982

Enhanced susceptibility of mice infected with murine cytomegalovirus to intranasal challenge with Escherichia coli: pathogenesis and altered inflammatory response.

Three-week-old mice inoculated intraperitoneally with murine cytomegalovirus (MCMV) and then challenged intranasally with Escherichia coli strain K1 demonstrated enhanced mortality (70%-90%) as compared with control animals infected with either pathogen alone (0-20%, P less than 0.05). Mortality was greatest when animals were challenged with E. coli on days 1 or 3 after MCMV inoculation. On day 3 of infection with MCMV, clearance of E. coli from blood and tissues was impaired, and there was a decreased inflammatory response to an E. coli-inoculated sponge implanted subcutaneously (geometric mean of 830 leukocytes in sponge fluid/mm3 in MCMV-infected animals vs. 8,510 leukocytes/mm3 in controls, P less than 0.01). On days 1 and 3 of MCMV infection, decreased leukocyte counts in sponge fluid correlated with increased levels of bacteremia (P less than 0.05). These results indicate that MCMV enhances susceptibility to an intranasal challenge with E. coli. A decrease in the inflammatory response may be one mechanism by which MCMV increases susceptibility to bacterial infections.

Animals↗