Skyrmion Transport and Annihilation in Funnel Geometries

Using atomistic simulations, we have investigated the transport and annihilation of skyrmions interacting with a funnel array under a current applied perpendicular to the funnel axis. We find that transport without annihilation is possible at low currents, when the motion is dominated by skyrmion-skyrmion interactions and skyrmions push each other through the funnel opening. Skyrmion annihilation occurs for higher currents when skyrmions in the upper half of the sample exert pressure on skyrmions in the bottom half of the sample due to the external current. Upon interacting with the funnel wall, the skyrmions undergo a size reduction that makes it easier for them to pass through the funnel opening. We find five phases as a function of the applied current and the size of the funnel opening: (i) pinned, (ii) transport without annihilation, (iii) transport with annihilation, (iv) complete annihilation, and (v) a reentrant pinning phase that only occurs for very narrow openings. Our findings provide insight into how to control skyrmion transport using funnel arrays by delineating regimes in which transport of skyrmions is possible as well as the conditions under which annihilation occurs.

Automatic ladybird beetle detection using deep-learning models

Fast and accurate taxonomic identification of invasive trans-located ladybird beetle species is essential to prevent significant impacts on biological communities, ecosystem functions, and agricultural business economics. Therefore, in this work we propose a two-step automatic detector for ladybird beetles in random environment images as the first stage towards an automated classification system. First, an image processing module composed of a saliency map representation, simple linear iterative clustering superpixels segmentation, and active contour methods allowed us to generate bounding boxes with possible ladybird beetles locations within an image. Subsequently, a deep convolutional neural network-based classifier selects only the bounding boxes with ladybird beetles as the final output. This method was validated on a 2, 300 ladybird beetle image data set from Ecuador and Colombia obtained from the iNaturalist project. The proposed approach achieved an accuracy score of 92% and an area under the receiver operating characteristic curve of 0.977 for the bounding box generation and classification tasks. These successful results enable the proposed detector as a valuable tool for helping specialists in the ladybird beetle detection problem.

An approach to automatic classification of Culicoides species by learning the wing morphology

Fast and accurate identification of biting midges is crucial in the study of Culicoides-borne diseases. In this work, we propose a two-stage method for automatically analyzing Culicoides (Diptera: Ceratopogonidae) species. First, an image preprocessing task composed of median and Wiener filters followed by equalization and morphological operations is used to improve the quality of the wing image in order to allow an adequate segmentation of particles of interest. Then, the segmentation of the zones of interest inside the biting midge wing is made using the watershed transform. The proposed method is able to produce optimal feature vectors that help to identify Culicoides species. A database containing wing images of C. obsoletus, C. pusillus, C. foxi, and C. insignis species was used to test its performance. Feature relevance analysis indicated that the mean of hydraulic radius and eccentricity were relevant for the decision boundary between C. obsoletus and C. pusillus species. In contrast, the number of particles and the mean of the hydraulic radius was relevant for deciding between C. foxi and C. insignis species. Meanwhile, for distinguishing among the four species, the number of particles and zones, and the mean of circularity were the most relevant features. The linear discriminant analysis classifier was the best model for the three experimental classification scenarios previously described, achieving averaged areas under the receiver operating characteristic curve of 0.98, 0.90, and 0.96, respectively.

Eight in one: morphological and molecular analyses reveal cryptic diversity in Amazonian alopoglossid lizards (Squamata: Gymnophthalmoidea)

Among the currently recognized species of Alopoglossus, the Amazonian Alopoglossus angulatus has the widest distribution. We here analyse variation in scutellation and morphometrics of A. angulatus by examining 785 specimens of Alopoglossus. We also analyse intra- and interspecific genetic structure and differentiation using two mitochondrial (Cytb and ND4) and two nuclear (SNCAIP and PRLR) genes from 97 samples. Both morphological and molecular analyses are based on specimens and samples from Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru and Suriname. Our results reveal A. angulatus as a monophyletic group composed of eight independently evolved lineages: A. angulatus s.s. plus three revalidated species plus two newly described species plus two putative species. We provide descriptions of all taxa, except for the putative species, including the first description of the neotype of A. angulatus and redescriptions of resurrected junior synonyms. Illustrations, diagnoses and geographical distribution maps are provided. Gene and species trees are also provided. The two new taxa recognized in this paper, along with the revalidation of three taxa, increase the total number of known species of Alopoglossus from nine to 14.

Infrared thermography for temperature measurement and non-destructive testing

The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed.

