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Biomedical subjects

M Abel

Publications and source records attributed to M Abel.

At least 37 records · Page 2Linked to original sources
PubMed1999

Pseudocholinesterase-activity reduction during cardiopulmonary bypass: the role of dilutional processes and pharmacological agents.

UNLABELLED: 1. Pseudocholinesterase (ChE) activity is a determinant of the elimination kinetics of several drugs used in anesthesia. The time course of ChE activity was investigated in 16 patients undergoing cardiosurgery for a cardiopulmonary bypass (CPB) in normothermia or hypothermia. 2. The onset of the CPB was accompanied by a decrease in ChE activity (-37%) (P<0.05) and protein concentration (-24%) (P<0.05). The quotient ChE activity/protein concentration was numerically reduced to a smaller extent (-15%) (P>0.05). After the CPB was finished, ChE activity and the protein concentration remained low for the remaining operation time. 3. There was no difference in ChE activity, measured in vitro at 37 degrees C, between the normothermic and hypothermic group (P>0.05). 4. There was no correlation between heparin concentration in serum and reduction of ChE activity in vitro (P>0.05). In vitro, the ChE activity was not affected by either heparin in doses as high as 10,000 U/ml or aprotinin in doses as high as 10,000 U/ml (P>0.05). 5. CONCLUSIONS: (1) ChE activity is reduced by CPB mainly by hemodilution and (2) the pharmacological agents used in the present anesthetic technique (heparin, aprotinin, midazolam, fentanyl, propofol and mivacurium) do not inhibit ChE activity at therapeutic serum concentrations.

Aged↗
PubMed1999

[From accreditation to certification. Quality management in a radiology department].

The leaders of a radiology department started a quality process based on ISO 9001 certification and the total quality management program. The purpose of this work is to match the conformity of this quality system to ANAES recommendations. If the concordance is obvious, the advantages of using quality insurance to get an accreditation are important. In conclusion, a quality process is proposed, it includes a quality insurance manual of ISO 9001 norm, the total quality management in the first point of the norm and the ANAES recommendations spread over the 20 points of the norm.

Accreditation↗
PubMed1998

Synthesis of aryl 3-O-beta-cellobiosyl-beta-D-glucopyranosides for reactivity studies of 1,3-1,4-beta-glucanases.

A series of substituted aryl beta-glycosides derived from 3-O-beta-cellobiosyl-D-glucopyranose with different phenol-leaving group abilities as measured by the pKa of the free phenol group upon enzymatic hydrolysis has been synthesised. Aryl beta-glycosides with a pKa of the free phenol leaving group > 5 were prepared by phase-transfer glycosidation of the per-O-acetylated alpha-glycosyl bromide with the corresponding phenol, whereas the 2,4-dinitrophenyl beta-glycoside was obtained by condensation of 1-fluoro-2,4-dinitrobenzene with the partially acetylated trisaccharide followed by acid de-O-acetylation. The aryl beta-glycosides have been used for reactivity studies of the wild-type Bacillus licheniformis 1,3-1,4-beta-D-glucan 4-glucanohydrolase. The Hammett plot log kcat versus pKa is biphasic with an upward curvature at low pKa values suggesting a change in transition-state structure depending on the aglycon.

Bacillus↗
PubMed1998

Type 1 diabetes and prediabetic state in a monozygotic triplet.

Type 1 diabetes mellitus (IDDM) results from a chronic process of autoimmune destruction of beta cells of the Langerhans islets. The presence of autoantibodies (ICA, GADA, anti-IA2, IAA) in serum precedes the clinical onset of the disease. Genetic predisposition for IDDM is connected with HLA, CTLA-4 and insulin gene region. The aim of the study was the genetic and immunological analysis of a triplet. One of them developed Type 1 diabetes mellitus. We analysed HLA class II, CTLA-4 and insulin gene polymorphisms in the whole family. Besides, we investigated immunological status of three brothers. All patients present identical genotype for VNTR loci: D1S80, D17S5 and Apo B, as well as for HLA-DRB1, -DQA1, -DQB1, CTLA-4 gene and all studied insulin gene polymorphisms. That proves their monozigosity. The triplet presents strong genetic predisposition for IDDM. The two patients without overt diabetes have increased levels of ICA, GADA, IA2 and IAA.

Abatacept↗
PubMed1998

The significance of oncometry for infusion therapy during pediatric heart surgery.

