Vagal nerve stimulator implantation: an otolaryngologist's perspective.

OBJECTIVE: This study was conducted to compare an otolaryngologist's experience with a cohort of epilepsy patients implanted with a vagal nerve stimulator (VNS) to previously published data. METHODS: Demographics, preoperative seizure frequency, medications, and complications were retrospectively collected from patients implanted by the senior author. Postoperative medications and seizure frequency were obtained from referring neurologists. RESULTS: Seventeen patients were implanted over a 24-month period. Average age was 28.3 years. Patients presented with petit mal (n = 3), tonic-clonic (n = 6), complex partial (n = 5), and grand mal (n = 8) seizures. Mean follow-up postimplantation was 13.5 months. Most patients had at least a 50% reduction of seizure frequency, with 3 patients being seizure free. There were no postoperative infections. One patient had left vocal cord immobility. The most common side effect was voice disturbance during device activation. CONCLUSION: Otolaryngologists are well equipped to perform VNS implantation and to diagnose and treat possible laryngeal side effects. EBM rating: C-4.     

The levels of plasma and salivary antioxidants in the patient with recurrent aphthous stomatitis

BACKGROUND: Despite plenty of research, the cause of recurrent aphthous stomatitis (RAS) remains obscure. It has been proposed that, the aetiological factors such as local trauma, smoking, vitamin deficiencies and viral infections lead to aphthae formation via final common pathway based on increased oxidative stress. The aim of this investigation was to evaluate the antioxidant enzyme superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) alterations in plasma and saliva, and in addition uric acid (UA) in saliva, in patients with RAS and healthy controls. METHODS: Thirty-two patients with RAS and 30 healthy controls were included into the study. The SOD, CAT, GSHPx and UA levels were measured in plasma and saliva in study and control groups. RESULTS: In the RAS group, although the mean SOD (P<0.001) and CAT (P<0.05) levels of plasma were lower, GSHPx (P<0.001) levels were higher than control group. The salivary concentrations of the SOD (P<0.001), CAT (P<0.05) and GSHPx (P<0.001) in RAS group were entirely opposite to plasma concentrations. UA were not significant between RAS group and controls. CONCLUSION: Since we found salivary SOD and CAT levels were high whereas plasma levels were low, it has been thought that, salivary defence mechanisms via antioxidant agents may be stimulated against to the ulcerous lesion. We consider that the organism might mobilize the antioxidant potential to the sites where they were needed. At this point, decrease of SOD and CAT levels in the plasma may be related to this shift. It is also thought that GSHPx secretion in the saliva may also be increased but the increase in its turnover may be responsible for the diminished activity.     

Preparation of ABCBA-type block copolymers by use of macro-initiators containing peroxy and azo groups

Some new macroinitiators ( 5 ) containing azo and peroxy groups were synthesized by transformation of esters of poly(ethylene glycol) ( 1 ) (PEG) of different molecular weight with hydroxyl end groups and an azo group in the middle into the corresponding polymers with tert-butylperoxycarbonyl end groups by reaction with terephthaloyl chloride and subsequently with tert-butyl hydroporoxide. Decomposition in the presence of styrene at 60°C or with 3,6,9-triazaun-decane-1,11-diamine in presence of methyl methacrylate gave the corresponding ABA block copolymer 6 and the ABBA block copolymer 7 , respectively. Both block copolymers were used as polymeric initiators. The ABCBA block copolymer 8 was synthesized from 6 and methyl methacrylate or from 7 and styrene by thermally induced polymerization at 80°C. The resulting block copolymers were separated from the homopolymers by selective solvent extraction and characterized by spectroscopic and fractional precipitation methods.     

