Epithelioid angiosarcoma associated with a Dacron vascular graft.

Angiosarcoma developed at the site of a Dacron vascular prosthesis 8 years after an aortobifemoral bypass graft insertion. The tumor was composed of epithelioid cells, which showed positive staining for cytokeratin and expression of the common endothelial markers CD31, CD34, and von Willebrand factor. Ultrastructural examination showed aggregates of large cells with intercellular lumina and focal perinuclear whorls of intermediate filaments. The patient, who had abdominal pain and weight loss, died of disseminated pelvic and abdominal disease 6 months after diagnosis. Sarcomas associated with vascular Dacron grafts and angiosarcomas associated with metal or polymer foreign bodies are rare. Their development is probably analogous to the common experimental development of foreign body-associated sarcomas in rodents. Physicians caring for patients with vascular grafts or metal foreign bodies should be aware of this complication.

Construction and characterization of an NaCl-sensitive mutant of Halomonas elongata impaired in ectoine biosynthesis.

Using transposon mutagenesis we generated a salt-sensitive mutant of the halophilic eubacterium Halomonas elongata impaired in the biosynthesis of the compatible solute ectoine. HPLC determinations of the cytoplasmic solute content showed the accumulation of a biosynthetic precursor of ectoine, L-2,4-diaminobutyric acid. Ectoine and hydroxyectoine were not detectable. This mutant failed to grow in minimal medium with NaCl concentrations exceeding 4%. However, when supplemented with organic osmolytes, the ability to grow in high-salinity medium (15% and higher) was regained. We cloned and sequenced the regions flanking the transposon insertion in the H. elongata chromosome. Sequence comparisons with known proteins revealed significant similarity of the mutated gene to the L-2,4-diaminobutyric acid acetyltransferase from the ectoine biosynthetic pathway in Marinococcus halophilus. Analysis of a PCR product demonstrated that the ectoine biosynthetic genes (ectABC) follow the same order as in M. halophilus.

Pretreatment with L-kynurenine, the precursor to the excitatory amino acid antagonist kynurenic acid, suppresses epileptiform activity in combined entorhinal/hippocampal slices.

The kynurenine pathway converts tryptophan into various compounds, including L-kynurenine, which in turn can be converted to the excitatory amino acid receptor antagonist kynurenic acid. The hypothesis that endogenously-produced kynurenic acid could have physiological effects was tested in combined entorhinal/hippocampal slices from adult rats. Specifically, perfusion with L-kynurenine (1 mM) was examined for its ability to suppress epileptiform activity produced by subsequent perfusion with buffer lacking added magnesium (nominal 0 mM magnesium buffer). Importantly, treatment with L-kynurenine did not appear to have depressant effects in itself, but it prevented spontaneous epileptiform activity in all 64 slices subsequently perfused with 0 mM magnesium buffer. In contrast, 45 slices that were not pretreated with L-kynurenine exhibited spontaneous epileptiform activity. These data support the hypothesis that endogenously-produced kynurenic acid can be produced and released in brain slices, where it can suppress excitatory activity in an "anticonvulsant' manner. Therefore, manipulation of the kynurenine pathway might constitute a useful new direction for anticonvulsant drug development.

Renovascular hypertension associated with neurofibromatosis: two cases and review of the literature.

The authors report two cases of renovascular hypertension associated with neurofibromatosis. A 19-year-old woman was admitted to our hospital with a complaint of abdominal pain and blood pressure of 180/120 mmHg. Examination revealed café-au-lait spots over her chest and extremities. Peripheral plasma renin activity (PRA) under basal conditions was 2.8 ng/ml/h and increased to 12.6 ng/ml/h after administration of 50 mg captopril. Plasma and urinary catecholamines were normal. Selective renal angiography showed left aneurysmal dilatation of the segmentary branch and right renal artery stenosis with multiple aneurysmal affecting different branches. Blood pressure was controlled by multiple drugs, including beta-blockers and angiotensin-converting enzyme inhibitor. Another patient, a 20-year-old woman, was admitted because of severe arterial hypertension, numerous café-au-lait spots, scoliosis, and mass over the right arm. PRA from the right renal vein was extremely elevated, and selective angiography demonstrated bilateral renal artery stenosis. Aortorenal bypass was performed successfully.

