Biomedical subjects

T Hollander

Publications and source records attributed to T Hollander.

8 recordsLinked to original sources

PubMed2001

The T lymphocyte structure CD60 contains a sialylated carbohydrate epitope that is expressed on both gangliosides and glycoproteins.

The CD60 antigen is expressed on a majority of T cells in autoimmune lesions, and anti-CD60 can activate T lymphocytes. CD60 has been defined as the GD3 ganglioside, and subsequently as the 9-O-acetylated form of GD3. However, other evidence suggests that anti-CD60 recognizes a glycoprotein or family of glycoproteins expressed by T lymphocytes. The current studies were undertaken to better define the identity of the CD60 antigen on both T cells and non-T cells. Treatment of intact cells with neuraminidases of various specificities confirmed that detection of the CD60 epitope depends on expression of an alpha2, 8-disialic acid carbohydrate linkage, as is found in GD3 and related gangliosides. However, the sialicacid polymer colominic acid inhibited anti-GD2 and anti-GD3, but not anti-CD60 from binding to cell surfaces. Expression of CD60 did not correlate with expression of GD3 on a variety of cell lines and T cell populations. Expression of CD60 and 9-O-acetyl-GD3 was roughly parallel on some non-T cell lines such as melanoma cells, but on T cells expression of CD60 was consistently greater. Antibodies to GD2, GD3 and 9-O-acetyl-GD3 were ineffective at inhibiting binding of anti-CD60 to CD60+ cells. Activation responses of T cells to anti-CD60 were inducible in either the presence or absence of a response to anti-GD3. A novel inhibitor of glucosyl ceramide synthesis, D-threo-1-phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (D-t-P4) reduced expression of GD3 much more than CD60 on activated T lymphocytes. Following biotinylation of HUT78 T cells, anti-CD60 immunoprecipitated a 70 kDa antigen. Taken together, the present data and previous findings suggest that anti-CD60 can recognize both a modified form of the GD3 ganglioside and a carbohydrate-dependent complex epitope present on one or more glycoproteins. This glycoprotein epitope may be the more abundant and functionally significant CD60 antigen on T lymphocytes, while 9-O-acetyl-GD3 is likely to be the principal structure recognized by anti-CD60 on melanoma cells. These findings emphasize the complexity of understanding the functional roles of carbohydrate epitopes in cell activation.

Antigens, CD↗

PubMed1997

The new commitment to patient satisfaction.

CheckUp helps dentists measure and increase patient satisfaction through easy, inexpensive patient surveys. The CheckUp survey is endorsed by the American Dental Association (ADA) and several state dental associations. This article discusses the importance of committing to and maintaining the highest possible level of patient satisfaction not only as a practice management strategy, but also as a source of pride in one's reputation as a professional.

Costs and Cost Analysis↗

PubMed1993

Characterization of the oligosaccharide structures on bee venom phospholipase A2.

The N-linked oligosaccharide structures on bee venom phospholipase A2 were investigated. The oligosaccharides on purified phospholipase A2 were released by hydrazinolysis and labeled in vitro by reduction with NaB3H4. Following purification, the labeled oligosaccharides were characterized by size exclusion chromatography in combination with digestion with specific glycosidases. Linkage positions were determined by methylation analysis. Four types of structures were identified on the molecule, all of which were of truncated high-mannose type and none of which contained any alpha-(1-->2)-linked mannose residues. The majority of the structures were Man3 oligosaccharides with (43%) or without (38%) a fucose residue linked alpha-(1-->6) to the reducing N-acetylglucosamine. The remaining 19% of the oligosaccharides on the molecule were identified as a Man5 oligosaccharide without core fucose (9.6%) and a core-fucosylated Man4 structure (9.2%).

Bee Venoms↗

PubMed1993

Isolation and expression of a cDNA clone encoding a bovine UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase.

NH2-terminal amino acid sequence obtained from a UDP-GalNAc:polypeptide N-acetylgalactosaminyl-transferase (GalNAc-transferase) isolated from bovine colostrum was used for the construction of synthetic oligonucleotide primers. Subsequent polymerase chain reaction and library screenings of a bovine intestine cDNA library produced seven positive clones. The largest clone had a 2294-base pair insert that contained an open reading frame coding for a protein composed of 559 amino acids with a predicted polypeptide molecular mass of 64,173 Da. The cloned molecule has no significant sequence homology to previously reported cloned glycosyltransferases, but appears to have a similar domain structure. It is a type II membrane protein with a 23-amino acid putative transmembrane region starting 8 amino acids from the NH2 terminus. The transmembrane segment of the molecule is immediately followed by a sequence rich in proline residues. The molecule contains three consensus sequences for N-linked glycosylation and five predicted sites for O-glycosylation. Northern blot analysis of poly(A+) mRNA isolated from Madin-Darby bovine kidney cells, bovine mammary tissue, and eight human tissues demonstrated the expression of two transcripts differing in size by approximately 1 kilobase. The cloned DNA was expressed in insect cells using a baculovirus vector. This resulted in an almost 100-fold increase in GalNAc-transferase activity in lysates prepared from cells infected with virus containing the GalNAc-transferase gene compared to cells infected with virus containing DNA coding for an unrelated molecule or uninfected cells. Immunoprecipitation from lysates prepared from infected cells labeled in vivo with [35S] methionine showed a large increase in the recovery of an approximately 67-kDa protein.

