The food for feed concept. Performance of broilers fed hotel food residues.

1. In recent times the use of food waste in animal diets has gained considerable attention because of the increasing demand to cover the needs of human population and the high prices of conventional, arable based, animal feeds.2. The aim of the present study was to investigate the effect of adding dried human food waste to the diet of meat-type chickens (broilers). Two hundred, one-day-old broilers were divided into two treatment groups, with 10 replicate pens containing 10 birds per pen. The duration of the study was 42 days. In the control (C), the diet did not contain any food waste, whereas in the second treatment (T) food waste residues from hotels made up 15% of the diet. Diets had similar crude protein and metabolisable energy content.3. Feed intake and body weight were recorded in order to calculate weight gain and feed conversion ratio (FCR). Carcase and breast muscle yield, the weight of selected internal organs and the level of selected biochemical and haematological parameters were determined. Quality of breast muscle meat was assessed.4. Broilers fed the control treatment consumed more feed and gained more weight compared to broilers fed waste; however, the FCR was similar. No major differences were seen for internal organ weights and haematological parameters, although some differences were observed in colour traits and shear force of meat. It was concluded that there is a potential for use of food waste in broiler diets.

The effect of dietary Chlorella vulgaris inclusion on goat's milk chemical composition, fatty acids profile and enzymes activities related to oxidation.

The impact of dietary supplementation with microalgae on goat's milk chemical composition, fatty acids (FA) profile and enzymes activities related to antioxidant mechanism has not been well documented. Thus, this study aimed to investigate the effects of dietary inclusion of Chlorella vulgaris on the following: (i) milk yield, chemical composition and FA profile, (ii) the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione transferase (GST) and glutathione peroxidase (GSH-Px) in blood plasma and (iii) the activities of SOD, GR and lactoperoxidase (LPO) in milk of goats. Furthermore, the oxidative stress indicators for measuring total antioxidant and free radical scavenging activity [ferric reducing ability of plasma (FRAP) and 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays] and oxidative stress biomarkers [malondialdehyde (MDA) and protein carbonyls (PC)] were also determined in blood plasma and milk of the animals. For this purpose, 16 cross-bred goats were divided into two homogenous groups. Each goat of both groups was fed individually with alfalfa hay and concentrates separately. The concentrates of the control group (Control) had no microalgae, while those of the Chlorella group were supplemented with 10 g lyophilized Chlorella vulgaris/kg concentrates (Chlorella). Thus, the average intake was 5.15 g Chlorella vulgaris/kg DM. The results showed that the dietary inclusion of Chlorella vulgaris had not noticeable impact on goat's milk yield, chemical composition and FA profile. Significantly higher SOD (by 10.31%) and CAT (by 18.66%) activities in the blood plasma of goats fed with Chlorella vulgaris compared with the control were found. Moreover, the dietary supplementation with Chlorella vulgaris caused a significant increase in SOD (by 68.84%) activity and a reduction in PC (by 24.07%) content in goat's milk. In conclusion, the Chlorella vulgaris inclusion in goat's diets improved the antioxidant status of both animals and milk.

Effect of under- and overfeeding on sheep and goat milk and plasma enzymes activities related to oxidation.

Twenty-four dairy sheep and goats, respectively, were assigned each to three homogenous subgroups per animal species and fed the same diet in quantities which met 70% (underfeeding), 100% (control) and 130% (overfeeding) of their energy and crude protein requirements. The results showed that the underfed sheep in comparison with the control had significantly lower glutathione reductase (GR), superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) activities and total antioxidant capacity (measured with Ferric Reducing Ability of Plasma [FRAP] assay) in their blood plasma. A significant increase in the glutathione transferase (GST) and GPX activities, malondialdehyde content and total antioxidant capacity (measured with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) [ABTS] assay) in the blood plasma of underfed goats compared with controls was observed, while the opposite happened for the GR and SOD activities. The underfeeding in both animal species caused a significant increase in the protein carbonyls (PC) content of their blood plasma. The overfeeding, compared with the control, caused a significant decline in the GPX activity and total antioxidant capacity (measured with FRAP) in the blood plasma of sheep while the opposite happened for the GPX and GST activities in the case of goats. The overfed animals, of both species, compared with the respective controls, had higher PC content in their blood plasma. The feeding level had no noticeable impact on the antioxidants' enzymes activities of milk in both animal species. Moreover, the underfeeding in the blood plasma and the overfeeding in milk of both animal species resulted into a significant increase in the PC content. Finally, only in sheep milk, the underfeeding, compared with the respective control, and overfeeding reduced significantly the total antioxidant capacity (measured with ABTS). The feeding level caused oxidative stress in both organism and milk but the response was different in animal species and needs further investigation.