Comparison of indium-111 octreotide and thallium-201 scintigraphy in patients mammographically suspected of having breast cancer: Preliminary results

Indium-111 octreotide and thallium-201 scintigraphic studies were compared in 21 patients (16 with palpable and five with non-palpable lesions) suspected of having breast malignancies on the basis of mammography. Early (15 min) and late (3 h)²⁰¹Tl (111 MBq) and 4-h and 24-h¹¹¹In-octreotide (111–148 MBq) static planar anterior images (matrix 256×256) were obtained on separate days. Images were evaluated both visually and quantitatively. Biopsy was performed following the imaging studies. Histopathology revealed 17 breast carcinomas (15 cases of invasive ductal carcinoma, one mucinous adenocarcinoma and one intraductal carcinoma) and four benign breast lesions (two fibroadenomas, one abscess and one case of fat necrosis). The means histopathologcial tumour size (mean largest diameter) was 3.38±1.9 cm.¹¹¹In-octreotide detected 16 of the 17 breast cancers (94%) while²⁰¹Tl detected 13 of them (76%). Both¹¹¹In-octreotide and²⁰¹Tl missed one nonpalpable carcinoma showing only an isolated cluster of microcalcifications on mammography. The smallest tumour size detected by both agents 1.5×1.5 cm. Of the four benign lesions, only the breast abscess revealed both²⁰¹Tl and¹¹¹In-octreotide uptake.¹¹¹In-octreotide scan also showed tracer uptake in five of the six patients with histologically proven axillary metastases, while four of these six patients showed²⁰¹Tl uptake. The tumour/background (T/B) ratios of late¹¹¹In-octreotide and²⁰¹Tl images were 1.71±0.38 and 1.46±0.30 respectively (P=0.039). In this preliminary study,¹¹¹In-octreotide yielded more favourable results than²⁰¹Tl in the detection of breast carcinomas. However, the diagnostic efficacy of¹¹¹In-octreotide imaging needs to be investigated in larger patient series.     

An in vitro study of nonadrenergic-noncholinergic activity on the cavernous tissue of mouse

The relaxant effects of electrical field stimulation (EFS) and exogenously applied acetylcholine (ACh) or acidified NaNO₂ (a-NaNO₂) were investigated in the isolated mouse corpus cavernosum precontracted with phenylephrine hydrochloride (PE). Tetrodotoxin (TTX) blocked the relaxant effects of EFS completely, whereas it had no effect on the responses to ACh or a-NaNO₂. Guanethidine and indomethacin failed to affect the electrically or ACh-induced relaxations. Atropine completely blocked the effect of ACh; however, it caused a slight reduction in the relaxation evoked by EFS.N ^G- Nitro-l-arginine (l-NOARG) reduced the effects of EFS and ACh significantly, but it was ineffective on the relaxations induced by a-NaNO₂. The inhibitory action ofl-NOARG was partly restored byl-arginine, but not byd-arginine. Methylene blue (MB) and hydroxocobalamin (HC) exhibited significant inhibition on the relaxations evoked by EFS, ACh and a-NaNO₂. Hydroquinone (HQ) reduced relaxation due to a-NaNO₂, but did not affect that of EFS and ACh. Our findings suggest that EFS-induced relaxations of mouse cavernosal tissue are mediated by a transmitter which probably resembles an organic nitrate.     

Caffeic acid phenethyl ester (CAPE) supplemented St. Thomas' hospital cardioplegic solution improves the antioxidant defense system of rat myocardium during ischemia-reperfusion injury.

BACKGROUND AND AIM OF STUDY: Cardioplegic arrest remains the method of choice for myocardial protection in cardiac surgery. Caffeic acid phenethyl ester (CAPE) prevents lipid peroxidation induced by ischemia-reperfusion injury and has a potent antioxidant property. We investigated the advantages of CAPE supplemented cardioplegic solution (St. Thomas' Hospital cardioplegic solution No.: 2) on the antioxidant defense system of myocardium against ischemia-reperfusion injury. MATERIAL AND METHODS: Isolated rat hearts were mounted on a nonrecirculating type of Langendorff apparatus. The hearts were arrested for 60 min with cardioplegic solution given at 20-min intervals and then reperfused for 15 min. The hearts were divided into three groups. Cold saline (0.9%, 4 degrees C) in group 1, St. Thomas' Hospital solution in group 2 and CAPE added St. Thomas' Hospital solution in group 3 were used as the cardioplegic solution. Krebs-Henseleit buffer solution was used for reperfusion. The tissues were examined biochemically for oxidative stress. RESULTS: Significant differences among the three groups existed in tissue myeloperoxidase (MPO), catalase (CAT), Na+-K+ ATPase activity and in the concentrations of malonydealdehyde (MDA) and 3-nitrotyrosine (3-NT). Group 2 showed significant changes in MPO (P = 0.04), Na+-K+ ATPase enzyme activity (P = 0.02) and the levels of MDA (P = 0.004) and 3-NT (P = 0.01) in comparison with group 1. Group 3 efficiently reduced MDA levels (P = 0.004) and also led to significant decrease in levels of MPO (P = 0.006), 3-NT (P = 0.01) and Na+-K+ ATPase activity (P = 0.01) and increase in the level of CAT (P = 0.004) in comparison with group 1. Significant changes were also found in the levels of MDA (P = 0.03), MPO (P = 0.04) and CAT (P = 0.009) in comparison between groups 2 and 3. CONCLUSIONS: We demonstrated that the administration of CAPE into cardioplegic solutions improves the antioxidant defense system of rat heart during the ischemia-reperfusion injury.     

