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C M Kramer

Publications and source records attributed to C M Kramer.

52 records · Page 3Linked to original sources
PubMed1992

Bacteria that degrade p-chlorophenol isolated from a continuous culture system.

Two Gram-positive coryneform bacteria that degraded p-chlorophenol isolated from a continuous culture system are characterized. Isolate B (probably and Arthrobacter sp.) completely removed the p-chlorophenol from a medium with a concomitant increase in cell density within 16 h. Isolate F similarly removed the p-chlorophenol within 28 h but without an increase in cell density. Isolates B and F also removed the p-chlorophenol from a medium with p-chlorophenol as the sole carbon source within 32 and 48 h, respectively. The optimal temperature for p-chlorophenol degradation by both organisms was 25 to 30 degrees C. The optimal pH range for p-chlorophenol degradation was pH 7-9 for isolate B and pH 8-9 for isolate F. Since these native environmental bacteria can degrade p-chlorophenol, they may have an important application in waste water treatment processes.

Arthrobacter↗
PubMed1992

Tracheal epithelial cell fatty acid composition modulates prostaglandin E2 and cAMP production.

Tracheal epithelial (TE) cells from both rabbits and humans, when cultured in defined serum-free media without lipid supplements, develop fatty acid profiles significantly different from freshly isolated epithelium, including a markedly decreased cellular content of arachidonic acid (AA). In rabbit TE cells, supplementation of media with a phospholipid-rich lipoprotein extract (Excyte III) plus 1 microM bovine serum albumin-complexed AA (Excyte/AA) restored the fatty acid composition of the cultured cells more similar to that of native airway epithelium than did supplementation of media with 5% fetal bovine serum (FBS). In human TE cells, Excyte/AA or 5% FBS increased AA content, but neither lipid supplement completely "normalized" the fatty acid profiles. Compared with lipid-unsupplemented cultures, basal production of prostaglandin E2 (PGE2) was increased by approximately four- to eightfold in rabbit and human TE cells supplemented with 5% FBS or Excyte/AA. In Excyte/AA-supplemented human TE cells, PGE2 production induced by 5 microM calcium ionophore A23187 was more than threefold greater than that of companion ionophore-stimulated unsupplemented monolayers, but PGE2 production was similar in both culture conditions in response to 10 microM exogenous AA. Thus increased cellular content and availability of AA, rather than changes in cyclooxygenase activity, appear to be responsible for the elevated PGE2 production in Excyte/AA-supplemented human TE cells. Secondary effects of lipid supplementation were also observed; Excyte/AA-supplemented human TE cells produced significantly less adenosine 3',5'-cyclic monophosphate (cAMP) in response to exogenous PGE2 and isoproterenol than did lipid-unsupplemented cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Prostaglandin E2 attenuates hyperoxia-induced injury in cultured rabbit tracheal epithelial cells.

We assessed the kinetics of hyperoxia-induced prostaglandin E2 (PGE2) production by cultured rabbit tracheal epithelial (TE) cells with different inherent capacities to generate PGE2 and the role of endogenous PGE2 production in protecting these cells from hyperoxic injury. Rabbit TE cells grown to confluence with or without lipid supplements [0.1% Excyte III (Miles-Pentex) and 1 microM arachidonic acid] were exposed for 2 h to control (5% CO2/air) or hyperoxic (5% CO2/90% O2) atmospheres at a gas-fluid interface. Serial cell culture effluents collected during exposure were analyzed for PGE2 by enzyme-linked immunoassay. Basal PGE2 production by lipid-supplemented cells was approximately 3-fold greater than that by unsupplemented cultures (p less than 0.01). In lipid-supplemented cells, PGE2 production doubled after 15 min of hyperoxic exposure (p less than 0.05) and then declined to approximately 50% of initial levels, whereas exposure to 5% CO2/air did not significantly change PGE2 production. In unsupplemented cells, neither control nor hyperoxic exposure altered PGE2 production. Hyperoxia-exposed TE cells had decreased ability to convert 10 microM exogenous arachidonic acid to PGE2, suggesting hyperoxia-induced inhibition of the enzymes involved in PGE2 synthesis. Lipid-supplemented cells were less susceptible to hyperoxic injury than unsupplemented monolayers, as evidenced by increased viability (trypan blue exclusion) and decreased generation of lipid peroxides (thiobarbituric acid reactive substances). Addition of exogenous PGE2 to unsupplemented cultures at concentrations that were produced by lipid-supplemented cells (2 ng/mL every 15 min) during hyperoxic exposure eliminated these differences in hyperoxia-induced lipid peroxidation and cytotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Morphologic injury and lipid peroxidation in monolayer cultures of rabbit tracheal epithelium exposed in vitro to ozone.

