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G Sulter

Publications and source records attributed to G Sulter.

12 recordsLinked to original sources
PubMed2000

Continuous pulse oximetry in acute hemiparetic stroke.

BACKGROUND AND PURPOSE: Hypoxemia can adversely affect ischemic brain tissue in laboratory animals. The aim of this study was to assess the value of early continuous monitoring with pulse oximetry in detecting arterial oxygen desaturations in patients with acute hemiparetic stroke, and the effects of oxygen administration. METHODS: Over a period of 6 months 49 consecutive patients with acute hemiparetic stroke of </=12 h duration were monitored for the first 48 h with pulse oximetry. Patients in whom arterial oxygen saturation (SaO(2)) fell beneath 96% for a period longer than 5 min were treated with oxygen administered via nasal prongs or oxygen mask. RESULTS: Thirty-one patients (63.3%) developed arterial oxygen desaturations. Of these patients 28 could effectively be treated with oxygen up to a flow-rate of 5 l/min. Only 3 patients required higher oxygen concentrations from 6 to 10 l/min. No acute adverse effects of oxygen treatment were observed. All patients with a history of cardiac and pulmonary disease developed drops in SaO(2). The occurrence of arterial oxygen desaturations was related to stroke severity (P=0.024), the presence of dysphagia (P=0.047), and older age (P=0.037). CONCLUSION: Patients with acute hemiparetic stroke frequently develop arterial oxygen desaturations. Continuous monitoring with pulse oximetry in this group of patients is a simple and useful method to detect drops in SaO(2) and to titrate oxygen administration.

Acute Disease↗
PubMed2000

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Journal Article↗
PubMed2000

Predicting outcome from coma: man-in-the-barrel syndrome as potential pitfall.

The Glasgow coma scale motor score is often used in predicting outcome after hypoxic-ischemic coma. Judicious care should be exerted when using this variable in predicting outcome in patients with coma following hypotension since borderzone infarction can obscure the clinical picture. We describe a patient who underwent skull base surgery for a schwannoma of the left facial nerve. The operation, which lasted for 10 h, was conducted under controlled hypotension. After the intervention the patient remained comatose with absent arm movements upon painful stimuli. An absent motor score usually carries a poor prognosis. However, magnetic resonance inversion recovery imaging of the brain showed bilateral hyperintense lesions in the arm-hand area indicative of borderzone ischemic damage. The patient received optimal supportive care and after 17 days he regained consciousness with 'man-in-the-barrel syndrome', which also further improved over time.

Coma↗
PubMed1999

From stroke unit care to stroke care unit.

In some stroke units continuous monitoring of blood pressure, electrocardiogram, body temperature, and oxygen saturation has become an integral part of the management of acute stroke. In addition, regular measurements of blood glucose are performed. Stroke units equipped with such monitoring facilities should be named 'stroke care units' by analogy with coronary care units. The goal of a stroke care unit is early detection and rapid correction of extracranial factors which may aggravate cerebral damage in ischemic brain, including hypoxia, hyperglycemia, hypotension, cardiac arrhythmias, and elevated body temperature.

Cerebrovascular Disorders↗
PubMed1999

Clinical trials with neuroprotective drugs in acute ischaemic stroke: are we doing the right thing?

Ischaemic stroke is a leading cause of death and long-lasting disability. Several neuroprotective drugs have been developed that have the potential to limit ischaemic brain damage and improve outcome for patients. While promising results with these drugs have been achieved in animal stroke models, all Phase III trials conducted so far indicate that these drugs have failed to live up to their promise. Despite the limits of animal models, which cannot mimic the clinical situation, the disappointing results of neuroprotective trials might largely be due to methodological problems. Future trials with neuroprotective drugs should be performed in stroke (care) units, after sufficient information regarding therapeutic time window, dosage, duration of therapy and safety has been gathered from pilot studies, and a better selection of target patients has been made. Much of this information can now be obtained by techniques that visualize the penumbra, such as combined diffusion-weighted and perfusion MRI. Consideration should also be given to clinical trials with well-designed combinations of treatments.