Effect of soya bean and fish oil inclusion in diets on milk and plasma enzymes from sheep and goat related to oxidation.

This study investigated the effects of dietary inclusion of soya bean oil combined with fish oil (SFO) on the activities of a) superoxide dismutase (SOD), glutathione reductase (GR), catalase (CAT) and glutathione transferase (GST) in blood plasma and b) SOD, GR, CAT and lactoperoxidase (LPO) in the milk of sheep and goats. Furthermore, the oxidative stress indicators for measuring total antioxidant activity and free radical scavenging activity [ferric reducing ability of plasma (FRAP) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays] and oxidative stress biomarkers [malondialdehyde (MDA) and protein carbonyl (PC)] were also determined in the blood plasma and milk of the animals. For this purpose, twelve dairy sheep and twelve dairy goats were assigned each to two homogenous subgroups. Treatments in both animal species involved a control diet without added oil and a diet supplemented with 5% soya bean oil and 1% fish oil. The results showed that the inclusion of SFO in the diets of sheep and goats increased significantly the activities of CAT and GR in their blood plasma. The same effect was observed for the activities of GST and FRAP in the blood plasma of goats. Moreover, the fact that the goats had significantly higher average daily PUFA intake (3.62 g/kg BW0.75 ) compared to sheep (2.51 g/kg BW0.75 ) resulted in an enhancement in the MDA content in their plasma. A significant increase in CAT activity in the milk in both animal species fed with SFO diets was also found. Finally, due to the higher apparent transfer rate of n-3 FA from the diet to the milk in sheep, the PC concentrations were found to be enhanced in their plasma and milk. In conclusion, the impact of dietary SFO supplementation on the oxidative status of body and/or on the milk of small ruminants depends not only on the daily PUFA intake, but also on the amount of n-3 FA that reach their milk.

The effect of dietary supplementation with rumen-protected methionine alone or in combination with rumen-protected choline and betaine on sheep milk and antioxidant capacity.

This study investigated the effects of dietary inclusion of rumen-protected methionine alone or in combination with rumen-protected choline and betaine on: (i) milk yield, chemical composition and fatty acids (FA) profile and (ii) blood plasma glutathione transferase (GST) activity of periparturient ewes. Furthermore, the oxidative stress indicators for measuring total antioxidant and free radical scavenging activity [ferric reducing ability of plasma (FRAP) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays] were also determined in plasma and milk of ewes. Thus, 45 ewes were divided into three equal groups. Each animal of the control group fed daily with a basal diet. The same diet was offered also in each animal of the other two groups. However, the concentrate fed to M group was supplemented with 2.5 g/kg rumen-protected methionine, while the concentrate fed to MCB group with 5 g/kg of a commercial product which contained a combination of methionine, choline and betaine, all three in rumen-protected form. The results showed that the M diet, compared with the control, increased significantly the ewe's milk fat and the total solids content. Likewise, a tendency for higher milk fat and total solids content in ewes fed the MCB diet was also observed. Both M and MCB diets had not noticeable impact on ewes milk FA profile. Significantly higher FRAP values in the blood plasma of ewes fed the MCB and in the milk of ewes fed with the M diet compared with the control were found. Additionally, significantly higher GST activity in the blood plasma of ewes fed the M diet, compared with the control, was observed. Moreover, a significant increase (by 20%) and a tendency for increase (by 16.72%) in the growth rate of lambs nursing ewes fed with M and MCB diets, respectively, compared to controls, were found.

