Post-carotid endarterectomy hypertension: association with elevated cranial norepinephrine

The cause and mechanism of post-carotid endarterectomy hypertension remains unknown. To determine the influence of the sympathetic and renin-angiotensin system, we measured cranial and peripheral plasma levels of catecholamine and renin in patients undergoing carotid endarterectomy. Baseline samples were drawn just before carotid clamping (sample I) and compared with study samples drawn immediately after clamp release (sample II), 2 to 6 hours after surgery (sample III), and then 18 to 24 hours after surgery (sample IV). The patients with post-carotid endarterectomy hypertension had an associated increase of cranial and peripheral norepinephrine levels in the postoperative hypertensive period whereas the patients without post-carotid endarterectomy hypertension did not. This association was most pronounced and statistically significant in cranial samples II (p = 0.032) and III (p = 0.005). Epinephrine and dopamine values did not correlate with post-carotid endarterectomy hypertension. Renin values were higher in cranial than in peripheral samples at time period 2 (p = 0.011), suggestive of a central nervous system Goldblatt phenomenon. However, the renin values did not correlate with post-carotid endarterectomy hypertension. We conclude that post-carotid endarterectomy hypertension is associated with elevated cranial norepinephrine levels, suggestive of a central nervous system sympathomimetic mechanism. Optimal prevention and treatment of this brief but frequently occurring hypertension should include a central-acting sympatholytic agent.     

High aggregate burden of somatic mtDNA point mutations in aging and Alzheimer's disease brain.

The mitochondrial theory of aging proposes that mitochondrial DNA (mtDNA) accumulates mutations with age, and that these mutations contribute to physiological decline in aging and degenerative diseases. Although a great deal of indirect evidence supports this hypothesis, the aggregate burden of mtDNA mutations, particularly point mutations, has not been systematically quantified in aging or neurodegenerative disorders. Therefore, we directly assessed the aggregate burden of brain mtDNA point mutations in 17 subjects with Alzheimer's disease (AD), 10 elderly control subjects and 14 younger control subjects, using a PCR-cloning-sequencing strategy. We found that brain mtDNA from elderly subjects had a higher aggregate burden of mutations than brain mtDNA from younger subjects. The average aggregate mutational burden in elderly subjects was 2 x 10(-4) mutations/bp. The bulk of these mutations were individually rare point mutations, 60% of which changed an amino acid. Control experiments ensure that these results were not due to artifacts arising from PCR error, mistaken identification of nuclear pseudogenes or ex vivo oxidation. Cytochrome oxidase activity correlated negatively with increasing mutational burden. These findings significantly bolster the mitochondrial theory of aging.     

Perigraft seroma: clinical, histologic, and serologic correlates

A 14 year retrospective study of perigraft seroma, defined as an enlarging sterile fluid collection at the site of a prosthetic graft, revealed well-documented cases in 5 of 118 extraanatomical bypasses (4.2 percent), 3 of 248 aortic reconstructive procedures (1.2 percent), and 1 of 395 femoropopliteal bypasses (0.3 percent). These nine cases involved four polytetrafluoroethylene and five Dacron grafts. There were five graft thromboses, one instance of limb loss, two graft infections, two deaths, and 13 separate surgical procedures related to the perigraft seroma. Histologic studies revealed a fibrous pseudomembrane lining the perigraft seroma wall and immature fibroblasts lining the graft. Sera from three patients with perigraft seroma, five patients with well-incorporated prosthetic grafts, and three healthy volunteer subjects were tested for in vitro evidence of fibroblast inhibition against fibroblast tissue cultures derived from the pseudomembrane of a perigraft seroma. Control fetal calf serum, sera from all three healthy subjects, and sera from all five patients with well-incorporated grafts allowed fibroblast proliferation. In contrast, sera from all three patients with perigraft seroma inhibited fibroblast growth. Furthermore, sera collected 1, 2, and 3 months after graft removal from one patient and serum collected 3 months after spontaneous resolution of a perigraft seroma from another patient failed to inhibit fibroblasts. We have concluded that patients with perigraft seroma have a high rate of graft and limb loss and require multiple reoperations. The pathogenesis of perigraft seroma appears to involve a humoral fibroblast inhibitor which prevents maturation and proliferation of perigraft fibroblasts, leading to poor graft incorporation. The decrease of inhibition below detectable levels after graft removal or spontaneous resolution of the perigraft seroma suggests that the graft may induce host production of the inhibitor. Effective therapy of perigraft seroma may include fibroblast modulation, removal of the inciting graft, or both.     

Enhancement of hepatic hemangiomas with levovist on coded harmonic angiographic ultrasonography.