Brain Ischemia↗
PubMed1999

Management of acute ischaemic stroke.

Over the past few years there have been enormous changes in the management of stroke patients. General practitioners, ambulance personnel/paramedics and the general public need to be well informed that stroke is a medical emergency. Prevention of secondary brain damage by normalising vital parameters and combating fever should already start at the scene or in the ambulance. Early recognition of stroke symptoms, immediate transfer to a suitable treatment facility, and rapid in hospital triage protocols should bring thrombolysis to a larger number of stroke victims. Admission to a unit that is dedicated to the care of stroke patients helps to reduce mortality and morbidity.

Brain Ischemia↗
PubMed1999

Use of the Barthel index and modified Rankin scale in acute stroke trials.

BACKGROUND AND PURPOSE: The Barthel Index (BI) and the Modified Rankin Scale (MRS) are commonly used scales that measure disability or dependence in activities of daily living in stroke victims. The objective of this study was to investigate how these scales were used and interpreted in acute stroke trials. METHODS: We identified from MEDLINE the major efficacy trials with neuroprotective drugs, thrombolytic drugs, and anticoagulants in acute ischemic stroke published between January 1995 and December 1998. We selected those trials that used the BI and/or MRS as outcome parameters. RESULTS: Fifteen trials fulfilling the inclusion criteria were identified. The BI was used in 13 and the MRS in 8. In 4 trials mean and median scores of the BI were used, and in 1 trial median scores of the MRS were compared. Primary end points included the BI in 7, the MRS in 6, and both the BI and MRS in 3. With regard to the BI, a variety of sum scores between 50 and 95 were used as cutoff scores to define favorable outcome. Favorable outcome on the MRS was defined as either </=1 or </=2. CONCLUSIONS: Among the efficacy trials in acute stroke, we found remarkable differences in the choice of primary end points and in the definition of favorable outcome on both the BI and MRS. This lack of consensus strongly hinders the design, interpretation, and comparison of acute stroke trials. In general, it may be easier to define poor outcome instead of favorable outcome. Poor outcome could be defined if any of the following end points are reached: death, institutionalization due to stroke, MRS >3, or BI <60.

Acute Disease↗
PubMed1998

Increased serum neuron specific enolase concentrations in patients with hyperglycemic cortical ischemic stroke.

A detrimental effect of hyperglycemia in ischemic brain has been demonstrated in laboratory experiments and it has been found that hyperglycemia in ischemic stroke is a predictor of poor outcome. We determined serum neuron specific enolase (NSE) concentrations in 41 consecutive patients with a cerebral hemispheric stroke between 12 and 24 h after stroke onset. In cortical ischemic strokes complicated by hyperglycemia (blood glucose concentration > 7 mmol/l) we found significantly higher NSE levels than in normoglycemic patients. In lacunar ischemic strokes NSE levels were not significantly different between normoglycemic and hyperglycemic patients. Our findings support the concept that hyperglycemia during acute cortical ischemic stroke is associated with enhanced neuronal cell death.

Aged↗
PubMed1998

A strong nitrogen source-regulated promoter for controlled expression of foreign genes in the yeast Pichia pastoris.

