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Biomedical subjects

R F Young

Publications and source records attributed to R F Young.

At least 91 records · Page 5Linked to original sources
PubMed1979

Unmyelinated axons in the trigeminal motor root of human and cat.

The fiber composition of the human and cat trigeminal "motor roots" were studied utilizing the electron microscope. Twelve to twenty percent of fibers in the human trigeminal motor root are unmyelinated whereas 9-15% are unmyelinated in the cat. The only previous examination of the fiber composition of the peripheral trigeminal motor nerve utilized the light microscope and indicated that less than 5% of fibers were unmyelinated in cat. No study of the fiber composition of the motor nerve root is available. The present results are similar to those recently obtained by others for spinal ventral roots. The function of unmyelinated fibers in the trigeminal "motor root" is unknown, however indirect evidence, both laboratory and clinical, suggests a potential sensory function for them. The findings question seriously the concept that the functional separation of the nervous system into motor and sensory systems has anatomical correlates in the spinal and cranial nerve roots. The results relate directly to our conceptualization of the nervous system and also to the design of methods for the treatment of intractable pain.

Animals↗
PubMed1979

Cerebrospinal fluid rhinorrhea following nasogastric intubation.

This report describes a normal individual who sustained injury to the cribriform plate during nasogastric intubation. Cerebrospinal fluid rhinorrhea, a potentially fatal complication, resulted and persisted for 5 months until it was surgically corrected. The relevant anatomy is reviewed and the importance of proper technique of nasal cannulation, with minimal or no use of force, or other instruments, is emphasized. The leading end of the tube should not be directed cephalad.

Cerebrospinal Fluid Rhinorrhea↗
PubMed1979

An evaluation of women pharmacists: current status and future projections as indicated by recent literature.

Pharmacy, resembling all autonomous medical professions, has a history of male practitioners. With the rapid increase in numbers of women entering the field, evaluation of their status and projections as to the impact upon the profession is indicated. Females currently comprise 18% of the practitioners and approximately 1/3 of the students in pharmacy schools, figures considerably in excess of the numbers of women physicians. In that the fields are similar in many respects, the comparative status of female practitioners in both was considered. Parallel patterns of stratification and representation in decision-making areas of the professions were found to exist, with males comprising the status hierarchy. A specific area of divergence was noted in that women in medicine appear to be more "career" and service motivated, while female pharmacists appear to value the ease to which role-blending is allowed. Pharmacy can expect to be increasingly "womanized", particularly in the hospital practice setting. This situation may not result in status gains for the females in the field.

Career Choice↗
PubMed1979

Recurrent intracerebral blastomycotic granuloma: diagnosis and treatment.

We present a patient with a recurrent intracerebral blastomycotic granuloma. The computerized tomographic scan appearance of this lesion is illustrated. Of the 81 reported cases of intracranial blastomycosis, only 35 have represented solid intracerebral lesions; the other patients have had spinal lesions or meningitis. This patient represents the first reported recurrence of an intracerebral blastomycotic granuloma. The treatment utilized, surgical resection combined with intravenous and intraventricular amphotericin B, represents a unique approach to this problem. The diagnosis and currently advocated treatment of intracranial blastomycosis is reviewed, particularly in regard to the potential for recurrence of blastomycosis.

Adult↗
PubMed1979

Dorsal spinal cord stimulation in the treatment of multiple sclerosis.

Previously published work indicated significant improvement in the symptoms of multiple sclerosis with dorsal spinal cord stimulation. In this study 23 patients with multiple sclerosis documented by history, examination, laboratory studies, and clinical course were treated with dorsal spinal cord stimulation and followed for 19 to 45 months (mean, 32 months). Pre- and postoperative clinical assessment was carried out using the Kurtzke Scale. Walking velocity, upper limb coordination, sphincter function, and sensory function were also evaluated quantitatively. No statistically significant objective improvement in any of these measures was demonstrated. Fifty per cent of the patients initially reported subjective symptomatic improvement, but this declined to 30% at last follow-up. Fifteen of 23 patients experienced complications related mainly to the hardware used and required a total of 21 subsequent operative procedures for correction of these complications. These results do not support the continued clinical use of dorsal spinal cord stimulation in the symptomatic treatment of multiple sclerosis.

Electric Stimulation Therapy↗
PubMed1978

Unmyelinated fibers in the trigeminal motor root. Possible relationship to the results of trigeminal rhizotomy.

Spinal ventral roots have been shown by electron microscopy to contain a substantial number of unmyelinated fibers. Physiological studies have confirmed that many of these subserve a sensory function. In this investigation the fiber spectrum of the human trigeminal motor root was studied by electron microscopy and it was determined that up to 20% of fibers were unmyelinated. This accounted for approximately 300 to 1000 fibers per root. Since visceral efferent fibers are thought not to occur in the trigeminal root, it appears likely that these unmyelinated fibers may be afferent in nature. It is believed that the presence of a substantial number of unmyelinated fibers in the trigeminal motor root may account for residual sensation or failure of pain relief after rhizotomy of the trigeminal portio major root.

Humans↗
PubMed1977

Facial pain.

Explore the source record for details and available documents.

Facial Neuralgia↗
PubMed1975

Projection of tooth pulp afferents to the cat trigeminal nucleus caudalis.

Unit activity was recorded extracellularly from cat medullary neurons following electrical stimulation of the canine tooth pulp. Response characteristics of the neurons quickly stabilized at specific suprathreshold stimulus intensities but such properties as spike latency, interspike interval and spike density varied systematically as intensity was raised to maximally effective values. Receptive fields were principally unilateral. The majority included both canines and extended into other oro-facial areas. Suppression of a pulpal response could be effected by preceding tooth stimulation with a conditioning stimulus applied to some other point in the receptive field of the responding cell at an appropriate interstimulus interval. In contrast, a pulpal response could be enhanced by presenting two stimuli successively to the same canine at such intervals. Similar enhancing effects followed simultaneous stimulation of spatially segregated loci in a field. The pulp-responsive neurons were localized histologically in, or in the immediate vicinity of, the nucleus caudalis of the spinal trigeminal complex where the possibility of their existence has been questioned previously. Most of the cells were situated along the ventromedial border of the nucleus, a region reported to contain other pain-related neurons with trigeminal fields.

Animals↗
PubMed1975

Regulation of ribosomal protein synthesis in Escherichia coli B/r.

The differential synthesis rate of ribosomal protein (r-protein), alpha-r (synthesis rate of r-protein divided by synthesis rate of total protein), was measured during the cell division cycle. It was observed that alpha-r remained essentially constant and was not measurably affected by duplication of the r-protein gene cluster (i.e., str-spc region) during the process of chromosome replication. It was further observed that the rate of total protein synthesis and r-protein synthesis increased continuously and uniformly during the entire cell cycle. This gene dosage independence of the synthesis rate of r-protein was similar to that observed earlier for the synthesis of ribosomal ribonucleic acid (rRNA). These observations indicate that the synthesis rates of the protein and RNA components of the ribosome are coordinately balanced during the entire cell division cycle and are not significantly perturbed by duplication of the r-protein or rRNA genes. Furthermore, this balanced synthesis insures that neither free rRNA nor free r-protein accumulate in appreciable amounts during balanced growth.

Bacterial Proteins↗