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Jones ED, Schneider RP, Lee SM, Bajaj KK. Magnetic-field-dependent excitonic photoluminescence linewidth in In0.48Ga0.52P semiconductor alloys. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:7225-7228. [PMID: 10002439 DOI: 10.1103/physrevb.46.7225] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Schneider RP, Christou NV, Nohr C. [Anomalies of immunoglobulin synthesis in vitro in surgical patients]. HELVETICA CHIRURGICA ACTA 1992; 59:315-9. [PMID: 1428920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It is known that blood mononuclear cells from surgical patients produce large amounts of IgG in vitro, and that this synthesis is not increased by pokeweed mitogen stimulation. The objective of the present study was to determine if this abnormal pattern of IgG synthesis extended to other immunoglobulin classes. Patients were stratified according to delayed type hypersensitivity as reactive (induration > 5 mm to > one skin test antigen), or anergic (no response). Healthy laboratory personnel were studied as controls. Mononuclear cells were cultured for 10 days, without or with pokeweed mitogen. IgG, IgM, and IgA in supernatant was measured using a competitive solid phase radioimmunoassay. Unstimulated IgG and IgA synthesis was increased in surgical patients, especially in those with reduced delayed type hypersensitivity responses. IgM synthesis was normal or low. With mitogen stimulation, normal increases in IgG synthesis were seen in control and reactive subjects. In anergic patients, IgG was not increased by pokeweed mitogen. For IgM, mitogen stimulation increased synthesis but to a lesser degree in patients than in controls. For IgA, synthesis was increased by mitogen stimulation in all groups. In conclusion, surgical patients show abnormalities in the pattern of spontaneous and mitogen stimulated immunoglobulin synthesis. The pattern varies for each isotype. B cell activation is present in surgical patients, especially those with reduced delayed type hypersensitivity. This suggests either recent antigenic stimulation, or non-antigen specific dysregulation of the B cell system in surgical patients.
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Schneider RP, Christou NV, Nohr C. Abnormal in vitro immunoglobulin synthesis in surgical patients. ARCHIVES OF SURGERY (CHICAGO, ILL. : 1960) 1992; 127:198-205. [PMID: 1540098 DOI: 10.1001/archsurg.1992.01420020084012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Blood mononuclear cells from surgical patients produce large amounts of IgG in vitro. This synthesis is not increased by stimulation with pokeweed mitogen. To determine if this abnormal pattern of IgG synthesis extended to other immunoglobulin classes, surgical patients were stratified according to delayed-type hypersensitivity responses as reactive or anergic. Healthy personnel were studied as controls. Mononuclear cells were cultured without or with pokeweed mitogen, and IgG, IgM, and IgA were measured in supernatants. Unstimulated IgG and IgA synthesis was increased in surgical patients, especially in those with reduced delayed-type hypersensitivity responses. Synthesis of IgM was normal or low. With mitogen stimulation, IgG synthesis was increased in control and reactive subjects, but not in anergic subjects. For IgM, mitogen stimulation increased synthesis to a less than normal level in all patients. For IgA, synthesis was increased in all groups.
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Schneider RP, Lynch MJ, Ericson JF, Fouda HG. Electrospray ionization mass spectrometry of semduramicin and other polyether ionophores. Anal Chem 1991; 63:1789-94. [PMID: 1789442 DOI: 10.1021/ac00017a024] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pneumatically assisted electrospray mass spectrometry of polyether ionophores yields several molecular ions. A single metal adduct molecular ion can be obtained by the addition of a neutral salt to the HPLC mobile phase. This approach may be useful in structural studies of unknown ionophores and in the development of specific methods for their analysis in complex matrices. Collision-induced dissociation of the molecular ions provides additional structural information and enhanced specificity for trace analysis. HPLC mobile-phase composition and flow rates have been optimized for on-line analysis. Best response and lowest background noise were obtained at the flow rate of 40 microL/min of a mobile phase containing a 20/80 mixture of water and acetonitrile. The development of a specific confirmatory assay for the new ionophore semduramicin in chicken liver demonstrates the usefulness of on-line HPLC pneumatically assisted electrospray mass spectrometry.
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Lynch MJ, Mosher FR, Schneider RP, Fouda HG, Risk JE. Determination of carbadox-related residues in swine liver by gas chromatography/mass spectrometry with ion trap detection. JOURNAL - ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTS 1991; 74:611-8. [PMID: 1917808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The ion trap detector (ITD), in combination with a capillary gas chromatograph and under chemical ionization conditions, offers sufficient sensitivity to determine carbadox-related residues as the methyl ester derivative of quinoxaline-2-carboxylic acid at 3 micrograms/kg or higher in porcine liver. A tetradeuterated internal standard of QME effectively compensates for losses incurred during sample preparation. The method produced mean levels of 3.3 (+/- 0.5), 5.5 (+/- 0.8), and 10.1 (+/- 0.9) micrograms/kg for liver fortified at 3, 5, and 10 micrograms/kg. When applied to analysis of samples containing incurred residues of 14C-carbadox at the low microgram/kg level, results were comparable to those obtained by reverse isotope dilution analysis.