In methylotrophic yeasts, glutathione-dependent formaldehyde dehydrogenase (FLD) is a key enzyme required for the metabolism of methanol as a carbon source and certain alkylated amines such as methylamine as nitrogen sources. We describe the isolation and characterization of the FLD1 gene from the yeast Pichia pastoris. The gene contains a single short intron with typical yeast-splicing signals near its 5' end, the first intron to be demonstrated in this yeast. The predicted FLD1 product (Fld1p) is a protein of 379 amino acids (approx. 40 kDa) with 71% identity to the FLD protein sequence from the n-alkane-assimilating yeast Candida maltosa and 61-65% identity with dehydrogenase class III enzymes from humans and other higher eukaryotes. Using beta-lactamase as a reporter, we show that the FLD1 promoter (PFLD1) is strongly and independently induced by either methanol as sole carbon source (with ammonium sulfate as nitrogen source) or methylamine as sole nitrogen source (with glucose as carbon source). Furthermore, with either methanol or methylamine induction, levels of beta-lactamase produced under control of PFLD1 are comparable to those obtained with the commonly used alcohol oxidase I gene promoter (PAOX1). Thus, PFLD1 is an attractive alternative to PAOX1 for expression of foreign genes in P. pastoris, allowing the investigator a choice of carbon (methanol) or nitrogen source (methylamine) regulation with the same expression strain.

Alcohol Oxidoreductases↗
PubMed1995

Regulation of bacterial sugar-H+ symport by phosphoenolpyruvate-dependent enzyme I/HPr-mediated phosphorylation.

The lactose-H+ symport protein (LacS) of Streptococcus thermophilus has a C-terminal hydrophilic domain that is homologous to IIA protein(s) domains of the phosphoenolpyruvate:sugar phosphotransferase system (PTS). C-terminal truncation mutants were constructed and expressed in Escherichia coli and their properties were analyzed. Remarkably, the entire IIA domain (160 amino acids) could be deleted without significant effect on lactose-H+ symport and galactoside equilibrium exchange. Analysis of the LacS mutants in S. thermophilus cells suggested that transport is affected by PTS-mediated phosphorylation of the IIA domain. For further studies, membrane vesicles of S. thermophilus were fused with cytochrome c oxidase-containing liposomes, and, when appropriate, phosphoenolpyruvate (PEP) plus purified enzyme I and heat-stable protein HPr were incorporated into the hybrid membranes. Generation of a protonmotive force (delta p) in the hybrid membranes resulted in accumulation of lactose, whereas uptake of the PTS sugar sucrose was not observed. With PEP and the energy-coupling proteins enzyme I and HPr of the PTS on the inside, high rates of sucrose uptake were observed, whereas delta p-driven lactose uptake by wild-type LacS was inhibited. This inhibition was not observed with LacS(delta 160) and LacS(H552R), indicating that PEP-dependent enzyme I/HPr-mediated phosphorylation of the IIA domain (possibly the conserved His-552 residue) modulates lactose-H+ symport activity.

Amino Acid Sequence↗
PubMed1989

Evidence for functional heterogeneity among microbodies in yeasts.

We have studied the biogenesis and enzymic composition of microbodies in different yeasts during adaptation of cells to a new growth environment. After a shift of cells of Candida boidinii and Hansenula polymorpha from glucose to methanol/methylamine-containing media, newly synthesized alcohol oxidase and amine oxidase are imported in one and the same organelle together with catalase; as a consequence the cells contain one class of morphologically and enzymatically identical microbodies. Similar results were obtained when Candida utilis cells were transferred from glucose to ethanol/ethylamine-containing media upon which all cells formed microbodies containing amine oxidase and catalase. However, when methanol-limited cells of H. polymorpha were transferred from media containing ammonium sulphate to those with methylamine as the nitrogen source, newly synthesized amine oxidase was incorporated only in part of the microbodies present in these cells. This uptake was confined to the few smaller organelles generally present at the perimeter of the cells, which were considered not fully developed (immature) as judged by their size. Essentially similar results were obtained when stationary phase cells of C. boidinii or C. utilis - grown on methanol and ethanol plus ammonium sulphate, respectively - were shifted to media containing (m)ethylamine as the nitrogen source. These results indicate that mature microbodies may exist in yeasts which no longer are involved in the uptake of matrix proteins. Therefore, these yeasts may display heterogeneities in their microbody population.

Alcohol Oxidoreductases↗