Antioxidant enzyme activities and total nitrite/nitrate levels in the collar model. Effect of nicardipine.

There is a large body of literature describing the causative role of oxidative stress mediated by increased levels of reactive oxygen species in the pathogenesis of cardiovascular disease such as atherosclerosis, hypertension, and restenosis after angioplasty. The positioning of a soft silicone collar around the rabbit carotid artery elicits intimal thickening. The findings from recent studies demonstrated that both intimal thickening and atherosclerosis lead to synthesis of inducible nitric oxide synthase, resulting in abundant amounts of nitric oxide. We investigated the effects of collaring and nicardipine treatment on the activities of antioxidant enzymes, superoxide dismutase and catalase, and total nitrite/nitrate levels, stable products of nitric oxide. Placing the collar increased the total nitrite/ nitrate levels and decreased superoxide dismutase activity in collared arteries. Treatment with nicardipine (20 mg/kg/day, s.c.) prevented enhanced nitric oxide degradation without affecting superoxide dismutase and catalase activities. Our results suggest that enhanced nitric oxide production and superoxide anion are generated in response to the collaring, resulting in oxidative stress within the segment in this model.     

Time-dependent changes in distribution of basic fibroblast growth factor immunoreactive cells in hippocampus after kainic acid injection in rat pups

Five-day-old Wistar albino rats were injected with kainic acid (KA) or saline i.p. to investigate time-dependent alterations in morphology and number of basic fibroblast growth factor (bFGF) immunoreactive (-ir) astrocytes and neurons in hippocampus at 15, 30, and 90 days after the injections. Sections were stained with cresyl violet for morphological evaluation and bFGF immunohistochemistry was used for quantitative evaluation of bFGF-ir cell density. Fifteen days after KA injection, there was gliosis but no neuronal loss although disorganization in CA1, CA3, CA4 pyramidal layers and neuronal loss were evident 30 and 90 days after the injection. KA injected rats demonstrated significantly increased number of bFGF-ir astrocytes throughout the hippocampus and pyramidal neurons in CA2 after 15 days and decreased number of bFGF-ir cells after 30 and 90 days. The decrease in the number of bFGF-ir astroglia and neurons in long term after KA injection may indicate a decrease in the production of bFGF and/or number of bFGF-ir cells suggesting that protective effects of bFGF may be altered during epileptogenesis in hippocampus.     

Audiovestibular disturbance in patients with systemic lupus erythematosus.

OBJECTIVE: The aim of this study was to evaluate the audiovestibular disturbance in patients with systemic lupus erythematosus (SLE). STUDY DESIGN AND SETTING: Twenty-eight patients with SLE and 28 healthy control subjects were included. Pure-tone audiometry, impedance audiometry, and electronystagmography (ENG) were used for baseline evaluation. Laboratory tests were carried out. Cranial and brain stem magnetic resonance imagings (MRI) were undertaken. RESULTS: Nineteen (67%) patients reported audiovestibular symptoms. Sensorineural hearing loss was found in 6 (21%) patients. Abnormal results on ENG were significantly higher (50%) (P < 0.01). Abnormal laboratory data were available from 26 patients (P < 0.05). MRI did not show any pathosis. CONCLUSION: The audiovestibular disturbances in SLE are more prevalent than previously recognized. Although no cause and effect relationship can be established by this type of study, it appears that a relationship exists. SIGNIFICANCE: Audiologic research should be directed toward routine, pure tone audiometry, and ENG assessment for patients with SLE to enable crucial treatment.     

Effect of persistently elevated intraabdominal pressure on healing of colonic anastomoses

BACKGROUND: The adverse effects of elevated intraabdominal pressure (IAP) on abdominal organs are realized, but its influence on anastomotic healing has not been studied. The aim of this study was to evaluate the effect of elevated IAP on healing of colonic anastomoses. METHODS: Thirty rats, which all had right colonic anastomoses, were divided into five groups. Group 1 was the control group, and group 2 had fecal peritonitis. IAP was maintained between 4 to 6 mm Hg in group 3, 8 to 12 mm Hg in group 4, and 14 to 18 mm Hg in group 5 until all rats were sacrificed on day 4. Bursting pressures and tissue hydroxyproline concentrations of anastomoses were then analyzed and compared. RESULTS: Mean +/- SEM of bursting pressures were 143+/-2.9 mm Hg in group 1, 72+/-14.4 mm Hg in group 2, 77.3+/-7.9 mm Hg in group 3, 57.5+/-11.2 mm Hg in group 4, and 40.1+/-9.6 mm Hg in group 5 (P<0.0001, one-way analysis of variance [ANOVA]). Mean +/- SEM of tissue hydroxyproline concentrations were 5.3+/-0.3 microg/mg in group 1, 4.7+/-0.5 microg/mg in group 2, 4.6+/-0.6 microg/mg in group 3, 3.6+/-0.5 microg/mg in group 4, and 2.4+/-0.2 microg/mg in group 5 (P = 0.0026, one-way ANOVA). The bursting pressure and hydroxyproline concentrations had good correlation (P<0.001, r = 0.76). CONCLUSIONS: Elevated IAP delays healing of colonic anastomoses and 4 to 6 mm Hg IAP delays healing as much as fecal peritonitis. More elevated IAP delays healing more than fecal peritonitis. These events may be clinically important and may result from local-systemic effects of IAP.     