Lrrk2 p.Q1111H substitution and Parkinson's disease in Latin America

Mutations in the LRRK2 gene are the most common genetic cause of Parkinson's disease, with frequencies displaying a high degree of population-specificity. Although more than 100 coding substitutions have been identified, only seven have been proven to be highly penetrant pathogenic mutations. Studies however are lacking in non-white populations. Recently, Lrrk2 p.Q1111H (rs78365431) was identified in two affected Hispanic brothers and absent in 386 non-Hispanic white healthy controls. We therefore screened this variant in 1460 individuals (1150 PD patients and 310 healthy controls) from 4 Latin American countries (Peru, Chile, Uruguay and Argentina). In our case-control series from Peru and Chile we observed an increased frequency of Lrrk2 p.Q1111H in patients (7.9%) compared to controls (5.4%) although the difference did not reach significance (OR 1.38; p = 0.10). In addition, the frequency of Lrrk2 p.Q1111H varied greatly between populations and further screening in a set of pure Amerindian and pure Spanish controls suggested that this variant likely originated in an Amerindian population. Further studies in other Latin American populations are warranted to assess its role as a risk factor for Parkinson's disease. Screening in Parkinson's disease patients from under-represented populations will increase our understanding of the role of LRRK2 variants in disease risk worldwide.

[Autonomic disturbances in Parkinson disease]

The current concept of Parkinson disease comprises a group of non-motor symptoms. Among these, dysautonomia is a common problem that deteriorates the quality of life of patients. In this article we review the most common dysautonomic manifestations that are observed in cardiovascular, gastrointestinal, urinary, genital and skin systems. Their possible role as risk factors, premotor symptoms and their implications in the pathogenesis of Parkinson disease are discussed. A general approach to the main syndromes, based in the available evidence and in our experience is also presented.

Successful response to intravenous immunoglobulin as rescue therapy in a patient with Hashimoto's encephalopathy

The authors describe the case of a 61-year-old woman who was admitted to our intensive care unit (ICU) due to impaired consciousness associated with generalised seizures. Her cerebrospinal fluid, electrolytes, acid-base analysis, and common laboratory and toxicology tests were normal. An MRI ruled out the presence of stroke or haemorrhage but showed severe leukoencephalopathy. Parkinson's disease, Creuzfeld-Jacob disease, vascular alterations, cancer, and rheumatological and metabolic diseases were evaluated and excluded. In view of her history of hypothyroidism despite adequate hormonal replacement and clinical behaviour, Hashimoto's encephalopathy was considered. Anti-thyroperoxidase levels were above 3000 IU/ml. The patient received 5 g of methylprednisolone followed by prednisone, but after a favourable initial response, returned to a comatose state. However, after administration of intravenous immunoglobulin (IVIG) 2 g/kg, the patient recovered with resolution of neurological symptoms and was discharged from the ICU 4 days after finishing IVIG treatment.

Local infiltration of gonyautoxin is safe and effective in treatment of chronic tension-type headache

BACKGROUND

Gonyautoxin are phycotoxins, whose molecular mechanism of action is a reversible block of the voltage-gated sodium channels at axonal level, impeding nerve impulse propagation.

OBJECTIVE

To evaluate clinical efficacy of gonyautoxin in the treatment of patients with chronic tensional-type headache.

METHODS

Open trial from September 2004 to 2005 in Hospital Clínico Universidad de Chile. Twenty-seven patients with chronic tension-type headache were locally infiltrated with gonyautoxins (50 micrograms) in ten sites considered as pain trigger points in a fixed infiltration protocol. In each site, a volume of 200 microlitres was injected. EMG recording was performed before and immediately after infiltrations. Main outcome measures are where a significantly drop-off in acute headache pain score occurs and number of days without headache pain.

RESULTS

No side effects were detected in the follow-up period. From base line of 2 weeks, 19 patients of 27 (70%) are the successfully responders to the treatment. They showed the remarkable immediate effect after infiltration demonstrated by trapezium EMG recording. Patients reported a fall in pain score 5 minutes post-injection from 5.0 +/- 2.8 to 1.6 +/- 1.6 (mean +/- SD). The responder showed an average of 8.1 +/- 9.9 weeks of headache pain-free, all of them without a second infiltration or use of any additional analgesic medication.

DISCUSSION

The therapeutic properties of gonyautoxin local infiltration in chronic tension-type headache patients are shown to be safe and effective. This report describes a new therapy for chronic tension-type headache involving local infiltrations of gonyautoxins. The immediate headache pain relief effect shown only minutes after toxin infiltrations were the most remarkable feature of this protocol. This is the first gonyautoxins testing report in the treatment of chronic tension-type headache.

