Biomedical subjects

A Avramov

Publications and source records attributed to A Avramov.

10 recordsLinked to original sources

PubMed2002

Preliminary background ozone concentrations in the mountain and coastal areas of Bulgaria.

Urban and non-urban rural ozone (O3) concentrations are high in Bulgaria and often exceed the European AOT40 ecosystem as well as the AOT60 human health standards. This paper presents preliminary estimates to establish background, non-urban O3 concentrations for the southern region of Bulgaria. Ozone concentrations from three distinctly different sites are presented: a mountain site influenced by mountain-valley wind flow; a coastal site influenced by sea-breeze wind flow; and a 1700-m mountain peak site without 'local' wind flow characteristics. The latter offers the best estimate of 46-50 ppb for a background O3 level. The highest non-urban hourly value, 118 ppb, was measured at the mountain-valley site.

Air Movements↗

PubMed2000

Remifentanil-based anesthesia versus a propofol technique for otologic surgical procedures.

Otologic procedures require a still surgical field and are associated with a 50% incidence of emetic symptoms. Propofol reduces nausea and vomiting but not intraoperative movement. This study compares a remifentanil/propofol anesthetic to a propofol/fentanyl combination to determine which provides the best perioperative conditions for otologic microsurgery. Eighty healthy patients were randomly assigned to receive one of the anesthetic combinations. Demographic data, hemodynamic variables, movement, and bispectral index monitoring values in addition to anesthetic emergence, nausea, vomiting, pain, and other recovery variables were compared between groups with appropriate statistical methods. Both groups were similar. Times to eye opening (7.7 +/- 0.7 vs 12.4 +/- 1.2 minutes) and extubation (9.8 +/- 0.9 vs 12.4 +/- 1.0 minutes) were shorter with remifentanil. This group also had lower hemodynamic variables and movement (23% vs 65%) under anesthesia. Postoperative pain was mild in both groups, but remifentanil patients had more than the propofol group. All other postoperative parameters were similar. Remifentanil-based anesthesia produces better hemodynamic stability, less movement, and faster emergence after otologic surgery, with propofol's antiemetic effect, for the same cost.

Adolescent↗

PubMed1997

Mechanisms of low back pain: a neurophysiologic and neuroanatomic study.

Idiopathic low back pain has confounded health care practitioners for decades. The cellular and neural mechanisms that lead to facet pain, discogenic pain, and sciatica are not well understood. To help elucidate these mechanisms, anesthetized New Zealand white rabbits were used in a series of neurophysiologic and neuroanatomic studies. These studies showed the following evidence in support of facet pain: an extensive distribution of small nerve fibers and endings in the lumbar facet joint, nerves containing substance P, high threshold mechanoreceptors in the facet joint capsule, and sensitization and excitation of nerves in facet joint and surrounding muscle when the nerves were exposed to inflammatory or algesic chemicals. Evidence for pain of disc origin included an extensive distribution of small nerve fibers and free nerve endings in the superficial annulus of the disc and small fibers and free nerve endings in adjacent longitudinal ligaments. Possible mechanisms of sciatica included vigorous and long lasting excitatory discharges when dorsal root ganglia were subjected to moderate pressure, excitation of dorsal root fibers when the ganglia were exposed to autologous nucleus pulposus, and excitation and loss of nerve function in nerve roots exposed to phospholipase A2.

Animals↗

PubMed1980