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M Haider

Publications and source records attributed to M Haider.

123 records · Page 7Linked to original sources
PubMedDate not supplied

Scanning transmission electron microscopy study of the molecular mass of amphipol/cytochrome b6f complexes.

The composition and mass of complexes between Chlamydomonas reinhardtii cytochrome b6f and low molecular mass amphipathic polymers ('amphipols') have been studied using biochemical analysis and scanning transmission electron microscopy at liquid helium temperature (cryo-STEM). Cytochrome b6f was trapped by amphipols either under its native 14-meric state or as a delipidated, lighter form. A good consistency was observed between the masses of either form calculated from their biochemical composition and those determined by cryo-STEM. These data show that association with amphipols preserved the original original state of the protein in detergent solution. Complexation with amphipols appears to facilitate preparation of the samples and mass determination by cryo-STEM as compared to conventional solubilization with detergents.

Animals↗
PubMedDate not supplied

Bioincompatible membranes place patients with acute renal failure at increased risk of infection.

The mortality of critically ill patients with acute renal failure (ARF) requiring hemodialysis remains high (> 50%), even though major improvements in the management of this disorder have been made. Sepsis has been identified as a major cause of death in ARF. Experimental data have suggested that bioincompatible membranes aggravate uremia induced neutrophil dysfunction. In the following two combined prospective, randomized, clinical studies, the effects of the biocompatibility of dialysis membranes on the susceptibility to infection were compared in 72 surgical and medical patients with ARF. The group of patients treated with biocompatible polyacrylonitrile membranes had a significantly lower incidence of bacterial infections and a lower relative and absolute mortality rate due to sepsis, compared to patients treated with bioincompatible cuprophane membranes. These investigations identified bioincompatibility as a factor that adversely affects the prognosis of critically ill patients with ARF.

Acrylic Resins↗
PubMedDate not supplied

Bioincompatibility of dialyzer membranes may have a negative impact on outcome of acute renal failure, independent of the dose of dialysis delivered: a retrospective multicenter analysis.

The mortality rate of critically ill patients with acute renal failure (ARF) has remained high. The impact of vigorous intermittent hemodialysis (IHD) on the outcome of ARF has not been validated. In this retrospective multicenter analysis, 154 patients with ARF were treated daily (intensive) or on alternate days (conventional) using complement and cell activating cuprophane (bioincompatible) or high-flux polysulfone dialyzer membranes with insignificant effects on circulating complement or cells (biocompatible). At initiation of IHD, all four groups were similar in patient characteristics and ARF factors. The use of synthetic membranes resulted in a reduced mortality rate (18% vs 45%; p < 0.001) and shorter duration of ARF (8 vs 15 sessions; p < 0.001). Daily IHD with cellulose based membranes tended to increase mortality rates compared with conventional cuprophane dialysis (37% vs 53%). Intensive IHD with polysulfone membranes resulted in a further decrease in overall mortality rates (15% vs 22%). This retrospective analysis shows that bioincompatibility of dialyzer membranes may be more important for the outcome of patients with ARF than the dose of dialysis. Its impact on outcome occurs independently of the dose of dialysis delivered.

APACHE↗
PubMedDate not supplied

Moderate carbon monoxide exposure during sleep: neuro- and psychophysiological effects in young and elderly people.

In order to assess age-related effects of carbon monoxide (CO) on brain wave-activity and sleep, auditory evoked potentials (AEP) were measured during sleep in 10 healthy young volunteers (20-25 years) and in a group (N = 10) of healthy elderly Ss (55-72 years) under control- and exposure-conditions in counterbalanced order. Sleep-stages were classified according to the Rechtschaffen and Kales scoring-system. In addition to electrophysiological measures memory-performance and subjective feeling (mood-scale) was assessed before and after sleep. Eight hours of CO-exposure (100 ppm) gave rise to about 8% COHb. In the group of young Ss there was a significant (p less than 0.05) increase of deep sleep (stages 3,4), and a decrease of stage REM-sleep during CO-exposure, whereas in elderly Ss similar but non-significant sleep-changes occurred. Some CO-related AEP-changes within different sleep-stages, namely shorter latencies in elderly Ss and higher amplitudes in young Ss, approached significance. Within the group of young Ss there was a tendency to more depressed mood after CO-exposure, as well as to CO-related impairment of memory consolidation; no such effects were observed in elderly Ss. The general hypothesis of more pronounced CO-susceptibility of elderly people was, therefore, not supported in this study.

Adult↗
PubMedDate not supplied

[Conditioning of stress induced blood glucose and blood lipid changes].

The evidence for acute metabolic changes following intensive stress arises from a number of experimental studies. In our investigations we could differentiate these results, as we demonstrated that there exist pronounced differences in the metabolic changes after single, multiple and repeated stress and that furthermore neutral signal stimuli--after a series of simultaneous presentations with the stressor stimul (= conditioning phase) may induce conditioned changes in blood glucose and some blood lipid fractions. According to our hypothesis these learned ("conditioned") stress reactions may play an important role in the development and maintainance of various psychosomatic disturbancies.

Adult↗