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Haim Bitterman

Publications and source records attributed to Haim Bitterman.

22 records · Page 2Linked to original sources
PubMed2002

High-frequency sound field and bubble formation in a rat decompression model.

High-frequency sound might cause bubble enlargement by rectified diffusion. The purpose of the present study was to investigate gas bubble formation in the immersed diving animal during exposure to high-frequency sound. Anaesthetised rats were subjected to a simulated diving profile while immersed inside a hyperbaric chamber. An acoustic beacon (pinger) was placed ventral to the animal's abdomen, transmitting at an intensity of 208.9 dB re 1 micro Pa and a frequency of 37 kHz. Six groups of eight animals were included in the study as in Table 1, breathing air (n = 4) or Nitrox 72/28 (n = 2), at a depth of 0 m, 30 m or 40 m. Immediately after decompression, the intestinal mesenterium was imaged, and frames were acquired digitally. The number of bubbles and their radii were analysed and compared among the groups. The mean bubble density for group 1 was 1.35 +/- 0.18 bubbles/mm(2), significantly higher when compared with the other groups (p < 0.0001). The average bubble radius for groups 1 and 2 was similar (12.57 +/- 4.1 and 10.63 +/- 1.8 microm, respectively), but significantly larger than in the other groups (p < 0.0002). The percentage of bubbles with a radius greater than 50 microm was significantly higher in group 1 (p < 0.0001). The results suggest that commercially available underwater pingers might enhance bubble growth during deep air diving.

Acoustics↗
PubMed2002

Divergent effects of oxygen therapy in four models of uncontrolled hemorrhagic shock.

Treatment with oxygen exerts beneficial effects and prolongs survival in hemorrhagic shock induced by controlled bleeding. We evaluated the effects of inhalation of 100% oxygen in four models of uncontrolled bleeding in rats: amputation of the tail, laceration of two branches of the ileocolic artery, incision of the spleen, and laceration of the lateral lobe of the liver. After tail amputation, oxygen caused a short and transient increase in mean arterial blood pressure (MABP; P < 0.01), decreased distal aorta (DA) blood flow by 27% (P < 0.01), and induced transient redistribution of blood flow to the superior mesenteric artery (SMA; P < 0.01). Later on, MABP in the oxygen group decreased gradually and was significantly lower than in air controls (P < 0.01). Oxygen therapy increased the mean blood loss by 40% (P < 0.01), increased blood lactate (P < 0.01), and shortened the survival time (P < 0.01). After laceration of two branches of the ileocolic artery, oxygen treatment caused a transient increase in MABP and redistribution of blood flow to the SMA that was followed by a comparable decrease in MABP, increase in vascular resistance, and decreased blood flow in the DA and SMA. In this model, oxygen did not affect bleeding volume, blood lactate, or survival. A similar transient regional hemodynamic effect was found when oxygen was administered after spleen or liver injury; however, in both models, oxygen maintained MABP at significantly higher values (P < 0.05). The results point to differential effects of oxygen in uncontrolled bleeding with benefits in bleeding from small parenchymal vessels and possible detrimental effect in bleeding from large size vessels.

Amputation, Traumatic↗
PubMed2002

[Pneumocystis carinii pneumonia in patients without acquired immunodeficiency syndrome (AIDS)].

The incidence of Pneumocystis Carinii pneumonia (PCP) may rise due to a more extensive use of immunosuppressive therapy. Information and guidelines in the last decade regarding prevention, diagnosis and treatment of the disease were based upon data collected in patients with Acquired Immuno Deficiency Syndrome (AIDS). However, scientific data regarding risk factors, clinical manifestations and treatment of PCP in patients without AIDS is accumulating. The major risk factors for acquiring PCP are hematological malignancies and treatment with immunosuppressive drugs, especially corticosteroids. The clinical course deteriorates more rapidly than in patients with AIDS and many patients have other opportunistic coinfections, especially with Cytomegalovirus and Candida. The duration of treatment may be shorter and drug tolerance is usually better than in patients with AIDS. However, mortality remains high even with appropriate treatment and necessitates a high index of suspicion and the use of empiric treatment even before a definitive diagnosis is made.

Candidiasis↗