COVID-19 enabled co-authoring networks: a country-case analysis.

In this paper we seek to examine the co-authoring pattern of a select group of researchers that are affiliated with a specific country. By way of making use of standard bibliometric analysis, we explore the publication evolution of all COVID-19-related peer reviewed papers that have been (co)-authored by researchers that are affiliated with Greek institutions. The aim is to identify its advancement over time, the institutions involved and the countries with which the co-authors are affiliated with. The timeframe of the study spans from the moment that WHO Director-General declared the novel coronavirus outbreak a public health emergency of international concern (WHO, 2020. Archived: WHO timeline-covid-19. Retrieved from Archived: Who Timeline-COVID-19. https://www.who.int/news/item/27-04-2020-who-timeline---covid-19. Accessed on 10 May 2020., Archived: WHO timeline-covid-19), January 2020, to October 2020. Findings indicate that there is a steady increase in the number of publications as well as the number of scientific collaborations over time. At a cross-country level, results suggest that the affiliated institutional sectors such as the Higher Education Sector (HES) and the Government Sector (GOV) contributed the most in terms of scientific output. On an international scale, the evolution of the scientific collaboration is imprinted and distributed as a chain of affiliations that linked nations together. Such chains are represented as clusters of countries, in which the scientific connections between different countries can be visualised. It can be reasoned that a significant amount of publications (20%) is affiliated with countries having "traditionally" major scientific impact on the field of Medicine. Supplementary Information: The online version contains supplementary material available at 10.1007/s11192-021-03952-9.

Composite description based on Salient Contours and Color information for CBIR tasks.

This paper introduces a novel image descriptor for content based image retrieval tasks that integrates contour and color information into a compact vector. Loosely inspired by the human visual system and its mechanisms in efficiently identifying visual saliency, operations are performed on a fixed lattice of discrete positions by a set of edge detecting kernels that calculate region derivatives at different scales and orientation. The description method utilizes a weighted edge histogram where bins are populated on the premise of whether the regions contain edges belonging to the salient contours, while the discriminative power is further enhanced by integrating regional quantized color information. The proposed technique is both efficient and adaptive to the specifics of each depiction, while it does not need any training data to adjust parameters. Experimental evaluation conducted on seven benchmarking datasets against 13 well known global descriptors along with SIFT, SURF implementations (both in VLAD and BOVW), highlight the effectiveness and efficiency of the proposed descriptor.

Epidemiology of Huntington disease in Cyprus: A 20-year retrospective study.

Huntington disease (HD) is most prevalent among populations of western European descent and isolated populations where founder effects may operate. The aim of this study was to examine the epidemiology of HD in Cyprus, an island in southern Europe with extensive western European colonization in the past. All registered HD patients in the Cyprus, since 1994, were included. Detailed pedigrees and clinical information were recorded and maps, showing the geographic distribution of HD, were constructed. Requests for genetic testing were also examined. The project identified 58 clinically manifested cases of HD belonging to 19 families. The 16 families of Cypriot origin were concentrated in a confined geographical cluster in southeast Cyprus. In 2015, prevalence of symptomatic HD was 4.64/100 000 population, while incidence was 0.12/100 000 person-years. Prevalence displayed a marked increase during the past 20 years. Disease characteristics of HD patients were similar to those reported in western European populations. Lastly, the uptake of predictive and/or prenatal testing was limited. HD disease characteristics, incidence and prevalence in Cyprus were comparable to western European populations. Together with the geographical clustering observed, these results support the possibility for a relatively recent founder effect of HD in Cyprus, potentially of western European origin.

Genetic findings of Cypriot spinal muscular atrophy patients.