The Hemiconvulsions-Hemiplegia-Epilepsy (HHE) syndrome: a transcranial magnetic stimulation-EEG study.

BACKGROUND: The Hemiconvulsions-Hemiplegia-Epilepsy (HHE) syndrome is currently regarded as an extremely rare condition. The etiological and pathophysiological mechanisms underlying this medical rarity as well as the optimal therapeutic approaches remain poorly defined and understood. We present the clinical, radiological and electroencephalography (EEG) findings of a patient with the HHE syndrome and describe the response of the continuously present epileptiform abnormalities to transcranial magnetic stimulation (TMS). CASE DESCRIPTION: A 33-year old male patient was referred to our department for investigation and management of intractable epilepsy. His seizures began at the age of three months when, during the course of a common febrile illness, he developed repetitive clonic seizures involving the left upper and lower limbs, followed by permanent left hemiplegia. After extensive investigations, he was diagnosed with "idiopathic" HHE syndrome. Currently, he suffers from left hemiplegia, severe intellectual impairment [Intelligence Quotient (IQ) <30] and asymmetric, bilateral tonic seizures occurring 1-3 times daily despite treatment with valproate, topiramate, lamotrigine, rufinamide, and perampanel. Brain magnetic resonance imaging revealed atrophy of the right hemisphere and serial EEGs disclosed continuous sharp waves, the generators of which were localized by electrical source imaging (ESI) to two distinct sources within the right hemisphere. Repetitive TMS [210 stimuli of 1 Hz at 100 % corticomotor threshold applied with a circular coil over the generators of epileptic discharges (EDs)] resulted in a statistically significant decrease of ED counts compared to sham stimulation and the post-verum TMS period. CONCLUSION: We present the clinical-laboratory profile and the long-term follow up of a patient with the HHE syndrome. Further, we describe the effects of TMS on EDs. The latter observation raises the possibility that TMS-EEG may be used in select cases with intractable epilepsy as a surrogate marker of responsiveness to more invasive modalities (i.e., cortical stimulation). HIPPOKRATIA 2017, 21(2): 101-104.

The role of bentonite binders in single or concomitant mycotoxin contamination of chicken diets.

Concomitant presence of mycotoxins is more likely to appear than a single mycotoxicosis since many mycotoxigenic fungi grow and produce their toxic metabolites under similar conditions. The present study was designed to evaluate the efficacy of 4 mycotoxin binders to protect meat-type chickens against single and concomitant administration in the feed of two mycotoxins, namely aflatoxin B1 (AFB1) and ochratoxin A (OTA) both at concentration of 0.1 mg/kg. A total of 440 as hatched, d-old, Ross 308 broilers were reared for 42 d. There were 11 dietary treatments. Chickens were fed on either an uncontaminated basal diet, basal diet and AFB1, basal with concomitant presence of AFB1 and OTA, basal diet and three binders A, B and C (1%) with or without AFB1 or basal diet and binder D (0.5%) with or without concomitant presence of AFB1 and OTA. Performance, carcass yield and several biochemical parameters were examined. Mycotoxin concentration in liver and breast muscle samples was determined. Broiler performance under concomitant mycotoxin contamination was poorer than that under single mycotoxicosis. Mycotoxin presence increased relative heart weight compared to that of broilers fed on uncontaminated diets. Only OTA and not AFB1 was detected and only in the liver. OTA concentration was four-fold lower in broilers fed on a diet with binder compared to those fed on contaminated diets without binder. In conclusion, the study revealed that binder composition and presence or not of multiple toxins may be important factors for optimum broiler performance under mycotoxicosis.

The effect of long-term under- and overfeeding on the expression of six major milk proteins' genes in the mammary tissue of goats.

