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Biomedical subjects

S Rothman

Publications and source records attributed to S Rothman.

At least 19 recordsLinked to original sources
PubMed2001

Biases about man-made cancer among researchers.

Can sociological variables significantly predict researchers' positions on a scientific issue? Carcinogenesis offers a good test case because it is not definitively established how important man-made substances are as contributors to human cancer. American cancer researchers divide on this issue, some broadly emphasizing the importance of man-made carcinogens, others consistently minimizing their importance relative to natural carcinogens. We find that cancer researchers who are male, are affiliated with a medical school, and have more publications, are more likely than their colleagues to minimize the importance of man-made carcinogens.

Disease↗
PubMed1999

The endocrine secretion of mammalian digestive enzymes by exocrine glands.

The exocrine pancreas and certain salivary glands of mammals secrete a variety of enzymes into the gastrointestinal tract, where they digest food. The same glands also release these enzymes into the bloodstream. This latter process has commonly been assumed to occur solely as the result of a pathological condition or as an inadvertent by-product of exocrine secretion due to the leakage of trace quantities of the enzymes into blood. However, a variety of evidence suggests that the endocrine secretion of digestive enzymes is a normal occurrence that can be of substantial magnitude in healthy individuals, is responsive to various physiological stimuli, and is distinct from exocrine secretion. Recent research has focused attention on this process as a promising means for the delivery of engineered proteins into the systemic circulation for pharmaceutical purposes. In this review, we survey research in this area and consider the evidence for the existence of an endocrine secretion of digestive enzymes, the cause of enzyme release into the bloodstream, its source within the tissue, and, finally, the physiological purposes that this secretion process might serve.

Animals↗
PubMed1997

Identification of a new strain of fastidious enterovirus 70 as the causative agent of an outbreak of hemorrhagic conjunctivitis.

A 1994 outbreak of acute hemorrhagic conjunctivitis in Israel was caused by an enterovirus 70 strain that was distinct from previously reported strains. Characterization was by electron microscopy (eye washes), reverse transcription-PCR (RT-PCR; eyewash, specimens, eye swabs, and tears), and sequence analysis of RT-PCR-amplified fragments from the 5' noncoding region and VP1.

Amino Acid Sequence↗
PubMed1996

The mydriatic effect of topical glycopyrrolate.

BACKGROUND: Glycopyrrolate, an anticholinergic agent that does not cross the blood-brain barrier, has several indications, but its mydriatic effect has never been tested. This study was carried out in order to compare the mydriatic effect of glycopyrrolate 0.5% to that of atropine sulfate 1%. METHODS: Glycopyrrolate 0.5% and atropine 1.0% were instilled separately in the eyes of albino rabbits. Pupil diameter and intra-ocular pressure were monitored. RESULTS: Mydriasis was noted within 5 min of glycopyrrolate instillation, reached near-maximal level at 15 min and persisted for 1 week. Glycopyrrolate 0.5% showed a faster, stronger and more persistent mydriatic effect than atropine 1.0%. Administration of glycopyrrolate 0.5% solution b.i.d. for 1 week did not affect intra-ocular pressure or produce any adverse reaction. CONCLUSION: Glycopyrrolate solution has the potential to deliver an ocular anticholinergic effect without causing associated central anticholinergic hazards.

Administration, Topical↗
PubMed1996

Brain effect of intracarotid administration of cisplatinum.

The antitumoral effect of Cisplatinum is well known, including its effect on brain tumors. With the purpose of establishing the effect of intraarterial cis-dichlorodiammine platinum (CDDP) on the brain, Cisplatinum was injected in rabbits that were sacrificed at different intervals. The general clinical and neurological condition of the rabbits was unaffected, and histopathological examination of the rabbit's brain was normal.

Animals↗
PubMed1991

Nonparallel transport and mechanisms of secretion.

After many years of controversy, it is now clear that at least some cells and tissues that secrete more than one product can vary the composition of the secreted mixture as the result of the differential transport of various substances out of the cells that secrete them. In this article we discuss this phenomenon, non-parallel transport or secretion, and how it has and continues to inform us about how cells release the products they manufacture. We focus on expression of the phenomenon in the secretion of digestive enzymes by the exocrine pancreas, where it has been studied most extensively.

