PubMed Health⌕ Search

Biomedical subjects

A Adler

Publications and source records attributed to A Adler.

At least 127 records · Page 7Linked to original sources
PubMed1988

Phosphorylation of multiple sites in a 15,000 dalton proteolipid from rat skeletal muscle sarcolemma, catalyzed by adenosine 3',5'-monophosphate-dependent and calcium/phospholipid-dependent protein kinases.

This study reports a partial characterization of a 15,000 dalton (15 kDa) proteolipid present in rat skeletal muscle sarcolemma. The proteolipid is phosphorylated by both cyclic AMP-dependent and calcium/phospholipid-dependent protein kinases, displays an isoelectric point (pI) of 5.9, and can be extracted from sarcolemma by acidified chloroform/methanol (2:1) or non-ionic detergents. Phosphoamino acid analysis and tryptic fingerprinting of the phosphorylated proteolipid indicate that both cyclic AMP- and calcium/phospholipid-dependent protein kinases predominantly phosphorylate serine residue(s) on a single tryptic peptide. Additivity experiments and thermolytic fingerprinting demonstrate a minimum of two distinct phosphorylation sites on the proteolipid, the phosphorylation of which is independently catalyzed by cyclic AMP-dependent and calcium/phospholipid-dependent protein kinases in vitro. This sarcolemma proteolipid, which appears to be identified to a sarcolemma protein previously reported to be phosphorylated upon addition of insulin in a GTP-dependent manner (Walaas, O., Walaas, E., Rye-Alertsen, A. and Horn, R.S. (1979) Mol. Cell. Endocrinol. 16, 45-55), therefore represents a possible membrane target for those neuronal and hormonal stimuli which can regulate cyclic AMP-dependent or calcium/phospholipid-dependent protein kinase activities in skeletal muscle.

Animals↗
PubMed1988

The influence of oxygen tension on membrane potential and tone of canine carotid artery smooth muscle.

In vascular smooth muscle of canine carotid artery segments the decrease in oxygen tension from approximately 550 mmHg to approximately 30 mmHg leads to a dose-dependent hyperpolarization and relaxation of the vessel strip. At PO2 values below approximately 15-20 mmHg depolarization and subsequent contraction were found. All changes of the parameters investigated were reversible. Indomethacin (10(-5) M) had no significant effect on the hypoxia-dependent potential and tension changes. The hyperpolarized part of the activation curve was obtained by plotting tension versus membrane potential values.

Animals↗
PubMed1988

Skeletal muscle sarcolemma proteins as targets for adenosine 3':5'-monophosphate-dependent and calcium-dependent protein kinases.

The present study documents the existence in rat skeletal muscle plasma membrane (sarcolemma) of a distinct set of proteins, most of which represent unknown protein species, which can be phosphorylated in vitro by addition of cAMP-dependent or calcium-dependent protein kinases. Under the experimental conditions used, cAMP-regulated protein phosphorylation appeared to be the most important phosphorylation system in these membranes, followed by the calcium/phospholipid-regulated, and, with only a few substrates detected, the calcium/calmodulin-regulated systems. No specific substrate for cGMP-dependent protein kinase was found. In contrast, calcium/calmodulin-regulated protein phosphorylation was the most important in the sarcoplasmic reticulum fraction. Most of the cAMP-regulated and calcium/phospholipid-regulated sarcolemma phosphoproteins appeared to be intrinsic membrane proteins, at least three of which appeared to be phosphorylated by both these protein kinases. These phosphoproteins may represent membrane targets for multiple hormone or transmitter actions in skeletal muscle cells. Our results, therefore, suggest that protein phosphorylation systems, particularly those regulated by cAMP or calcium/phospholipid, may be more important in the regulation of sarcolemma function than hitherto believed.

Animals↗
PubMed1988

Interleukin 2 induction of lymphokine-activated killer (LAK) activity in the peripheral blood and bone marrow of acute leukemia patients. I. Feasibility of LAK generation in adult patients with active disease and in remission.

