Isolation on a remote island: genetic and morphological differentiation of a cosmopolitan odonate.

Although low levels of genetic structure are expected in highly widespread species, geographical and/or ecological factors can limit species distributions and promote population structure and morphological differentiation. In order to determine the effects of geographical isolation on population genetic structure and wing morphology, 281 individuals of the cosmopolitan odonate Pantala flavescens were collected from four continental (Central and South America) and five insular sites (Polynesian islands and the Maldives). COI sequences and eight microsatellite loci were used to characterize genetic diversity and genetic structure between and within locations. Linear and geometric morphometry were used to evaluate differences in the size and shape of wings. Genetic analysis showed a global genetic difference between the continental and insular sites. American locations did not show genetic structure, even in locations separated by a distance of 5000 km. Easter Island showed the lowest values of genetic diversity (mainly mitochondrial diversity) and the highest values of genetic differences compared to other insular and continental sites. Individuals from Easter Island showed smaller forewings, a different abdomen length to thorax length ratio, and a different configuration of anal loop in the hindwings. Thus, the greater isolation, smaller area, and young geological age seem to have determined the genetic and morphological differences in P. flavescens of Easter Island, where selection could promote a loss of migratory behavior and may improve other life history traits, such as reproduction. This work provides new insight into how microevolutionary processes operate in isolated populations of cosmopolitan species.

Treatment outcome results from the Bulgarian Acromegaly Database: adjuvant dopamine agonist therapy is efficient in less than one fifth of non-irradiated patients.

OBJECTIVE: We described biochemical outcome in regards to different treatment modalities in patients with acromegaly in Bulgaria. PATIENTS AND METHODS: It was a retrospective analysis using data from the Bulgarian Acromegaly Database. Patients with eligible data on at least one treatment modality were included in the study. Disease control was assessed by both GH and IGF-1 values or by GH/IGF-1 alone in cases with one marker. Last follow-up was median 7.0 (range 0.5-51) years after diagnosis. RESULTS: We identified 534 patients with interpretable data, 65.4% of whom were females. Overall surgical cure rate was 28.8%. Adjuvant bromocriptine and cabergoline treatment was analyzed in 133 and 70 patients with disease control achieved in 18.8% and 31.4% respectively. Patients without prior radiotherapy had 16.3% and 18.2% control rates respectively. Predictors of response to dopamine agonist (DA) therapy were disease activity, radiotherapy and medication dose. Adjuvant somatostatin analog (SSA) treatment led to biochemical control in 38.6% of 70 patients. Combination of SSA and cabergoline led to remission in 25% of 20 patients. Growth hormone receptor antagonist (GHRA) alone or in combination resulted in remission in 61.5% of 13 patients. Approximately one third of the patients were cured median 10 years after irradiation. Overall disease control was observed in 51.4% of our patients increasing to 70.3% in the last 5 years of the study period. CONCLUSION: DAs are efficient in less than 20% of non-irradiated patients. They are a good cost-effective alternative for carefully selected patients.

Uso del chupete de entretención en la primera infancia y su influencia en el desarrollo posterior de sobrepeso y obesidad entre los 5 y 18 años de edad / Pacifier use in early childhood and its influence on further development of overweight and obesity between 5 and 18 years old

Para evaluar el efecto que tendría el uso del chupete de entretención durante los primeros 5 años de vida sobre el peso futuro de esos niños entre los 5 y 18 años de edad, se evaluó el estado nutricional de 400 niños de 5 a 18 años en una consulta pediátrica general privada y se les investigó mediante encuesta a la madre, sobre el uso del chupete y tiempo de su uso entre el ano y los 5 años de edad. En el grupo que no usó chupete, los varones representaron un 48% las ninas 52%; 62,3% tenían sobrepeso y 16,6% presentó obesidad. En el grupo que si usó chupete, los varones representaron el 53,8% las niñas un 46.2% y el 30,7% tenía sobrepeso y sólo 5,3% presentó obesidad. Los grupos fueron comparables en sexo y edad. No se encontraron diferencias por sexo en el uso del chupete. El porcentaje de niños eutróficos, fue significativamente mayor en el grupo que usó chupete en relación a los niños que no usaron chupete. El porcentaje de niños con sobrepeso u obesidad fue significativamente mayor en el grupo de niños que no usaron chupete en relación a los niños que usaron chupete. Tanto el análisis bivariado como el logístico multivariado, considerando el uso del chupete como variable dependiente, el estado nutricional, sexo y edad, son consistentes en que sólo la variable estado nutricional se asoció al uso del chupete.