Spinal muscular atrophy (SMA) is an autosomal recessive, neurodegenerative disorder characterised commonly by proximal muscle weakness and wasting in the absence of sensory signs. Deletion or disruption of the SMN1 gene causes the disease. The SMN1 gene is located within an inverted duplication on chromosome 5q13 with the genes SMN2, NAIP and GTF2H2. MLPA analysis of 13 Cypriot SMA patients revealed that, 12 patients carried a homozygous SMN1 gene deletion and one patient carried two copies of the SMN1 gene. Two of 13 cases were a consequence of a paternally originating de novo mutation. Five genotypes were identified within the population, with the most frequent being a homozygous SMN1 and NAIP genes deletion. In conclusion, genotype-phenotype correlation revealed that SMN2 is inversely related to disease severity and that NAIP and GTF2H2 act as negative modifiers. This study provided, for the first time, a comprehensive overview of gene copy numbers and inheritance patterns within Cypriot SMA families.

Huntington's disease in Greece: the experience of 14 years.

A large scale genetic and epidemiological study of Huntington's disease (HD) was carried out in Greece from January 1995 to December 2008. Diagnostic testing was carried out in 461 symptomatic individuals, while 256 were tested for presymptomatic purposes. The diagnosis of HD with a CAG expansion ≥ 36 was confirmed in 278 symptomatic individuals. The prevalence of HD in Greece was estimated at approximately 2.5 to 5.4:100,000, while the mean minimum incidence was estimated at 2.2 to 4.4 per million per year. The molecular diagnosis of HD was confirmed in the majority of patients (84.4%) sent for confirmation. The false-positive cases 15.6% were characterized by the absence of a family history of HD and the presence of an atypical clinical picture. The uptake of predictive testing for HD was 8.6%. A prenatal test was requested in six pregnancies. The findings of our study do not differ significantly from those of similar studies from other European countries despite the relative genetic isolation of Greece. Of interest is the identification of clusters of HD in Greece. The presence or absence of a family history of HD should be interpreted cautiously, during the diagnostic process.

Absence of aprataxin gene mutations in a Greek cohort with sporadic early onset ataxia and normal GAA triplets in frataxin gene.

Phenotype of patients with the aprataxin gene mutation varies and according to previous studies, screening of aprataxin gene could be useful, once frataxin gene mutation is excluded in patients with normal GAA expansion in frataxin gene. In the present study, we sought to determine possible causative mutations in aprataxin gene (all exons and flanking intronic sequences) in 14 Greek patients with sporadic cerebellar ataxia all but one without GAA expansion in frataxin gene (1 patient was heterozygous). No detectable point mutation or deletion was found in the aprataxin gene of all the patients. Our results do not confirm the previous studies. This difference may be attributed to the different populations studied and possible different genetic background. It is still questionable whether the screening for aprataxin mutation in Greek patients' Friedreich ataxia phenotype is of clinical importance; larger, multicenter studies are necessary to clarify this issue.

High frequency of Friedreich's ataxia carriers in the Paphos district of Cyprus.

A cluster of Friedreich's ataxia patients has been previously investigated in two neighbouring villages of the Paphos district of Cyprus. Molecular genetic studies revealed that all patients had the most common mutation, a homozygous expansion of the GAA triplet repeat in the first intron of the frataxin gene. The present study is aimed at estimating the mutation carrier frequency in the broader area of Paphos. Overall, 1050 individuals originating from the Paphos district took part in the programme. Blood samples were collected for a period of 18 months, on a voluntary basis, after signing a consent form, and analysis of the GAA triplet repeat was performed. The frequency of mutation carriers in the broader area of the Paphos district, and excluding the two neighbouring cluster villages, is estimated to be high. We recommend that an organized prevention programme be implemented to cover the population from this region.

Management of gastrointestinal bezoars: an analysis of 23 cases.