Milk protein synthesis in the mammary gland involves expression of six major milk proteins' genes whose nutritional regulation remains poorly defined. In this study, the effect of long-term under- and overfeeding on the expression of as1-casein: CSN1S1, as2-casein: CSN1S2, ß-casein: CSN2, κ-casein: CSN3, α-lactalbumin: LALBA and ß-lactoglobulin: BLG gene in goat mammary tissue (MT) was examined. Twenty-four lactating dairy goat, at 90-98 days in milk, were divided into three homogenous subgroups and fed the same ration, for 60 days, in quantities which met 70% (underfeeding), 100% (control) and 130% (overfeeding) of their energy and crude protein requirements. The results showed a significant decrease in mRNA of CSN1S2, CSN2, CSN3 and LALBA genes in the MT of underfed goats compared with the overfed and on the CSN1S1 and BLG gene expressions in the MT of underfed goats compared with the respective control and overfed. CSN2 was the most abundant transcript in goat MT relative to the other milk proteins' genes. Significantly positive correlations were observed between the mRNA levels of caseins' and BLG genes with the milk yield. Moreover, a significant correlation was found between the mRNA levels of CSN1S2 with the milk protein, lactose content and lactose yield and also between the LALBA gene expression with the lactose content and lactose yield respectively. In conclusion, the feeding level and consequently the nutrients availability affected the milk lactose content, protein and lactose yield as well as the milk volume by altering the CSN1S1, CSN1S2, CSN2, CSN3, LALBA and BLG gene expression involved in their metabolic pathways.

Functional analysis of 3'UTR polymorphisms in the caprine SLC11A1 gene and its association with the Mycobacterium avium subsp. paratuberculosis infection.

The study aimed to investigate whether the genetic polymorphisms in the 3'UTR of the caprine SLC11A1 gene are functional, and to assess the role of MAP as a regulatory parameter in gene expression. To this goal we constructed plasmids expressing the Luciferase reporter gene in transient transfections of a mouse (Balb/c) macrophage cell line (RAW264.7), incorporating those polymorphisms that our previous work indicated as more prominent in terms of SLC11A1 expression and responsiveness to MAP infection. Gene expression variation was recorded on the average of the respective measurements after exposure to Mycobacterium avium subsp. paratuberculosis (MAP) combined with microbial antigens and cytokines. In silico analysis of the region under study allowed identification of one cis-acting RNA element, five putative transcriptional regulatory elements and 85 3'end microRNA binding sites. The two polymorphic regions (regions A and B) of the 3'UTR of the caprine SLC11A1 gene were recognized as regulators of its activity, at transcriptional and post-transcriptional level. The GT16 polymorphism at region A, combined with the GT8 polymorphism at region B, results in up-regulation of the SLC11A1 gene. The specific genotype was also found to be more responsive to MAP exposure at a statistically significant level.

Volatile profiles of healthy and aflatoxin contaminated pistachios.

The volatile profile of four different groups of dried pistachios namely: H: healthy, NC: naturally contaminated with aflatoxin, AC: artificially contaminated with aflatoxigenic strains of the fungi Aspergillus flavus and ANT: artificially contaminated with non-toxigenic strains of the fungi A. flavus, was determined. The volatiles were isolated by the HS-SPME method and determined by GC-FID and GC-MS, whereas aflatoxin by HPLC. Seventy two volatile compounds were identified almost equally distributed among the above four studied groups. The predominant chemical compounds were monoterpenes, alcohols, ketones, aldehydes, esters and hydrocarbons. The monoterpenes, mainly determined as α-pinene and α-terpinolene were detected in all samples. Even though the general volatile profile was similar among groups, some differences were detected between healthy and contaminated groups of samples. When some key volatiles such as eight-carbon and seven-carbon alcohols and aldehydes were used along with the species-specific sesquiterpenes and the other terpenes detected, a correct classification was obtained in H, NC, AC and ANT groups, as was demonstrated by cluster and discriminant analyses. This evidence provides a potential tool for distinguishing contaminated samples on the basis of characteristic volatile patterns.

