PubMed Health⌕ Search

Biomedical subjects

L Greenbaum

Publications and source records attributed to L Greenbaum.

29 records · Page 2Linked to original sources
PubMed1989

Identification of the alternatively spliced exons of murine CD45 (T200) required for reactivity with B220 and other T200-restricted antibodies.

Cell lines expressing specific variants of murine CD45 (T200) were established by infection with retroviral constructs of four cDNAs encoding different forms of CD45. These lines were then used to determine which sequences encoded by alternatively spliced exons of CD45 were required to generate antigenic determinants recognized by anti-CD45 mAbs. The binding of two B220 antibodies (14.8 and RA32C2) to CD45 was dependent on the expression of the first alternatively spliced exon (exon A). A third B220 antibody, RA3-6B2, did not bind to any of the forms of CD45 expressed on fibroblasts. A newly defined anti-CD45R antibody, C363.16A, reacts with an antigenic site dependent upon the expression of the second alternatively spliced exon, exon B.

Animals↗
PubMed1989

A monoclonal antibody to murine CD45R distinguishes CD4 T cell populations that produce different cytokines.

CD4 T cell clones have been shown to be functionally heterogeneous in the mouse. However, it is not known if normal CD4 T cells are also functionally heterogeneous, or whether functional specialization is a result of cloning and long-term culture. To approach this question, a monoclonal antibody reacting with a subset of CD4 T cells has been prepared by immunization of rats with different cloned T cell lines all sharing the same functional activity. This monoclonal antibody reacts with a subset of CD45 (T200) molecules by binding to a determinant requiring the expression of the second variable exon of the CD45 molecule. Some CD4 T cells bear high levels of this marker, while others react only weakly. This antibody was used to separate CD4 T cells into two subpopulations. The brightly staining population was found to produce interleukin (IL) 2 and not IL 4, while the weakly staining population produced IL 4 and not IL 2. These data demonstrate that CD4 T cells in normal mice are already functionally committed, and that they differentially express forms of CD45 that contain the second variable exon.

Animals↗
PubMed1986

Correlates of early disability in Huntington's disease.

Functional disability in Huntington's disease usually results from a combination of the movement disorder, intellectual decline, and psychopathological changes, but the unique contribution of each element has never been investigated. The Shoulson-Fahn functional capacity rating scale measures independence in such daily activities as eating, dressing, and managing personal finances, and is used to stage the illness and follow its progression. To determine which problems contribute most to reduced functional capacity as the disease evolves, we reviewed the records of 48 consecutive patients who were evaluated for intellectual and emotional status and motor disability. Each patient was staged and rated for functional capacity at the time of the examinations. Thirty-three of these patients were followed over several years with repeat evaluations at 6-month intervals. Intellectual impairment and depression correlated significantly with reduced functional capacity. However, when the somatic symptoms of depression were eliminated from the analysis, its relationship to functional capacity was no longer significant. Duration of illness, motor disability, and age at onset also had little impact. Neuropsychological test performance and functional capacity deteriorated over time. Our data suggest that intellectual impairment is a major factor in reducing functional capacity in the early stages of Huntington's disease.

Activities of Daily Living↗
PubMed1982

Virion DNA of ground squirrel hepatitis virus: structural analysis and molecular cloning.

The structure of the encapsidated DNA genome of ground squirrel hepatitis virus (GSHV) has been examined by restriction endonuclease cleavage, nucleic acid hybridization, and molecular cloning. GSHV virion DNA is a relaxed circular molecule of approximately 3,200 bases in length; most molecules harbor an extensive single-stranded region which is largely confined to one-half of the genome. The full-length viral DNA strand is covalently bound to protein. The single-stranded region can be repaired in vitro by the action of the endogenous virion polymerase, exogenously added DNA polymerase from avian myeloblastosis virus, or both. Restriction enzyme cleavage of viral DNA from different isolates demonstrated that multiple variants of GSHV exist in nature. The genomes of two such strains have been cloned in Escherichia coli, and their physical maps have been determined. Nucleic acid hybridization studies revealed that the strains share sequence homology with the DNA of human hepatitis B virus. Regions homologous to the coding regions for the surface and core antigens of human hepatitis B virus have been localized on the GSHV chromosome. Molecular cloning experiments have also led to the identification of a region of the viral genome which is altered in a procaryotic host.

