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Biomedical subjects

J Kaufman

Publications and source records attributed to J Kaufman.

At least 163 records · Page 9Linked to original sources
PubMed1991

Angiotensin-converting enzyme inhibitors and cough. Prevalence in an outpatient medical clinic population.

To determine the frequency of ACE inhibitor cough in an outpatient medical clinic population, a cross-sectional epidemiologic survey using mailed questionnaires was done. Patients were randomly selected from a computerized hospital pharmacy data base. The overall prevalence of cough was 19 percent in the ACE inhibitor groups compared with 9 percent in the hydrochlorothiazide-treated group. The observed odds ratio for cough among ACE inhibitor users was 2.3 (95 percent CI, 1.02 to 5.00). This study is the first systematic investigation of frequency and characteristics of ACE inhibitor cough that includes a control group. Our results suggest that cough may more frequently accompany treatment with ACE inhibitors than has been previously reported. We recommend that physicians specifically inquire about cough in patients taking an ACE inhibitor. Recognition of this side effect may prevent unnecessary testing and treatment of patients receiving ACE inhibitors.

Ambulatory Care↗
PubMed1991

Home care cost-effectiveness for respiratory technology-dependent children.

We evaluated home care costs and the cost-effectiveness of home care vs alternative institutional care for respiratory technology-dependent children in a Medicaid Model Waiver Program. "Cost-savings" was measured as the difference between the established Medicaid reimbursable charges to enact an individualized care plan at a long-term care institution and the actual Medicaid reimbursements for home care. Ten patients--six dependent on mechanical ventilation and four with a tracheostomy who were receiving oxygen--were included in the analysis. The mean (+/- SD) annual home care costs were $109,836 +/- $20,781 for ventilator-dependent children and $63,650 +/- $12,350 for oxygen-dependent patients with a tracheostomy, representing annual savings of approximately $79,000 per patient and $83,000 per patient, respectively. The largest portion of home care reimbursements was for nursing care, accounting for 69.0% and 59.0% of the two patient groups. The full program (50 patients) has the potential for a savings of $4 million per year.

Child↗
PubMed1990

MHC-like molecules in some nonmammalian vertebrates can be detected by some cross-reactive monoclonal antibodies.

mAb to human and mouse MHC molecules were tested for binding to blood or spleen cells of various nonmammalian vertebrates by immunofluorescence and flow cytometry. Those that bound were used to immunoprecipitate cross-reactive molecules from biosynthetically or cell surface-labeled spleen or blood cells. In addition, mAb to human MHC molecules were screened by Western blots. As expected from the results with xenoantisera, there were few mAb that cross-reacted, and many of these cross-reactions were not specific for MHC-like molecules. Less than 10% of the mAb tested bound to the cells of any particular species, with very few positive for more than one species. Of those mAb that bound cells, many failed to precipitate any radioactive bands, and most bands precipitated were not recognizable as MHC-like molecules. Five mAb reacted with Xenopus class II, one of which also immunoprecipitated axolotl class II. Another of these reacted with a candidate for class II in the lamprey, but this molecule had features unlike those expected for mammalian class II molecules. Four other mAb reacted with candidate molecules. in the trout and shark. None of the mouse alloantibodies immunoprecipitated nonmammalian vertebrate MHC-like molecules. In contrast to the results with most xenoantisera, the mAb cross-reacting with amphibian class II molecules recognized a number of different linear epitopes on the surface of the polymorphic non-Ig beta 1 domain of class II molecules. Few mAb recognized bands in Western blots of nonmammalian vertebrate cells and the candidate molecules from fish had features different from known mammalian MHC molecules.

Amphibians↗
PubMed1990

MHC-like molecules in some nonmammalian vertebrates can be detected by some cross-reactive xenoantisera.