BACKGROUND: The colloid osmotic pressure (COP) is not routinely assessed during pediatric heart surgery. Two cases of unrecognized hyperoncotic states associated with renal failure have been observed after pediatric heart surgery. We studied the hypothesis that the COP cannot be estimated from the total plasma protein (TPP) or albumin level. METHODS: The course of COP and its correlation to the TPP and albumin level were investigated in 25 children undergoing elective heart surgery. Infusion therapy was performed solely on the basis of clinical parameters and TPP/albumin levels. COP values were determined in a blinded fashion at the end of the study. RESULTS: No correlation between TPP/albumin and the COP could be determined preoperatively. On arrival at the ICU correlation was strong. A weak correlation was observed at 24 hours and 48 hours after surgery. However, the observed wide range of the confidential bands indicates that the COP cannot be estimated correctly, neither from the TPP, nor from the albumin level. Due to colloidal oversubstitution COP was significantly increased compared to preoperative level at 48 hrs following surgery. CONCLUSIONS: As estimation of COP from TPP or albumin level is inaccurate, oncometry should be performed during pediatric heart surgery.

Blood Proteins↗
PubMed1997

The significance of oncometry for infusion therapy during pediatric heart surgery.

The colloid osmotic pressure (COP) is not routinely assessed during pediatric heart surgery. Two cases of unrecognized hyperoncotic states associated with renal failure have been observed after pediatric heart surgery. We studied the hypothesis that the COP cannot be estimated from the total plasma protein (TPP) or albumin level. The course of COP and its correlation to the TPP and albumin level were investigated in 25 children undergoing elective heart surgery. Infusion therapy was performed solely on the basis of clinical parameters and TPP/albumin levels. COP values were determined in a blinded fashion at the end of the study. No correlation between TPP/albumin and the COP could be determined preoperatively. On arrival at the ICU correlation was strong. A weak correlation was observed at 24 hours and 48 hours after surgery. However, the observed wide range of the confidential bands indicates that the COP cannot be estimated correctly, neither from the TPP, nor from the albumin level. Due to colloidal oversubstitution COP was significantly increased compared to preoperative level at 48 hrs following surgery. As estimation of COP from TPP or albumin level is inaccurate, oncometry should be performed during pediatric heart surgery.

Age Factors↗
PubMed1996

Renal failure associated with unrecognized hyperoncotic states after pediatric heart surgery.

Despite severe alteration of transcapillary fluid exchange during cardiopulmonary bypass, colloid osmotic pressure is not routinely assessed. Infusion therapy during pediatric heart surgery is determined by clinical parameters and on the basis of total plasma protein level alone. Following this concept, postoperative renal dysfunction associated with unrecognized hyperoncotic disturbances has been observed in two children. Hyperoncotic states may not be identified by routine laboratory parameters.

Acute Kidney Injury↗
PubMed1996

Performance of erroneously filled sevoflurane, enflurane and other agent-specific vaporizers.

OBJECTIVE: Erroneous filling of an agent-specific anesthesia vaporizer may result in concentration and potency outputs that are very different from those expected from the concentration dial setting. Enflurane and sevoflurane have relatively similar saturated vapor pressures (SVPs 175 mmHg and 160 mmHg, respectively, at 20 degrees C) and potencies (MACs 1.68% and 2%, respectively). We derived an equation to relate the vapor concentration output of an agent-specific vaporizer to the gas inflow splitting ratio (SR) created by the vaporizer and the SVP of the potent inhaled agent. METHODS: To test the validity of this equation, we filled an Enfluratec 4 enflurane vaporizer with sevoflurane and a Penlon PPV Sigma sevoflurane vaporizer with enflurane and compared the vapor concentration outputs with our predictions. RESULTS: The equation accurately predicted the vapor concentration outputs of the erroneously filled enflurane and sevoflurane vaporizers. The potency (MAC) output of the erroneously filled Enfluratec 4 vaporizer decreased by 22%-33%, and that of the Penlon PPV Sigma sevoflurane vaporizer increased by 21%-31% from those expected from the concentration dial settings. CONCLUSION: When an agent-specific variable bypass vaporizer is erroneously filled, the vapor concentration outputs can be predicted from the splitting ratio created by setting the vaporizer concentration dial and the SVP of the agent.

Anesthetics, Inhalation↗
PubMed1996

Contrasting methods of collecting data on injectors' risk behaviour.

In this paper two contrasting methods of collecting data on drug injectors' needle and syringe sharing practices are considered, namely: direct questions about any previous sharing in the last 6 months, and vignettes in which injectors are asked to indicate whether they would be prepared to share injecting equipment in a range of situations. Injectors' statements of their preparedness to share are far in excess of their reports of actual sharing. The possible reasons for this discrepancy are considered, including that injectors may have under-reported the level of their actual sharing. It is suggested that in future studies aiming to collect risk behaviour data should seek to combine methods rather than to rely solely upon direct questioning of any past sharing.