OBJECTIVE: To evaluate the pattern of contrast enhancement with Levovist on coded harmonic angiographic ultrasonography of hepatic hemangiomas. METHODS: Twenty hemangiomas were evaluated with coded harmonic angiographic ultrasonography and a microbubble contrast agent. Verification of the diagnosis of a hemangioma was made by means of dynamic computed tomography (n = 8), dynamic magnetic resonance imaging (n = 1), radionuclide scanning (n = 6), or follow-up ultrasonography (n = 5). Ultrasonographic images were obtained before contrast agent administration and with a bolus injection of 2.5 g of a microbubble contrast agent (300 mg/mL Levovist; Schering AG, Berlin, Germany) every 10 to 15 seconds for 5 minutes. The contrast enhancement patterns of the 20 hemangiomas were assessed. RESULTS: The tumor diameters as measured on ultrasonography were 7 to 97 mm (mean, 26.7 mm). Of the 20 hemangiomas, peripheral globular enhancement with progressive centripetal fill-in was shown in 15 (75%), rimlike enhancement with progressive centripetal fill-in was shown in 2 (10%), and homogeneous enhancement was shown in 1 (5%). In the remaining 2 lesions (10%), the enhancement patterns could not be seen, because they were not found on coded harmonic angiographic ultrasonography. CONCLUSIONS: Coded harmonic angiographic ultrasonography with a microbubble contrast agent can depict the typical enhancement pattern in most hepatic hemangiomas.     

Effect of continuous postoperative epidural analgesia on intestinal motility

The effect of postoperative epidural bupivacaine on intestinal motility was studied by measuring the transit time of barium contrast through the intestines in 16 patients after resection of the left colon and/or rectum. Fourteen patients served as controls and received postoperative injections of pentazocine. Mean transit time through the intestinal tract was 35 h in the epidural group and 150 h in the control group, a difference that is significant at the 0.1 per cent level. The average time before passage of flatus and faeces was different between the two groups at the 0.1 per cent level. We conclude that postoperative epidural bupivacaine constitutes an effective means of analgesia after colorectal surgery and is associated with a short duration of intestinal paralysis.     

Umbilical portion of recipient's left portal vein: a useful vascular conduit in dual living donor liver transplantation for the thrombosed portal vein.

We considered performing living donor liver transplantation (LDLT) in a larger-size recipient. When the recipient was large-sized, or when the donor liver was severely steatotic or had a right-to-left volume discrepancy. We devised dual living donor liver transplantation (DLDLT) to make up for graft size insufficiency and to secure the donor's safety. However, portal vein thrombosis (PVT) presented a challenge for DLDLT because of the need for intact right and left portal veins for the implantation of both liver grafts. Our 52-year-old male patient with hepatitis B cirrhosis had suffered from repeated esophageal and gastric variceal bleeding and underwent 2 trials of a transjugular intrahepatic portosystemic shunt (TIPS). He developed TIPS occlusion and PVT involving the area just above the spleno-mesenteric confluence to the right and left PV. Also, the right PV orifice was destructed and difficult to isolate because of severe periportal inflammation and neointima growth in the TIPS mesh. The patient's two sons were inadequate for donation because of right-to-left volume discrepancy. Therefore, DLDLT using 2 left lobes was necessary to compensate for graft-size insufficiency and to secure donor safety, and we substituted an intact umbilical portion of recipient's left PV for the destroyed right PV. The patient recovered well, and liver function has been normal for more than a year. In conclusion, the umbilical portion of recipient's left PV can be a useful vascular substitute for the reconstruction of a thrombosed main portal branch in DLDLT.     

Cyclin E, p27 and mutant p53 do not predict the prognosis in AJCC stage II colorectal carcinomas.

BACKGROUND/AIMS: Carcinogenesis is characterized by the abnormal regulation of cell cycle. The abnormal expression of the regulators of cell cycle may be related to the prognosis. Since the clinical significance of the expression of the three proteins in colorectal carcinomas is still controversial, we evaluated the prognostic value of the expression of cyclin E, p27 and mutant p53 in stage II colorectal cancer. METHODS: The expression levels of cyclin E, p27 and mutant p53 proteins in 41 patients with stage II colorectal carcinomas were analyzed by immunohistochemistry. RESULTS: In the univariate analysis, the level of CEA at diagnosis was associated with disease relapse. In the multivariate analysis, the clinicopathological variables such as age, gender, site of primary tumor, tumor size, state of tumor differentiation and preoperative plasma CEA level were not associated with disease relapse. When Kaplan-Meier survival curves were constructed to determine the prognosis, cyclin E, p27 and mutant p53 expressions did not predict poor prognosis. CONCLUSIONS: Our results suggested that the expression of cyclin E, p27 and mutant p53 proteins did not predict the clinical outcome in the stage II colorectal carcinomas.