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Biomedical subjects

D Forest

Publications and source records attributed to D Forest.

At least 19 recordsLinked to original sources
PubMed2004

Identification and activity-dependent labeling of peripheral sensory structures on a spionid polychaete.

In marine sedimentary habitats, chemoreception is thought to coordinate feeding in many deposit-feeding invertebrates such as polychaetes, snails, and clams. Relatively little is known, however, about the chemosensory structures and mechanism of signal transduction in deposit feeders. Using electron microscopy, confocal laser scanning microscopy (CLSM), and immunohistochemistry, we investigated the structure and function of putative chemosensory cells on the feeding appendages of a deposit-feeding polychaete species, Dipolydora quadrilobata. Tufts of putative sensory cilia were distributed over the prostomium and feeding palps and typically occurred next to pores. Examination of these regions with transmission electron microscopy revealed multiciliated cells with adjacent glandular cells beneath the pores. The sensory cells of prostomium and palps were similar, displaying an abundance of apical mitochondria and relatively short ciliary rootlets. Staining with antiserum against acetylated alpha-tubulin was examined by CLSM, and revealed axonal processes from putative sensory tufts on the palp surface to palp nerves, as well as many free nerve endings. Activity-dependent cell labeling experiments were used to test the sensitivity of putative sensory cells on the palps to an amino acid mixture that elicited feeding in previous behavioral experiments. In static exposures, the number of lateral and abfrontal cells labeled in response to the amino acid mixture was significantly greater than in the controls. Ultrastructural, positional, and now physiological evidence strongly suggests that spionid feeding palps are equipped with sensory cells, at least some of which function as chemoreceptors.

Amino Acids↗
PubMed2001

Formation of cryptophanes from their precursors as viewed by liquid secondary ion mass spectrometry.

The formation of cryptophane-A (C1) and the deuterated cryptophanes C2-C6 from their respective precursors P1-P6 in a mass spectrometer ion-source was evidenced by liquid secondary ion mass spectrometry (LSIMS). Mass-analyzed ion kinetic energy experiments performed on the precursor molecular ions suggested that cryptophane formation occurred mainly in the liquid-matrix before desorption rather than in the gas phase. In addition, we observed that the presence of cations, such as lithium or sodium ions, inhibited the formation of the cryptophane molecular ions. In the light of these results we used the LSIMS technique to investigate the formation of the new cryptophanes C7-C13. All the data collected support the idea that a direct comparison can be made between these experimental findings and chemistry in solution.

Journal Article↗
PubMed1991

[Electrical dental anesthesia (EDA), an alternative to local anesthesia?].

Electrical dental anesthesia has recently been suggested as an alternative to local anesthetics for the control of pain related to certain dental acts. This article updates the evidence which supports the efficiency, indications and contra-indications of such a procedure. Although this technique has certain advantages, its use is limited by: 1) how cooperative the patient may be; 2) the time required to explain the procedure to the patient and that which is required to produce the needed clinical effect; and, 3) how efficient it may be relative to the patient in question and the dental treatment rendered.

Anesthesia, Dental↗
PubMed1991

[AIDS paranoia].

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Radiopacity of glass ionomer dental materials.

The radiopacity of glass ionomer dental materials is quite variable. The use of a poorly radiopaque material as a base under other restorative materials can mislead the dentist to a diagnosis of recurrent decay. This study investigates the radiopacity of these materials and proposes a minimal radiopacity under which a material should not be used as a base or liner. All base, liner, and core formulations of glass ionomer under investigation were more radiopaque than dentin. All restorative and luting formulations of glass ionomer under investigation were less radiopaque than dentin and therefore should be avoided as bases or liners.

Analysis of Variance↗
PubMed1989

I. Stylohyoid chain ossification: a discussion of etiology.

Not all patients with cervicopharyngeal pain related to the stylohyoid apparatus can be diagnosed as having Eagle's syndrome. An attempt is therefore made to classify these patients according to etiology. First, a diagnosis of Eagle's syndrome is applied to symptomatic patients in whom elongated, ossified styloid processes develop within a period of time posttraumatically. Second, a diagnosis of stylohyoid syndrome is applied to patients in whom elongated styloid processes and/or stylohyoid chain ossification develop early in life as an anatomic anomaly, and in whom symptoms later develop. Last, a diagnosis of pseudostylohyoid syndrome is applied to patients in whom, because of aging, a tendinosis at the junction of the stylohyoid ligament and the lesser horn of the hyoid bone develops. It is hoped that such a simplified classification may lead to a global understanding of the causes of such symptomatology, a more practical approach to treatment, and less confusion among the professions in regard to terminology.

Facial Pain↗
PubMed1989

II. Stylohyoid chain ossification: a discussion of etiology.

It has been estimated that between 2% and 4% of the general adult population has radiographic evidence of an ossification of the stylohyoid chain. In an effort to prove that this is also the case in children and adolescents, 150 panoramic radiographs were examined at the Department of Pedodontics of St. Justine's Hospital in Montreal, Quebec, Canada. A total of 300 styloid processes and stylohyoid chains were evaluated and measured radiographically. The patients' mean age was 11 years. The mean length of the styloid processes was 10 mm. Forty percent of the population without symptoms studied showed some evidence of stylohyoid ligament ossification. Sixty percent of these were males; 40% were females. It was also found that 65.6% had no history of cervicopharyngeal trauma on review of the medical and dental histories.

Adolescent↗