The potential effect of the use pacifier of use during the first 5 years of life on the weight of the child between 5 and 18 years of age was assessed. The nutritional status of 400 children between 5 and 18 years of age in a private pediatric practice was investigated by questioning the mother on pacifier use between one and 5 years of age. In the group that did not use pacifier, males accounted for 48%, girls for 52%, and 62.3% were overweight and 16.6% obese. In the group using a pacifier, males accounted for 53.8%, girls 46.2% and 30.7% were overweight and only 5,3% were obese. The groups were comparable in age and sex and there were no gender differences in the use of pacifiers. The percentage of eutrophic children was significantly higher in the group who used a pacifier in relation to the one who did not. The prevalence of overweight or obesity was significantly higher in the group of children who did not use a pacifier in relation to children who used a pacifier. Both bivariate and multivariate logistic analysis, considering the use of a pacifier as a dependent variable and nutritional status, sex and age, are consistent in that only the variable nutritional status was associated with pacifier use.

[Characteristics and prognosis of visual deficit caused by parasellar meningiomas].

UNLABELLED: Meningiomas are the most common slow growing tumors of the central nervous system which arise from the arachnoid cells. One certain group of them--tuberculum sellae (TS), cavernous sinus (CS), anterior clinoid (AC), and planum sphenoidale (PS) meningiomas, a group often called "parasellar", present with monocular or binocular visual deterioration, which is often unrecognized by patients until visual loss is severe and the tumor has reached a significant size. AIM: To describes the type of visual deficit, severity of the symptoms and surgical treatment of tumors with the above mentioned localization. MATERIAL AND METHODS: During the period 2003-2007 year, 93 patients (31 man, 62 women) diagnosed with meningiomas of the TS (31 cases), CS (16 cases), AC (21 cases), PS (17 cases), (see text) - 8, were diagnosed and operated on in the Department of Neurosurgery, University Hospital "St. Ivan Rilsky", Sofia, Bulgaria. Retrospective analysis was done. RESULTS: Age at diagnosis ranged from 12 to 74 years, but the majority of cases were in the 5th and 6th decade of life. Localization of was: TS 33%, CS 17%, AC 24%, PS 18% and with more than one area affected in 8 %. The most common symptom was slowly progressing loss of monocular visual acuity (81% of cases). 68% of patients presented with already severely deteriorated vision (0.1-0). Neuro-ophthalmological examination (see text) the patients. Computed tomography and magnetic resonance imaging were the main diagnostic methods. "Gross" total resection was achieved in 62%, subtotal in 12%, partial in 26% of the cases. There was early improvement in 57% of the patients. Death due to cardio-respiratory insufficiency occurred in one case. CONCLUSION: the progressive monocular visual deficit is often the first clinical symptom of the parasellar menigiomas. The early diagnosis is important for the success of surgery. Close collaboration between different specialists (ophthalmologists, neurologist and neurosurgeons) is essential for treatment of these tumors and prevention of the visual deterioration.

[Malignant progression of an anaplastic ganglioglioma into a glioblastoma multiforme--report on two cases and review of the literature].

