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Biomedical subjects

E Roth

Publications and source records attributed to E Roth.

At least 181 records · Page 10Linked to original sources
PubMed1985

Semi-automated high-performance liquid chromatographic determination of cyclosporine A in whole blood using one-step sample purification and column-switching.

A highly sensitive and semi-automated high-performance liquid chromatographic method, utilizing acetonitrile protein precipitation and column-switching, is described for the determination of cyclosporine A in whole blood. Following a rapid manual acetonitrile treatment of the blood samples, the supernatant is loaded automatically onto a 5-micron high-speed protein separation column without any further clean-up operations. The fraction containing cyclosporine A is switched to a 3-micron C18 reversed-phase high-speed column by a microprocessor-controlled column-switching unit for final separation and detection by absorption at 214 nm. Minimal sample handling and efficient separation resulted in a high recovery (75 +/- 3%) of cyclosporine A from blood and a detection limit as low as 2 micrograms/l with a highly reproducible and linear response up to 2500 micrograms/1 using 0.5 ml of sample. A separation cycle including regeneration of the first column is finished in 15 min, and this system was used continuously for ca. 1000 blood samples from heart, liver, kidney, pancreas and bone marrow recipients without change in separation parameters or material replacement. The method described allows accurate and very fast daily routine monitoring of cyclosporine A in large numbers of blood samples from transplant recipients.

Autoanalysis↗
PubMed1985

Spacer sequences downstream of the 28S RNA coding region are part of the mouse rDNA transcription unit.

Evidence is presented that more than 300 bp of spacer sequences downstream of the 28S RNA coding sequence are part of the mouse rDNA transcription unit. Studies in two cell-free transcription systems as well as analysis of cellular RNA indicate that RNA polymerase I does not terminate within the 334 bp 3' terminal spacer sequences contained in the rDNA clone used. Quantitative hybridization data, S1 mapping experiments and Northern analysis of nuclear RNA showed that the 14 kb pre-rRNA molecules hybridize with the same efficiency to both the 28S and the 3' NTS specific DNA probe. This indicates that the rRNA precursor contains both at the 5' and 3' end several hundreds bases of external transcribed spacer sequences which are eliminated in subsequent processing reactions.

Animals↗
PubMed1985

Physicochemical behaviour and structural characteristics of membrane-bound acetylcholinesterase from Torpedo electric organ. Effect of phosphatidylinositol-specific phospholipase C.

Quantitative solubilization of the phospholipid-associated form of acetylcholinesterase (AChE) from Torpedo electric organ can be achieved in the absence of detergent by treatment with phosphatidylinositol-specific phospholipase C (PIPLC) from Staphylococcus aureus [Futerman, Low & Silman (1983) Neurosci. Lett. 40, 85-89]. The sedimentation coefficient on sucrose gradients of AChE solubilized in detergents (DSAChE) varies with the detergent employed. However, the coefficient of AChE directly solubilized by PIPLC is not changed by detergents. Furthermore, PIPLC can abolish the detergent-sensitivity of the sedimentation coefficient of DSAChE purified by affinity chromatography, suggesting that one or more molecules of phosphatidylinositol (PI) are co-solubilized with DSAChE and remain attached throughout purification. DSAChE binds to phospholipid liposomes, whereas PIPLC-solubilized AChE and DSAChE treated with PIPLC do not bind even to liposomes containing PI. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis shows that PIPLC-solubilized AChE, like unmodified DSAChE, is a catalytic subunit dimer; electrophoresis in the presence of reducing agent reveals no detectable difference in the Mr of the catalytic subunit of unmodified DSAChE, of AChE solubilized by PIPLC and of AChE solubilized by Proteinase K. The results presented suggest that DSAChE is anchored to the plasma membrane by one or more PI molecules which are tightly attached to a short amino acid sequence at one end of the catalytic subunit polypeptide.

Acetylcholinesterase↗
PubMed1985

The laboratory use of butylnitrite for the production of methemoglobin.