Bezoars (BZs) represent the most common foreign bodies of the gastrointestinal tract. Clinical symptoms varying from no symptoms to acute abdominal obstruction. Our goal is to present our experience with a review of the literature. In this study, 23 patients with BZs of the upper gastrointestinal system (GIS) were treated in the surgical department of two generals hospitals in northwest Greece. The size of BZs, localization, predisposing factors, clinical symptoms, morbidity, and mortality were analyzed. Conservative treatment, endoscopic procedures, and surgical treatment were also parameters under consideration. Nineteen patients presenting with phytobezoars and four female patients presented with psychological disorders and mental retardation with trichobezoars. More than one half of them (57%) had previous gastric surgery. Surgical morbidity rate was 28%, whereas the endoscopic morbidity was 11%. Mortality was 4% and 0% for the surgical and endoscopic groups, respectively. The differences in morbidity and mortality rates between the two groups were not statistically significant. BZs are commonly found in the stomach and small intestine, especially in patients who underwent previous gastric surgery. Small bowel obstruction is the most common complication. When uncomplicated, endoscopic or surgical removal of the BZs can be performed easy and effectively.

Phenotypic and cellular expression of two novel connexin32 mutations causing CMT1X.

OBJECTIVE: To determine the phenotypic and cellular expression of two novel connexin32 (Cx32) mutations causing X-linked Charcot-Marie-Tooth disease (CMT1X). METHODS: The authors evaluated several members of two families with CMT1X clinically, electrophysiologically, pathologically, and by genetic testing. The Cx32 mutations were expressed in vitro and studied by immunocytochemistry. RESULTS: In both families, men were more severely affected than women with onset in the second decade of life. In the first family, the phenotype was that of demyelinating polyneuropathy with variable involvement of peripheral nerves. There was clinical evidence of CNS involvement in at least three of the patients, with extensor plantar responses and brisk reflexes. In the second family, the affected man presented with symmetric polyneuropathy and intermediate slowing of conduction velocities, whereas affected women had prominent asymmetric atrophy of the leg muscles. The authors identified two novel missense mutations resulting in L143P amino acid substitution in the first family and in V140E substitution in the second family, both located in the third transmembrane domain of Cx32. Expression of these Cx32 mutations in communication-incompetent HeLa cells and immunocytochemical analysis revealed that both mutants were retained intracellularly and were localized in the Golgi apparatus. In contrast to wild-type protein, they did not form gap junctions. CONCLUSION: These novel connexin32 (Cx32) mutations cause a spectrum of clinical manifestations characteristic of Charcot-Marie-Tooth disease (CMT1X), including demyelinating or intermediate polyneuropathy, which is often asymmetric, and CNS involvement in one family. The position and cellular expression of Cx32 mutations alone cannot fully predict these phenotypic variations in CMT1X.

Needle-knife papillotomy: a safe and effective technique in experienced hands.

BACKGROUND/AIMS: Results from studies evaluating needle-knife papillotomy are conflicting. The aim of this retrospective study was to assess the safety and efficacy of needle-knife papillotomy as a precut procedure to achieve biliary access during ERCP. METHODOLOGY: During a period of seven years, ERCP was performed 938 times. During this time, needle-knife papillotomy was carried out in 68 patients, with complete follow-up obtained in all patients. The follow-up concentrated on the safety and efficacy of the procedure and short-term complications. RESULTS: Cannulation of the common bile duct was successful immediately after needle-knife papillotomy in 44 patients (66%), during a second ERCP in 18 patients (26%), and in a third ERCP in 2 patients (3%) achieving a total cannulation rate of 94%. There were no needle-knife papillotomy related deaths. Complications included bleeding in 5 patients (7%), and pancreatitis in 3 patients (4%). All complications were managed conservatively. CONCLUSIONS: Our experience indicates that needle-knife papillotomy is a versatile, effective and safe technique of gaining biliary access in patients in whom deep cannulation proves impossible and biliary access is considered essential.

Linkage of otosclerosis to a third locus (OTSC3) on human chromosome 6p21.3-22.3.