INTRODUCTION: Ganglioglioma is an uncommon type of primary brain tumors. In most of the cases the tumor demonstrates benign clinical behaviour with long-term patients' survival. We present two cases ofhistologically confirmed anaplastic ganglioglioma in which malignant progression into a glioblastoma multiforme was seen. CASE 1: A 36 year-old female with known Turner syndrome and recent history of single generalized seizure. The contrast-enhanced magnetic resonance imaging (MRI) showed an infiltrating lesion of the left frontal lobe. The tumor was excised partially and the histological result was anaplastic ganglioglioma (World Health Organization - WHO. gr. III). No additional neurological deterioration occurred after the procedure. A postoperative radiotherapy was performed with total dose of 60 Gy. The patient was symptom-free for one year taking her anticonvulsant medications. Control neuroimaging studies (computer tomography - CT, and MRI) were made because of progressive headache, right limbs weakness and speech disturbances. A local tumor recurrence was found and the patient underwent second operative intervention with gross total tumor resection. The histological result was glioblastoma multiforme (WHO gr. IV glioma). The patient improved after the procedure. An involvement of the contralateral cerebral hemisphere was found on control CT-scan ten months later. The patient died after one month, 23 months after her initial diagnosis. CASE 2: A 17 year-old female with recent history of progressive headache and three generalized seizures preceded by involuntary movements of the right limbs. MRI data for large, heterointense tumor lesion in the left frontal lobe was found. A subtotal tumor removal was made. The histological result was anaplastic ganglioglioma (WHO gr. ILL). The patients' headache and right side hemiparesis improved after the intervention. She was seizure-free taking her anticonvulsant medications. Thirty-day-long fractionated radiotherapy was performed with total dose of 60 Gy. The patient remained symptom-free for thirteen months after initial surgical procedure. During the next month the patients, partial motor seizures relapsed. Progressive headache, diplopia, and visual acuity impairment also developed. The ventriculoperitoneal shunt was implanted with neuroimaging data for internal hydrocephalus development. The patients' headache and visual disturbances improved after the procedure. Data for additional local tumor growth was found on control CT-scan one month later. The patient underwent subtotal excision of the lesion and the actual histological result was glioblastoma multiforme. The patient deteriorated after the intervention according to her right limbs paresis and died one month and half later. 20 months after the initial diagnosis. CONCLUSION: The gangliogliomas are uncommon in clinical practice. The tumor behaviour may vary between the patients in spite of the similar histological characteristics which indicates the possible presence of different tumor subtypes.

[Orbital lymphoma].

INTRODUCTION: Orbital lymphomas are neoplasms with increasing incidence in recent years in immunocompromised, as well as immunocompetent patients, which defines their social importance. AIM: To describe and analyze the experience of the University hospital "'Sv. Ivan Rilski" with the treatment of this pathology for the period 1997-2008. MATERIAL AND METHODS: Fourteen patients (8 females, 6 males - 13 primary orbital lymphomas, 1 systemic lymphoma). Mean age at diagnosis was 65.6 years (from 50 to 80 years). In 2/3 of the patients the lesion was localized in left eye, without a case with bilateral orbital involvement. Seven cases the diagnosis was made 6 months from the onset of symptoms, 5 cases - 1 year and 2 cases - more than one year. The most common clinical symptoms were exophthalmus (12 case), tumor or bulging mass of the eyelid - 8, diplopy - 6, decreased visual acuity - 5. Intraconal localization of the tumor was in 6 cases, extraconal - 2. intra-extraconal - 6. The diagnosis was made by neuro-ophthalmologist and precised with the aid of CT and MRI. All the patients were operated on with the following approaches - fronto-orbital - 9 cases, lateral - 3, anterior orbitotomy (without bone resection) - 2 cases. In six cases "'gross total" resection was achieved, in the rest of the cases the resection was partial. On histological examination, a high grade lymphoma was established in 2 cases with primary orbital lymphoma and one case with systemic lymphoma. All other cases were diagnosed as low-grade B-call small lymphocytic non-Hodgkin's lymphoma. Long-term survival (over 5 years) was observed in 4 cases with primary lymphoma, whereas the patient with systemic form of the disease died 10 months after the operation.

Virtual simulation of neuroendoscopic procedures: early clinical experience with ventricular lesions.

BACKGROUND: Virtual endoscopy (VE) is a new and promising imaging technology. Applied to neuroendoscopy it allows preoperative simulation of a procedure and evaluation of the individual intraventricular anatomy in selected cases. Along with neuronavigation and real time intraoperative imaging, VE is expected to improve the safety and efficacy of neuroendoscopic procedures. PATIENTS AND METHODS: Between April 2003 and February 2004 VE simulation was performed in 13 randomly selected patients subjected to endoscopic procedures. Pathological entities included 4 cases with aqueduct stenosis, 4 with suprasellar arachnoid cysts, 2 tumors of the posterior third ventricle, 1 colloid cyst, 1 hyperplasia of the choroid plexus and 1 case with multiloculated hydrocephalus due to intraventricular septations. In 8 patients VE was accomplished preoperatively, in another 5 it was done after the operation, using data sets from neuronavigation imaging planning in 4 patients, and in one case using postoperative imaging studies. T (1)-weighted 3D image sets were acquired on a 1.5 T GE Genesis SIGNA MR scanner and VE reconstruction was performed using the General Electric Navigator software. The VE images were compared with the real images obtained during the endoscopic procedures and evaluated for their impact on the planning of the operative approach. RESULTS: VE implementation succeeded in all 13 patients. Major neuroanatomic reference structures were easily recognizable in all cases. Membranous structures such as the thinned floor of the third ventricle or cyst walls were identifiable in only 46 % of the cases. In 6 cases (46 %) VE showed anatomical variants and details relevant for the endoscopic procedure that were not identified on conventional MR images. CONCLUSIONS: VE has proved to be an important adjunct to the preoperative planning of neuroendoscopic procedures and its routine application is suggested.

