The problem of missing clinical data for research in psychopathology: some solution guidelines

There are no guidelines to help psychiatric researchers statistically adjust for missing data. We discuss the problems resulting from missing values, and illustrate some of them with examples from our work. Using structured instruments, we obtained clinical information from 241 patients. Some instrument items were not rated, and these did not occur randomly: hallucinations and delusions were most frequently unrated, especially in chronic schizophrenics, and patients with high scores for other psychopathology. Systematically assigning an intermediate value between present and absent to nonrated items was a satisfactory solution, unaffected by nonrandom missing values. This simple solution was equivalent to a complicated one (vectoring) in discriminating patients. When relationships between variables are linear, we recommend the intermediate value method as a practical solution to missing values. We stress that missing values do not mean missing information, and the most common response to missing values (dropping subjects) is least informative.     

Lymphedema as a presenting sign of toxocariasis

Summary Toxocariasis in children is usually an asymptomatic infection and those with clinical illness have non-specific systemic or local manifestations. We present a 24-month-old boy with bilateral lymphedema of the feet as the main clinical manifestation of toxocariasis. The child presented with limping and nonpitting edema of both feet. Laboratory investigation revealed leucocytosis of <20,000/mm³ with a differential count of <50% eosinophils. No other cause of edema was found. The ELISA for toxocariasis revealed a high titer of 1:4,096. The limping and the lymphedema disappeared during the third week of his illness. We suggest that toxocariasis should be considered as a possible cause of lymphedema and eosinophilia in young children.Zusammenfassung Die Toxocariasis nimmt bei Kindern in der Regel einen asymptomatischen Verlauf. Wenn Krankheitszeichen auftreten, handelt es sich um unspezifische Allgemeinsymptome oder lokale Symptome. Wir berichten über einen 24 Monate alten Jungen, bei dem ein bilaterales Lymphödem der Füße die Hauptmanifestation der Toxocariasis war. Das Kind hinkte und hatte an beiden Füßen ein nicht dellenbildendes Ödem. Dabei bestand eine Leukozytose von >20 000/mm³ mit >50% Eosinophilen im Differentialblutbild. Andere Ursachen für das Ödem waren nicht zu finden. Der ELISA für Toxocariasis ergab einen hohen Titer von >1:4 096. Hinken und Lymphödem verschwanden im Verlauf von drei Wochen. Wir verweisen auf die Möglichkeit einer Toxocariasis als mögliche Ursache für Lymphödem und Eosinophilie bei kleinen Kindern.

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Lymphödem als Primärsymptom einer Toxocariasis

     

Laparoscopic management of suspicious adnexal masses

OBJECTIVE: Our aim was to evaluate the feasibility and applicability of operative laparoscopy in the management of adnexal masses that do not meet the standard serum CA 125 and ultrasonographic criteria for benignity. STUDY DESIGN: One hundred thirty-eight patients underwent operative laparoscopy for removal of suspicious adnexal masses. The CA 125 level was >35 mIU/ml in 39 of 138 (28%) patients; ultrasonographic findings were abnormal in 127 of 138 (92%); masses were >10 cm in 43 of 138 (32%) of patients. RESULTS: Malignancies were discovered in 14% (19/138) of patients. Eight percent (11/138) of the procedures were converted to laparotomy, six because of inability to dissect the mass laparoscopically and five for staging or debulking of carcinoma. Operative times ranged from 25 to 210 minutes, with a mean of 86. Three major complications were encountered-an enterotomy and a lacerated vena cava, both of which were repaired laparoscopically, and a small bowel herniation through a lateral port site that required reoperation. Hospital stays ranged from 0 to 11 days, with a mean of 1.5. In two patients with "apparent" stage I adnexal carcinomas recurrence was diagnosed 6 and 38 months after surgery. CONCLUSIONS: Laparoscopic management of suspicious adnexal masses is technically feasible, with a low rate of morbidity and a short hospital stay. Adnexal carcinomas can be identified and managed appropriately with staging and complete resection as indicated. (Am J Obstet Gynecol 1996;175:1451-9.)     

