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Biomedical subjects

S Calderon

Publications and source records attributed to S Calderon.

At least 19 recordsLinked to original sources
PubMed1997

The coronoid process as a cause of mandibular hypomobility--case reports.

In an attempt to draw the clinician's attention to the coronoid process site while evaluating the aetiology of the restriction of mandibular opening, four cases are illustrated. These cases represent a diversity of causes hampering the free rotational movement of the coronoid process in space during jaw function. Case 1 is an example of unilateral hyperplastic coronoid process and osteochondroma; case 2 shows unusually shaped short and divergent coronoid processes combined with a bucally displaced maxillary third molar on one side; cases 3 and 4 represent an anatomical variation of an extremely narrow vestibular space due to the close proximity of the medial aspect of the coronoid process to the distal molar. It is suggested that each clinical examination include the width of the buccal vestibular space while performing mandibular movements.

Adult↗
PubMed1996

Human delta opioid receptor: functional studies on stably transfected Chinese hamster ovary cells after acute and chronic treatment with the selective nonpeptidic agonist SNC-80.

The SNC-80 series of nonpeptidic agonists for the delta-opioid receptor are being developed as potential analgesic drugs. It is important to understand their acute and chronic effects at human delta-opioid receptors. Thus, we measured the ability of SNC-80 and [D-Pen2,4'-Cl-Phe4,D-Pen5]enkephalin to inhibit forskolin-stimulated adenylyl cyclase activity in recombinant Chinese hamster ovary cells stably expressing the cloned human delta-opioid receptor. The calculated EC50 values for [D-Pen2,4'-Cl-Phe4,D-Pen5]enkephalin and SNC-80 were 0.6 +/- 0.1 nM and 6.3 +/- 0.1 nM, respectively. Pretreatment of these cells with SNC-80 (100 nM) for 24 hr produced 1) a time-dependent reduction of delta receptor density, as measured by radioligand binding studies with [3H]naltrindole; 2) a shift in the EC50 value of SNC-80 from 7.7 +/- 4.2 nM to 44.1 +/- 12 nM, as measured by the cyclic AMP assay; 3) a reduction in the maximum inhibition of adenylyl cyclase activity from 86% to 48%; 4) a marked increase in the forskolin stimulation of basal cyclic AMP accumulation by nearly 100% (from 442 pmol/mg of protein to 824 pmol/mg of protein); and 5) a 5-fold increase in forskolin-stimulated cyclic AMP accumulation after addition of naltrindole. These studies showed that SNC-80 produced desensitization and down-regulation of human delta-opioid receptors in recombinant Chinese hamster ovary cells after chronic treatment and that this effect was associated with an increase in adenylyl cyclase activity.

Animals↗
PubMed1995

Disturbed lower denture stability due to lipoma in the floor of the mouth.

An unusual case of lipoma arising in the floor of the mouth of a 70-year-old man is presented. The unusual appearance suggests that the tumour be included as a rare possibility in the differential diagnosis of swellings in the floor of the mouth that can also adversely affect lower denture stability.

Aged↗
PubMed1995

Developmental arrest of tooth bud after correction of mandibular fracture.

A case of multiple fractures of the mandible following a car accident in a five-year-old patient is reported. The fracture line passed distal to the first molar tooth bud. The fracture was treated by wire osteosynthesis and skeletal fixation. During the ensuing 18 months, a gradual arrest of the development of the first molar tooth bud was radiologically observed. The eruption process had not been disturbed, and the tooth erupted at the age of 6 1/2 years. Since the distal root had completely failed to develop and the mesial roots showed a diminished size, the tooth was extracted. Histopathological examination revealed disturbed dentin apposition, there was almost complete obliteration of the pulp chamber by globular dentin, and evidence of root resorption.

Child, Preschool↗
PubMed1995

Radiographic features of anterior buccal mandibular depression in modern human cadavers.

The anterior buccal mandibular depression (ABMD) becomes significant when evaluating edentulous patients prior to implant insertion. The features of the ABMD in dry mandibles from ancient populations have been reported. In the present study the prevalence and radiological appearance of the ABMD and the influence of soft tissue superposition on its radiological detectability in the jaws of modern human cadavers were evaluated. The prevalence of ABMD was 32%. The presence of soft tissue significantly influenced the radiopacity of the ABMD area and the degree of definition of the borders (p=0.0003 and 0.0001 respectively). Changes in the trabecular pattern were observed in 36% of the cases without soft tissue compared with 29% with soft tissue. The ABMD was more readily detected on CT scans than on conventional periapical or panoramic radiographs.