Lrrk2 mutations in South America: A study of Chilean Parkinson's disease

Pathogenic substitutions in the leucine-rich repeat kinase 2 protein (Lrrk2), R1441G and G2019S, are a prevalent cause of autosomal dominant and sporadic Parkinson's disease in the Northern Spanish population. In this study we examined the frequency of these two substitutions in 166 Parkinson's disease patients and 153 controls from Chile, a population with Spanish/European-Amerindian admixture. Lrrk2 R1441G was not observed, however Lrrk2 G2019S was detected in one familial and four sporadic Parkinson's disease patients. These findings suggest Lrrk2 G2019S may play an important role in Parkinson's disease on the South American Continent and further studies are now warranted.

Association of GST M1 null polymorphism with Parkinson's disease in a Chilean population with a strong Amerindian genetic component

We have studied the association of a null mutation of Glutathione Transferase M1 (GST M1*0/0) with Parkinson's disease (MIM 168600) in a Chilean population with a strong Amerindian genetic component. We determined the genotype in 349 patients with idiopathic Parkinson's disease (174 female and 175 male; 66.84+/-10.7 years of age), and compared that to 611 controls (457 female and 254 male; 62+/-13.4 years of age). A significant association of the null mutation in GST M1 with Parkinson's disease was found (p=0.021), and the association was strongest in the earlier age range. An association of GSTM1*0/0 with Parkinson's disease supports the hypothesis that Glutathione Transferase M1 plays a role in protecting astrocytes against toxic dopamine oxidative metabolism, and most likely by preventing toxic one-electron reduction of aminochrome.

Addiction to apomorphine: a clinical case-centred discussion

AIM

To report the case of a patient, who in the context of an anti-Parkinsonian therapy, developed addiction to apomorphine.

METHODS

Clinical case description.

RESULTS

Apomorphine is a dopaminergic agonist that acts directly on D2 receptors. It has been used in alcoholism, male sexual dysfunction and with diagnostic and therapeutic purposes in Parkinson's disease (PD).

CONCLUSIONS

The present work describes the case of a woman with PD who developed a loss of control over the consumption of apomorphine that resulted in a significant impairment of her functioning. PD patients with high frequency develop different psychiatric symptoms. Conversely, anti-Parkinsonian drugs also generate psychiatric symptoms that can be experienced by the patient as pleasant sensations ('alerting', 'awakening', 'activating', hypomania and hypersexuality). In spite of this, addiction to these drugs in patients with PD is a very rare phenomenon. Currently, the prescription of apomorphine has been extended to patients with erectile dysfunction, which may increase the prevalence of addiction cases or of severe psychiatric symptoms.

CADASIL presenting with a movement disorder: A clinical study of a Chilean kindred

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary vascular disease that usually begins with migraine, followed by repeated strokes and progressive dementia. We describe an unusual clinical presentation of this condition in members of a Chilean family with an established NOTCH3 mutation. We report early clinical, neuropsychological, transcranial ultrasound, magnetic resonance imaging (MRI), cerebral blood flow, and skin biopsy findings on these patients. Of the patients, 2 presented with facial dystonia, 1 of whom had abnormal single photon emission computed tomography and transcranial ultrasound studies after normal brain MRI scans. Our report emphasizes that CADASIL must be considered in the study of patients with secondary dystonia.

[Blindness caused by an ischemic optic neuropathy by spontaneous carotid dissection. Report of a case]

In young and middle age subjects, spontaneous carotid dissection is an increasingly recognized cause of ischemic stroke. Their usual presentation is facial pain with a Horner syndrome and a contra lateral paresis. Blindness has been reported as a presenting symptom in only a few cases. We report a 50 years old man who presented with amblyopia in the left eye, without periocular pain. Fundoscopy showed papilledema and a peripapillar hemorrhage, compatible with an ischemic optic neuropathy. A magnetic resonance angiography confirmed a left carotid dissection.

[Comparative bioavailability study of two formulations of risperidone available in the Chilean market]

BACKGROUND

Bioavailability of a particular drug can vary according to the formulation used. Therefore, studies of comparative bioavailability of different formulations of a same drug are worthwhile.

AIM

To compare the bioavailability of two risperidone formulations available in the Chilean market.