The 24-Hour Sleep Propensity Function: Experimental Bases for Somnotypology

The present study investigated the temporal structure of sleep propensity during 48 hours using an ultrashort 7-min sleep/13-min wake cycle. Eight subjects were tested under two experimental conditions of either attempting sleep, or resisting sleep after a monitored night in the laboratory. Electrophysiological recordings were carried out during the 7-min trials. The temporal structure and the overall level of sleepiness of the 48-hour sleep propensity functions calculated from the amount of total sleep in each trial revealed a high within-subjects stability. This was found both across the two days of the study within conditions, and across conditions. Also, diurnal levels of sleepiness were systematically related to nocturnal sleep parameters. Subjects having short nocturnal sleep latencies and higher sleep efficiencies slept more during the day. It is proposed that the structure and level of the sleep propensity function can be used to characterize individuals along two dimensions of somnotypology: "morningness-eveningness" and "sleepy-alert."     

Exposure of melanoma cells to dacarbazine results in enhanced tumor growth and metastasis in vivo.

PURPOSE: In recent years, the incidence of cutaneous melanoma has increased more than that of any other cancer. Dacarbazine is considered the gold standard for treatment, having a response rate of 15% to 20%, but most responses are not sustained. Previously, we have shown that short exposure of primary cutaneous melanoma cells to dacarbazine resulted in the upregulation of interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF). The purpose of the present study was to determine how long-term exposure of melanoma cells to dacarbazine would affect their tumorigenic and metastatic potential in vivo. MATERIALS AND METHODS: The primary cutaneous melanoma cell lines SB2 and MeWo were repeatedly exposed in vitro to increasing concentrations of dacarbazine, and dacarbazine-resistant cell lines SB2-D and MeWo-D were selected and examined for their ability to grow and metastasize in nude mice. RESULTS: The dacarbazine-resistant cell lines SB2-D and MeWo-D exhibited increased tumor growth and metastatic behavior in vivo. This increase could be explained by the activation of RAF, MEK, and ERK, which led to the upregulation of IL-8 and VEGF. More IL-8, VEGF, matrix metalloproteinase-2 (MMP-2), and microvessel density (CD-31) were found in tumors produced by SB2-D and MeWo-D in vivo than in those produced by their parental counterparts. No mutations were observed in BRAF. CONCLUSION: Our results have significant clinical implications. Treatment of melanoma patients with dacarbazine could select for a more aggressive melanoma phenotype. We propose that combination treatment with anti-VEGF/IL-8 or MEK inhibitors may potentiate the therapeutic effects of dacarbazine.     

Recycled Untreated Rubber Waste for Controlling the Alkali–Silica Reaction in Concrete

Recycled rubber waste (RW) is produced at an alarming rate due to the deposition of 1.5 billion scrap tires annually around the globe, which causes serious threats to the environment due to its open land filling issues. This study investigates the potential application of RW in concrete structures for mitigating the alkali–silica reaction (ASR). Various proportions of RW (5%, 10%, 15%, 20%, and 25%) partially replaced the used aggregates. RW was procured from a local rubber recycling unit. Cubes, prisms, and mortar bar specimens were prepared using a mixture design recommended by ASTM C1260 and tested for evaluating the compressive and flexural strengths and expansion in an ASR conducive environment for specimens incorporating RW. It was observed that the compressive and flexural strength decreased for specimens incorporating RW compared to that of the control specimens without RW. For example, an 18% and an 8% decrease in compressive and flexural strengths, respectively, were observed for specimens with 5% of RW by aggregates volume at 28 days. Mortar bar specimens without RW showed an expansion of 0.23% and 0.28% at 14 and 28 days, respectively, indicating the potential ASR reactivity in accordance with ASTM C1260. A decrease in expansion was observed for mixtures incorporating RW. Specimens incorporating 20% of RW by aggregate volume showed expansions of 0.17% at 28 days, within the limit specified by ASTM C1260. Moreover, specimens incorporating RW showed a lower reduction in compressive and flexural strengths under an ASR conducive environment compared to that of the control specimen without RW. Micro-structural analysis also showed significant micro-cracking for specimens without RW due to ASR. However, no surface cracks were observed for specimens incorporating RW. It can be argued that the use of RW in the construction industry assists in reducing the landfill depositing issues with the additional benefit of limiting the ASR expansion.     