Rabbit antisera raised to human and chicken MHC molecules were used to immunoprecipitate cross-reactive molecules from biosynthetically and cell surface-labeled spleen and/or blood cells of representative vertebrate species. Five major points emerged: 1) There were many nonspecific cross-reactions using these techniques, so various criteria were developed to distinguish these from true MHC-like molecules. 2) Only very small subpopulations of immunogen-specific antibodies cross-reacted with MHC-like molecules in other nonmammalian species. These subpopulations were different for each species and even within a species, sometimes being so limited as to behave like alloantisera. This led to a very scattered pattern of true cross-reactions that sometimes failed to reflect the properties of the bulk antibody population. 3) Antisera containing antibodies to class II beta- and class I alpha-chains cross-reacted better and more widely than those to B-G, class II alpha and, in general, beta 2-microglobulin. 4) Some cross-reactive antibodies were clearly directed to epitopes on the surface of the mature heterodimers, but many seemed to recognize nonlinear cryptic determinants, presumably in the contact regions between the chains. These latter antibodies recognized biosynthetic intermediates and also a variety of unusual cell surface MHC-like molecules present in reptile and amphibian, but absent in the mammal and chicken cells tested. These included E homodimers whose relationship to chicken B-G molecules is unknown. 5) MHC-like molecules were identified in a bird, three reptiles, and two amphibians, but no molecules with the expected properties were found with these reagents in any of the fish tested.

Amphibians↗
PubMed1990

T cell precursor migration towards beta 2-microglobulin is involved in thymus colonization of chicken embryos.

beta 2-microglobulin (beta 2m) attracts hemopoietic precursors from chicken bone marrow cells in vitro. The cell population responding to beta 2m increases during the second period of thymus colonization, which takes place at days 12-14 of incubation. The precursors from 13.5 day old embryos were isolated after migration towards beta 2m in vitro and shown to be able to colonize a 13 day old thymus in ovo, where they subsequently acquire thymocyte markers. In contrast these beta 2m responsive precursors did not colonize embryonic bursa, i.e. differentiate into B lymphocytes. During chicken embryogenesis, peaks of beta 2m transcripts and of free beta 2m synthesis can only be detected in the thymus. The peak of free beta 2m synthesis in the thymus and the increase of beta 2m responding bone marrow cells both occur concomitantly with the second wave of thymus colonization in chicken embryo, facts which suggest that beta 2m mediated chemotaxis is involved in the second wave.

Animals↗
PubMed1990

Size polymorphism of chicken major histocompatibility complex-encoded B-G molecules is due to length variation in the cytoplasmic heptad repeat region.

B-G antigens are cell-surface molecules encoded by a highly polymorphic multigene family located in the chicken major histocompatibility complex (MHC). Rabbit antisera to B-G molecules immunoprecipitate 3-6 bands from iodinated erythrocytes by sodium dodecyl sulfate (SDS) gels under reducing conditions. These are all B-G molecules because they all map to the B-G region of the chicken MHC in congenic and recombinant chickens, most are directly recognized by the antisera, most form disulfide-linked dimers, and none bear N-linked carbohydrate. Both apparent homodimers and heterodimers are found, which bear intrachain disulfide bonds. All 3-6 bands have different mobilities in SDS gels between different haplotypes, ranging from 30 to 55 kDa. This size polymorphism is not affected by glycosidase treatment or addition of protease inhibitors. Partial proteolysis of cell surface-iodinated B-G molecules generates extremely similar patterns of spots, both within and between haplotypes. These surface-iodinated peptides bear either interchain or intrachain disulfide bonds. Additional peptides are generated by proteolysis of B-G molecules iodinated after isolation. Thus, it appears that the extracellular regions of these molecules are very similar and that the length polymorphism is due to variations in the cytoplasmic regions. Inspection of the cDNA-derived protein sequence in this region shows many heptad repeats, which may allow variation in length by step deletion and alternative splicing. The repeats indicate an alpha-helical coiled-coil structure, which could form an interaction between subunits of the dimer or with the cytoskeleton or both.

Amino Acid Sequence↗
PubMed1990

Use of digoxin Fab immune fragments in a seven-day-old infant.