Clinical otosclerosis (OMIM 166800/605727) has a prevalence of 0.2-1% among white adults, making it the single most common cause of hearing impairment in this group. It is caused by abnormal bone homeostasis of the otic capsule with the consequent development of sclerotic foci that invade the stapedio-vestibular joint (oval window) interfering with free motion of the stapes. Impaired ossicular chain mobility results in a conductive hearing loss. We identified the first locus for otosclerosis (OTSC1) on chromosome 15 in 1998 and reported a second locus (OTSC2) on chromosome 7 last year. Here we present results of a genome wide linkage study on a large Cypriot family segregating otosclerosis. Results of this study exclude linkage to OTSC1 and OTSC2 and identify a third locus, OTSC3, on chromosome 6p. The defined OTSC3 interval covers the HLA region, consistent with reported associations between HLA-A/HLA-B antigens and otosclerosis.

Treatment of proctalgia fugax with botulinum A toxin.

Two recent studies described a temporal association between a high-amplitude and high-frequency myoelectrical activity of the anal sphincter and the occurrence of proctalgia, which suggest that paroxysmal hyperkinesis of the anus may cause proctalgia fugax. We describe a single case of proctalgia fugax responding to anal sphincter injection of Clostridium botulinum type A toxin. The presumed aetiology of proctalgia fugax is discussed and the possible mechanism of action of botulinum toxin (BTX) in this condition is outlined. Botulinum A toxin seems to be a promising treatment for patients with proctalgia fugax, and further trials appear to be worthwhile for this condition, which has been described as incurable.

Enzymatic treatment of sanitary landfill leachate.

The objective of this investigation was to study the effectiveness of applying enzymes (bioaugmentation) for enhancement of biological treatability of leachates generated in a typical municipal solid waste sanitary landfill. The basic purpose of enzyme use is to enforce the biodecomposition of organic constituents, as well as to reduce nitrogen content. A laboratory-scale sequencing batch (bio)reactor (SBR) was used for the examination of enzymatic application. The effect of different operation strategies on the efficiency of this biological treatment process was studied to optimize performance, especially for the removal of nitrogen compounds and of biodegradable organic matter. It was found that the enzymatic process was able to remove organic matter effectively (expressed as BOD5 and COD) and nitrogen content, color and turbidity.

Mapping of the second Friedreich's ataxia (FRDA2) locus to chromosome 9p23-p11: evidence for further locus heterogeneity.

Friedreich's ataxia (FRDA), the most-common form of autosomal recessive ataxia, is inherited in most cases by a large expansion of a GAA triplet repeat in the first intron of the frataxin (X25) gene. Genetic heterogeneity in FRDA has been previously reported in typical FRDA families that do not link to the FRDA locus on chromosome 9q13. We report localization of a second FRDA locus (FRDA2) to chromosome 9p23-9p11, and we provide evidence for further genetic heterogeneity of the disease, in a family with the classic FRDA phenotype.

A novel form of distal hereditary motor neuronopathy maps to chromosome 9p21.1-p12.

Distal hereditary motor neuronopathies (dHMNs) form a heterogeneous group of rare disorders characterized by distal weakness and wasting in the limbs with no significant sensory involvement. Harding has classified dHMNs into seven categories based on clinical and genetic criteria. We report a novel form of autosomal recessive dHMN in 7 consanguineous families located in the Jerash region of Jordan. Onset of the disease is between 6 and 10 years of age and is characterized by weakness and atrophy of the lower limbs associated with pyramidal features. Within 2 years, symptoms progress to the upper limbs. Neurophysiological studies typically show normal conduction velocities, reduced compound motor action potential amplitudes, normal sensory nerve action potentials, and chronic neurogenic changes on needle electromyography. No significant abnormalities are seen on sural nerve biopsy. We call this novel form of dHMN Jerash hereditary motor neuronopathy. We studied the families at the molecular genetic level and mapped the Jerash hereditary motor neuronopathy gene to an approximately 0.54-cM region on chromosome 9p21.1-p12, flanked by microsatellite polymorphic marker loci D9S1845 and D9S1791. A maximum LOD score of 19.80 at theta = 0.001 was obtained between the disease and locus D9S1878.