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Biomedical subjects

E Helidonis

Publications and source records attributed to E Helidonis.

At least 19 recordsLinked to original sources

Multifocal bigerminal mature teratomas of the head and neck.

Teratomas and dermoids or hairy polyps of the head and neck are rare congenital tumours, often confused and reported to appear as single masses, that may cause upper aerodigestive tract impairment. Their histological classification, origin and embryological basis of development have been a topic of debate in the past and recent literature. We report a case of an infant presenting with a multifocal bigerminal teratoma in the nasopharynx and the neck, causing a deep neck infection, and discuss the unique clinicopathological aspects of this case.

Female↗

[Bilateral paraganglioma of the vagus nerve].

Paragangliomas are rare, usually benign tumours of the head and neck region, located along the cranial nerves and the big vessels. Vagus paraganglioma represents less than 3% of all cases of paragangliomas of the head and neck. Approximately 10% of vagus paragangliomas are presented as bilateral masses. We present the case of 75 year old female with bilateral paraganglioma, and papillary cancer of the thyroid gland at the time of diagnosis. Diagnostic and therapeutic procedures are discussed with special regard to possible complications.

Aged↗

Safety of the ArF193 excimer laser for the removal of dental plaque and calculi: an in vitro histological study.

OBJECTIVE: To assay the safety of the ArF excimer laser in the integrity of human pulp elements. BACKGROUND DATA: The use of lasers in dentistry remains controversial, in spite of their increasing application in medical practice. The main reason for this discrepancy is the frequent report of damage to surrounding tissues and the dental pulp, due to the energy transfer, from the site of laser impact. The progress made on laser technology during the last 10 years, could overcome this obstacle and allow the use of lasers in dentistry. METHODS AND RESULTS: The present study reports the use of the ArF 193 excimer laser, under conditions of strict control of frequency and fluency, for the ablation of dental carries, plaque, and calculi, by the use of a new, articulated arm. We have tested 10 teeth, extracted for prosthetic reasons, immediately after extraction. Our in vitro results show that the ArF193 excimer laser does not produce any harm to the dental pulp (at least at the photo- or electronic microscopy level), whereas in a matter of seconds, it can be effective in removing all dental deposits. In addition, the use of the flexible articulated arm, makes this treatment comfortable and easier for both the dentist and patient. CONCLUSION: Under a strict control of laser technology, and the use of the new articulated arm presented, the use of the ArF excimer laser in dentistry is safe and comfortable.

Dental Calculus↗

Carbamazepine levels in head hair of patients under long-term treatment: a method to evaluate the history of drug use.

Carbamazepine (CBZ) concentrations were determined in the sections of head hair from 40 patients (22 males and 18 females), ages 5 to 81, who were receiving this drug systemically. Hair treatment included dissolution, liquid phase extraction procedures, and immunoassay (Abbott TDx) or high-pressure liquid chromatography (HPLC) analytical techniques. The mean values of CBZ levels in the hair from the 1st section (close to hair root) to the 5th section for female patients were 26.82, 19.18, 17.28, 15.09, and 14.62 micrograms/g according to HPLC measurements. Immunoassay gave generally slightly higher results. The mean values of CBZ in the hair sections according to the immunoassay technique were 30.53, 21.90, 19.83, 17.45, and 16.99 micrograms/g, respectively, from the 1st to the 5th sections. The corresponding mean values for male patients by HPLC and immunoassay techniques were 21.97, 17.30, 15.03, 13.02, and 11.21 micrograms/g and 25.98, 20.52, 17.15, 14.87, and 12.31 micrograms/g. Generally, a reduction of drug concentrations in hair from the first to the subsequent segments was observed. Higher amounts of CBZ were deposited in black, untreated hair (e.g., not dyed or permed). CBZ concentrations in hair sections were found to be dependent on the dosage (r = 0.979, p < or = 0.001) but not on the gender. The data indicate the possible use of hair section testing as a marker of the dosage history and the compliance of patients under long-term treatment with CBZ.

Adolescent↗

Fractionated carboplatin radiosensitization: a phase I dose-escalation study.