We report the use of digoxin immune Fab in a seven-day-old male neonate for treatment of digoxin poisoning. The patient was being treated with digoxin for paroxysmal supraventricular tachycardia (PSVT). The prescription was written for digoxin elixir (50 micrograms/ml), 10 micrograms bid; however, it was dispensed as 100 micrograms bid. The patient had received seven of these doses over three and one half days prior to arrival at the emergency department. The patient received 40 mg of digoxin immune Fab fragments over one hour to bind a calculated maximum digoxin dose of 600 micrograms. The only complication was a transient episode of relative hypoglycemia 13 to 22 hours postinfusion with measured glucose readings between 43 and 52 mg/dl. The hypoglycemia responded to supplemental glucose and advancement of feedings. We believe that in massive and rapid electrolyte shifts in the neonate caused by digoxin immune Fab, glucose should be monitored closely.

Digoxin↗
PubMed1990

The MHC molecules of nonmammalian vertebrates.

There is very little known about the long-term evolution of the MHC and MHC-like molecules. This is because both the theory (the evolutionary questions and models) and the practice (the animals systems, functional assays and reagents to identify and characterize these molecules) have been difficult to develop. There is no molecular evidence yet to decide whether vertebrate immune systems (and particularly the MHC molecules) are evolutionarily related to invertebrate allorecognition systems, and the functional evidence can be interpreted either way. Even among the vertebrates, there is great heterogeneity in the quality and quantity of the immune response. The functional evidence for T-lymphocyte function in jawless and cartilagenous fish is poor, while the bony fish seem to have many characteristics of a mammalian immune system. The organization and sequence of fish Ig genes also indicate that important events in the evolution of the immune system and the MHC occurred in the fish, but thus far there is no molecular evidence for recognizable MHC-like molecules in any fish. There is clearly an MHC in amphibians and birds with many characteristics like the MHC of mammals (a single genetic region encoding polymorphic class I and class II molecules) and evidence for polymorphic class I and class II molecules in reptiles. However, many details differ from the mammals, and it is not clear whether these reflect historical accident or selection for different lifestyles or environment. For example, the adult frog Xenopus has a vigorous immune system with many similarities to mammals, a ubiquitous class I molecule, but a much wider class II tissue distribution than human, mouse and chicken. The Xenopus tadpole has a much more restricted immune response, no cell surface class I molecules and a mammalian class II distribution. The axolotl has a very poor immune response (as though there are no helper T cells), a wide class II distribution and, for most animals, no cell surface class I molecule. It would be enlightening to understand both the mechanisms for the regulation of the MHC molecules during ontogeny and the consequences for the immune system and survival of the animals. These animals also differ markedly in the level of MHC polymorphism. Another difference from mammals is the presence of previously uncharacterized molecules. In Xenopus and reptiles, there are two populations of class I alpha chain on the surface of erythrocytes, those in association with beta 2m and those in association with a disulfide-linked homodimer.(ABSTRACT TRUNCATED AT 400 WORDS)

Amphibians↗
PubMed1990

Ontogenic appearance of MHC class I (B-F) antigens during chicken embryogenesis.

Expression of chicken MHC class I (B-F) antigens during ontogeny was determined by binding of anticlass I antibody and appearance of B-F transcripts by Northern blotting in chicken organs during embryogenesis until 2 weeks after hatching. MHC class I transcripts first become detectable in day 6.5 of embryogenesis. B-F cell-surface expression first becomes detectable in hemopoietic organs by day 10-12 of embryogenesis and somewhat later in nonhemopoietic organs. Flow cytometry analysis of hemopoietic cells throughout embryogenesis revealed B-Fhi and B-Flo cell populations. The percentage of B-F+ cells in spleen and bone marrow decreased around hatching, which could reflect either cell flows in these organs during this period or the sensitivity of hemopoietic cells to hatching stress.

Animals↗
PubMed1990

Bronchiolitis obliterans. A new clinical-pathologic complication of irradiation pneumonitis.