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Schneider RP, Christou NV, Meakins JL, Nohr C. Humoral immunity in surgical patients with and without trauma. ARCHIVES OF SURGERY (CHICAGO, ILL. : 1960) 1991; 126:143-8. [PMID: 1992991 DOI: 10.1001/archsurg.1991.01410260027004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We measured antitetanus toxoid antibody responses after blunt (n = 24) and penetrating (n = 7) trauma and compared them with responses in patients without trauma (n = 55). Patients were defined as anergic or reactive on the basis of delayed type hypersensitivity response. The response to tetanus toxoid vaccination on admission of patients surviving trauma for over 2 weeks was defined as the ratio of day 14 to day 0 serum IgG antitetanus toxoid levels. Antitetanus toxoid responses were normal after both blunt and penetrating trauma. When stratified according to delayed type hypersensitivity responses, patients with trauma showed better antibody responses than patients without trauma. Major infection rates were similar between trauma groups (three of 24 with blunt trauma vs two of seven with penetrating trauma) and independent of delayed type hypersensitivity (two of 20 reactive patients vs three of 11 anergic patients), in contrast to patients without trauma (one of 19 reactive patients vs 15 of 36 anergic patients). We conclude that decreased delayed type hypersensitivity after moderate trauma is temporary, and that this transient immunodeficiency is not as strongly associated with reduced antibody responses and increased risk of infection as anergy in surgical patients without trauma.
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Williams AT, Schneider RP. Chylous ascites should suggest constrictive pericarditis even in a patient with cirrhosis. J Clin Gastroenterol 1990; 12:581-4. [PMID: 2230003 DOI: 10.1097/00004836-199010000-00019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Chylous ascites, a milky, high triglyceride fluid is usually found in patients with lymphatic obstruction from malignancy. We describe a patient with cirrhosis who developed constrictive pericarditis and chylous ascites. Long-standing portal hypertension compounded by elevated central venous pressure provided several pathophysiologic contributions to the formation of the chylous ascites. Chylous ascites even in a cirrhotic requires prompt assessment for conditions leading to elevated central venous pressure.
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Abstract
Perdiem is a bulk laxative (mostly psyllium) formulated as granules; these granules can adhere together and cause esophageal impaction and gastric bezoars. I have reported three cases of esophageal impaction caused by Perdiem. Although endoscopic manipulation is the currently favored treatment, bougienage relieved these impactions easily. One patient also had a gastric bezoar. Doctors and patients need to be aware of this potential complication from Perdiem.
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Schneider RP, Merz V, Meuli R, Anderegg A, Preitner J, Mosimann R. [Conservative treatment of splenic injuries in the adult]. HELVETICA CHIRURGICA ACTA 1989; 56:195-8. [PMID: 2674062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Because of the risk of overwhelming post-splenectomy infection, the current trend favors conservative treatment for splenic trauma. Out of a total of 70 cases of splenic trauma in adults seen over the last 5 1/2 years, 19 spleens were preserved, 13 with, 6 without operations. Ten operated spleens were examined by Duplex-sonography, on average 38 months after surgery. The results show that in all cases, the spleen was morphologically and hemodynamically restored to normal.
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Fouda HG, Twomey TM, Schneider RP. Liquid chromatographic analysis of doxazosin in human serum with manual and robotic sample preparation. J Chromatogr Sci 1988; 26:570-3. [PMID: 2976067 DOI: 10.1093/chromsci/26.11.570] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A specific method for the determination of the antihypertensive drug doxazosin in human serum is described. The method utilizes the related drug prazosin as an internal standard and is based on a simple extraction scheme followed by analysis by reversed-phase ion suppression high-performance liquid chromatography (HPLC) on an alumina-based column with fluorescence detection. The method is completely automated with a flexible robotic system for the analysis of drugs in biological fluids. The robotic automation of the method allows a 20% increase in the sample throughput and the savings of about 7 man-hours a day. Both the manual and robotic procedures yield precise quantitative results over the therapeutically relevant concentration range of 0.5 to 20 ng/mL of serum.
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Schneider RP, Zürcher F, Egli T, Hamer G. Determination of nitrilotriacetate in biological matrices using ion exclusion chromatography. Anal Biochem 1988; 173:278-84. [PMID: 3189809 DOI: 10.1016/0003-2697(88)90190-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A sensitive method for the determination of nitrilotriacetate in biological growth media and cell-free extracts by ion exclusion chromatography is described using HCl as an eluant. The eluant conductivity was chemically suppressed with a membrane suppressor and a conductivity detector was used for subsequent detection. The membrane was continuously regenerated with a tetrabutylammoniumhydroxide solution. The detection limit for nitrilotriacetate in cell-free extract was 11 mg/liter, while for nitrilotriacetate in growth media it was 1 mg/liter. Interference by compounds present in biological matrices with the determination is discussed.
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Abstract
Achalasia is often a familial disease and may be inherited in association with other familial defects. I report a patient born with a familial facial dysostosis, Treacher Collins syndrome, who also has achalasia to propose that these two defects are associated familial disorders in this patient.