Traumatic abdominal hernia associated with large bowel strangulation: case report and review of the literature.

A rare case of traumatic rupture of the abdominal wall with ventral herniation and strangulation of the right colon is presented. The defect was detected by computed tomography on admission. The patient was operated on 3 days after injury, and irreversible ischaemia of the right colon was found. Right hemicolectomy was performed. The pathogenesis and treatment of this complication is discussed.

Celiac artery aneurysm: diagnosis by color Doppler sonography and three-dimensional CT angiography.

Celiac artery aneurysms are rare vascular lesions that are sometimes found incidentally during abdominal imaging. Their significance is in their potential to rupture, which can lead to death. We present the case of a celiac artery aneurysm diagnosed by color Doppler sonography and 3-dimensional CT angiography.

Dacron graft aneurysm treated by endovascular stent-graft.

A 72-year old man who underwent aorto-bifemoral bypass with insertion of a Dacron graft 18 years previously presented with an aneurysm in the left limb of his graft. Angiography also demonstrated a bilateral occlusion of the popliteal arteries. Computed tomography (CT) angiography was performed and showed a localized dilation of 3 cm in the left limb of the graft, which had a diameter of 14 mm throughout. In view of the technical difficulties of a surgical procedure, an endovascular stent was considered. Through a left femoral arteriotomy, a stent graft was inserted and deployed in the left limb of the graft. This resulted in total exclusion of the Dacron graft aneurysm. To the best of our knowledge, this is the first report of such a procedure.

Septic emboli from a radial artery catheter with local manifestations of subacute bacterial endocarditis.

Septic emboli, giving rise to physical signs similar to those of subacute bacterial endocarditis, are extremely rare complications of radial artery catheterization. A case is reported with splinter hemorrhages and Janeway lesions, resulting from an infected radial artery catheter. Five other cases with these signs are collected from among 21 patients with localized septic complications described in the literature. The duration of radial artery catheterization was 4 days or longer in all cases, and Staphylococcus aureus was the offending agent in all. We conclude that arterial lines should be removed as early as possible, and in any case they should be pulled out at the earliest sign of a local complication. In the presence of signs of local infection, antistaphylococcal treatment should be given until results of cultures are available.

CT angiography of the carotid arteries in trauma to the neck.

OBJECTIVES: serious vascular injuries to the neck may be asymptomatic or masked by other life-threatening conditions. Angiography, the "gold standard" vascular imaging modality, is an invasive procedure. Moreover, it is time-consuming and thus may delay a needed vascular intervention. The results of screening angiography are negative in more than 80% of cases. Therefore other less invasive and faster screening tests, such as the Doppler ultrasound and magnetic resonance angiography, have been tested. This retrospective study was done to evaluate the use of CT angiography (CTA) in suspected vascular injuries of the neck. METHODS: from 1995 to 1998, 16 patients with suspected traumatic carotid artery injury underwent CTA. Twelve of these patients had penetrating injuries and four had blunt injuries to the neck. CTAs were obtained by Elscint Twin Flash Spiral Scanner, while MIP reconstructions were carried out on an Omnipro, Elscint (Indy, Silicon Graphics) work station and interpreted by a radiologist. RESULTS: all the CTAs were diagnostic. Positive findings included one complete tear of the right common carotid artery (confirmed by surgery) due to a penetrating injury and one bilateral internal carotid artery thrombosis after blunt injury to the neck. In addition, three patients with multiple trauma were operated on, due to either proximity only or questionable neurological findings. Surgical exploration confirmed the negative findings seen on CTA. CONCLUSION: CT angiography of the carotid arteries in cervical trauma may be used as an accurate decisive tool for a needed surgical intervention. More studies with larger number of patients and comparison with angiography are needed.