The feasibility of in vitro interleukin 2 (IL-2) activation and expansion of mononuclear cells (MNCs) derived from adult patients with acute myelogenous leukemia (ANLL) was studied. Patients' natural killer (NK) and lymphokine-activated killer (LAK) cell activity was compared with that of normal donors in terms of: (a) cytolytic activity (four-hour 51Cr release assay) against an NK-sensitive target (K562), NK-resistant targets (Raji/Daudi), and fresh/cryopreserved autologous and allogeneic leukemic blasts; (b) proliferation and expansion in culture with 1,000 U/mL recombinant IL 2 (rIL 2); and (c) the cell surface phenotype of the cultured cells. In 21 of 24 patients with active disease (AP) MNCs derived from the peripheral blood (PBL) or bone marrow (BM) could be cultured and expanded in the presence of rIL 2. These cultures initially contained between 30% and 50% blasts, and during 2 to 4 weeks of culture destruction of blasts and enrichment of up to 60% in cells with the morphology of large granular lymphocytes (LGLs) was observed. Expansion in culture varied between two- and 100-fold. MNCs from all patients in remission (RP) could be activated by rIL 2 and expanded up to 30-fold after 1 to 3 weeks in culture. NK activity of fresh PBLs from AP was significantly lower than in normal controls, whereas NK activity of RP was within the normal range. High levels of postactivation NK and LAK activity on K562/Raji/Daudi and on fresh/cryopreserved leukemic blasts was generated in approximately 50% of cases of AP and in most RP. Cell surface phenotype studies showed that cultured cells derived from ANLL patients were significantly enriched (up to 40%) in NKH-1 (Leu 19) positive cells, with RP LAK cells also expressing a high proportion of CD16 positive cells (up to 40%). This study has shown that it is feasible to activate and significantly expand killer cells derived from active disease and remission ANLL patients during 1 to 3 weeks culture with IL 2 with good maintenance of cytolytic activity. Both initial NK activity and LAK generation was optimal in remission patients. Based on data from this study, a clinical protocol has been developed for treatment of early relapse ANLL patients with LAK cells cultured for 1 to 3 weeks and systemic IL 2.

Acute Disease↗
PubMed1987

Insulin increases membrane protein kinase C activity in rat diaphragm.

Calcium/phospholipid-dependent protein kinase activity (protein kinase C) was identified in rat diaphragm membrane and cytosol fractions by means of in vitro phosphorylation either of histones or of a specific 87 kDa protein substrate, combined with phosphopeptide-mapping techniques. Both insulin and tumor-promoting phorbol ester treatment of the diaphragm preparations led to increased protein kinase C activity in the membrane fractions. In contrast to the phorbol ester, however, insulin did not induce a concomitant decrease in cytosolic activity, indicating that translocation of the enzyme had not taken place. Thus, insulin appears to increase specifically membrane protein kinase C activity in rat skeletal muscle, possibly through a mechanism not identical to that induced by phorbol esters.

Animals↗
PubMed1987

Ultrasound-guided brain abscess aspiration in neonates.

Four cases of brain abscess in neonates are described, diagnosed by ultrasonography and CT. All abscesses were confirmed surgically. One patient was operated on 5 weeks after diagnosis because of initial parental refusal. The etiology in all cases was meningitis superimposed on an hypoxic-ischemic insult. Two cases had a single abscess while the other two had multiple lesions. All cases were operated on with intraoperative ultrasound examination through the fontanelle. The case with delayed aspiration showed complete evolution from localized cerebritis to complete capsule formation with mass effect. One abscess was sterile, and in the others grew Klebsiella pneumoniae and Enterobacter aerogenes. The microorganism initially isolated from the lumbar CSF was also found in the abscess. Even after sterilization of the lumbar CSF, all abscesses were still present. Ultrasound examination and CT are compared.

Brain Abscess↗
PubMed1987

Active specific immunotherapy of renal cell carcinoma patients: a prospective randomized study of hormono-immuno-versus hormonotherapy. Preliminary report of immunological and clinical aspects.