The use of volatile butylnitrite in place of sodium nitrite for the in vitro production of methemoglobin was explored in studies of G6PD-deficient red cells and for measurements of the red cell methemoglobin reductase activity. It was found that butylnitrite vapor caused a more rapid oxidation of intracellular hemoglobin than sodium nitrite and required fewer washes for removal. Hence a more rapid preparation of the cells was possible. Both cytochemical detection of G6PD-deficient cells in a female heterozygote for G6PD deficiency and the screening test for a methemoglobin reductase deficiency could be performed with butylnitrite as well as with sodium nitrite. This small modification of these standard procedures promises to save time and facilitate processing of many samples during genetic screening of relevant populations.

Erythrocytes↗
PubMed1985

[Amino acid and protein metabolism in critically ill patients].

This study set out to investigate the alteration of amino acid (AA) and protein metabolism in patients with malnutrition, sepsis, acute pancreatitis and liver diseases. The results showed that in preoperative patients with malnutrition or protein catabolism (decreased levels of plasma proteins, increased urea production rate) the postoperative complications were significantly increased. An increased postoperative infusion of branched chain AA did not improve postoperative nitrogen retention nor plasma protein syntheses in patients with colon or rectum CA. Patients with sepsis or acute pancreatitis had drastically reduced levels of total muscular free AA, mainly due to a fall in muscle glutamine. In septic patients also the hepatic levels of free AA were decreased. These changes of AA metabolism found in clinical situation were not always reflected by results found in experimental rat models (sepsis, pancreatitis, burn injury). The parenteral administration of a synthetic dipeptide containing glutamine and alanine decreased the muscular decrease of glutamine and alanine and increased the hepatic uptake of these two AA in a catabolic dog model. In critically ill patients changes in amino acid and protein metabolism lead to a protein catabolic situation. Urea production rate and muscle glutamine levels seem to be closely related to the prognosis of catabolic patients.

Adult↗
PubMed1985

Closed head injury in spinal cord injured patients: retrospective study of loss of consciousness and post-traumatic amnesia.

Previous studies of trauma-related spinal cord injured patients suggest that 25% to 50% of these patients sustain a concomitant cranio-cerebral trauma. A loss of consciousness (LOC) of 20 minutes' duration or a post-traumatic amnesia (PTA) lasting 24 hours has been associated with deficits in concentration, attention, memory, and higher-level cognitive functions. These may present as significant factors influencing learning and adaptation during and after the formal rehabilitation process. A systematic review was performed of the medical records of 101 trauma-related spinal cord injured patients who were admitted to Northwestern Memorial Hospital and the Rehabilitation Institute of Chicago within seven days of injury. The reported incidence of LOC and PTA in spinal cord injured patients was evaluated, and these data were compared with the level and etiology of injury, and with radiographic work-up, if any, for head injury. Eighty-seven percent of all emergency room admissions and 67% of all rehabilitation admissions were assessed for LOC. Fewer than 25% of all patients in both settings were assessed for PTA. Forty-two percent of all patients reported LOC, PTA, or both occurring simultaneously with the spinal cord injury. Assessment and incidence were unrelated to level of injury but were influenced by etiology. One-third of the patients who reported LOC, PTA, or both underwent further evaluation with computed tomographic (CT) scan or radiography of the skull. Assessment of LOC is conducted more consistently in the ER than in the rehabilitation setting. Assessment of PTA is performed infrequently despite its relevance to the rehabilitation process. Head injury may frequently be associated with traumatic spinal cord injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Liver amino acids in sepsis.

The metabolic derangement of sepsis leads to changes of the plasma and muscle amino acid (AA) pattern. In this study the influence of a septic process on liver AA pattern was investigated. In seven patients with abdominal sepsis, liver AA concentrations were determined during surgery and compared with those of four patients who had undergone cholecystectomy. In sepsis lowered AA levels were found for most of the AAs. Outstanding decreases exhibited the levels of the gluconeogenetic AAs (especially threonine and alanine), the branched chain AAs, lysine, and taurine. In the patients who did not survive the septic process, the depletion of these AAs was even amplified. Slightly increased AA levels were analyzed for P-ethanolamine, cystathionine, citrulline, beta-alanine, tyrosine, and phenylalanine. The results indicate a disturbed free AA pattern of the septic liver. Despite the increased flux of gluconeogenetic AA from muscle to liver in sepsis, as reported by several authors, no accumulation of these AAs occurs in the liver.