Numerous reports have documented airway epithelial damage and lipid peroxidation in the lungs of animals exposed to ozone. However, the response of isolated tracheal epithelial (TE) cells to ozone has not been extensively studied. To assess ozone-induced injury in cultured TE cells, an in vitro exposure system was developed in which cells were maintained at gas-fluid interface analogous to in vivo conditions. Confluent monolayer cultures of rabbit TE cells were exposed for 30 min to atmospheres of 5% CO2/air containing 0.05, 0.1, 0.5, 1, 2, 4, 6, or 8 ppm ozone. Morphologic injury was assessed by phase-contrast microscopy and by determination of TE cell number and viability (trypan blue dye exclusion) pre- and postexposure, and the lipid peroxide content of TE cells was measured as thiobarbituric acid (TBA) reactive substances. Exposure to 5% CO2/air alone did not affect monolayer morphology, cell number of viability. Cultures exposed to 0.05 or 0.1 ppm ozone demonstrated no consistent light microscopic changes, whereas exposure to 0.5 ppm and higher ozone concentrations caused distortion of monolayer morphology, cytoplasmic vacuolization, and decreased viability. Exposure to 0.5 or 1 ppm resulted primarily in cytoplasmic vacuolization while exposure to 2, 4, 6, or 8 ppm induced more pronounced cellular injury associated with cell necrosis (viability post 8 ppm ozone 75.0 +/- 7.0%, vs. 95.9 +/- 2.6% for 5% CO2/air controls). Ozone exposure also caused changes in cell shape, which on occasion resulted in loss of cell-to-cell contact. Increased production of TBA-reactive substances was detected in TE cells following ozone exposure, including exposure to 0.05 and 0.1 ppm. The morphologic changes induced by in vitro ozone exposure in the cultured TE cells were similar to those described in the tracheal epithelium of ozone-exposed animals and occurred independent of recruited inflammatory cells or extravasated circulating mediators.

Animals↗
PubMed1990

Effect of fatty acid profiles on the susceptibility of cultured rabbit tracheal epithelial cells to hyperoxic injury.

To investigate the role of cellular fatty acid content on the susceptibility of airway epithelial cells to hyperoxic injury, monolayer cultures of rabbit tracheal epithelial (TE) cells were grown to confluence in serum-free media with or without a commercial mixture of cholesterol esters and phospholipid-rich lipoproteins (Excyte III, Miles-Pentex, Kankakee, IL) in conjunction with arachidonic acid complexed to BSA. Monolayer cultures were then exposed to control (5% CO2/air) or hyperoxic atmospheres (95% oxygen/5% CO2) for 2 h using an in vitro system in which cells were maintained at a gas-liquid interface analogous to in vivo conditions. Hyperoxic injury was assessed by cell viability (trypan blue exclusion) and by the generation of lipid peroxides measured as thiobarbituric acid (TBA) reactive substances. Changes in TE cell and cell culture effluent fatty acid content induced by exposure to control or hyperoxic atmospheres were analyzed by gas chromatography. TE cells grown in lipid-unsupplemented media had fatty acid profiles characteristic of essential fatty acid deficiency, whereas the fatty acid content of lipid-supplemented TE cells more closely resembled those of acutely recovered TE cells. Lipid-unsupplemented cells were more susceptible to hyperoxic injury as demonstrated by decreased viability and increased production of TBA-reactive substances compared to cells maintained in lipid-supplemented media. In both lipid-supplemented and unsupplemented cells, hyperoxic exposure was associated with a decreased relative cellular content of the monounsaturated and polyunsaturated fatty acids (PUFA) and an increased content of saturated fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

The carboxylmethylation of cerebral membrane-bound proteins increases with age.