Continuous-wave lasing of a stoichiometric Yb laser material: KYb(WO4)2.

For the first time to the authors' knowledge, continuous-wave laser emission of the stoichiometric crystal KYb(WO4)2 was achieved at 1068 nm. The 125-microm-thin sample was directly water cooled and pumped at 1025 nm by a Ti:sapphire laser. The maximum output power at room temperature was 20 mW.

Síndromes linfoproliferativos crónicos en Chile: estudio prospectivo de 132 casos / Chronic lymphoproliferative disorders in Chile: a prospective study in 132 patients

Background: Chronic lymphoproliferative disorders include a variety of diseases which are often a diagnostic problem for clinical hematologists. Aim: To study prospectively the distribution and incidence of chronic lymphoproliferative disorders in Chile and compare them with those of other Western, Latin American and Oriental countries. Patients and methods : A group of 132 patients were studied in a 36 months period (1999-2001), with a panel of monoclonal antibodies. A score for chronic lymphocytic leukemia was employed to differentiate it from other B-cell disorders. Results : The median age was 63 years old (range 32-94). Most patients had B-cell tumors (109) and the rest (23), T-cell tumors (82 percent vs 18 percent). Forty five percent of patients with B-cell tumors had a chronic lymphocytic leukemia (CLL), while the others were disseminated lymphomas. The incidence of T-cell tumors was slightly higher than that of other Western countries. Noteworthy is that the most common of these disorders was adult T cell leukemia/lymphoma (ATLL), in concordance with the high HTLV-1 seroprevalence in Chile. Conclusions : A morphologic, immunophenotypic and pathological study in a large number of patients with chronic lymphoproliferative disorders in Chile, shows a relatively low incidence of CLL when compared to other chronic B-cell tumors and a high representation of ATLL associated to HTLV-1 infection, compared with other Western countries. The lower incidence of CLL in our study might be due to patient's selection and/or underdiagnosis of this disease as a substantial proportion of CLL are asymptomatic

The complexity of linkage analysis with neural networks.

As the focus of genome-wide scans for disease loci have shifted from simple Mendelian traits to genetically complex traits, researchers have begun to consider new alternative ways to detect linkage that will consider more than the marginal effects of a single disease locus at a time. One interesting new method is to train a neural network on a genome-wide data set in order to search for the best non-linear relationship between identity-by-descent sharing among affected siblings at markers and their disease status. We investigate here the repeatability of the neural network results from run to run, and show that the results obtained by multiple runs of the neural network method may differ quite a bit. This is most likely due to the fact that training a neural network involves minimizing an error function with a multitude of local minima.

A comparison of two algorithms, MultiMap and gene mapping system, for automated construction of genetic linkage maps.

Using the GAW11 Problem 2 data set, we compared the performance of two automated map construction algorithms, MultiMap and GMS (Gene Mapping System). The MultiMap algorithm iteratively adds markers in a stepwise manner to the map, while the GMS algorithm seeks to find the best order of the whole set of markers by selective permutations of logically formed subgroups of the markers. While it is difficult to compare these two rather different algorithms, we found that, on these data, GMS performed better than MultiMap, placing more markers in their true order on average, with little order ambiguity. In addition, as the number of markers increased, GMS was less computationally demanding than MultiMap. However, it MultiMap placed a marker, it was almost always in the correct order. In contrast, GMS often placed a group of markers on the wrong end of the map; such incorrect placements occur when the evidence for placement on one end or the other is not strong. Thus, there is room for further algorithmic developments that combine the strengths of both the MultiMap and GMS approaches.

