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Biomedical subjects

M Abel

Publications and source records attributed to M Abel.

At least 55 records · Page 3Linked to original sources
PubMed1995

Expression of receptors for advanced glycation end products in peripheral occlusive vascular disease.

The cellular interactions of advanced glycation end products (AGEs), which have been hypothesized to contribute to the development of vascular lesions, occur, at least in part, through their binding to a novel integral membrane protein, the receptor for AGEs (RAGE). Studies of human vascular segments show that endothelial RAGE expression at the antigen and mRNA level was variable and usually at low levels in samples from healthy individuals. In contrast, patients with a range of peripheral occlusive vascular diseases, with or without underlying diabetes, demonstrated prominent enhancement of endothelial RAGE expression. Smooth muscle cells and nerves in the vessel wall showed constitutively high levels of RAGE expression that were unchanged with aging (from 1 to 92 years) or by the presence of vascular disease. These data suggest that RAGE is likely to have ligands other than AGEs, and that multiple factors in addition to AGEs impact on its expression. Taken together, our findings suggest that RAGE may contribute to the pathogenesis of a range of vascular disorders.

Adult↗
PubMed1995

The importance of colloid osmotic pressure measurements to prevent oncotic overdosage during cardiac surgery.

OBJECTIVE: Colloidal infusion therapy during cardiac surgery has changed from the principal use of human albumin to the preference for synthetic colloids. Despite the possible interference of synthetic plasma expanders with the biuret determination of total plasma protein (TPP), perioperative infusion therapy is frequently directed on the basis of TPP and albumin levels. The hypothesis that the level of TPP or albumin does not reflect the plasma colloid osmotic pressure (COP) if synthetic plasma expanders are used was studied. MATERIALS AND METHODS: In 61 patients undergoing elective cardiac surgery the course of COP and its correlation to the TPP and albumin levels were investigated. Natural and artificial colloids were used for colloidal infusion therapy. RESULTS: No correlation between TPP/albumin levels and COP was found preoperatively and on arrival at the ICU, only a weak correlation was observed at 24 hours and 48 hours postoperatively. The wide range of the confidential interval indicates that the COP cannot be estimated correctly neither from the TPP nor the albumin level. The postoperative COP was significantly increased compared to the preoperative levels indicating oncotic overdosage. CONCLUSIONS: In order to avoid oncotic disturbances, indication for colloidal volume replacement during cardiac surgery should be controlled by oncometry if natural and synthetic colloids are administered.

Blood Proteins↗
PubMed1995

Expression of receptors for advanced glycosylated end-products in renal disease.

BACKGROUND: Advanced glycation endproducts (AGEs) are believed to mediate long-term complications in diabetes mellitus. In this context we studied the expression of the receptor for AGEs (RAGE) in the kidney of patients with a variety of different renal diseases. METHODS: RAGE was detected by immunocytochemistry in renal biopsies. We compared the staining for RAGE in nine patients with diabetic nephropathy, 20 with inflammatory and/or immune complex and 10 with non-inflammatory renal diseases. Normal renal tissue from seven patients with tumour nephrectomies served as controls. RESULTS: In controls the only cells expressing RAGE constitutively were interstitial cells and vascular smooth muscle cells (6/7), while distal tubular cells were rarely positive (1/7). Endothelial cells of arteries/arterioles, glomerular endothelial cells, podocytes, and capsular epithelial cells were consistently negative. In diabetic nephropathy, inflammatory and/or immune complex, and non-inflammatory renal diseases, all cell types mentioned above became positive for RAGE. Whilst the distribution of RAGE in the tissue was quite similar, staining intensity in inflammatory and/or immune complex diseases was higher than in diabetic nephropathy. CONCLUSION: RAGE induction in the kidney is not specific for diabetic nephropathy and occurs in other types of renal diseases as well.

Adolescent↗
PubMed1994

[Diabetic coma with deep hypothermia. Successful resuscitation with hemofiltration].