In vitro expression of the SLC11A1 gene in goat monocyte-derived macrophages challenged with Mycobacterium avium subsp paratuberculosis.

Johne's disease or paratuberculosis is a chronic, progressive intestinal disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). One of the genes that have been targeted with regard to resistance or sensitivity to paratuberculosis is the SLC11A1 (solute carrier family 11 member A1). Here we extend our previous work to the sequence and structure analysis of the caprine SLC11A1 gene and we assess the functional impact of the most frequent polymorphisms of the 3' UTR region of the SLC11A1 gene to its expression in goat macrophages exposed in vitro to MAP. The role of these polymorphisms in primary immune response is also investigated with connection to gene expression of two interleukins (IL), one of which pro (IL-1a), and the other anti-inflammatory (IL-10). In order to assess gene response, quantitative detection of the SLC11A1, IL-10 and IL1a mRNA was performed by real time PCR before, and at 1, 3 and 24h after exposure of primary cultures of peripheral blood monocyte-derived macrophages to MAP, collected from 54 goats of the Greek native goat breed. Sequence analysis of the 3' UTR end of the caprine SLC11A1 gene determined its full length to be 522 bases. Structure analysis confirmed the presence of two microsatellites consisted of a variable number of guanine-thymine repeats (regions A and B). The homozygous B7 genotype [B(GTn)7/7] was associated at a statistically significant level with increased expression of the SLC11A1 and IL-1α genes indicating increased in vitro responsiveness and therefore resistance of mononuclear derived macrophages to MAP infection.

Topiramate promotes neurological recovery in a new model of traumatic brain injury in rats.

The aim of this study is to investigate the neuroprotective effects of the anticonvulsant topiramate in a new model of traumatic brain injury in rats. A new model of traumatic brain injury, based on the weight-drop technique, was developed for the purpose of this study. Seventy-five male Wistar rats weighing 320-470 g were studied. All rats were anesthetized, subsequently submitted to a round craniectomy in the left parietal region and a weight of 50 g was used for the production of a cortical contusion. In study I, 44 rats were randomized in three groups to receive either topiramate 40 mg/kg (n=13), topiramate 60 mg/kg (n=14), or water for injection (n=17) i.p. 30 min after the injury and every 12 h thereafter for 3 days. The rats were tested clinically 24 h, 72 h, 10 days and 20 days after the injury. On day 21 the animals were sacrificed and the brains were removed and prepared for histopathological analysis. In study II, 19 rats were randomized to receive either topiramate 60 mg/kg (n=10) or water for injection (n=9) i.p. 30 min after the injury and every 12 h (four doses in total). 48 h after the injury the animals were sacrificed and the brains were rapidly removed and analyzed for water content with the dry-wet weight technique. The animals that received topiramate performed significantly better in neurological tests compared to the animals that received vehicle ten (P<0.05) and 20 (P<0.001) days after the injury. There was no difference between the high and the low dose of the drug. Topiramate had no effect on the anatomic volume of the lesion. The animals that received topiramate had a tendency to present with less cerebral edema formation, but the difference was not statistically significant (P>0.05). These findings suggest that topiramate promotes neurological recovery in rats after traumatic brain injury without affecting the final size of the traumatic lesion and that it might play a role in the reduction of post-traumatic cerebral edema.

Long-term results of stem cell transplantation for MS: a single-center experience.

