Successful hyperbaric oxygen treatment of life-threatening hemorrhagic cystitis after allogeneic bone marrow transplantation.

Hemorrhagic cystitis (HC) is a major cause of morbidity after allogeneic bone marrow transplantation (BMT). Many therapies have been investigated to prevent or treat HC, but effective treatment for HC is still limited. While the efficacy of hyperbaric oxygen therapy has been established for HC due to chemotherapy and/or radiation therapy, its role in HC occurring after allogeneic BMT has yet to be defined. We report two cases of life-threatening late-onset HC after allogeneic BMT in children, which resolved after treatment with hyperbaric oxygen.

[Usefulness of preadmission autologous blood donation and intraoperative autotransfusion using the "cell saver" for the patients with abdominal aortic aneurysm repair].

To evaluate the effectiveness of preadmission autologous blood donation (PABD) and intraoperative autotransfusion (IAT) in reducing the homologous transfusion requirement of abdominal aortic aneurysm (AAA) resection, we retrospectively reviewed 232 AAA cases from January 1991 to December 1999. The patients were separated into three groups. The group I (n = 101) received no PAPD and IAT. The group II (n = 58) received only IAT. The group III (n = 73) received both PAPD and IAT. Surgical data indicating operative time and intraoperative blood loss did not differ among the three groups. However, the incidence of requirement for homologous transfusion in group III (19.2%) is significantly less than those of group I (63.4%) or group II (51.7%), although there was no significant difference between group I and group II. We concluded that the combination of PAPD and IAT are useful for reducing the incidence of requirement for homologous transfusion in the patients with aneurysmal resection.

L-arginine inhibits smooth muscle cell proliferation of vein graft intimal thickness in hypercholesterolemic rabbits.

OBJECTIVE: The effect of the chronic administration of L-arginine on intimal thickness and the kinetics of smooth muscle cell proliferation in autovein grafts in hypercholesterolemic rabbits were examined. METHODS: Male rabbits were fed a 1% cholesterol diet (control group) and a 1% cholesterol diet supplemented by 2.25% L-arginine HCl in drinking water (arginine group). Each group underwent reversed autologous vein bypass grafting of the left common carotid artery using the left external jugular vein. At 2 or 4 weeks after operation, intimal cell proliferation was determined by 5-bromo-2'-deoxyuridine (BrdU) incorporation and intimal thickness of the graft was measured with an ocular cytometer. At 4 weeks after operation, endothelium-dependent responses were examined by isometric tension recording. RESULTS: At 4 weeks after operation, the level of plasma arginine and citrulline are significantly higher in the arginine group (n = 7), compared with the control (n = 7). Intimal thickness in the arginine group (n = 7) was significantly reduced, compared with that of the control (n = 7). At 2 weeks after operation, the BrdU labeling index of the control (n = 5) was significantly higher than that of the arginine group (n = 5). At 4 weeks after operation, ACh caused endothelium-dependent relaxation in the arginine group (n = 4), while in the control (n = 4), ACh did not relax. CONCLUSIONS: These results suggest that smooth muscle cell proliferation of the rabbit jugular vein grafts during hypercholesterolemia occurs at an early stage after graft implantation, prior to the development of intimal thickness. Intimal thickness of vein graft during hypercholesterolemia was reduced by chronic administration of dietary L-arginine, by inhibiting smooth muscle cell proliferation. The enhancement of NO production in the blood vessel wall may therefore be useful for preventing late graft failure.

Eicosapentanoic acid reduces the intimal thickening of autogenous vein grafts and enhances endothelium-derived relaxing factor.

The present study examined the effect of purified eicosapentanoic acid (EPA) on intimal thickening of an autogenous vein graft. In addition, experiments were performed to determine whether EPA supplementation would alter the endothelium-dependent responses of the reversed vein graft. Segments of femoral veins were grafted into the femoral arteries of dogs. Six dogs received regular chow (control group) and six other dogs regular chow with 1500 mg/day 90.0% pure EPA (EPA group). At 6 weeks after surgery, the vein grafts were removed from the dogs, cut into rings, and suspended in organ chambers for isometric tension recording. In some rings, the endothelial cells were removed. When the rings taken from the control group were contracted with norepinephrine, adenosine diphosphate (ADP) and A23187 caused endothelium-dependent relaxations. In the EPA group, the endothelium-dependent responses to ADP were significantly augmented, while A23187 caused comparable endothelium-dependent relaxations. Direct relaxation in response to sodium nitroprusside was comparable between the two groups. Intimal thickening of the grafts in the control group (29.0 +/- 1.8 microns) was significantly (P < 0.05) greater than in the EPA group (12.5 +/- 1.8 microns). These results suggest that EPA enhances the release of endothelium-derived relaxing factor in autogenous vein grafts. This may be one of the effects of EPA in reducing the intimal thickening of autogenous vein grafts.

Do some tyrosine hydroxylase-immunoreactive neurons in the human ventrolateral arcuate nucleus and globus pallidus produce only L-dopa?

The presence of 'tyrosine hydroxylase (TH)-only'-immunoreactive (IR) neurons is reported for the first time in the human hypothalamic region and basa ganglia, using immunohistochemical technique. 'TH-only'-IR neurons were demonstrated in the ventrolateral part of the arcuate nucleus and medial segment of globus pallidus. These neurons lacked aromatic L-amino acid decarboxylase (AADC)-, dopamine-beta-hydroxylase (DBH)-, and dopamine (DA)-immunoreactivity. The above results suggest that these 'TH-only'-IR neurons are not dopaminergic, and possibly contain L-DOPA as an end-product.

Endothelium-dependent relaxation in response to aggregating platelets in porcine femoral veins and its modulation by diet.

The present study examined the protective role of the venous endothelium against aggregating platelets and its modulation by diet. Yorkshire pigs were fed a regular chow (control pigs), 2% high-cholesterol diet (for 10 weeks, cholesterol-fed pigs), and regular chow plus cod-liver oil (30 ml/day for 4 weeks, oil-fed pigs). Endothelium-dependent responses were examined in vitro in rings of femoral veins in the presence of the inhibitor of cyclooxygenase indomethacin. In control pigs, aggregating platelets, serotonin, and ADP caused endothelium-dependent relaxations. The platelet-induced relaxations were attenuated by methiothepin (a combined 5-HT1 and 5-HT2 serotonergic blocker) or apyrase (an ADPase and ATPase) and were abolished by the combination of the two agents. In quiescent rings, platelets caused contractions, which were reduced in the presence of endothelium; the contractions were prevented by ketanserin (a 5-HT2 serotonergic blocker) or methiothepin but not by R 68 070 (a thromboxane A2 receptor blocker) or dazoxiben (a thromboxane-synthetase blocker). In cholesterol-fed pigs, the platelet-induced relaxations were not altered, whereas in oil-fed pigs, the endothelium-dependent relaxations to platelets, serotonin, and ADP were augmented. Platelet-induced contractions were significantly reduced in rings with endothelium from oil-fed pigs, whereas the contractions were comparable in rings without endothelium among the three groups. Endothelium-dependent relaxations in response to the calcium ionophore A23187, direct relaxations in response to sodium nitroprusside, and direct contractions in response to potassium chloride were comparable among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)