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Biomedical subjects

Amir Abramovich

Publications and source records attributed to Amir Abramovich.

6 recordsLinked to original sources
PubMed2006

Longevity network: construction and implications.

The vast majority of studies on longevity have focused on individual genes/proteins, without adequately addressing the possible role of interactions between them. This study is the first attempt towards constructing a "longevity network" via analysis of human protein-protein interactions (PPIs). For this purpose, we (i) compiled a complete list of established longevity genes from different species, including those that most probably affect the longevity in humans, (ii) defined the human orthologs of the longevity genes, and (iii) determined whether the encoded proteins could be organized as a network. The longevity gene-encoded proteins together with their interacting proteins form a continuous network, which fits the criteria for a scale-free network with an extremely high contribution of hubs to the network connectivity. Most of them have never been annotated before in connection with longevity. Remarkably, almost all of the hubs of the "longevity network" were reported to be involved in at least one age-related disease (ARD), with many being involved in several ARDs. This may be one of the ways by which the proteins with multiple interactions affect the longevity. The hubs offer the potential of being primary targets for longevity-promoting interventions.

Aging↗
PubMed2006

Subpleural microvascular flow velocities and shear rates in normal and septic mechanically ventilated rats.

Changes in pulmonary microhemodynamics are important variables in a large variety of pathological processes. We used in vivo fluorescent videomicroscopy of the subpleural microvasculature in mechanically ventilated rats to directly monitor microvascular flow velocity (FV) and shear rate in pulmonary arterioles, capillaries, and venules in healthy rats and in septic rats 20 h after cecal ligation and puncture (CLP). Observations were made through a small thoracotomy after injection of fluorescent microspheres (D = 1 microm) into the systemic circulation. The FVs were calculated off-line by frame-by-frame measurements of the distance covered by individual microspheres per unit of time. In healthy rats, inspiratory FV were 1322 +/- 142 microm/s in subpleural arterioles and 599 +/- 25 microm/s in capillaries. The highest FV was found in venules (1552 +/- 132 microm/s). The calculated shear rates were 547 +/- 62/s in arterioles and 619 +/- 19/s in capillaries. The highest shear rates were detected in venules (677 +/- 59/s). No significant changes in FV and shear rates were observed throughout the 1-h observation period in any of the microvascular compartments. Pulmonary microvascular FV and shear rates found in sham-operated rats in the CLP experiments were not significantly different from values of healthy rats. The CLP caused a significant increase in leukocyte sequestration in the lungs and a mean of 27% to 34% decrease in FV in all sections of the pulmonary microvasculature (P < 0.001 in capillaries and P < 0.05 in venules). Also, CLP caused a 23% decrease in capillary shear rate that reached only borderline statistical significance (P < 0.06) and a significant 35% decrease in mean shear rate in venules (P < 0.05). Fluorescent videomicroscopy is offered as a stable and reproducible method for in vivo determinations of pulmonary microhemodynamics in clinically relevant models of sepsis.

Animals↗
PubMed2005

Effects of inhaled nitric oxide on lung injury after intestinal ischemia-reperfusion in rats.

Splanchnic ischemia/reperfusion (I/R) induces a systemic inflammatory response with acute lung injury. Impaired production of endothelial nitric oxide (NO) plays a key role in this process. We evaluated the effects of early treatment with inhaled NO (iNO) on lung microcirculatory inflammatory changes during splanchnic I/R. I/R was induced in rats by occlusion of the superior mesenteric artery (SMA; 40 min) and reperfusion (90 min). Four groups were studied: Control, anesthesia only; Sham, all surgical procedures without I/R, ventilated with air; Air, SMA I/R, ventilation with air; and NO, SMA I/R, ventilation with NO (20 ppm) starting 10 min before reperfusion. Intravital video microscopy was used to monitor pulmonary macromolecular flux and capillary flow velocity (CFV). Leukocyte infiltration was determined by morphometry. SMA I/R decreased mean arterial blood pressure, capillary CFV (P < 0.01), and shear rate (P < 0.01), and increased pulmonary macromolecular leak by 138% +/- 8% (P < 0.001). iNO markedly attenuated the increase in macromolecular leak (P < 0.01), blunted the decrease in capillary CFV (P < 0.05) and shear rate (P < 0.05), and prevented the increase in leukocyte infiltration of the lungs after SMA I/R (P < 0.05). The direct, real-time, in vivo data suggest that early institution of low-dose iNO therapy effectively ameliorates the acute remote pulmonary inflammatory response after splanchnic I/R.

Administration, Inhalation↗
PubMed2002

Cardiogenic shock complicating acute carbon monoxide poisoning despite neurologic and metabolic recovery.

We report the cases of 2 previously healthy young patients with acute carbon monoxide intoxication who deteriorated to cardiogenic shock in the face of apparent metabolic and neurologic recovery. Prolonged exposure to sublethal levels of carbon monoxide (>24 hours, carboxyhemoglobin level of 20.4% and 22.6%) and massive binding of the toxin to myocardial myoglobin and mitochondrial cytochrome chain enzymes might explain their protracted cardiac failure. The good response to inotropic agents and the findings of repeated echocardiographic studies support the probable diagnosis of myocardial stunning. Complete cardiac recovery was observed in both patients.

Adult↗
PubMed2002

Performance of infusion pumps during hyperbaric conditions.

BACKGROUND: Many hyperbaric facilities use infusion pumps inside the chamber. It is therefore important to ensure that this equipment will perform accurately during hyperbaric conditions. The authors tested the function and accuracy of the Imed 965 and Infutec 520 volumetric infusion pumps, the Easy-pump MZ-257 peristaltic infusion pump, and the Graseby 3100 syringe pump. METHODS: The authors calculated the deviations of infused volumes at low and high rates (12-18 and 60-100 ml/h) on three different hyperbaric protocols (up to 2.5, 2.8, and 6 atmospheres absolute [ATA]), resembling a standard hyperbaric oxygen treatment and US Navy treatment tables used for decompression illness and for arterial gas embolism. Two examples of each pump model were examined in every experiment. RESULTS: The Easy-pump MZ-257 failed to function completely beyond a chamber pressure of 1.4 ATA, making it unsuitable for use inside the hyperbaric chamber. The Graseby 3100 failed to respond to all keyboard functions at 2.5-2.8 ATA, making it unsuitable for use in most hyperbaric treatments. The Imed 965 performed within an acceptable volume deviation (< or =10%) during most hyperbaric conditions. During the compression phase of the profiles used, and for the low infusion rates only, exceptional volume deviations of 20-40% were monitored. The Infutec 520 demonstrated an acceptable deviation (within 10%) throughout all the hyperbaric profiles used, unaffected by changes in ambient pressure or infusion rate. CONCLUSIONS: Commercially available infusion pumps operating during hyperbaric conditions demonstrate substantial variations in performance and accuracy. It is therefore important that the hyperbaric facility staff make a careful examination of such instruments to anticipate possible deviations in the accuracy of the equipment during use.

Humans↗