OBJECTIVE: To report long-term results of a phase I/II study conducted in a single center in order to investigate the effect of hemopoietic stem cell transplantation (HSCT) in the treatment of multiple sclerosis (MS). METHODS: Clinical and MRI outcomes of 35 patients with aggressive MS treated with HSCT are reported after a median follow-up period of 11 (range 2-15) years. RESULTS: Disease progression-free survival (PFS) at 15 years is 44% for patients with active CNS disease and 10% for those without (p=0.01); median time to progression was 11 (95% confidence interval 0-22) and 2 (0-6) years. Improvements by 0.5-5.5 (median 1) Expanded Disability Status Scale (EDSS) points were observed in 16 cases lasting for a median of 2 years. In 9 of these patients, EDSS scores did not progress above baseline scores. Two patients died, at 2 months and 2.5 years, from transplant-related complications. Gadolinium-enhancing lesions were significantly reduced after mobilization but were maximally and persistently diminished post-HSCT. CONCLUSION: HSCT is not a therapy for the general population of patients with MS but should be reserved for aggressive cases, still in the inflammatory phase of the disease, and for the malignant form, in which it can be life-saving. HSCT has an impressive and sustained effect in suppressing disease activity on MRI. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that HSCT results in PFS rates of 25%. PFS rate was significantly better in patients with active MRI lesions; HSCT also resulted in a significant reduction in the number and volume of gadolinium-enhancing lesions on MRI.

Estimation of the spread of pathogenic mycobacteria in organic broiler farms by the polymerase chain reaction.

Organic poultry breeding allows for increased exposure of birds to soil, faeces, and wildlife, which have been associated with the transmission of mycobacterial infections. Therefore the aim of this study was to investigate the spread of the major pathogenic mycobacteria in organically reared broilers in Greece using a diagnostic algorithm that relied on a combination of the polymerase chain reaction (PCR) and the restriction fragment length polymorphism analysis (RFLP). Liver, spleen and gonads from 81 to 150 days old broilers were aseptically collected post-mortem. 500 broilers from a population of 35,370, reared in the 25 registered as organic farms in Greece for the 2005 were used. DNA was isolated and incorporated to PCR targeted to 16S-rRNA gene (for Mycobacterium spp.), IS6110 (for Mycobacterium tuberculosis complex-MTBc), IS1245 (for Mycobacterium avium complex-MAC), IS901 (for M. avium subsp. avium-MAA) and hsp65 (for Mycobacterium genavense, by PCR-RFLP). The mean prevalence of mycobacteria detected by PCR with a 95% confidence interval was estimated to 4.4-8.8%. The relevant percentage with regard to the mycobacterial species that were included in this study was 0.17-2.03% for MAC, 2.11-3.39% for MTBc and 0.66-3.08% for mycobacteria not belonging to any of the above groups. None of the mycobacteria detected were identified as MAA or M. genavense. Considering that avian tuberculosis has been eradicated from conventional farms, the level and the pattern of positivity recorded here, indicates that our results may be associated with the specific conditions that apply to organic breeding.

Lorazepam-induced effects on silent period and corticomotor excitability.

TMS studies on the CNS effects of benzodiazepines have provided contradictory results. The objective of this study is to describe the effects of lorazepam on silent period (SP) and corticomotor excitability. Twelve healthy male subjects (median age 35 years) were studied at baseline, following i.v. lorazepam administration and after reversal of the benzodiazepine effects with i.v. flumazenil. Lorazepam was given at a low-dose in one subject (0.0225 mg/kg bolus + 2 microg/kg/h infusion) and at a high-dose (0.045 mg/kg bolus + 2.6 microg/kg/h infusion) in the rest. Threshold (Thr) was measured at 1% steps. SPs were investigated with two complementary methods. First, SPs were elicited using a wide range of stimulus intensities (SIs) (from 5 to 100% maximum SI at 5% increments). At each SI, four SPs were obtained and the average value of SP duration was used to construct a stimulus/response (S/R) curve of SI versus SP .The resulting S/R curves were then fitted to a Boltzman function, the best-fit values of which were statistically compared for each experimental condition (i.e., baseline vs. lorazepam vs. flumazenil). Second, a large number of SPs (n=100) was elicited during each of the three experimental conditions using blocks of four stimuli with an intensity alternating between MT and 200% MT. This method was employed so as to reveal the dynamic, time-varying effects of lorazepam and flumazenil on SP duration at two stimulus intensity (SI) levels. MEP recruitment curves were constructed at rest and during activation and fitted to a Boltzman function the best-fit values of which were statistically compared for each experimental condition. Lorazepam at a low dose did not affect Thr, SP, or the active MEP recruitment curves. The high dose also had no effect on Thr and the active MEPs whereas the resting MEP recruitment curves were depressed post-lorazepam at the higher range of stimulus intensities. With regard to SP, the Max value of the S/R curve decreased from 251+/-4.6 ms at baseline to 215.2+/-3.1 ms post-lorazepam (P<0.01). V50 also decreased significantly (from 47.92+/-0.9% to 43.73+/-0.81%, P<0.01) whereas there was no significant change regarding slope and SP Thr. The statistical analysis of the SP S/R curves as well as the study of SPs at two SI levels revealed that lorazepam reduced SP duration when high intensity stimuli were used (>60%). In contrast, at low SIs a small increase in SP duration was noted post-drug. Enhancement of GABAergic inhibition by lorazepam results in a reduction of SP duration when high SIs is used. At the lower range of SIs, a small but statistically significant increase in SP duration is observed. The kinetic behavior of this phenomenon as well as the possible underlying mechanisms are discussed.