A 41-year-old woman with severe juvenile diabetes mellitus suffered from profound hypothermia after loss of thermoregulation in diabetic ketoacidosis. She was found unconscious, without measurable blood pressure; the electrocardiogram (ECG) showed bradycardia of 30 min and the rectal temperature was 23.7 degrees C. The patient received mechanical ventilation, fluid therapy, warmed gastric lavage, and, unfortunately, inotropic medication. She was transferred to a department of cardiac surgery in order to continue the therapy with cardiopulmonary bypass (CPB). On arrival, the patient had a rectal temperature of 27.3 degrees C, the ECG showed an absolute arrhythmia with a frequency of 70/min, and the blood pressure was 63/43 mmHg. We decided to use a rapidly available but not highly invasive venovenous hemofiltration technique for slowly rewarming the patient. Vascular access was achieved by percutaneous femoral vein cannulation with a Shaldon catheter. The hemofiltration system (Gambro AK-10, Gambro AB, Sweden) was instituted with a blood flow rate of 200 ml/min. The hemofiltration monitor controls the pumps for filtering and substituting fluid volumes and allows the infusion solutions to be heated up to 40 degrees C. Sinus rhythm resumed without antiarrhythmic medications at a temperature of 29.5 degrees C, and within 8 h the patient was rewarmed to 35.5 degrees C. After treatment of the adult respiratory distress syndrome caused by pneumonia, she was discharged from the intensive care unit to complete treatment with no evidence of any permanent organ damage. We conclude that hemofiltration may be the method of choice for rewarming deeply hypothermic patients when their circulation is preserved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Hypertension in young, healthy Zucker obese rats is not responsive to reduced salt intake.

Hypertension in insulin resistant states is, in part, salt and volume dependent. The Zucker obese rat, a model of hypertension associated with insulin resistance, has been shown to exhibit a pressor response to a fourfold increase in NaCl intake, from 1 to 4 g/100 g. However, it is not clear if blood pressure is responsive to less severe manipulations, or if a NaCl restricted diet results in a depressor effect comparable to the pressor effect of adding supplementary NaCl to a normal diet. Consequently, we have determined the effects of NaCl restriction on blood pressure in Zucker lean and obese rats. Twenty-four 6-wk-old female Zucker lean and obese rats were randomly assigned to either a normal diet (1 g/100 g NaCl) or a NaCl restricted (0.26 g/100 g) diet for 4 wk. Direct intra-arterial blood pressure was then measured in conscious, unrestrained animals via a femoral cannula connected to a low volume pressure transducer and physiological recorder. Animals fed both diets grew normally, and there was no effect of diet on either food consumption or growth rate. Blood pressure was significantly higher in the obese than the lean rats. However, reducing NaCl intake had no effect on blood pressure in either group. Heart rate was not significantly different among the 4 groups. These data demonstrate that moderate reductions in dietary NaCl intake are without effect on blood pressure in Zucker obese rats despite their pressor response to large quantities of NaCl.

Animals↗
PubMed1994

Adverse effects of depolarising neuromuscular blocking agents. Incidence, prevention and management.

Muscle relaxants block neuromuscular transmission, acting at nicotinic acetylcholine receptors of the neuromuscular junction. Suxamethonium (succinylcholine) is a depolarising agent, whereas all other relaxants in clinical use are nondepolarising. The desired neuromuscular block results from the structural similarity of muscle relaxants to acetylcholine, enabling the interaction with receptors at the neuromuscular junction. Adverse effects of suxamethonium are generally related to its agonist mode of action. Autonomic cardiovascular effects may result. Other adverse effects include anaphylactic or anaphylactoid reactions, and histamine release. Various disease states may present specific considerations in the use of muscle relaxants. Although many complications of muscle relaxants (such as prolonged block or resistance) are easily treated, others may require immediate intervention and vigorous therapy. Careful selection of appropriate relaxants for particular patients will usually prevent the occurrence of complications.

Arrhythmias, Cardiac↗
PubMed1994

Adverse effects of nondepolarising neuromuscular blocking agents. Incidence, prevention and management.

Nondepolarising muscle relaxants block neuromuscular transmission, acting as antagonists of the nicotinic receptors at the neuromuscular junction. Their undesired effects are frequently caused by interaction with acetylcholine receptors outside this junction, and autonomic cardiovascular effects may result. Other adverse effects include anaphylactic or anaphylactoid reactions, and histamine release. Various disease states may present specific considerations in the use of nondepolarising muscle relaxants. Although many complications of these drugs (such as prolonged block or resistance) are easily treated, others may necessitate immediate intervention and vigorous therapy. Careful selection of an appropriate relaxant for a particular patient will usually prevent the occurrence of complications.

Anaphylaxis↗
PubMed1993

Automated patient acuity. Linking nursing systems and quality measurement with patient outcomes.

Traditional patient classification systems no longer provide a useful function for nursing management. Value from these systems can only be realized through major revisions and integration with other systems. The resulting transformed system, linking patient outcomes, cost of care, and quality measurements together, provides a valuable measurement tool and enables nursing to demonstrate their value to the industry. The authors describe their rationale and experience in designing such a system.

California↗
PubMed1992

Correlation between myocardial ischemia and changes in arterial resistance during coronary artery bypass surgery.