Effect of Nitroglycerin Inhalation on Patients with Pulmonary Hypertension Undergoing Mitral Valve Replacement Surgery

Background: The aim of this study was to investigate the postoperative hemodynamic effects of nitroglycerin inhalation on patients with pulmonary hypertension undergoing mitral valve replacement surgery.

Methods: Twenty patients who underwent mitral valve replacement surgery were included in the study. In the surgical intensive care unit, at T0 (before the inhalation of nitroglycerin), basal systemic and pulmonary hemodynamics were recorded. Then, 2.5 [mu]g [middle dot] kg-1 [middle dot] min-1 nitroglycerin liquid nebulized by a 2-l gas flow of 40% oxygen and air mixture was administered to the patients who were diagnosed as having pulmonary hypertension (mean pulmonary arterial pressures > 25 mmHg). The same parameters were measured at the first (T1), third (T2), and fifth (T3) hours after the beginning of this treatment and 1 h after the end of nitroglycerin inhalation (T4).

Results: There were no statistically significant differences at T0, T1, T2, T3, or T4 with respect to heart rate, mean arterial pressure, systemic vascular resistance, cardiac index, mixed venous oxygen saturation, arteriovenous oxygen content difference, or arterial carbon dioxide tension. However, mean pulmonary artery pressure, pulmonary vascular resistance, and intrapulmonary shunt fraction were significantly lower, and the arterial oxygen tension/fraction of inspired oxygen ratio was higher at T1, T2, and T3 when compared to that of T0 and T4.     

Effect of N-acetylcysteine on blood and tissue lipid peroxidation in lipopolysaccharide-induced obstructive jaundice.

In obstructive jaundice, free radical production is increased and antioxidative activity is reduced. N-Acetylcysteine (NAC) has a beneficial effect with anti-inflammatory and antioxidant activity, acting as a free radical scavenger. NAC inhibits inducible nitric oxide synthase, suppresses cytokine expression/release, and inhibits adhesion molecule expression and nuclear factor kappa B. The aim of this study was to investigate the effects of NAC on liver/renal tissue and serum lipid peroxidation in lipopolysaccharide (LPS)-induced obstructive jaundice. We randomized 60 rats into 6 groups: group 1, Sham; group 2, obstructive jaundice (OJ) induced after bile-duct ligation; group 3, OJ + NAC (100 mg kg- 1 subcutaneously); group 4, OJ + LPS (10 mg kg-1); group 5, OJ + NAC + LPS; and group 6, OJ + LPS + NAC. For each group, the biochemical markers of lipid peroxidation and the antioxidant products were measured in serum and liver/renal tissue after sacrifice. Almost all lipid peroxidation products levels were increased and antioxidant products levels were decreased in groups who received LPS (groups 4, 5, and 6), but the effect was less remarkable when NAC was administered before LPS (group 5). The same trend was seen for groups with OJ +/- LPS who did not received NAC or received it after induced toxemia (groups 2, 4, and 6) as compared to groups 1 and 3. Moreover, in the case of OJ + LPS, rats treated with NAC before LPS (group 5) had lower lipid peroxidation products levels and higher antioxidant products levels as compared to those who did not received NAC (group 4). This phenomenon was not reproducible with NAC administered after LPS (group 6). Thus, results of this study showed that NAC prevents the deleterious effects of LPS in obstructive jaundice by reducing lipid peroxidation in serum and liver/renal tissue if administered before LPS. Nonetheless, NAC failed to prevent the lipid peroxidation in the case of established endotoxemia in obstructive jaundice.