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Biomedical subjects

R S Baker

Publications and source records attributed to R S Baker.

At least 145 records · Page 8Linked to original sources
PubMed1973

Hemagglutination inhibition of passively sensitized red blood cells.

It has been shown that sheep red blood cells sensitized with the polysaccharides of Haemophilus influenzae type B and pneumococcal types I, III, IV, VII, VIII, XII, and XIV respond readily in hemagglutination-inhibition testing and exhibit antigen inhibition at levels of 0.09 to 4.0 ng.

Animals↗
PubMed1967

Purification of large quantities of influenza virus by density gradient centrifugation.

New zonal centrifuges can conveniently process as much as five orders of magnitude (10(5)) greater sample volumes than conventional swinging-bucket rotors. The continuous-sample-flow-with-banding versions may be used in series with ancillary purification procedures. Here we have studied the combined process: absorption and elution of influenza virus with barium sulfate followed by concentration and isopycnic banding of the virus in a buffered sucrose gradient. Kilogram quantities of impurity have been rapidly separated from grams of purified virus, which have been conveniently concentrated several hundred-fold by the purification process. Experimental vaccines made by these procedures are being evaluated.

Animals↗
PubMed1966

Influenza virus purification with the zonal ultracentrifuge.

Sufficient amounts of influenza virus (density, 1.185; size, 722S) can be highly purified (22,000 chicken cell agglutinating units per milligram of protein) with a zonal ultracentrifuge, used first in a rate process followed by isopycnic banding, to permit its detailed biological and physical-chemical evaluation.

Animals↗
PubMedDate not supplied

Nuclear magnetic resonance imaging in neuro-ophthalmology. Demonstration of a pontine glioma.

The development of nuclear magnetic resonance imaging techniques provides the physician with a non-invasive means of obtaining anatomic, physiologic and biochemical information about neuro-ophthalmic disorders. The authors summarize the principles of nuclear magnetic resonance imaging and present a case report illustrating its particular application to the demonstration of a pontine glioma.

Adult↗
PubMedDate not supplied

Pontine infarction: angiography and magnetic resonance imaging.

Magnetic resonance imaging (MRI) has several advantages over other central nervous system imaging techniques in the posterior fossa. The usefulness of MRI in demonstrating important clinico-anatomic correlations in neuro-ophthalmologic disease of the brainstem is illustrated by a case of a pontine infarction causing abnormal horizontal gaze with preserved vertical gaze and convergence.

Basilar Artery↗
PubMedDate not supplied

Ocular motor abnormalities from head trauma.

Head injuries cause the hospitalization of 200-300 persons per 100,000 population per year. Ophthalmologists provide diagnostic and therapeutic care to those trauma victims with damage to the globe, optic nerve, orbit, and ocular motor system. Eye movements can be affected by damage at any level of the central nervous system or peripheral motor unit. Comprehensive ocular motor assessment of the trauma patient can substantially contribute to the understanding of the patient's injury, recovery, and rehabilitation. This review examines all aspects of head and face trauma that can lead to ocular motility disturbances.

Brain Stem↗
PubMedDate not supplied

Chromium(VI) and apparent phenotypic reversion in Salmonella TA100.

After treatment with potassium chromate at concentrations causing ultramicroscopic cellular lesions, a significant proportion (up to 75%) of TA100 colonies fail to replicate on fresh minimal plates containing biotin. This suggests that chromium(VI) may not always induce his- reversion to his+ in Salmonella TA100. The terms 'false' or phenotypic reversion have been used to distinguish such instances from 'true' or genotypic reversion, where progeny his+ cells readily grow on biotin replica plates. Results of the present study indicate that the majority of chromate-exposed colonies, initially scored as his-, are identifiable as his+ after 24 h culture on nutrient agar. Moreover, chromate exerts a cytostatic effect on TA100 since early colony development is suppressed at high chromate concentrations. A gradual chemical reduction of chromium(VI) ions by normal media compounds is probably responsible for the re-emergence of colony growth during prolonged incubation of test plates. Thus, temporary growth inhibition at high chromate concentration appears to be responsible for most of the non-replicating colonies detected in mutagenicity assays of chromium(VI).

Chromates↗
PubMedDate not supplied

Idiopathic intracranial hypertension (pseudotumor cerebri) in pediatric patients.

Improved evaluation of visual features of idiopathic intracranial hypertension in pediatric patients has resulted in the demonstration of optic neuropathy which may be reversible. A wide variety of etiologic associations should be investigated to provide definitive therapy; however, nonspecific means often will be required to lower intracranial pressure. It is hoped that a double-blind controlled trial of medical therapies and another for surgical therapies will be conducted to elucidate optimum management of this condition.

Adolescent↗
PubMedDate not supplied

Extraocular muscles: basic and clinical aspects of structure and function.

Although extraocular muscle is perhaps the least understood component of the oculomotor system, these muscles represent the most common site of surgical intervention in the treatment of strabismus and other ocular motility disorders. This review synthesizes information derived from both basic and clinical studies in order to develop a better understanding of how these muscles may respond to surgical or pharmacological interventions and in disease states. In addition, a detailed knowledge of the structural and functional properties of extraocular muscle, that would allow some degree of prediction of the adaptive responses of these muscles, is vital as a basis to guide the development of new treatments for eye movement disorders.

Animals↗
PubMedDate not supplied

Eye injuries in athletics and recreation.

Sports-related eye injuries represent a significant eye health hazard worldwide. In the USA, it is estimated that eye injuries from sports account for more than 100,000 physician visits per year at the cost of greater than $175 million. The sports responsible for the greatest number of injuries are baseball, ice hockey, and racquet sports. In the USA there are over 189 million participants in these sports with a disproportionate number (one-third) of injuries involving the pediatric population. The most common injuries are abrasions and contusions, followed by more serious injuries, including hyphema. Substantial reduction in the incidence of eye injuries through prevention has been demonstrated in the sport of hockey which can serve as a model for other sports. Specific criteria for protective eyewear must be developed. Polycarbonate plastic lenses and frames which are sturdy and impact resistant provide optimal protection. Lensless goggles, street wear and spectacle correction glasses do not provide adequate eye protection. The ophthalmologist's role in preventing sports-related eye injuries includes addressing particular sports participants needs, identifying one-eyed athletes, and informing patients of the need for protective eyewear.

Athletic Injuries↗