Silent period to transcranial magnetic stimulation: construction and properties of stimulus-response curves in healthy volunteers.

Silent period (SP) is widely used in transcranial magnetic stimulation studies. Methodologically, SP is usually elicited at stimulus intensities corresponding to a certain percentage of corticomotor threshold. Because this approach might lead to factitious SP changes, the present study was designed to develop, in a stepwise manner, a method for investigating SP independently of corticomotor threshold. First, stimulus-response (S-R) curves of SP against stimulus intensity (SI) were constructed and quantitatively described in healthy volunteers. Second, various methodological issues such as the optimum model for describing the relationship between SP duration and SI and the importance of the type of stimulating coil were addressed. Finally, the proposed method and a commonly used method (eliciting SPs at 130% MT SI) were directly compared for a group of epileptic patients for whom administration of oxcarbazepine resulted in significant corticomotor threshold elevation. Twenty-one subjects (eleven females, median age, 38 years) were studied. SPs were obtained with a figure-of-eight coil using a standardized procedure (recording, FDI). Pilot experiments indicated that at least four trials were required, at each intensity level, to estimate the mean SP duration within 10% of the true mean. Therefore, SPs were determined from the average of four trials with 5% increments from 5 to 100% maximum SI. In a second set of experiments, SPs were obtained for fifteen subjects using a circular coil. In a third set of experiments, eight epileptic patients were studied before and after administration of oxcarbazepine (mean dose 1553 mg, range 900-1800 mg). The S-R curves were fitted to a Boltzman function and to first-order to fourth-order polynomial and sigmoid functions. The Boltzman function described the data accurately (R2=0.947-0.990). In addition, direct comparison of the six models with an F-test proved the superiority of the first. The best-fit parameters of the reference curve, i.e. the maximum and minimum values, the slope, and V50 (the SI at which SP duration is halfway between Min and Max) were 230.8+/-3.31 ms (x+/-SEM), -11.51+/-3.31 ms, 11.56+/-0.65%, and 49.82+/-0.65%, respectively. When the curves obtained with the circular coil were compared with those obtained with the figure-of-eight coil, there were differences between V50 (51.69+/-0.72 vs 47.95+/-0.82, P<0.001) and SP threshold (31.15 vs 24.77, P<0.01) whereas the other best-fit values did not differ significantly. Oxcarbazepine increased corticomotor threshold from 45.3+/-5.8% at baseline to 59.4+/-10.4% (P<0.001). According to the commonly used method, the drug significantly prolonged SP (from 117.6+/-42.4 ms to 143.5+/-46.5 ms, P<0.001) and, consequently, enhanced brain inhibition. In contrast, study of the SP curves led to the conclusion that oxcarbazepine does not affect the Max value and slope but significantly increases V50 and SP threshold (from 54.5+/-4.9% to 59.9+/-7.2% and from 29.1+/-6.4% to 34.6+/-6.8%, respectively, P<0.01). These findings imply that oxcarbazepine does not enhance brain inhibitory mechanisms. Thus, in situations characterized by significant changes in corticomotor threshold the proposed method provides results clearly different from a commonly used approach. It is concluded that S-R curves obtained with a figure-of-eight coil in 5% increments and fitted to a Boltzman function provide an accurate, comprehensive, and clinically applicable method for exploring SP.