Recently, we have characterized a membrane-bound (mb) component of brain protein carboxylmethyltransferase II (PCMT) which effectively carboxylmethylates endogenous mb methyl-accepting proteins (MAPs). (Neurochem. Int., 10 (1987) 155). We have also shown that exposing mb-MAPs to mild alkali leads to a marked increase in their recognition by PCMT. Since one of the likely consequences of the alkaline treatment appears to be the deamidation of selected protein-bound asparagines or aspartates, followed by the formation, in their place, of D-or L-isoaspartates, it is reasonable to assume that mb-MAPs constitute unique targets for the mb-PCMT because they contain such unnatural aspartate residues. Testing the relevance of this notion to the aging of cerebral mb-MAPs we focus in this report on age-related changes involving mb-MAPs. When two-or six-times washed (in 50 mM NaPO4 buffer, pH 6.5) 17,500 g, 30-min membranes or Percoll-gradient purified synaptic membranes were prepared from young (3-4 months) and old (11-12 months) rat brains and were incubated with 20 microM [3H]methyl S-adenosyl-L-methionine at pH 6.0, mb-MAP carboxyl[3H]methylation was significantly more intense in the old than in the young membranes, no additional increase being noted at 28-35 months. Mb-MAP carboxylmethylation increases were confirmed over a wide range of membrane protein concentrations and incubation times and are taken to reflect age-related modifications of the primary structure of susceptible mb-MAPs. To investigate these, we incubated young and old membranes, as well as their Lubrol-Px (1%) extracts (30 min, 0 degree C), with 0.05 M NH4OH for 90 min at 37 degrees C, a treatment which left PCMT activity largely unaffected. Our findings reveal that the effect of the NH4OH treatment on the generation of carboxylmethylatable sites was markedly smaller in "old" than in "young" proteins, suggesting that "new" carboxylmethylatable sites are generated in susceptible mb-MAPs in situ, by a process accompanying, or otherwise marking, the natural aging of neural membrane proteins.

Aging↗
PubMed1987

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) enhances antibody production and protein kinase activity in murine B cells.

Treatment of murine spleen cells with 30 nM TCDD resulted in an approximately 3 fold increase in unstimulated antibody production after 3 days in culture. This response was not accompanied by increased cellular proliferation and may represent an effect of TCDD on B cell activation or differentiation. Since PMA is capable of activating B cells, presumably via PKC, we have compared the effects of PMA and TCDD on protein kinase activation and phosphorylation of endogenous proteins in a highly purified preparation of B cells. In contrast to a reduction of cytosolic PKC activity, the expected effect of PMA, TCDD caused an increase in basal kinase activity with no effect on PKC activity. Addition of either PMA or TCDD resulted in enhanced phosphorylation of a similar profile of proteins, including proteins of Mr 12.2, 14.6, 29.2, 52.3 and 62.7 KDa. Addition of TCDD also resulted in the increased phosphorylation of a protein of Mr 45.2, which was unaffected by PMA. Combined treatment with PMA and TCDD resulted in additive responses. The additive effects of PMA and TCDD suggest an interaction at the level of protein phosphorylation which is mediated by different kinases. Therefore, TCDD may be stimulating B cells via an early effect on an unidentified protein kinase.

Animals↗
PubMed1986

Lack of direct effect of 2,3,7,8-tetrachlorodibenzo-P-dioxin (TCDD) on protein kinase C activity in EL4 cells.

In vivo administration of TCDD produces an increase in the level of Protein Kinase C in the hepatic plasma membrane. We have studied the direct effects of TCDD on cultured EL4 thymoma cells, which contain a large amount of Protein Kinase C and respond to phorbol esters with rapid translocation of the kinase to the membrane, followed by growth inhibition, adherence to substrate and production of interleukin 2. TCDD (10-1000 nM) did not compete with 3H-phorbol dibutyrate for binding to cytosolic Protein Kinase C, and had no effect on Protein Kinase C activity in vitro. TCDD did not stimulate translocation of Protein Kinase C to the membrane, and did not affect phorbol ester-stimulated translocation. TCDD did not inhibit EL4 cell growth or affect phorbol ester induced growth inhibition, and failed to stimulate production of interleukin 2. Thus, TCDD does not appear to activate Protein Kinase C in EL4 cells.