Early results of a prospective, randomized trial of active, specific immunotherapy adjunctive to nephrectomy in all stages of RCC are presented. Forty-three patients with median followup of 30 m, who were randomly allocated to either immuno-hormonotherapy arm (IMT), or hormonotherapy alone (HT), are evaluated in terms of progression-free interval (PFI) and overall survival by life table method. Immunotherapy consisted of autologous irradiated tumor cells (AITC), admixed with bacillus Calmette-Guérin (Glaxo) administered by the intradermal and endolymphatic route. Clinical results of this study show only a trend for advantage of the experimental (IMT) arm over the control (HT) arm, this trend did not reach statistical significance level: prolongation of disease free period in stages I-III with localized disease (p less than 0.1) and prolongation of survival in patients with metastatic disease (p less than 0.07). A correlation was established between induction of cutaneous delayed hypersensitivity (DTH) to AITC and prolonged PFI and survival: patients with positive DTH had a significantly better course of disease than those who could not be converted to positivity after repeated immunizations. Positive in vitro leukocyte migration inhibition against autologous tumor preparations correlates well with positive in vivo cutaneous DTH. Some immunological aspects of active immunization with autologous tumor cells are discussed.

BCG Vaccine↗
PubMed1986

Evidence that insulin and guanosine triphosphate regulate dephosphorylation of the beta-subunit of the insulin receptor in sarcolemma membranes isolated from skeletal muscle.

When sarcolemma membranes isolated from rat skeletal muscle were incubated with [gamma-32P]ATP, a membrane protein of apparent Mr 95,000 was rapidly phosphorylated, with the 32P content reaching a maximum within 2 s. On the basis of immunoprecipitation with anti-insulin-receptor antiserum, phosphoamino acid analysis and Mr, this protein probably represents the beta-subunit of the insulin receptor. Similarly, on incubation of the membrane with adenosine 5'-[gamma-[35S]thio] triphosphate the 95 kDa protein was thiophosphorylated, indicating thiophosphorylation of the beta-subunit of the insulin receptor on the basis of immunoprecipitation studies. The effect of insulin on the phosphorylation of this protein in the membrane was studied. Insulin induced a 20% decrease in the 32P labelling of the protein when the membranes were phosphorylated for 10 s. This insulin effect was dose-dependent, with half-maximal effect obtained at 2-3 nM-insulin. Addition of GTP, but not GDP or guanosine 5'-[beta, gamma-imido]triphosphate, enhanced the effect to 35% inhibition, with half-maximal effect of GTP obtained at 0.5 microM. GTP had no effect on the phosphorylation of the protein in the absence of insulin. Analysis of this insulin effect showed that insulin increased the rate of dephosphorylation of the 95 kDa protein in the membrane. In contrast, insulin had no effect on thiophosphorylation of the 95 kDa membrane protein after incubation with adenosine 5'-[gamma-[35S]thio]triphosphate. Since thiophosphorylated proteins are less sensitive to phosphatase action, these investigations suggest that insulin stimulated a protein phosphatase activity in a GTP-dependent manner. The possibility that GTP-regulatory proteins are involved in the action of insulin on the phosphorylation of the insulin receptor and other membrane proteins is discussed.

Animals↗
PubMed1986

The effect of cimetidine on PBL from healthy donors and melanoma patients: augmentation of T cell responses to TCGF mitogens and alloantigens and of TCGF production.

The effect of cimetidine, an H-2 receptor antagonist, on activation of PBL from both normal individuals and melanoma patients was studied. It has been shown that cimetidine enhanced, though moderately, the production of TCGF from normal PBL after PHA-P stimulation. In addition, cimetidine significantly augmented TCGF-induced proliferation of normal PBL, as well as proliferation induced by allogeneic cells (MLC) by PPD, Con A, and PHA. In PBL samples where coincubation with cimetidine had limited or no effect, preincubation of PBL with cimetidine prior to the addition of IL-2 and other T cell activators showed a significant enhancement effect. This effect mediated by cimetidine was further demonstrated on PBL from melanoma patients whose T cell responses were initially low. The possibilities are discussed that: (a) cimetidine treatment inactivates suppressor cell activity, thus enhancing T cell mediated responses; or (b) cimetidine may act directly at effector cell level.

