Treatment of venous malformations in pediatric population – three- year experience

Venous malformations (VMs) are a type of vascular malformations that result in abnormal development of veins that become extensible over time due to an error in vascular morphogenesis. They usually appear in newborns or in early adulthood as a bluish, soft, swollen and eventually painful skin formation. Treatment includes conservative therapy, sclerotherapy and surgical excision. Aim of the paper is to evaluate the therapeutic effect of scleraotherapy in pediatric patients with venous malformations. Material and methods: In a three-year period, from 2019 to 2021, venous malformation was found in 33 patients aged 4 to 14 years (average age: 8 years). Pain as a symptom occurred in 8 patients. Two patients had lesions measuring up to 5 cm and 5 cm respectively, while in the remaining subjects the lesion was over 5 cm. Ultrasound was performed routinely in all subjects, and MRI in two patients. Conservative treatment was instituted in 13 patients with venous malformations of the extremities, surgical excision with local reconstruction was performed in 11 patients, and sclerotherapy with bleomycin under general anesthesia was performed in 8 patients. Combined treatment was used in one patient that presented with venous malformation of the upper arm that underwent partial sclerotherapy with subsequent operative excision due to a phlebolith. Follow-up examinations revealed regression of the change not only from functional but from aesthetic aspect as well. Conclusion: Sclerotherapy is the established golden standard, first-line treatment for venous malformations. Excellent results were achieved as the reduction of the lesions was below 50% of the initial size. However, the modality of treatment should be individualized to each patient as it can sometimes require a combination of more than one treatment option. Venous malformations are best treated early, but they usually recur over time. Treatment helps relieve symptoms and control the growth of vascular malformations.

Differences between reaction time to stimulus onset and offset: Evidence for post-perceptual effects

Reaction time to stimuli offset is usually longer than to stimuli onset (offset disadvantage). According to V. Di Lollo et al. (2000), such disadvantage arises from the need to suppress the automatically arisen response to stimulus onset that necessarily precedes the offset. If such is the case, one expects the onset–offset difference to decrease as the delay between stimulus onset and offset (i.e. foreperiod) increases. Results of the first experiment confirmed this hypothesis. A potential confounding factor was identified, however, related to different sensory consequences after the response (i.e. light offset vs. light onset in the reaction time to stimulus onset and offset tasks, respectively). We thus reasoned that, besides suppression, the action effect could influence the results. Results of the second experiment in which the sensory consequences were equalized confirmed the role of the action effect and suggest that, when such an effect is removed, suppression plays a little role in offset disadvantage.

Response-related factors in reaction time to stimulus onset and offset tasks

According to V. Di Lollo et al. (2000), the difference in reaction time to stimulus onset and offset is related to response suppression. By using electromyographic activity recording, in the first experiment, we investigated whether both premotor and motor parts are affected by the task. Furthermore, in the second experiment, we investigated how other response-related factors, such as response type, could contribute to the difference between reaction time to stimulus onset and offset. In the first experiment, eleven subjects 29 ± 4.6 years old (six women and five men) performed reaction time tasks to stimulus onset and offset, and their response-related muscular activity was recorded. Sixteen 21.6 ± 1.5 years old subjects (eight women, eight men) participated in the second experiment, in which two types of responses were required. The results have revealed that differences in the reaction time to stimulus onset and offset are independent of response type and are related to the premotor part of reaction time only.

Fucoidans from brown seaweeds Sargassum hornery, Eclonia cava, Costaria costata: structural characteristics and anticancer activity

Fucoidans were isolated by water extraction and ion-exchange chromatography from brown algae Eclonia cava, Sargassum hornery, and Costaria costata collected near of Korean coasts. The structures of fucoidans were investigated. Fucoidan from E. cava was mixture of sulfated rhamnogalactofucan and galactofucan. Fucoidan from C. costata was a sulfated galactofucan. Fucoidan isolated from S. hornery was separated into three fractions: a homofucan sulfate, a homofucan but without sulfate groups, and a sulfated rhamnofucan. The results clearly showed that fucoidans play an inhibitory role in colony formation in human melanoma and colon cancer cells and may be effective antitumor agents.