Carboplatin is one of the most common drugs used for radiochemotherapy of cancer. However, the best way to combine the drug with fractionated radiotherapy has not been established. In the present study the authors investigated which maximum tolerated daily bolus dose of carboplatin would allow safe radiopotentiation for 10 consecutive radiotherapy days, the scheme being repeated twice during the 6 weeks that a conventional radiotherapy scheme lasts. Seventy-two patients with lung or pelvis malignancies were included in a dose escalation study. Twenty-four patients comprised the first baseline cohort and were treated with radiotherapy alone. The daily dose of carboplatin was escalated starting from 38 mg/m2 daily (for 10 days) and increasing by 7 mg/m2 per day. Six patients were to be included in each cohort. All 12 patients treated at the 38 mg/m2 and 45 mg/m2 dose level completed two cycles of 10-day carboplatin treatment with no grade III-IV toxicity. Granulocyte colony-stimulating factor effectively averted the incidence of neutropenia and allowed the administration of the second carboplatin 10-day cycle in five of six patients at the 52 mg/m2 daily dose level. Platelet grade III-IV toxicity was observed in all 12 patients (six supported with granulocyte colony-stimulating factor and six with granulocyte colony-stimulating factor and recombinant human erythropoietin) treated at the 59 mg/m2 daily dose level and none of them received the second cycle of chemotherapy. Twelve patients were treated at the same dose level using amifostine 500 mg before carboplatin infusion. Two patients interrupted chemotherapy because of severe nausea and vomiting. Nine of 10 who accomplished the 10-day treatment had platelet levels more than 90,000/microl on day 28 and completed the second 10-day cycle without severe toxicity. Acute radiation toxicity did not increase in the carboplatin cohorts. In this study the authors established a high-dose fractionated carboplatin schedule that can be safely administered during radical radiotherapy.

Adult↗

Determination of phenytoin in sections of head hair: a preliminary study to evaluate the history of drug use.

Phenytoin (PH) levels were determined in the head hair of twenty five patients (fourteen males and eleven females, aged from five to seventy seven years old) who were receiving this drug chronically. The assay method involved sectional hair analysis by dissolution and liquid phase extraction procedures, using both high pressure liquid chromatography (HPLC) and immunoassay (Abbott TDx) techniques. Five sections were studied, the first being the one closet to the root. The phenytoin levels of the hair sections ranged: a) 1st: 0.68 to 39.56 micrograms/g (mean 16.12 micrograms/g), b) 2nd: 0.85 to 34.15 micrograms/g (mean 9.45 micrograms/g), c) 3rd: 1.33 to 27.90 micrograms/g (mean 3.72 micrograms/g), d) 4th: 1.10 to 10.96 micrograms/g (mean 3.04 micrograms/g) and e) 5th: 1.05 to 7.00 micrograms/g (mean 2.84 micrograms/g) according to the HPLC analysis. The immunoassay technique gave similar results. The mean values of phenytoin in the hair sections according to the immunoassay technique were: 16.28; 9.47; 3.77; 3.22; 2.97 micrograms/g, respectively from the 1st to the 5th section. A reduction of drug concentrations in hair from the first to the consecutive segments was observed. Higher amounts of phenytoin were deposited in black, untreated hair in comparison to blond brown or grey hair. Phenytoin concentrations in hair sections correlated with the oral daily dosage of the drug. Our data indicate to the use of hair testing as a marker of the dosage history and evaluation of the compliance of patients under long treatment with phenytoin.

Adolescent↗

Microtia grade as an indicator of middle ear development in aural atresia.

OBJECTIVE: To correlate the appearance of the external ear with the development of the middle ear in patients with congenital aural atresia. DESIGN: Retrospective analysis of patients with congenital aural atresia. Obtain the microtia grades assigned to affected ears and correlate them with atresia scores that describe the degree of the middle ear malformation. SETTING: University of Texas-Houston Otolaryngology Clinic (1988 to 1992). PATIENTS: A total of 199 ears with congenital microtia and aural atresia and 25 ears with canal stenosis without microtia were identified, all of which had been previously evaluated by high-resolution computed tomography of the temporal bone, and then assigned an atresia score. Patients with Treacher Collins syndrome were not included in our study. RESULTS: The average atresia score in cases with grade I microtia was 8.5; grade II microtia, 7.2; and grade III microtia, 5.9. In cases with canal stenosis without microtia, the average atresia score was 8.3. CONCLUSION: The better developed the external ear, the better developed the middle ear.

Child↗

A study on the otoscopical and audiological findings in patients with Down's syndrome in Greece.

One hundred and twenty patients (children) with Down's Syndrome were examined by the Audiological Dept. at 'Aghia Sophia' Children's Hospital during the period 1988-1990. Of these 73 (60.8%) were boys and 47 (37.2%) were girls. Their ages varied from 7-18 years of age with an average age of 14.8 years. Physical examination included otoscopy, tympanometry, and in some cases auditory brainstem audiometry. It is worth noting that a high percentage of these patients were unable to cooperate in this study, therefore making it obligatory to utilize objective measures for hearing evaluation.

Acoustic Impedance Tests↗

Otorhinolaryngological diseases in the Minoan era.

Minoan civilization was one of the civilizations of the past and flourished in the island of Crete between the years 2600 B.C. and 1100 B.C. Archaeological excavations brought to the light buildings and items, showing that the Minoans had an extensive knowledge about hygiene and health matters. Among the items were idols, depicting anatomical parts of the human body and different pathological changes. These idols were offered by suffering people to gods and goddesses in order to beg for their help in curing them. In a study carried out on idols kept in the Heraklion Museum, a number of interesting anatomical details and pathological changes, concerning the head and neck area were recognized.

Archaeology↗