Surgical management of intraosseous skull base tumors with aid of Operating Arm System.

Invasion of bone and critical neurovascular structures often impedes complete resection of intraosseous skull base neoplasms, and these lesions tend to recur unless all infiltrated bone is removed. Evolving experience with image guidance over the past few years indicates the potential value of neuronavigation in skull base lesions diffusely infiltrating or fixed to bone structures. We report our early experience with the Radionics Operating Arm System (OAS), specifically emphasizing its utility as an adjunct in the treatment of intraosseous skull base tumors, mainly meningiomas. In April 1995 the OAS was introduced into clinical use at the neurosurgical university clinic in Münster, Germany. Since then, the system's utility has been explored in 10 patients out of the total neuronavigation series presenting with intraosseous skull base tumors (nine females and one male, mean age 47 years; nine meningiomas, one chordoma). For navigational planning, both 3-mm computed tomography scans and a set of 3-mm fat-suppression magnetic resonance images were chosen. At least four adhesive skin markers were used for system calibration. The system was technically usable in all cases in this small series. Because of the relative immobility of the bone structures and/or the tumor, no significant deviation from the preoperative registration accuracy was noted at the end of the procedures. The main advantages were easier localization and resection of infiltrated bone, which is often not grossly identifiable, even under the microscope. Our preliminary experience with the OAS suggests that image guidance is helpful in this type of lesion, providing better anatomical orientation during surgery and delineating tumor margins and their relation to critical neurovascular structures. The problem of a possible intracranial tumor and brain shift can be neglected in these lesions. The system facilitates resection by volumetric contour information, allowing more aggressive and complete resection.

Lipofuscin product accumulation, insufficient antioxidant defence in erythrocytes and plasma and enhanced susceptibility to oxidative haemolysis after thermal trauma.

The mechanism of increased susceptibility of red blood cells to oxidative haemolysis in the early post-burn period remains unclear. In this study it was revealed that the accumulation of lipofuscin products in red blood cells was accompanied by the elevation of oxidative haemolysis on the 24th hour after thermal trauma of rats (full thickness skin, on 20% of TBSA). Enhanced thiobarbituric acid reactive substrates (TBARS) and lowered levels of antioxidants such as alpha-tocopherol, ceruloplasmin and albumin were found in plasma. The activity of superoxide dismutase (SOD) and the concentration of alpha-tocopherol and reduced glutathione (GSH) in erythrocytes were also diminished. The results from this study suggest that plasma and intracellular antioxidant deficiency can potentiate oxidative membrane damage. There was a positive correlation (r = 0.72) between increased levels of lipofuscin products and oxidative haemolysis of red blood cells. The enhanced susceptibility of erythrocytes to oxidative haemolysis may be considered as an indirect but sensitive indicator of the impaired antioxidant defence of these blood cells following thermal skin injury. The decreased resistance of red blood cell to oxidative haemolysis under the conditions of reduced antioxidant defence of erythrocytes and blood plasma suggests that adequate antioxidant therapy could prevent all these complications after thermal skin injury.

Analysis of bipolar disorder using affected relatives.

We have analyzed the GAW10 data from several studies of bipolar affective disorder (BPAD) using the software packages SimIBD and SIMWALK2. SimIBD implements a simulation-based affected-pedigree-member (APM) statistic, called SimAPM, as well as an APM-like statistic, also called SimIBD, that measures identical-by-descent (IBD) sharing. SIMWALK2 uses Markov chain Monte Carlo techniques to compute several IBD-based statistics on the degree of marker-allele clustering among all affected relatives. We have found no strong evidence of linkage to either chromosome 5 or 18. However, we did find that several markers showed p-values less than 0.01 and may deserve further study.

Neuroprotective effects of preischemia intraarterial magnesium sulfate in reversible focal cerebral ischemia.