MATERIAL AND METHODS

The bioavailability of a local risperidone formulation (Spiron) was compared with the original formulation of the drug (Risperdal) in 12 healthy volunteers, aged 19 +/- 1 years. A single dose of 3 mg was given orally, using a randomized double blind protocol in two periods. Fifteen blood samples were obtained at regular intervals, until 24 h after drug administration. Risperidone plasma levels were measured by high pressure liquid chromatography. pharmacokinetic parameters were calculated using a computer program that is independent of compartmental analysis.

RESULTS

The area under the curve of plasma concentration versus time, from 0 to infinite (ABC0-infinity) and from 0 to 24 h (ABC0-24), early exposure (ABC from 0 to maximal time) and maximal plasma concentrations were significantly lower for Spiron. Half life time and time to achieve the maximal concentration were similar for the two formulations.

CONCLUSIONS

According to bioequivalence tests suggested by the Food and Drug Administration (FDA) of the United States (90% confidence interval for the difference of long transformed mean pharmacokinetic parameters), the formulations Risperdal and Spiron, cannot be considered interchangeable.

[Prevalence of carotid atherosclerosis in patients with cerebrovascular occlusive disease]

BACKGROUND

Hispanics have a greater incidence of stroke and prevalence of intracranial atherosclerosis than whites.

AIM

To study the prevalence of extracranial atherosclerosis among patients admitted to a hospital with an ischemic stroke.

MATERIAL AND METHODS

A prospective study in stroke patients admitted to a Neurology ward in a University Hospital. All were subjected to a CT scan, carotid duplex-Doppler ultrasonographic examination with Doppler measurement of blood flow velocity, permeability and plaques. Cardiac emboli were searched with transthoracic and transesophageal echocardiography.

RESULTS

One hundred ten patients (39 women), aged 67.5 +/- 11.4 years old were studied. Stroke was atherothrombotic in 46 (41.8%), embolic in 30 (27.3%), lacunar in 27 (24.6%) and of other type in 7 (6.4%). Ninety two patients (84.4%) had high blood pressure, 38% had high cholesterol levels, 35% had a cardiac disease and 26% were smokers. Thirty five subjects (31.8%) had a normal carotid ultrasonography, 46 (41.8%) had mural plaques, 16 (14.5%) had multiple plaques without occlusion, 13 (11.8%) had a partial occlusion and 7 (6.4%) had a total occlusion. Logistic regression analysis disclosed no significant relationship between stroke types and carotid atherosclerosis. Age was the only significant predictor for carotid atherosclerosis.

CONCLUSIONS

The prevalence of severe carotid atherosclerosis in this group of stroke patients was less than expected.

Endoscopic laser surgery in the treatment of radiation failure of early laryngeal carcinoma

BACKGROUND

This study was undertaken to analyze the local control rates and survival of patients undergoing endoscopic laser surgery for squamous cell carcinoma of the larynx as a salvage procedure for recurrent tumors after radiotherapy.

METHODS

Twenty-four patients underwent endoscopic laser surgery for radiation failure at our hospital from 1988 to 1995. All patients were men, between 45 and 88 years old. The localization of the recurrence was in the supraglottis in 3 cases and in the glottis in 21 cases. The postirradiation recurrences were staged rT1 in 18 patients and rT2 in 6 patients.

RESULTS

Local recurrence after laser surgery developed in six patients (25%) who had a total laryngectomy. Voice preservation was thus achieved in 75% of patients. No patient died because of the laryngeal cancer, and the observed 5-year survival rate was 76%.

CONCLUSIONS

These results indicate that in selected cases, endoscopic laser surgery may be used successfully for treating radiation failure of early laryngeal carcinomas.

Effects of supplementation with folic acid and antioxidant vitamins on homocysteine levels and LDL oxidation in coronary patients