Cells, Cultured↗
PubMed1985

Development of resistance to MOPC-315 plasmacytoma after intralesional and intraperitoneal melphalan therapy of tumor-bearing BALB/c mice. II. Enhancement of in vitro cell-mediated cytotoxicity by combined chemotherapy-immunotherapy.

As previously reported, tumor-bearing BALB/c mice can be cured by split-course melphalan therapy, with 40-60% of the treated animals developing resistance to subsequent challenge with viable MOPC-315. The present study deals with the identification of effector-cytotoxic cells that may be developed as a result of chemotherapy-induced tumor regression and their possible potentiation by active, specific immunization with melphalan- and glutaraldehyde-treated MOPC-315 plasmacytoma cells. The cytotoxic potential of spleen-derived lymphocytes in treated animals could be demonstrated only after in vitro sensitization against mitomycin-treated MOPC-315 cells. Lymphocyte-mediated cytotoxicity, as measured against syngeneic 51Cr-labeled MOPC-315, could be detected in melphalan-cured animals and was significantly enhanced by active immunization as compared to the cytotoxicity seen in normal and tumor-bearing mice. With the use of M109 syngeneic, unrelated tumor cells as control targets in the assay, no cytotoxicity was detected. Macrophage cytotoxicity was not significantly enhanced in any of the treatment groups described, with these assays performed 6-8 weeks following treatment and cure. When in vitro killing of MOPC-315 targets was tested with the use of peritoneal macrophages harvested shortly following cure of ascitic tumor by ip injected melphalan, the cytotoxic response was significantly enhanced. In conclusion, following chemotherapy-mediated cure of established MOPC-315 tumors, splenic lymphocytes exhibited enhanced antitumor cytotoxicity, which was further augmented by active immunization. Macrophage activation, as measured by direct cytotoxicity against MOPC-315 targets, was found to occur locally and early following the event of melphalan-induced tumor regression.

Animals↗
PubMed1984

Intralesional injection of interleukin-2-expanded autologous lymphocytes in melanoma and breast cancer patients: a pilot study.

The clinical effect of intralesional injection of interleukin-2 (IL-2)-cultured autologous lymphocytes was assessed in seven patients with cutaneous, recurrent tumor nodules (12 melanoma and 8 mammary cancer lesions). Each tumor nodule was injected 3-10 times, once weekly, with IL-2-cultured lymphoid cells (CLC), 40-400 million cells at each injection. Lymphoid cells obtained from buffy coats were separated on Ficoll-Paque, cryopreserved in liquid nitrogen, thawed, and cultured for 1-2 weeks in the presence of crude IL-2 (containing phytohemagglutinin) before injection. CLC were tested for sterility, percent E-rosette-forming cells, and cytotoxicity against K562, allogeneic melanoma, and breast cancer cell lines and autologous tumor cells. Enhanced cytotoxicity was expressed by IL-2 CLC, as compared with nonstimulated peripheral blood lymphocytes (PBL). Arrest of tumor growth (compared with untreated lesions) was observed in eight lesions and partial regression in three lesions. Moreover, complete regression was noted in one large melanoma lesion treated with low-dose irradiation prior to intralesional administration of CLC and in three small intracutaneous melanoma lesions treated with CLC only. Histopathological findings of responding lesions showed infiltration with lymphoid cells and macrophages, with the tumor cells sparsely dispersed. No untoward side effects of CLC injections were observed. The present study points to the feasibility of trials of adoptive immunotherapy in cancer patients as indicated by the following: (a) response of lymphoid cells to IL-2 adequate--although reduced--in patients with metastatic disease, including those after chemo- or radiotherapy; (b) possibility of cryopreservation of PBL and repeated culturing in IL-2 after thawing, with cytotoxic activity unimpaired; (c) demonstrably enhanced cytotoxicity in vitro of IL-2 CLC; (d) demonstrable--although limited--clinical response to in situ treatments with IL-2 CLC; (e) good tolerance of treatment with CLC.

Breast Neoplasms↗