Cell Line↗
PubMed1986

Substrates for protein kinase C in cytosol of EL4 mouse thymoma cells.

Phorbol esters trigger production of interleukin 2 by EL4 thymoma cells via an interaction with specific receptors, now considered to be identical with protein kinase C. Several in vitro substrates for protein kinase C were characterized by incubating cytosol from phorbol ester-responsive and -nonresponsive cells with [32P]adenosine triphosphate and CaCl2 with or without phosphatidylserine and diolein and separating proteins by gel electrophoresis. Phosphorylation of these proteins was calcium dependent in the range of 1-100 microM and stimulated by 10-150 micrograms of phosphatidylserine per ml. Calcium concentrations above 500 microM inhibited 32P incorporation and decreased phospholipid stimulation. Phorbol-12-myristate-13-acetate stimulated phosphorylation of these proteins, with a maximal concentration of 10 nM, providing strong evidence that these are protein kinase C substrates. The substrates for protein kinase C coeluted with the enzyme after binding to a phosphatidylserine affinity column in a calcium-dependent manner. Molecular weights of the protein kinase C substrates in sensitive cell cytosol were approximately 92,000, 84,000, 70,000, 67,000, 53,000, 45,000, 40,000, 36,000, and 20,000. A similar EL4 line which has phorbol ester receptors and protein kinase C, but does not produce interleukin 2 in response to phorbol esters, lacked the Mr 45,000 substrate and often also lacked the Mr 40,000 and 36,000 substrates. These proteins were also analyzed by two-dimensional electrophoresis. These results provide evidence of differences in the two cell lines in the ability of some proteins to serve as substrates for protein kinase C. Four proteins in a highly purified preparation of protein kinase C, at molecular weights of 66,000, 74,000, and 78,000 (all with pI 6.5-7.1) and of 62,000 (pI 6.2-6.4), were protein kinase C substrates, one of which is probably protein kinase C.

Animals↗
PubMed1985

The phantom earache. Temporomandibular joint dysfunction in children.

Temporomandibular joint dysfunction is a benign, relatively uncommon childhood disorder and should be considered in children who have intermittent unilateral otalgia of three to four days' duration and whose audiographic, tympanometric, and clinical otologic examinations reveal normal findings. Most of the patients in our study had undergone orthodontic therapy during the year preceding the onset of temporomandibular joint dysfunction, and the vast majority of them had received orthodontic treatment within two weeks of each episode of otalgia. The diagnosis can be confirmed clinically by reproducing the pain associated with masticatory muscle spasm by palpation of the preauricular areas, intraotic manipulation, and palpation of the pterygoid muscles. Treatment consists of administering acetaminophen, applying hot compresses to the preauricular area, and opening and closing the mouth 30 to 40 times after each compress as an effort to interrupt the muscle spasm.

Adolescent↗
PubMed1984

Regulation of phosphatidylinositol turnover, calcium metabolism and enzyme secretion by phorbol dibutyrate in neutrophils.

The action of the tumor promoter, phorbol 12,13-dibutyrate (PDBu), on rabbit peritoneal and human neutrophils is associated with stimulation of 14C-arachidonic acid incorporation into phospholipids within 1-2 min. Stimulated 14C-arachidonate incorporation was relatively selective for phosphatidylinositol (PI) in rabbit neutrophils. In contrast, the secretory response of human neutrophils to PDBu coincided with stimulated label incorporation into phosphatidylserine (PS), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidic acid (PA) and PI. Significant increases in label incorporation were observed with PDBu concentrations as low as 2 nM, and the dose response of stimulated label incorporation paralleled that of evoked lysozyme secretion. A parallel, but partial, inhibition of PDBu-stimulated PI labeling and enzyme release was observed after exposing rabbit neutrophils to calcium-deprived medium, whereas calcium deprivation failed to significantly depress either of these stimulant actions of PDBu in human neutrophils. Further, in rabbit neutrophils PDBu elicited an increase in cell associated 45Ca. However, PDBu was unable to promote the incorporation of 32P orthophosphate into PI or enhance phospholipase A2 activity in broken cells. These findings suggest that one expression of the interaction between phorbol esters and their receptors on neutrophils involves the turnover of arachidonic acid in phospholipids. This stimulated turnover of arachidonate may be a critical step in the cascade of events associated with neutrophil activation.