A patient underwent chest irradiation for small-cell carcinoma of the left lung. Several weeks following cessation of irradiation, the patient developed hypoxemia and reticulonodular densities within the radiation port. Open lung biopsy yielded a pathologic diagnosis consistent with irradiation pneumonitis along with a previously unreported association, bronchiolitis obliterans. Bronchiolitis obliterans should be included in the pathologic description of irradiation pneumonitis.

Biopsy↗
PubMed1990

Fatal swine influenza pneumonia during late pregnancy.

Serious morbidity or death from swine influenza infection is unusual in the immunocompetent host. We present a fatal case of pneumonia caused by this virus in a previously healthy 32-year-old woman during her third trimester of pregnancy, and review all published case reports of swine influenza in United States civilians. Pregnancy may be a predisposing factor to fulminant infection with swine influenza virus.

Adult↗
PubMed1990

An animal model for instructing and the study of in situ arterial bypass.

A canine model that used the cephalic vein to bypass from the brachial to the ulnar artery was designed for use in instructing and evaluating surgical technique needed for constructing an in situ arterial bypass. This model was used for instructing vascular residents in the in situ vein bypass technique. The use of this model enabled the resident to become more adept with the instruments for valve incision and construction of small vessel anastomosis. The improvement in the resident's operative technique was reflected by a decrease in the number of technical complications (missed valves, missed arteriovenous fistulas, poorly constructed anastomoses) and improved patency rate.

Animals↗
PubMed1989

Role of B-mode venous mapping in infrainguinal in situ vein-arterial bypasses.

Two hundred and eighty patients underwent B-mode mapping (B-map) of their saphenous vein over a period of 3 years (1984-1987) before lower limb revascularization. B-map deemed that 229 veins were suitable for bypass, 26 were questionable and 25 were unsuitable. A successful bypass was achieved in 97.8 per cent of the suitable group (all in situ), 85 per cent of the questionable group (in situ and composite vein), and 80 per cent of the unsuitable group (composite vein). At a minimum follow-up period of 1 year the overall patency rate was 95.0 per cent with a revision rate of 15.8 per cent. There was no correlation between revision rate and vein complexity or calf vein diameter. Calf vein diameter greater than 2.5 mm was correlated with a successful bypass (P less than 0.001). It is concluded that B-map is the investigation of choice for saphenous vein assessment before infrainguinal bypass surgery.

Aged↗
PubMed1989

B-G cDNA clones have multiple small repeats and hybridize to both chicken MHC regions.

We used rabbit antisera to the chicken MHC erythrocyte molecule B-G and to the class I alpha chain (B-F) to screen lambda gt11 cDNA expression libraries made with RNA selected by oligo-dT from bone marrow cells of anemic B19 homozygous chickens. Eight clones were found to encode B-G molecules which hybridize with sequences in the chicken MHC as defined by congenic strains; the fusion proteins react with multiple immune but not preimmune sera, they select antibodies from the antisera to B-G, which then react with distinct erythrocyte B-G protein patterns, and they elicit antibodies from mice which in turn react with authentic B-G proteins. None of the clones represent a complete message, some--if not all--bear introns, and none of them match with any sequences presently stored in the data banks. The following new information did, however, emerge. At least two homologous transcripts are present in this homozygous chicken, thereby formally proving the existence of an expressed multigene family. The 3' ends (3'UT) are simple sequences with 80% nucleotide identity between clones, while the 5' ends (either coding or noncoding) are composed of multiple short repeats which are far less similar. These repeats could explain the bewildering variation in size of B-G proteins within and between haplotypes. Southern blots of genomic chicken DNA gave complex patterns for most probes, with many bands in common using different probes, but few bands in common between haplotypes. The sequences detected are all present in the MHC, based on the congenic lines CB and CC. Most of these sequences map into the B-G region, but some map into the B-F/B-L region as defined by the haplotypes B15, B21, and their apparently reciprocal recombinants B21r3 and B15r1.

Animals↗