Animals↗
PubMed1968

Kinins and anti-inflammatory steroids.

1. This investigation was designed to re-examine the possibility that anti-inflammatory steroids interfere with the kinin-forming system.2. We conclude that the anti-inflammatory action of corticosteroids cannot be explained by the inhibition of kinin formation. This view is based on the following findings.3. Neither hydrocortisone nor prednisolone nor dexamethasone inhibited the activation or activity of intrinsic plasma kinin forming enzymes resulting from dilution, incubation with kininase inhibitors, or exposure to glass, monosodium urate microcrystals or to precipitated complexes of rheumatoid factor and aggregated human gamma-globulin.4. Hydrocortisone did not inhibit the action of the active kinin-forming enzymes, human salivary or urinary kallikrein, or plasmin on purified kininogen.5. Hydrocortisone, prednisolone and dexamethasone did not inhibit the hydrolysis of benzoyl-arginine-ethyl ester by human plasmin, plasma kallikrein or hog pancreatic kallikrein.6. Kinin formation occurred normally in plasma taken from two patients receiving betamethasone and one receiving prednisone.

Animals↗
PubMedDate not supplied

Timing of peritoneal dialysis catheter removal after pediatric renal transplantation.

BACKGROUND: A peritoneal dialysis (PD) catheter is in place at the time of kidney transplantation in children receiving PD. Removal of the catheter eliminates the risk of catheter-related infections. However, the patient benefits from leaving the catheter in place if dialysis is necessary posttransplantation. There is currently no consensus on the proper timing of PD catheter removal after kidney transplantation in children. OBJECTIVE: To identify the risks and benefits of an in-dwelling PD catheter after renal transplantation in children. DESIGN: Retrospective single-center study of infectious complications and posttransplantation PD catheter use in 31 renal transplantations in 26 children. RESULTS: Peritoneal dialysis catheters were used postoperatively in 13 of the 31 transplantations. In 12 instances the catheter was needed during the first month after transplantation, and 2 of the patients involved did not have a catheter in place when needed. Six catheter-related infections occurred in 5 patients posttransplantation, with only 1 infection taking place within 1 month after transplantation. CONCLUSION: Our data suggest that the need for catheter use occurs predominantly during the first month, while infectious complications usually happen later. This strongly suggests that PD catheters should not be removed until approximately 1 month after kidney transplantation.

Adolescent↗
PubMedDate not supplied

Estimation of total creatinine clearance is unreliable in children on peritoneal dialysis.

OBJECTIVE: To test the reliability of creatinine clearance in children on peritoneal dialysis (PD). DESIGN: Longitudinal, case-controlled. SETTING: Routine clinic visits at the pediatric dialysis unit of the Universitätskinderklinik of Vienna. PATIENTS: Eleven children (2-13 years, 10-55 kg) with end-stage renal disease on PD. INTERVENTIONS: Creatinine clearance (CCr) was determined by measuring creatinine excretion (ECr) over 24 hours in both dialysate and urine. Each child had three to five separate measurements of their CCr. At the same time we also calculated the Schwartz formula clearance from the patient's height and serum creatinine, using a modified correlate. MAIN OUTCOME MEASURES: Reliability of CCr was assessed by two approaches. First, we compared each serial measurement with the mean value for each patient and thereby assessed the "intramethodical" variability. Second, we compared each CCr with the simultaneous formula clearance and assessed the "intermethodical" disagreement. RESULTS: Twenty-seven percent of the measurements of CCr were classified as unreliable based on a comparison with the mean value for each patient. Reliability was closely correlated with residual renal function (p < 0.01); only 12% of the measurements in the anuric patients were classified as unreliable (vs 31% in the patients with residual renal function). The simultaneous formula clearance was less variable than the CCr. The formula clearance had a sensitivity of 93% and a specificity of 60% for detecting unreliable values of CCr. CONCLUSION: Estimation of total CCr is unreliable in pediatric patients on PD. A simultaneous formula clearance can be used to detect which values are unreliable.

Case-Control Studies↗