Adolescent↗
PubMed1995

Erroneous mass spectrometer readings caused by desflurane and sevoflurane.

OBJECTIVE: Medical mass spectrometers are configured to detect and measure specific respiratory and anesthetic gases. Unrecognized gases entering these systems may cause erroneous readings. We determined how the Advantage 1100 (Perkin-Elmer, now Marquette Gas Systems, Milwaukee, WI) and PPG-SARA (PPG Biomedical Systems, Lenexa, KS) systems that were not configured to measure desflurane or sevoflurane respond to increasing concentrations of these new potent volatile anesthetic agents. METHODS: Desflurane 0% to 18% in 3% increments or sevoflurane 0% to 7% in 1% increments in 5-L/min oxygen was delivered to the Advantage and PPG-SARA mass spectrometry systems. For each concentration of each agent, the displayed gas analysis readings and uncompensated collector plate voltages were recorded. RESULTS: The Advantage 1100 system read both desflurane and sevoflurane mainly as enflurane and, to a lesser extent, as carbon dioxide and isoflurane. For enflurane(E) readings < 9.9%, the approximate relationships are: %Desflurane = 1.6E; %Sevoflurane = 0.3E. These formulas do not apply if E > 9.9% because of saturation of the summation bus. PPG-SARA read desflurane mainly as isoflurane(I) and, to a lesser extent, as nitrous oxide. PPG-SARA read sevoflurane mainly as enflurane(E) and, to a lesser extent, as nitrous oxide and halothane. The approximate relationships are: %Desflurane = 1.11 (for I < 9%); %Sevoflurane = 2.1E. CONCLUSIONS: Advantage 1100 and PPG-SARA systems not configured for desflurane or sevoflurane display erroneous anesthetic agent readings when these new agents are sampled. Advantage 1100 also displays falsely elevated carbon dioxide readings when desflurane is sampled.

Anesthetics↗
PubMed1995

Practice parameters for sigmoid diverticulitis. The Standards Task Force American Society of Colon and Rectal Surgeons.

It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all of the circumstances presented by the individual patient.

Acute Disease↗
PubMed1995

The preparedness to share injecting equipment: an analysis using vignettes.

This paper reports on the use of vignettes to study drug injectors' preparedness to share injecting equipment. Separate vignettes referring to borrowing and passing on injecting equipment have been submitted to 505 injecting drug users in Glasgow. Injectors were asked to identify their own likely response in each of the situations described within the vignettes. It was shown that even among those injectors not reporting any actual sharing in the last 6 months a significant proportion would still be prepared to share injecting equipment within certain situations. The preparedness to share injecting equipment was seen to be influenced by such factors as social distance, sex and length of time injecting. It is suggested that even in situations where drug injectors may have modified their behaviour in the direction of lower levels of reported sharing, a propensity to share may remain. This suggests the continuing need to provide injectors with easy access to sterile injecting equipment; in addition, services working with injecting drug users may need to focus not only upon actual sharing behaviour but also upon what we have described here as the preparedness to share. Indeed, the latter dimension should stand as a warning to services of the potential for sharing injecting equipment to increase in the future.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Changes in plasma cholinesterase activity and mivacurium neuromuscular block in response to normothermic cardiopulmonary bypass.

The effect of reduced plasma cholinesterase (ChE) activity in response to normothermic cardiopulmonary bypass (CPB) on mivacurium neuromuscular block was studied in nine patients anesthetized with propofol/fentanyl. Mivacurium was injected intravenously as an initial bolus of 150 micrograms/kg; repeat doses of 75 micrograms/kg were given when the evoked twitch tension attained 75% of control. With the institution of CPB, the previously normal ChE activity was reduced by 42% and remained low until the end of the procedure. The times of onset (time from the end of injection to maximum neuromuscular block) of the maintenance doses of mivacurium were 26% longer during than before or after CPB (P < 0.05). Their DUR25% (time from end of injection to recovery of neuromuscular transmission to 25% of control) were 13 +/- 3 min (means +/- SD) before, 14 +/- 4 min during, and 16 +/- 4 min (P < 0.05) after CPB. It is concluded, that, although markedly reducing the patient's previously normal ChE activity, normothermic CPB had little effect on the time characteristics of mivacurium neuromuscular block.

Aged↗