Adolescent↗
PubMed1985

Amino acid concentrations in plasma and skeletal muscle of patients with acute hemorrhagic necrotizing pancreatitis.

We measured amino acid concentrations in plasma and skeletal muscle of three groups of patients with acute hemorrhagic pancreatitis: (a) patients without secondary organ lesions, (b) patients also suffering from kidney damage, and (c) patients in whom the pancreatitis was accompanied by sepsis and multiple organ failure. In all three groups, especially the third group, the amino acid concentrations in both plasma and muscle were below normal. Glutamine was only 14% of normal in muscle tissue of the third group. Onset of renal insufficiency was indicated by increasing values for 3-methylhistidine and cystathionine; multiple organ failure, by increased concentrations of methionine and phenylalanine in plasma. The low amino acid concentrations of patients with acute pancreatitis can be explained as a combined effect of semistarvation and hypercatabolism. Changes in the plasma concentrations of amino acids did not reflect necessarily the concentrations in muscle tissue.

Acute Disease↗
PubMed1985

Cognitive dysfunction and mild closed head injury in traumatic spinal cord injury.

Previous investigators have reported that 25%-50% of traumatic spinal cord injury (SCI) patients sustain loss of consciousness (LOC), posttraumatic amnesia (PTA), or both concurrently with their SCI. A LOC of 20 minutes or less, or a PTA of 24 hours has been associated with prolonged time off work, and deficits in attention, concentration, memory, and judgment. Consequently, many traumatic SCI patients may also be the victims of a concomitant closed head injury (CHI) with cognitive sequelae. To test this hypothesis, a prospective study was conducted of 30 consecutive trauma-related SCI patients admitted to the Rehabilitation Institute of Chicago to determine the incidence of CHI and cognitive dysfunction (CD). The Halstead Category Test (HCT) was administered to each patient between 8 and 12 weeks after injury, and was considered abnormal if the patient committed 51 or more errors. Fifty-seven percent (n = 11) of all patients had abnormal HCT scores suggestive of higher level cognitive dysfunction. Patients with a new CHI had a mean HCT score of 65.2, as compared to 63.5 for patients with a premorbid CHI, and 46.3 for patients without a history of CHI. Although there was a trend toward higher HCT scores in patients who had any history of CHI, these differences did not reach statistical significance. The results of this study suggest that many trauma-related SCI patients are at risk for CD eight weeks after injury. Such cognitive abnormalities would be expected to impede rehabilitation and retard the requisite learning of new skills.

Adolescent↗
PubMed1985

[Changes in protein metabolism in cachexia and catabolism].

Cachexia as a consequence of a catabolic state (stress metabolism) and cachexia as a consequence of too small food intake (inanition metabolism) have to be distinguished from each other fundamentally. A typical amino acid distribution in plasma, muscle, and liver can be observed in the protein catabolic patient. The glutamine metabolism seemed to be of special interest in the severe catabolic patient (e. g. sepsis). Glutamine is the amino acid with the biggest part of the free amino acid pool. This glutamine pool is reduced in the protein catabolic patient. A connexion seems to exist between the lower muscle glutamine concentration and the prognosis of the patient. The parenteral nutrition can stimulate the protein synthesis, but not suppress the protein hydrolysis. Perhaps catabolic factors as, for instance, interleucine I take part in that. These stimulate the protein hydrolysis over the prostaglandin metabolism.

Amino Acids↗
PubMed1984

Evaluation of endocrine ophthalmopathy with saccadic eye movements.