Flexural Performance of Encased Pultruded GFRP I-Beam with High Strength Concrete under Static Loading

There is an interesting potential for the use of GFRP-pultruded profiles in hybrid GFRP-concrete structural elements, either for new constructions or for the rehabilitation of existing structures. This paper provides experimental and numerical investigations on the flexural performance of reinforced concrete (RC) specimens composite with encased pultruded GFRP I-sections. Five simply supported composite beams were tested in this experimental program to investigate the static flexural behavior of encased GFRP beams with high-strength concrete. Besides, the effect of using shear studs to improve the composite interaction between the GFRP beam and concrete as well as the effect of web stiffeners of GFRP were explored. Encasing the GFRP beam with concrete enhanced the peak load by 58.3%. Using shear connectors, web stiffeners, and both improved the peak loads by 100.6%, 97.3%, and 130.8%, respectively. The GFRP beams improved ductility by 21.6% relative to the reference one without the GFRP beam. Moreover, the shear connectors, web stiffeners, and both improved ductility by 185.5%, 119.8%, and 128.4%, respectively, relative to the encased reference beam. Furthermore, a non-linear Finite Element (FE) model was developed and validated by the experimental results to conduct a parametric study to investigate the effect of the concrete compressive strength and tensile strength of the GFRP beam. The developed FE model provided good agreement with the experimental results regarding deformations and damaged patterns.     

Forecasting the Post-Pandemic Effects of the SARS-CoV-2 Virus Using the Bullwhip Phenomenon Alongside Use of Nanosensors for Disease Containment and Cure

The COVID-19 pandemic has the tendency to affect various organizational paradigm alterations, which civilization hasyet to fully comprehend. Personal to professional, individual to corporate, and across most industries, the spectrum of transformations is vast. Economically, the globe has never been more intertwined, and it has never been subjected to such widespread disruption. While many people have felt and acknowledged the pandemic’s short-term repercussions, the resultant paradigm alterations will certainly have long-term consequences with an unknown range and severity. This review paper aims at acknowledging various approaches for the prevention, detection, and diagnosis of the SARS-CoV-2 virus using nanomaterials as a base material. A nanostructure is a material classification based on dimensionality, in proportion to the characteristic diameter and surface area. Nanoparticles, quantum dots, nanowires (NW), carbon nanotubes (CNT), thin films, and nanocomposites are some examples of various dimensions, each acting as a single unit, in terms of transport capacities. Top-down and bottom-up techniques are used to fabricate nanomaterials. The large surface-to-volume ratio of nanomaterials allows one to create extremely sensitive charge or field sensors (electrical sensors, chemical sensors, explosives detection, optical sensors, and gas sensing applications). Nanowires have potential applications in information and communication technologies, low-energy lightning, and medical sensors. Carbon nanotubes have the best environmental stability, electrical characteristics, and surface-to-volume ratio of any nanomaterial, making them ideal for bio-sensing applications. Traditional commercially available techniques have focused on clinical manifestations, as well as molecular and serological detection equipment that can identify the SARS-CoV-2 virus. Scientists are expressing a lot of interest in developing a portable and easy-to-use COVID-19 detection tool. Several unique methodologies and approaches are being investigated as feasible advanced systems capable of meeting the demands. This review article attempts to emphasize the pandemic’s aftereffects, utilising the notion of the bullwhip phenomenon’s short-term and long-term effects, and it specifies the use of nanomaterials and nanosensors for detection, prevention, diagnosis, and therapy in connection to the SARS-CoV-2.