Microbial keratitis following penetrating keratoplasty.

PURPOSE: To investigate the prevalence of microbial keratitis, predisposing risk factors and treatment modalities in patients who developed keratitis following penetrating keratoplasty (PK). PATIENTS AND METHODS: The records of 285 patients who had undergone PK between January 1991 and December 1995 in a tertiary care center were reviewed. Patients who developed postoperative microbial keratitis were evaluated for predisposing risk factors, microbiological etiology, response to broad spectrum antibiotic therapy and subsequent PK. Patients were mainly treated with fortified topical antibiotics with or without repeat PK. RESULTS: Of the 285 patient records reviewed, microbial keratitis developed in 21 eyes of 21 patients (7.4%). Seventy-one percent of infections occurred within 6 months after grafting. Keratitis initially began from the donor-recipient border in 16 cases (76.2%) and were central or paracentral in 5 patients. Predisposing risk factors included loose or exposed suture (9), suture removal (1), persistent epithelial defect (3), graft failure (3), contact lens wear (1), Stevens-Johnson syndrome (1). Fifteen (71.4%) patients were culture-positive consisting of Streptococcus pneumoniae (7), Staphylococcus aureus (5), Pseudomonas aureginosa (2), and Hemophilus influenzae (1). Forty-three percent of patients were successfully treated with medical therapy only. Seven patients underwent second PK for visual rehabilitation and 4 for tectonic purposes. After medical and surgical therapy, graft clarity was achieved in 17 (81%) of patients. CONCLUSIONS: The microbial keratitis following PK is a major postoperative problem affecting the long term prognosis. Careful selection of patients, and preoperative and postoperative control of risk factors, may decrease the frequency of this complication. Several factors, including loose or exposed sutures, epithelial defects, ocular surface disorders, and graft failure, may predispose patients to develop microbial keratitis following PK.     

Renal resistive indexes and some renal functions in liver cirrhotic children

BACKGROUND: The aim of the present study was to investigate renal vascular resistive changes in children with different stages of liver cirrhosis without obvious renal failure. METHODS: Twenty-nine children (14 girls, 15 boys, mean age 11.6 years) with cirrhosis and 20 healthy children (mean age 10.3 years) were investigated for renal vascular resistance with Doppler ultrasonography, urinary sodium, N-acetyl-beta-D glucosaminidase (NAG) and microalbuminuria excretion. RESULTS: The measurements of renal resistive indexes (RRI) were significantly higher in cirrhotic patients than the control group (0.69 +/- 0.07 vs 0.62 +/- 0.02, P < 0.0001). RRI measurement was found to be increased in decompensated cirrhotic patients than in compensated cirrhotic patients (0.73 +/- 0.05 vs 0.67 +/- 0.08, P < 0.0001). A significant positive relationship was observed between RRI and child score (r = 0.53). Urine NAG/Cr ratio was significantly higher in cirrhotic patients than in the control subjects (P < 0.001). Microalbumin concentrations were increased in the patients with decompensated cirrhosis than in the controls (P = 0.02). Patients with ascites and portal hypertension showed increased RRI values. CONCLUSIONS: We conclude that patients with cirrhosis are at risk of renal deterioration, which can not be detected by serum urea, creatinine, and glomerular filtration rate. The increase of RRI is associated with the progress of hepatocellular disease, and also the development of ascites and portal hypertension. Elevated urinary sodium excretion, elevated urinary NAG/Cr ratio and microalbuminuria might have a prognostic value especially in patients with Child scores> 6. Hence, monitoring RRI is a non-invasive means of studying early renal hemodynamic alteration in childhood cirrhosis.     

Acute Lymphoblastic Leukemia as a Second Malignant Neoplasm in a Child with Medulloblastoma

Second malignant neoplasm in childhood is increasing due to advances in therapy modalities. Acute lymphoblastic leukemia as a second malignancy following the treatment of medulloblastoma is a very rare condition. A 13-year-old boy was diagnosed as acute lymphoblastic leukemia following radiotherapy and chemotherapy for treatment of medulloblastoma.