The arterial resistometer provides continuous on-line monitoring of changes in arterial resistance. Resistance index (Ri), which bears a direct relationship to systemic vascular resistance (SVR), is defined by the equation Ri = P'/(dP'/dt), where dP'/dt is the peak dP/dt of the arterial waveform, and P' is the pressure at dP'/dt. In 42 patients with unstable angina, changes in Ri were studied at six periods during aortocoronary bypass surgery before tracheal intubation, during tracheal intubation, leg elevation, presternotomy, sternotomy, and dissection of the internal mammary artery. Thirty-four episodes of ischemia (0.1 mV ST segment changes) were observed in 26 patients. All ischemic episodes were associated with increased Ri (mean increase, 102 +/- 52%). Elevation of the pulmonary capillary wedge pressure correlated with ischemia during the preintubation, intubation, and sternotomy periods, but not in the remaining periods. Changes in arterial pressure and heart rate were not good predictors of ischemia. The prevalence of ST segment changes increased markedly during all periods of anesthesia with increase in Ri (P less than 0.05). Ninety-one percent of ST segment changes were associated with a 25% increase from the baseline Ri. Raising the cutoff point to a greater than or equal to 75% increase in Ri improved the specificity of Ri in ischemia detection from 61% to 92%. An increase of greater than or equal to 75% in Ri occurred in only 8% of cases without ST segment changes. It was found that an increase in Ri as depicted by the arterial resistometer was the best hemodynamic correlate of myocardial ischemia.

Adult↗
PubMed1992

Greater neuromuscular blocking potency of atracurium during hypothermic than during normothermic cardiopulmonary bypass.

Previous studies drew attention to the greater neuromuscular blocking potency of atracurium during, than before or after, hypothermic cardiopulmonary bypass (CPB) while disregarding the periods of normothermic perfusion. We recorded the evoked twitch tension in 15 patients during nitrous oxide/narcotic anesthesia who were undergoing open heart surgery. Atracurium was injected as an initial bolus dose of 460 micrograms/kg. Waning neuromuscular blockade was enhanced by repeat injections of 138 micrograms/kg whenever the twitch tension attained 25% of control. During hypothermic (< 32 degrees C) and normothermic (> 34 degrees C) CPB, the times of onset of the maintenance doses were 57% and 18% longer, respectively, than before CPB (P < 0.05). Maintenance doses of atracurium were required every 24 +/- 4 min (mean +/- SD) before CPB, every 45 +/- 8 min (P < 0.05) during hypothermia, every 22 +/- 3 min during normothermic perfusion, and every 23 +/- 3 min after CPB. In conclusion, the patients' changing demand of atracurium paralleled the changes of temperature rather than the institution and cessation of CPB.

Aged↗
PubMed1991

Response to suxamethonium in a myasthenic patient during remission.

A cumulative dose followed by an infusion was used to determine the dose response to suxamethonium in a patient with diagnosed myasthenia gravis who was in true remission (asymptomatic while receiving no therapy). The ED50 and ED90 values for suxamethonium were 0.08 mg/kg and 0.20 mg/kg, and an infusion rate of 3.2 mg/kg/hour was required to maintain a 90-95% depression of the single twitch response as monitored by integrated electromyography. These values are within the range for normal patients, and we conclude that myasthenic patients during a true remission may not demonstrate resistance to suxamethonium.

Anesthesia↗
PubMed1991

[A computerized database for problem patients in pediatric anesthesia].

A computerized database for use in pediatric anesthesia and in the perioperative care of patients with malformation syndromes and rare diseases is presented. A total of 2200 syndromes are listed, and the database contains helpful data, experience, guidelines and literature references relevant to about 500 rare diseases. The access to the databank, its structure and the probable benefits of the system are explained and discussed.

Anesthesiology↗
PubMed1990

[Brain stem dysfunction in Arnold-Chiari II syndrome].

Among 76 patients suffering from myelomeningocele treated during 1978 to 1987 there were 12 children with brain stem signs as a sequel to Arnold-Chiari II syndrome. In 2 of these patients only stridor was seen, in 4 stridor with attacks of apnoea, in 2 attacks of apnoea with dysphagia, and in 4 children stridor, attacks of apnoea and dysphagia. Hence, it will be necessary to modify the classification given by Charney et al (4) in respect of brain stem patterns of signs according to three grades, since the signs of stridor, apnoea and dysphagia can be combined with each other in different ways. The prognosis is infaust if all 3 signs and hence grade III of brain stem lesions are present. On the whole, 6 out of 12 patients with brain stem signs died. For this reason, a possible Arnold-Chiari malformation should always be considered if stridor is observed, and, if necessary, early decompression treatment by means of a shunt revision should be performed.

Arnold-Chiari Malformation↗