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Abstract
Herpes simplex virus may cause esophagitis, usually in patients with malignant neoplasms or immunocompromise. We have reported three cases of herpes simplex esophagitis in healthy young men, all of whom had positive mucosal biopsy culture for herpes simplex virus. All three patients recovered quickly without specific therapy.
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Christian CD, Schneider RP. Fatty tumor of the liver in a patient with Cushing's syndrome. ARCHIVES OF INTERNAL MEDICINE 1983; 143:1605-6. [PMID: 6870443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cushing's syndrome is occasionally associated with unusual deposition of fat. A case is reported of fatty mass of the liver in a patient with nodular adrenal hyperplasia.
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Schneider RP, Beaudreau GS. Characterization of the adenosine triphosphatase of avian myeloblastosis virus. Arch Biochem Biophys 1979; 196:475-83. [PMID: 225998 DOI: 10.1016/0003-9861(79)90299-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Marshall JP, Schneider RP. Systemic argyria secondary to topical silver nitrate. ARCHIVES OF DERMATOLOGY 1977; 113:1077-9. [PMID: 889335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A case of generalized argyria secondary to topical silver nitrate use on the oral mucosa is described, and the nature and history of argyria reviewed. The patient has extreme pigmentation of her skin and abdominal viscera, as seen on physical examination, gastroduodenoscopy, and laparotomy. Her use of silver nitrate applicators was uncontrolled by her dentist and pharmacist, and the diagnosis of argyria was not made until 2 1/2 years of heavy usage had passed. Avoidance of similar cases requires the careful scrutiny of silver-containing medicinal usage by all health practitioners and pharmacists. Although the systemic distribution of silver in both elemental and ionic forms can be linked with no systemic toxicity, the resultant pigmentation can be devastating to the patient.
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Schneider RP, Roach AC. An antacid tasting: the relative palatability of 19 liquid antacids. South Med J 1976; 69:1312-3. [PMID: 982107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The taste of liquid antacids is proposed as a major factor in patient compliance in taking such medication when prescribed. A study was made of the relative palatability of 19 antacids. The antacids can be divided into three groups of varying palatability (p less than 0.05).
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Schneider RP. Mechanism of inhibition of rat brain (Na + K)-adenosine triphosphatase by 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT). Biochem Pharmacol 1975; 24:939-46. [PMID: 125592 DOI: 10.1016/0006-2952(75)90423-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Schneider RP, Donaldson RM, Babior BM. Evidence for the solubilization of the intestinal intrinsic factor receptor by sonication of ileal brush borders. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 373:58-65. [PMID: 4429729 DOI: 10.1016/0005-2736(74)90105-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Schneider RP, Bernstein RB. A comparison of gastric acid back-diffusion in control and alcoholic patients. THE AMERICAN JOURNAL OF DIGESTIVE DISEASES 1973; 18:567-72. [PMID: 4717681 DOI: 10.1007/bf01072220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Schneider RP, Wiley WR. Transcription and degradation of messenger ribonucleic acid for a glucose transport system in Neurospora. J Biol Chem 1971; 246:4784-9. [PMID: 4998057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Schneider RP, Wiley WR. Kinetic characteristics of the two glucose transport systems in Neurospora crassa. J Bacteriol 1971; 106:479-86. [PMID: 5573732 PMCID: PMC285119 DOI: 10.1128/jb.106.2.479-486.1971] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Glucose is transported across the cell membrane of Neurospora crassa by two physiologically and kinetically distinct transport systems. System II is repressed by growth of the cells in 0.1 m glucose. System I is synthesized constitutively. The apparent K(m) for glucose uptake by system I and system II are 25 and 0.04 mm, respectively. Both uptake systems are temperature dependent, and are inhibited by NaN(3) and 2,4-dinitrophenol. Glucose uptake by system II was not inhibited by fructose, galactose, or lactose. However, glucose was shown to be a noncompetitive inhibitor of fructose and galactose uptake. The transport rate of [(14)C]3-0-methyl-d-glucose (3-0-MG) was higher in cells preloaded with unlabeled 3-0-MG than in control cells. The rate of entry of labeled 3-0-MG was only slightly inhibited by the presence of NaN(3) in the medium. Further, NaN(3) caused a rapid efflux of accumulated [(14)C]3-0-MG. These data imply that the energetic step in the transport process prevents efflux.
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Abstract
Sugar uptake systems in Neurospora crassa are catabolically repressed by glucose. Synthesis of a low K(m) glucose uptake system (system II) in Neurospora is derepressed during starvation for an externally supplied source of carbon and energy. Fasting also results in the derepression of uptake systems for fructose, galactose, and lactose. In contrast to the repression observed when cells were grown on glucose, sucrose, or fructose, system II was not repressed by growth on tryptone and casein hydrolysate. System II was inactivated in the presence of 0.1 m glucose and glucose plus cycloheximide but not by cycloheximide alone. Inactivation followed first-order kinetics with a half-time of 40 min. The addition of glycerol to the uptake medium had no significant effect on the kinetics of 3-0-methyl glucose uptake, suggesting that the system was not feedback inhibitable by catabolites of glycerol metabolism.
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