RESUMO
BACKGROUND/AIMS: Normal pressure hydrocephalus (NPH) is a potentially reversible neurological syndrome commonly characterized by gait disturbance, urinary incontinence, and dementia. Hydrocephalus e-vacuo (He-v) is also characterized by the occurrence of dementia but does not show gait disturbance or urinary incontinence and has no evident cerebrospinal fluid (CSF) pressure elevation. Kynurenic acid (KYNA), an endogenous metabolite of the L-kynurenine (L-KYN) pathway of L-tryptophan (L-TRP) degradation, is an antagonist of glutamate N-methyl-D-aspartic acid and alpha-7 nicotinic cholinergic receptors that have been linked to dementia. We investigated KYNA, L-KYN, and L-TRP levels in human CSF and serum during the aging process in 30 healthy control individuals. In addition, clinical parameters and L-TRP metabolites in CSF and serum were evaluated in four patients with NPH and five with He-v. METHODS: KYNA, L-KYN, and L-TRP levels in CSF and serum were determined using highperformance liquid chromatography. RESULTS: Healthy controls showed a significant decrease in serum albumin with age. Compared with their corresponding controls and unlike patients with He-v, patients with NPH (age ≤ 50 years) had significant increases in CSF protein (241%, p < 0.001), CSF albumin (246%, p < 0.001), CSF IgG (328%, p < 0.001), and CSF:serum IgG (321%, p < 0.001) and CSF:serum albumin (257%, p < 0.001) ratios. Controls had significant increases in KYNA, L-KYN, and L-TRP levels in the CSF with advancing age but not in the serum. Compared with the corresponding controls, KYNA levels were significantly increased in the CSF of patients with NPH (141%, p < 0.05) and He-v (225%; p < 0.01). Additionally, the serum levels of KYNA were increased in patients with NPH and He-v to 161% and 156% of controls, respectively (both p < 0.01). The serum levels of L-KYN and L-TRP were significantly reduced in patients with He-v but not in patients with NPH. C-reactive protein, as a marker of inflammation, was significantly increased in the serum of patients with He-v but not in patients with NPH, compared with the corresponding controls. CONCLUSION: The aging process is related to elevated CSF levels of KYNA, L-KYN, and L-TRP levels. There are significant differences in clinical parameters between the two forms of hydrocephalus and these differences might have diagnostic utility. The occurrence of dementia in patients with either form of hydrocephalus might be at least partly related to elevated KYNA levels in the CNS and/or periphery.
RESUMO
OBJECTIVE: We analyzed the use of an electrosurgical bipolar vessel sealing system for radical abdominal hysterectomy. METHODS: We compared operating time, transfusion requirements and other surgical parameters in 52 patients undergoing radical abdominal hysterectomy with systematic pelvic +/- paraaortic lymphadenectomy for stage IB1-IIB cervical cancer between January 2001 and June 2004. At 21 operations between January 2001 and March 2002, the parametrium, paracolpos and vaginal cuff were resected with clamps and the pedicles suture ligated; 31 operations between November 2001 and June 2004 were done with a bipolar vessel sealing system (LigaSure Vessel Sealing System, Valleylab, Boulder, CO). Four surgeons did all operations. Data were compared with the t test. RESULTS: Patients operated with the LigaSure system received fewer packed RBC transfusions than those operated with clamps (mean, 0.61 +/- 1.1 vs. 2.14 +/- 2.6 units, respectively; P = 0.01), even when looking at patients who underwent only pelvic (without paraaortic) lymphadenectomy (mean, 0.52 +/- 1.1 vs. 1.29 +/- 1.2 units, respectively; P = 0.02). The transfusion rate in the two groups was 26% (8/31) and 67% (14/21), respectively (P < 0.05). Operating time did not differ significantly (199 +/- 33 vs. 213 +/- 45 min, respectively). There were no significant differences between the groups in number of pelvic nodes removed, febrile morbidity, postoperative stay, or days until residual urine <100 ml. One patient in the LigaSure group developed a ureterovaginal fistula that resolved with stenting. CONCLUSION: The LigaSure system appears useful to reduce blood loss at radical abdominal hysterectomy.