Horizontal saccades were examined in 25 patients with hyperthyroidism and/or endocrine ophthalmopathy (EOP) using the infrared reflection method. With one exception none had restriction of horizontal eye movements. Conventional saccadic parameters were usually normal. A standardized test for muscle fatigue, however, gave pathological results in all but one of the patients with EOP, and also in three of seven patients with hyperthyroidism but no clinical EOP. In one of the latter the oculographic abnormality disappeared with treatment, while another developed clinical EOP. Performing a saccadic fatigue test seems to be useful for detecting early EOP and especially for monitoring its course.

Adult↗
PubMed1984

[The effect of p-bromophenacylbromide, a phospholipase A inhibitor, in experimental acute pancreatitis in rats].

In this study the effect of p-bromophenacylbromide (p-BPAB), an inhibitor of phospholipase A, was studied in acute pancreatitis in an experimental rat model. Acute pancreatitis was produced by instillation of 0.4 ml bile into the pancreatic duct. p-BPAB was injected i.p. in a dosage of 0.25 micrograms/g b.wt. 30 min before, 30 min after, or 4h after the onset of pancreatitis. Prophylactic and early administration of p-BPAB inhibited severe morphological changes, such as necrosis and hemorrhages. Moreover, during administration of the inhibitor, decreased plasma concentrations of serum lipase and amylase (P less than 0.001) were monitored and compared with untreated animals. These therapeutic effects of p-BPAB were not seen in rats in which the inhibitor was injected 4 h after the onset of pancreatitis. As a result the phospholipase inhibitor, p-BPAB, reduces the clinical and morphological manifestations of acute pancreatitis. The effect of p-BPAB is dependent on the time of administration.

Acetophenones↗
PubMed1984

Characterization of activities and forms of cholinesterases in human primary brain tumors.

The activities and molecular forms of cholinesterases were studied in a collection of primary brain tumors consisting of primarily gliomas and meningiomas, together with samples of forebrain taken postmortem from patients suffering from diseases unrelated to the nervous system. Both types of tumors, as well as normal forebrain, contained substantial amounts of cholinesterase activity and some gliomas contained exceptionally high levels. In both normal forebrain and meningiomas, acetylcholinesterase (acetylcholine hydrolase; EC 3.1.1.7) accounted for almost all the cholinesterase activity, but in almost all gliomas elevated pseudocholinesterase (acylcholine acylhydrolase; EC 3.1.1.8) could be detected. The cholinesterase activity of both normal forebrain and gliomas migrated on sucrose gradients as a major component of 10-11 S together with a minor component of 4-5 S. In meningiomas a light (4.5 S) form was the principal component.

Acetylcholinesterase↗
PubMed1984

Effects of burns on amino acid levels in rat plasma, liver and muscle.

In this study the influence of a severe catabolic situation (scalding and nitrogen deprivation) on amino acid (AA) metabolism was investigated in an experimental rat model. Scalding of 25 per cent of the total body surface area (TBSA) and hypocaloric alimentation (5.6 kcal per 100 g rat per day, no nitrogen) resulted in mean daily nitrogen losses of -0.27 +/- 0.3 g. Compared to anabolic growing rats this nitrogen catabolism significantly reduced the total free AA content of muscle (-47 per cent, P less than 0.001) and liver (-39 per cent, P less than 0.001). The total plasma AA concentrations were slightly increased in catabolic rats (+10 per cent). In catabolic rats muscle glycine concentrations dropped significantly (-79 per cent, P less than 0.001), while glutamine concentrations decreased by 22 per cent, which was not significant. Branched chain AA and phenylalanine were significantly elevated both in muscle and in plasma. Scalding and nitrogen depletion in rats leads to characteristic changes in plasma, muscle and liver AA concentrations, which are comparable to the results obtained in catabolic patients. However, the low muscle glycine concentrations in burned rats differ from the clinical observations where glutamine rather than glycine concentrations in muscle tissue are reduced. The rat model seems to be well suited for studying the influence of various therapeutic approaches such as different forms of parenteral nutrition or hormonal substitution on nitrogen catabolism.

Amino Acids↗