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Biomedical subjects

G Duncan

Publications and source records attributed to G Duncan.

208 records · Page 12Linked to original sources
PubMedDate not supplied

Sectional neuroanatomy of the upper limb II: shoulder and upper arm.

This article is the second in a series of three that presents an anatomic functional guide to the peripheral innervation of the shoulder and upper limb. It illustrates the axial anatomy of the shoulder and upper arm. The next article continues this format for the lower arm and hand. Together, all three papers can be used to rapidly identify each upper limb muscle and its innervation(s). They can also be used to locate the peripheral nerve trunks, and correlate lesions with the classic pattern(s) of muscle denervation and altered sensation.

Brachial Plexus↗
PubMedDate not supplied

Sectional neuroanatomy of the upper limb III: forearm and hand.

This paper is the last of three articles that describe the functional anatomy of the upper limb. It extends the series by presenting the axial anatomy of the forearm and hand. In addition, it provides a table that defines the patterns of muscle denervation specific to six representative sites. This set of articles is clinically useful because it can be used to rapidly identify and describe the innervation of the muscles and skin of the upper limb.

Forearm↗
PubMedDate not supplied

Sectional neuroanatomy of the lower limb I: lower back and hip.

This series of two articles is structured to provide anatomically accurate functional schematics of the motor and sensory innervation of the lower back, hip, and lower limb. This first paper provides radiographically oriented schematic axial sections of the lower back and hip in which the muscles are appropriately color-coded to match the peripheral nerves. A companion color-coded summary table allows prediction of unique patterns of denervation from 25 lesion sites. These are divided into three categories (roots T12 to S4, four plexal quadrants, and 11 sectional levels). Correlation between an imaging abnormality at one of these lesion sites and the predicted denervation pattern ensures the lesion is, in fact, clinically significant. The next article will continue this color-coded approach into the lower limb.

Electromyography↗
PubMedDate not supplied

Sectional neuroanatomy of the lower limb II: leg and foot.

The authors have produced a pair of articles that can be used to rapidly identify back, hip, and lower limb muscles and their innervation(s). This article presents the motor and sensory innervation of the lower limb by color-coding structures to match their peripheral nerves. It provides a companion summary table that allows prediction of unique patterns of denervation from 12 lesions sites.

Back↗
PubMedDate not supplied

Sectional imaging anatomy: pelvic ring ligaments.

The purpose of this article is to describe the complex anatomy of the pelvic ligaments. It uses schematics to display 10 color-coded ligaments in relation to the bony architecture. This atlas and the accompanying summary of the classification of pelvic ligamentous injuries is designed to encourage the use of magnetic resonance imaging in cases of pelvic ring trauma.

Fractures, Bone↗
PubMedDate not supplied

The pharmacologic approach in differential diagnosis of chronic pain.

Chronic pain of unknown cause below waist level was evaluated in 100 patients by using the Differential Spinal Block (DSB) in a multidisciplinary pain clinic setting. The classic DSB approach, refined for better control of psychologic variables, was found to be a safe and effective means of differentiating various pain mechanisms. We found that, of all patients tested, 55% had pain of central or psychogenic origin and 30% had sympathetically mediated pain, as compared with 15% who had somatic pain. A long-term follow-up of these patients confirmed this impression. These results substantiated the importance of psychologic variables, in dicating the necessity for use of behavioral-based therapies in conjunction with the routine use of the refined diagnostic DSB procedure in patients with chronic pain.

Adolescent↗
PubMedDate not supplied

Horseradish peroxidase studies in animals with neuromuscular transpositions.

Horseradish peroxidase (HRP) is used to trace axonal connections from the motor end-plate to the driving neuron. This technique has confirmed that the neurons activating the sternothyroid muscle are located in the cervical spinal cord, while those controlling the posterior cricoarytenoid (PCA) are found in the nucleus ambiguus ipsilaterally. Eight rabbits underwent a sternothyroid ansa pedicle implantation to the PCA at the time of sectioning the recurrent laryngeal nerve ipsilaterally. After two months, four of these animals received HRP injections into the previously implanted PCA. Brainstem staining HRP did not reveal any retrograde transport to the motor neurons that were known to control the sternothyroid. Possible for the failure of retrograde transport are discussed.

Animals↗
PubMedDate not supplied

A method for the measurement of L-phenylalanine mustard in the mouse and dog by high-pressure liquid chromatography.

The distribution of L-phenylalanine mustard (L-PAM) was studied in dogs and mice by high-pressure liquid chromatography. Separation of L-PAM from its products of hydrolysis was accomplished with a mu-Bondapak C18 column, a solvent system composed of 2-methoxyethanol/0.1% acetic acid, and solvent programming with a step gradient. Complete separation was effected in less than 15 min. The half-life for disappearance of L-PAM from mouse blood was 41 min, whereas that from dog blood was 29 min. The monohydroxy derivative of L-PAM, L-MOH, disappeared from dog serum with a half-life of 32 min. L-MOH was not detectable in mouse tissue other than blood at times greater than 15 min after injection. In the dog at 4 hr after injection, the tissue/serum concentration ratios were greater than 1 for liver, spleen, intestine, skeletal muscle, urinary bladder and gallbladder. The concentration of L-PAM in the bile was approximately 500 times higher than that in serum.

Animals↗
PubMedDate not supplied

Distribution and elimination of melphalan in rats and monkeys and distribution in tumors of mice bearing L1210 or P388 leukemias sensitive and resistant to this agent.

Following iv injection, melphalan was eliminated monophasically from rat serum (half-life = 0.87 hour) and monkey serum (half-life = 1.9 hours) and in rat bile (half-life = 2.4 hours) and monkey urine (half-life = 1.3 hours). In rat bile and monkey urine, 2% and 20% of the dose, respectively, was excreted in 12 hours as unchanged melphalan. At each time of tissue assay (0.5-4 hours after injection), rat spleen contained less melphalan than serum, liver, or kidneys. The kidneys and bile of monkeys contained more melphalan that serum, liver, or spleen. Only a small amount of radioactivity from labeled melphalan appeared in the feces of monkeys. Melphalan reached higher concentrations in implants of P388 and L1210 leukemia cells sensitive to melphalan than in cell lines resistant to this drug. Furthermore, the amounts of radioactivity bound to macromolecules of the sensitive tumors were higher.

Animals↗