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Biomedical subjects

Y Samuel

Publications and source records attributed to Y Samuel.

10 recordsLinked to original sources

Underwater, low-frequency noise in a coastal sea turtle habitat.

Underwater sound was recorded in one of the major coastal foraging areas for juvenile sea turtles in the Peconic Bay Estuary system in Long Island, New York. The recording season of the underwater environment coincided with the sea turtle activity season in an inshore area where there is considerable boating and recreational activity, especially during the summer between Independence Day and Labor Day. Within the range of sea turtle hearing, average noise pressure reached 110 dB during periods of high human activity and diminished proportionally, down to 80 dB, with decreasing human presence. Therefore, during much of the season when sea turtles are actively foraging in New York waters, their coastal habitats are flooded with underwater noise. During the period of highest human activity, average noise pressures within the range of frequencies heard by sea turtles were greater by over two orders of magnitude (26 dB) than during the lowest period of human activity. Sea turtles undoubtedly are exposed to high levels of noise, most of which is anthropogenic. Results suggest that continued exposure to existing high levels of pervasive anthropogenic noise in vital sea turtle habitats and any increase in noise could affect sea turtle behavior and ecology.

Acoustics↗

Sokolow-Lyon voltage criteria in sickle cell patients.

The electrocardiogram remains the most commonly used method of cardiac assessment in developing countries. To determine the prevalence of electrocardiographic left ventricular hypertrophy (LVH) and the clinical significance of Sokolow-Lyon voltage criteria in sickle cell patients, echocardiographic and ECG findings were studied in 112 patients (71 with haemoglobin SS disease and 41 with haemoglobin SC disease). Electrocardiographic left ventricular hypertrophy (ECGLVH) defined as Sokolow-Lyon voltage > or = 35 mm was detected in 39 (55%) SS patients and 11 (27%) SC patients. This prevalence was higher in men than in women. There were statistically significant trends for increasing prevalence of ECGLVH with height (p < 0.007 in SS, and p < 0.01 in SC, patients) and with left ventricular internal dimension (p < 0.05 in SS, and p < 0.01 in SC, patients). But no significant trend was found with increasing posterior wall (PWT) or interventricular septal thickness (IVST). Sensitivity of Sokolow-Lyon criteria for detection of echocardiographic left ventricular hypertrophy was 63% and 33% in SS and SC patients, respectively, and specificity was 51% and 74%, respectively. Sokolow-Lyon voltage correlated with left ventricular mass in SS and SC patients (r = 0.44, p < 0.01 and r = 0.32, p < 0.05) and with left ventricular internal dimension (r = 0.2, p < 0.01 and r = 0.32, p < 0.05) but not significantly with PWT and IVST. We conclude that, in sickle cell patients, the electrocardiographic LVH mainly indicates the existence of an eccentric echocardiographic LVH with increase of left ventricular internal dimension.

Adolescent↗

[Natural history of sickle cell anemia].

Sickle-cell anaemia is characterized by three categories of clinical signs: anaemia, vaso-occlusive phenomena and infective complications, which are described here according to age. The natural history of the disease can be divided into four periods: the neonatal period which is asymptomatic but important to organize an effective protection; the first 5 years of life are characterized by a high risk of mortality, a high level of morbidity due to severe infections, episodes of acute anaemia and painful crises typical of that age-group; the life of older children and adolescents is dotted with painful crises; it is in this period that degenerative tissue pathology begins; in adulthood, the acute episodes are less frequent, but multiple complications develop. Some of them (cerebral vascular accidents or lung diseases) may be fatal, while others are the source of chronic and disabling lesions, notably ocular, orthopaedic and renal lesions, which affect the functional prognosis. Pregnancy remains a high risk. There is, therefore, a striking contrast between the basic physiopathological mechanism (polymerization of haemoglobin S) and the various clinical manifestations which depend on the type of haemoglobin, on the social and sanitary conditions in each country and on other reasons which remain to be elucidated.

Adolescent↗

Paraganglioma of the supraglottic larynx.

Supraglottic paraganglioma is described in an 80-year-old woman who presented with a small shiny-red mass at the posterior aspect of the left aryepiglottic fold. Histological examination revealed the typical 'zellballen' pattern of extra-adrenal paragangliomas. The tumor was locally excised and did not recur at 24 months follow-up.

Aged↗

Invasive multiple supraglottic squamous cell papillary carcinoma in an adult. Report of a case.

Invasive papillary squamous cell carcinoma of the supraglottic larynx is described in an adult male. The clinicopathological appearance was that of a multiple growth which displayed various gradients of neoplastic changes: in situ, microinvasion, frank invasion of cartilage and cervical node metastases. No previous history of radiotherapy was elicited. The growth was excised by supraglottic laryngectomy and neck dissection. Typical metastatic papillary formations were observed in lymph nodes.

Carcinoma, Papillary↗

Malignant melanoma of the head and neck in children. Review of the literature and report of a case.

Perusal of the literature revealed that until 1970, 13 children with malignant melanoma of the head and neck had been reported. This group includes two cases of melanoma that developed in a giant cell nevus, as well as one case of congenital melanoma. The biologic features of prepubertal melanoma appear basically analogous to those of the adult variety. Malignant melanoma of the auricle is described in a 2 1/2-year-old child. Surgical therapy was given, and BCG vaccination was used as an adjuvant. The patient is alive and free of signs of the disease 2 1/2 years following the operation. This appears to be the third reported case of malignant melanoma of the external ear in a child.

Child, Preschool↗