Hyperhomocysteinemia is an important cardiovascular risk factor. Serum homocysteine levels are specially dependent on folate nutritional status. In addition, the oxidative modification of low-density lipoproteins (LDLs) in the endothelial microenvironment is a damaging factor that can be modified with fat-soluble antioxidant vitamins. The present study was done to assess the effect of a supplementation of folic acid and antioxidant vitamins on homocysteine levels and in vitro LDL oxidation in patients with coronary artery disease. Twenty-three patients with angiographically proven coronary artery disease were given supplements for 15 d consisting of one capsule twice a day of a multivitamin preparation containing 0.65 mg folic acid, 150 mg alpha-tocopherol, 150 mg ascorbic acid, 12.5 mg beta-carotene, and 0.4 microgram vitamin B12. Serum lipids, vitamin and homocysteine levels, and in vitro LDL oxidation were measured before and after the supplementation period. During the supplementation period, serum folate levels increased from 5.0 +/- 1.5 to 10.8 +/- 3.8 ng/mL (P < 0.001), vitamin B12 increased from 317.4 +/- 130.4 to 334.5 +/- 123.8 pg/mL (P < 0.05), and alpha-tocopherol increased from 8.2 +/- 5.1 to 13.7 +/- 7.9 mg/L (P < 0.001). Serum homocysteine levels decreased from 8.7 +/- 4.3 to 6.3 +/- 2.2 mumol/L (P < 0.001). In vitro LDL oxidation decreased from 2.6 +/- 1.1 to 1.6 +/- 1.1 nmol malondialdehyde/mg protein (P < 0.001). In comparing patients with healthy controls, basal levels of folate were lower in the patients, whereas vitamin B12, alpha-tocopherol, and homocysteine levels were similar. No changes in serum lipid levels or body weight were observed. In conclusion, a short-term supplementation with folic acid and antioxidant vitamins can reduce serum homocysteine levels and in vitro LDL oxidation in patients with coronary artery disease.

[Our experience with 1 mg BCG vaccine instillation in T1 stage cancer of the bladder]

We studied 67 patients with bladder cancer in stage T1, with terminated BCG treatment and in pursuit. No stage Ta neither carcinoma in situ was included. The protocol was: beginning of treatment upon retiring vesical catheter, instilation of 1 mg of liofilized BCG vaccine (16 x 10(6) bacilles) in 40-50 ml of intravesical saline solution. A weekly instilation during the first month. An instilation each 15 days during the second and third month and one monthly until complete 12 months of treatment. Also was carried out an study of T lymphocites and cytokines.

RESULTS

The average followup of the 67 patients treated was 51.3 months. 17 patients relapses (25.4%). A 33% were grade 3 and 27% grade 2. Like complications there was a case of inguinal TBC adenititis, 2 TBC prostatitis, 2 TBC cistitis and 5 cases of slight disuric syndrome. The study of subpopulations of lymphocites in peripheral blood demonstrated a significant increase of CD3 and CD4/CD8 ratio. The interleukin 2 measurement in serum also increased significantly after the BCG instilations.

CONCLUSIONS

Our protocol gets similar results to the higher doses, but with minimal complications diminishing the relapses of the tumors in stage T1. A monthly maintenance dose would help to maintain immunity.

Zinc supplementation increases growth velocity of male children and adolescents with short stature

We assessed the effect of zinc supplementation on growth velocity in 79 children and adolescents (48 males, 38 females) with idiopathic short stature. Their height-for-age was < 5th percentile (NCHS standards) and their weight-for-age was normal. Patients were assigned randomly to a supplemented group (S) to receive Zn 10 mg/day or to a placebo (P) group, according to gender and age, and were followed-up for 12 months using a double-blind design. Weight, height, armspan, length of lower segment and plasma and hair concentrations of Zn were measured at 0, 3, 6 and 12 months. On admission and at 6 months, energy, protein, dietary fiber and zinc intakes were similar for groups S and P; mean zinc intake was < 6.5 mg/day. No differences were found in plasma zinc, hair zinc, weight, armspan or lower segment increments. Pre-adolescent males in group S had a significantly greater increase in stature compared with group P (6.2 +/- 2.1 versus 4.5 +/- 1.2 cm/year p < 0.025); z score improved from -2.42 to -2.24 in group S and from -2.63 to -2.61 in group P. For adolescent males, the difference was also significant (8.3 +/- 1.5 versus 6.2 +/- 2.1 cm/year; p < 0.025). No differences were noted in females. In Chilean male schoolchildren and adolescents with idiopathic short stature, zinc supplementation increases growth velocity over a 12-month period.

[Evaluation of prostatic specific antigen after a digital rectal examination: experience with 36 patients]

Levels of prostatic specific antigen may be modified with procedures over the prostatic gland. We measured this antigen in 36 hospitalized patients before and immediately after a digital rectal examination. Antigen levels were 8.3 +/- 21.3 ng/ml before and 13.8 +/- 27.5 ng/ml after the examination (NS). It is concluded that digital rectal examination did not modify antigen levels in our sample.

[Treatment of bladder neoplasm: vesical instillation of BCG vaccine in microdoses]

We administered BCG at microdoses (1 mg) to 34 patients after surgical operation for bladder cancer, from 1981 to 1989. A 9% recurrency rate was observed during a 42 month follow up period. This is not significantly different from that observed with 120 mg doses, which are associated to known complications.