Age Distribution↗
PubMed1994

Flexible waveguides for IR laser radiation and surgery applications.

Flexible plastic waveguides were developed to deliver IR radiation, especially at 10.6 microns, which is the CO2 laser radiation wavelength. The waveguide is made from teflon tube with the inner wall coated with a metal layer and a dielectric overlayer. The internal diameter (ID) is 1.0 mm, length 1.0-1.2 m, and the distal tip decreases moderately to ID approximately 0.6 mm. The distal part on the last 10 centimeters is coated externally with a metal layer. Maximum power that can be delivered at the outlet is approximately 30 W and 10.6 x 10(3) W/cm2. This type of waveguide was used in several medical operations to evaluate its cutting characteristics and the resistances to heat reflection from the tissue while operating in orifices containing liquid substances.

Carbon Dioxide↗
PubMed1994

Head and neck manifestations of tumoral calcinosis.

Intraoral facial and laryngeal features of tumoral calcinosis are reviewed in six patients of Jewish-Yemenite descent. Extraoral features included calcified masses, erythematous patches, and angular cheilitis. Oral soft tissue findings included papillary hyperplasia of the lip vermilion and velvety-red macules on the tongue, palate, and buccal mucosa. Gingival findings included advanced periodontitis and an erythematous marginal gingivitis. In all patients, orthognathic evaluation revealed a concave profile, retruded maxilla, and relative mandibular prognathism. Although previously reported clinical dental abnormalities were not present, extracted teeth demonstrated abnormal dentin. Hoarseness was present in all patients and was the earliest appearing feature in two patients. The appearance of these head and neck findings preceded the classical manifestations of tumoral calcinosis and may be helpful in the early diagnosis of this entity. The varied reported features of tumoral calcinosis support the notion that this disease may present multiple formes frustes with variable clinical expressivity.

Adolescent↗
PubMed1994

Peripheral osteoma of the mandible: a study of 10 new cases and analysis of the literature.

Ten new cases of peripheral osteoma of the mandible are described. These lesions are uncommon and only 15 other cases have been reported in the English language literature over the past 30 years. There is evidence to suggest that the peripheral osteoma of the mandible is a traumatically induced reactive lesion and that muscle traction plays a role in its initiation. In view of this possibility, the term "parosteal osseous hyperplasia" may be more appropriate for those lesions in which a positive history of trauma preceded the onset.

Adolescent↗
PubMed1994

Radiological findings in jaws and skull of neurofibromatosis type 1 patients.

Maxillary and mandibular lesions in neurofibromatosis Type 1 (NF1) in patients are described. Radiographic manifestations include radiolucent lesions with well-defined, poorly-defined or irregular diffuse borders. Mandibular lesions were not associated with the inferior alveolar nerve as it coursed within the mandible. In three patients the lesions extended considerably into the cranial bones. The necessity for routine radiographic and CT evaluation of NF1 patients is emphasized.

Adolescent↗
PubMed1993

PCP: a review of synthetic methods for forensic clandestine investigation.

A review of the synthetic routes to phencyclidine (PCP, 1-(1-phenylcyclohexyl)piperidine) available in the open literature is presented. The emphasis herein is directed toward the forensic investigation of clandestine PCP laboratories. Six published synthetic routes to PCP/analogs are discussed. Each method is rated for overall yield, degree of difficulty and potential hazard, in order to assist the forensic chemist in evaluation of a particular clandestine operation. One clandestine recipe is illustrated and discussed.

Forensic Medicine↗
PubMed1993

Epidermal nevus syndrome with maxillary involvement.

A female patient with epidermal nevus syndrome is reported. There were linear epidermal nevi, hemihyperplasia of the limbs and tongue, macrocephaly, several ophthalmic malformations, and multiple radiolucent lesions in the limbs and sacroiliac region. At age 14 years, she developed a giant cell granuloma of the maxilla.

Abnormalities, Multiple↗
PubMed1993

Intraoral acinic cell carcinoma.

Three cases of acinic cell carcinomas in minor salivary glands of the oral cavity are reported. The tumors were slow-growing and asymptomatic and were treated by wide local excision. A long-term follow-up showed no metastasis. One patient had local recurrence. Generally, this malignant tumor has the potential to recur and metastasize many years after initial diagnosis and treatment. Total excision has been the established treatment of choice. The contribution of radiotherapy and chemotherapy remains unclear.

Aged↗