Animals↗
PubMed1979

Treatment of inoperable lung carcinoma: a combined modality approach.

Twenty-four patients with inoperable lung carcinoma other than of the small cell type who received cis diamminedichloro platinum (II)-based combination chemotherapy were further treated with all available treatment modalities: radiation therapy, lung resection, chemotherapy, and immunotherapy. There were 2 operative deaths, and 2 patients died 6 and 8 months postoperatively of cardiac causes. Postmortem examination on these 4 patients revealed no evidence of residual tumor. The remaining 20 patients are alive 7 to 33 months from the onset of chemotherapy and 4 to 27 months following lung resection. These results, although preliminary, are encouraging, and further study is in progress.

Adenocarcinoma↗
PubMedDate not supplied

Current and future applications of cardiovascular magnetic resonance imaging.

Magnetic resonance imaging (MRI) is one of the newest and most exciting imaging techniques for the cardiovascular system. Its present clear-cut clinical indications include the diagnosis of pericardial disease, aortic disease, cardiac masses, congenital heart disease, anomalous coronary arteries, and right ventricular dysplasia. However, the indications for cardiovascular MRI are growing as its spatial resolution and versatility is increasingly acknowledged. MRI is now recognized as the gold standard measure of left ventricular size and global and regional function. Valvular function can be interrogated in a straightforward fashion. Indications that are now available in some institutions and will be more widespread in the near future include magnetic resonance dobutamine stress testing and magnetic resonance perfusion imaging with or without vasodilator stress. Coronary artery imaging for diagnosis of the severity of disease remains in development, as does imaging of coronary flow and flow reserve. Other exciting applications currently being investigated include real-time imaging and intravascular MRI, enabling imaging from the inside of vessels outward, thereby enhancing the ability to image atherosclerotic plaque. The applications of MRI to the cardiovascular system are rapidly expanding and will continue to do so in the new millennium.

Coronary Angiography↗
PubMedDate not supplied

Generation of lipoxygenase metabolites of arachidonic acid by monolayer cultures of tracheal epithelial cells and intact tracheal segments from rabbits.

We compared the profile of lipoxygenase metabolites of arachidonic acid (AA) generated by cultured rabbit tracheal epithelial (TE) cells with that produced by intact rabbit tracheal segments at baseline and following addition of exogenous AA or calcium ionophore A23187. Lipoxygenase metabolites in effluent media were resolved by high-pressure liquid chromatography and quantitated by radioimmunoassay for monohydroxyeicosanoid (HETE) and leukotriene (LT) metabolites [5-, 12-, and 15-HETE; LTB4, LTC4, LTD4]. Following incubation with exogenous AA (10 micrograms/ml), cultured TE cells generated immunoreactive products that coeluted with authentic 5-, 12-, and 15-HETE standards. 12-HETE was the predominant metabolite. Whereas the generation of HETEs by TE monolayers was dependent on addition of exogenous AA, intact tracheal segments demonstrated a baseline production of 12-HETE and lesser amounts of 5- and 15-HETE as well as unidentified metabolites with UV absorbance at 280 nm. Incubation of tracheal segments with AA resulted in augmented metabolite production. In cultured TE cells, small quantities of HETEs were present intracellularly esterified to membrane phospholipids or free in the cytosol, and significant increases in free cytosolic 12- and 15-HETE were detected postincubation with AA. Calcium ionophore (5 microM) did not induce significant increases in HETE production in either cultured TE cells or tracheal segments. Minimal or no immunoreactive LTs B4, C4, and D4 were produced by TE monolayers or tracheal segments at baseline or following addition of AA or ionophore. Production of HETEs by cultured TE cells was not associated with decreased viability, release of intracellular lactic dehydrogenase, or loss of cells from the monolayers. Preincubation of monolayer cultures or tracheal segments with 5,8,11,14-eicosatetraynoic acid prior to addition of exogenous AA inhibition metabolite production. Our observations provide further documentation for the generation of lipoxygenase metabolites by TE cells and suggest that the array of metabolites generated by cultured TE cells may not be representative of the entire spectrum of AA metabolites produced by intact native epithelium.

Animals↗