Percutaneous stent placement in malignant cases of superior vena cava syndrome.

PURPOSE: Superior vena cava (SVC) syndrome is caused by SVC stenosis or occlusion, frequently as a consequence of lung cancer or a mediastinal tumor. SVC syndrome is characterized by unpleasant symptoms and the condition usually leads to death if untreated. Treatment with radiation therapy and chemotherapy may produce an initial relief, whereas operations with bypass are associated with high mortality and morbidity. The PURPOSE of our study was to show the efficiency of percutaneous stenting in the SVC for relieving SVC syndrome secondary to malignant diseases. PATIENTS AND METHODS: From January 1999 to March 2003, 17 patients with malignant SVC syndrome were evaluated at the "Metaxa" Cancer Hospital. Their caval stenoses were confirmed by means of computed tomography and venography. There were 15 males and 2 females with a median age of 62 years (range 47-79). The SCV syndrome was caused by malignant disease in all patients: bronchogenic carcinoma in 14 and lymphoma in 3. All patients underwent placement of a self-expandable (wallstent) endovascular (vena cava) prosthesis. RESULTS: All procedures were successfully carried out without complications. The average time for wallstent placement was 37 min. There was no sign of bleeding and the wallstent was well positioned on chest roentgenograms. All patients, without exception, noticed an immediate improvement, with relief of dyspnea and rapid resolution of headache. Cyanosis disappeared over the first hour and swelling resolved gradually over the first 24 hours. CONCLUSION: Percutaneous venous wallstent placement in the SVC is a simple, safe and effective technique to rapidly relieve SVC syndrome caused by malignant diseases.

The repeatability of corticomotor threshold measurements.

Threshold (Th) is a neurophysiological parameter frequently used in TMS studies. The present study was designed to investigate the repeatability of the Th measurements by reexamining healthy subjects over various time points. Overall, 82 subjects (median age: 19 years, range: 12-65) entered the study. Following a baseline examination, there were six retest sessions: S0 (n = 8 hemispheres reexamined, mean interval x = 19 min), S1 (n = 34 hemispheres reexamined, mean interval x = 4 days), S2 (n = 32 hemispheres, x = 29 days), S3 (n = 30 hemispheres, x = 106 days), S4 (n = 30 hemispheres, x = 183 days) and S5 (n = 30 hemispheres, x = 1867 days). Stimulation was performed with a figure of eight coil and Th was defined at 1% steps. At baseline, controls had an MT of 41.1 +/- 8. Mean difference of MT from baseline was 0.62 on S0 (95% confidence interval (CI) of the difference: -1.04 to +2.29), 0.13 on S1 (95% CI: -1.2 to +1.5), -0.03 on S2 (95% CI: -1.1 to +1.06), -2.07 on S3 (95% CI: -4.33 to +0.19), 0.15 on S4 (95% CI: -0.98 to +1.28) and 0.87 on S5 (95% CI: -0.49 to +2.23). None of these differences were statistically significant (repeated measures ANOVA, P > 0.05). The upper limit of MT difference that an individual subject might have with a probability of 95% (measurement error) was 8. The repeatability of the method was found to be independent from the age of the subjects, the magnitude of threshold or the test-retest interval. The topography of corticomotor threshold was also investigated. Minimal threshold values were obtained from a restricted area of scalp sites that always included the fixed stimulation point of the current protocol. Therefore, using a fixed stimulation point is an adequate technique for measuring threshold. In conclusion, threshold is a stable parameter on an individual and group basis. These data quantify the repeatability of the method and may prove useful in the interpretation of findings during longitudinal studies.