The known cytoprotective properties of MgSO4 led the authors to study its effects on infarct size in rats when administered intraarterially before reversible focal ischemia. Following an intracarotid infusion of MgSO4 in the amount of 30 mg/kg (24 animals), 90 mg/kg (18 animals), or an equal volume of vehicle (23 animals), middle cerebral artery occlusion was produced in rats by means of an intraluminal suture technique. Reperfusion occurred after 1.5 (42 animals) or 2 hours (23 animals) of ischemia. Automated, volumetric measurements of 2',3',5'-triphenyl-2H-tetrazolium chloride-stained coronal brain sections demonstrated a statistically significant decrease in infarct size for MgSO4 treatment groups compared to controls. Cytoprotection was greater in animals subjected to 1.5 hours of ischemia (28.4% reduction in infarct volume, p < 0.001, Student's t-test), than in those having 2 hours of ischemia (19.3% reduction, p < 0.05). Animals given 90 mg/kg MgSO4 prior to 1.5 hours of ischemia (12 animals) showed a 59.8% reduction in infarct volume compared to controls (11 animals, p < 0.001) and a 43.1% reduction compared to the 30 mg/kg group (11 animals, p < 0.001). Analysis of variance demonstrated the statistically significant effects of MgSO4 doses on infarct volume across all groups (F = 22.95, p < 0.0001). The neuroprotective effect of intraarterial MgSO4 in this model is robust, dose dependent, and related to the duration of ischemia. The compound may be valuable for limiting infarction if given intraarterially before induction of reversible ischemia during cerebrovascular surgery.

Reversible focal ischemia model in the rat: correlation of somatosensory evoked potentials and cortical neuronal injury.

Somatosensory evoked potentials (SEPs) are valuable in experimental stroke studies, but only a few reports have dealt with small rodent models. Our experiments aimed to reproduce SEP monitoring during reversible middle cerebral artery occlusion (MCAo) in a surgical model of open craniotomy and vessel manipulations in the rat. The changes of median nerve SEPs were correlated to the degree of local cortical neuronal injury in the forelimb area. Based on a pilot group (n = 11) both parameters were examined at 2 h after reperfusion in a subsequent study with increase of MCAo time from 1 (n = 7) to 2 h (n = 7); 5 rats were sham operated. A significantly delayed and incomplete recovery of SEPs, expressed as a percentage of the mean preocclusion values was observed with 2 h compared to 1 h MCAo (20.8% versus 6.0% change in the latency and 59.5% versus 2.2% in the amplitude of the primary cortical response). The functional outcome was found to correlate consistently with the degree of neuronal damage in 1 and 2 h reversible MCAo (2.5% versus 79.2% severely damaged neuronal types III and IV). Our findings suggest, that 2 h MCAo followed by 2 h reperfusion produces a submaximal neuronal injury and partial electrical recovery in the periphery of the occluded vascular territory and could be therefore used as a reliable model for assessment of cerebroprotective drug efficacy.

Answering the connectionist challenge: a symbolic model of learning the past tenses of English verbs.

Supporters of eliminative connectionism have argued for a pattern association-based explanation of language learning and language processing. They deny that explicit rules and symbolic representations play any role in language processing and cognition in general. Their argument is based to a large extent on two artificial neural network (ANN) models that are claimed to be able to learn the past tenses of English verbs (Rumelhart & McClelland, 1986, Parallel distributed processing, Vol. 2, Cambridge, MA: MIT Press; MacWhinney & Leinbach, 1991, Cognition, 40, 121-157). In this article we critically review Rumelhart and McClelland's as well as MacWhinney and Leinbach's ANN models and conclude that they do not succeed in the assigned task of learning the past tenses of English verbs. In order to answer their challenge to the symbolic processing approach, we present our symbolic pattern associator (SPA)-a general-purpose pattern associator that can learn to associate arbitrary discrete patterns. We carried out several experiments with the SPA using the same set of verbs that was used in MacWhinney and Leinbach's simulation with more realistic training and testing procedures. The SPA outperformed the connectionist models by a wide margin in the accuracy of learning, and successful inductive generalizations to unseen verbs. Our SPA has very natural and psychologically realistic explanations to many psychological effects such as U-shaped learning curve, and is much closer to human subjects in predicting past tense of the pseudo-verbs. In contrast to ANNs, whose internal representations are entirely opaque, the SPA can represent the acquired knowledge in the form of production rules that allow for further higher-level processing and integration, resulting in linguistically realistic associative templates for irregular verbs and production rules for regular verbs. In the light of these findings, we conclude that eliminative connectionists' vision of cognition as simple pattern association and pattern recognition without symbolic representation is inadequate. Pattern association as such does not imply rule-less or cue-based models of language acquisition or of human learning in general.