Amino Acid Sequence↗

PubMed1980

Visually monitored postrotary nystagmus in seven autistic children.

Therapists who evaluate the sensorimotor functions of autistic children have become increasingly interested in monitoring their responses to vestibular stimulation. In this study, the duration of the nystagmus reflex is visually monitored and then measured by means of a stop-watch. Each of 7 autistic subjects received 18 sessions (36 trials) of horizontal semicircular canal stimulation during a period of 25 days. In each trial a graduated acceleration in a hand operated rotating chair preceded an abrupt stop, with a rapid deceleration from 180 degrees/second to 0 degree/second. Although subject option (intentional response) imposes limitations on the data interpretation, inspection of the nystagmus functions over time suggests the following: substantial trial-to-trial variability; substantial subject-to-subject variability; greater scores following trials to the subjects' left (the direction of the second trial in each session) than to the right (the direction of the first); and no evidence of consistent change for most subjects in nystagmus duration across the 36 trials. Implications for clinical evaluation of nystagmus are discussed.

Autistic Disorder↗

PubMedDate not supplied

Effect of prior nucleoside use on the two-year virological response to an initial protease inhibitor regimen in HIV-infected patients.

PURPOSE: This retrospective study investigates the effect of prior nucleoside (nucleoside reverse transcriptase inhibitor [NRTI]) experience on 2-year virologic response to an initial protease inhibitor-highly active antiretroviral therapy (PI-HAART) regimen. METHOD: 152 patients who started a PI (excluding saquinavir hard gel capsule [hgc] as a sole PI) with two NRTIs between January 1996 and May 1998 at two HIV treatment sites were included. RESULTS: 109 patients (71%) were NRTI experienced. 106 patients received two new NRTIs, and 32 received one new NRTI. Overall, 51% of patients had a virologic response (HIV viral load <400 copies/mL); the mean follow-up was 28 months. Virologic response was associated with the use of at least one new NRTI (relative risk [RR] 2.1; p =.031) but not with prior NRTI experience (p =.19). A complete virologic response was most likely to occur when two new NRTIs were used (RR 2.3) rather than one new NRTI (RR 1.8), but this was not significant (p =.12). CONCLUSION: This study suggests that prior nucleoside experience is not a key predictor of 2-year virologic response in patients who receive at least one new NRTI in an initial PI-HAART regimen.

Adult↗

PubMedDate not supplied

Antithymocyte gamma globulin, low-dosage cyclosporine, and tapering steroids as an immunosuppressive regimen to avoid early kidney failure in heart transplantation.

Cyclosporine is a powerful immunosuppressive agent that unfortunately has significant renal toxicity. Two risk factors associated with a high incidence of kidney failure in patients receiving cyclosporine have been described in the literature. In an effort to decrease the possibility of renal toxicity with the use of cyclosporine, we use low-dosage cyclosporine, antithymocyte gamma globulin, and tapering dosages of steroids as an immunosuppressive regimen. Twenty-one patients had orthotopic heart transplants from January 1985 to January 1986. Sixteen of 21 patients or 70% had at least one high risk factor for kidney failure. There were no episodes of acute kidney failure, and the blood urea nitrogen and creatinine levels that were recorded over an average of 8.5 months per patient did not increase significantly from preoperative values. Seventeen of 21 or 81% of the patients are alive and functioning fully. The incidence of rejection per patient was 0.9, and there were no biopsy-proven severe rejections. One patient died at 5 months; the autopsy showed generalized moderate rejection. There were 0.24 episodes of infection per patient, with one patient who died from Pneumocystis pneumonia. With this immunosuppression protocol, early postoperative kidney dysfunction was avoided. The incidences of rejection and infection were within acceptable range, and the quality of life in the 17 survivors is excellent.

Acute Kidney Injury↗

PubMedDate not supplied

[Serum testosterone response to chorionic gonadotropin (HCG) injection in normal and cryptorchid children (author's transl)].

Plasma testosterone (ng/ml) was measured in a group of prepuberal children with intrascrotal testes (n = 15) and in a group of prepuberal cryptorchid children (7 unilateral and 3 bilateral; n = 10) before and after stimulus with 3000IU of HCG (Group A) and with 5000IU (Group B). The serum testosterone before HCG stimulus was similar in normal (Group A: 1.10 +/- 0.03: Group B: 1.18 +/- 0.31) as well as in those of the cryptorchid children (Group A: 1 +/- 0.28; Group B: 1.19 +/- 0.36). The stimulus with 3000IU of HCG did not significantly raise the plasma testosterone in both normal (2.42 +/- 1.09) and cryptorchid children (1.70 +/- 0.5). The stimulus with 5000IU of HCG increased the plasma testosterone to 3.52 +/- 1 in normal children and 3.26 +/- 1.2 in cryptorchid children (p less than 0.05 with respect to the pre HCG values), with no difference in the response between the normal and the cryptorchid children.

Child↗