Animals↗
PubMed1991

The relationship between the light scattering properties of zymogen granules and the release of their contained proteins.

The optical density of suspensions of the digestive enzyme-containing zymogen granule, a roughly spherical 1 micron diameter membrane-enclosed subcellular structure isolated from the exocrine pancreas of mammals, is reduced greatly when they are suspended in physiological media. This reduction in optical density is accompanied by the release of the granule's protein contents. It has traditionally been assumed that this property is due to granule lysis; that is, dissolution of the particle and its consequent disappearance as a strongly scattering object. Thus, lysis would decrease optical density by decreasing the number density of suspended spheres (N) according to Beer's law. However, as a general matter, changes in the optical density of suspensions of spheres may be a function of changes in the refractive index (m) or radius (r) of the objects as well. In this study, we apply Mie theory of scattering by small particles, which, in conjunction with Beer's law, allows us to evaluate whether changes in the scattering properties of granule suspensions are due to changes in N, m or r. Scattering by granule suspensions was reduced in three ways-pH, calcium ion concentration, and detergent concentration. A simple reduction in particle number did not account for decreased scattering and protein release in any of these circumstances. Instead, the changes appear attributable to decreases in particle size and refractive index.

Animals↗
PubMed1991

Cytochrome c oxidase-associated Leigh syndrome: phenotypic features and pathogenetic speculations.

Fourteen new cases of cytochrome oxidase (COX)-associated Leigh syndrome (LS) are combined with 20 reported cases to describe the clinical, laboratory, and radiological features of this devastating metabolic condition. Three clinical stages are identified. Most patients have normal neurological development during the first 8-12 months (stage I). Somatic complaints are common, including chronic diarrhea, recurrent vomiting, anorexia, and decelerating body and head growth. The second stage evolves during late infancy and early childhood when motor regression becomes evident. Eye signs, altered breathing patterns, pyramidal, extrapyramidal, and cerebellar signs emerge and sudden clinical deterioration occurs during intercurrent infectious or metabolic stress. The last stage may extend from 2 to 10 years and is manifested by extreme hypotonia, swallowing difficulties and undernutrition. Feeding assistance is necessary and seizures may occur. The CSF lactate concentration is consistently elevated and MRI abnormalities are seen in the subcortical structures. COX deficiency affects most tissues, but is not always generalized. For example, 3 patients with a cardiomyopathy had normal COX activity in cultured skin fibroblasts. Nearly normal amounts of cross-reacting material are present by ELISA and immunoblot analyses. Parental consanguinity has been found in several families, the hereditary pattern is recessive and males are affected more commonly (2:1). The biomolecular abnormality causing COX deficiency in LS is unknown, but the available evidence implicates a nuclear-encoded protein that affects the structure or the stability of the holoenzyme complex.

Adolescent↗
PubMed1991

Lumbar facet fracture as a possible source of pain after lumbar laminectomy.

This study compared 50 patients with lumbar facet fractures and continued pain after lumbar laminectomy with a postlaminectomy control group without facet fractures. Computed tomographic analysis compared variables including direct measurements of bone resection. Average follow-up between surgery and postsurgical computed tomographic examination was 3.2 years. In the fracture group, more than one half of the bone immediately above the flare of the inferior articular process at the level of the laminectomy, measured in a medial to lateral direction, had been resected. No one in the control group had more than one quarter of this bone removed (P = .0001). Lumbar facet fractures may be one cause of late postlaminectomy pain. Caution in resection of a particular area of bone may avoid this problem.

Follow-Up Studies↗
PubMed1989

Comparison of computerized tomography parameters of the cervical spine in normal control subjects and spinal cord-injured patients.

The cross-sectional area and the sagittal and transverse diameters of the cervical spinal canal were measured, using high-resolution, thin-section computerized-tomography images, in 100 control subjects and forty-two patients who had a traumatic injury to the spinal cord. No significant differences were found between the control and the spinal cord-injured group with regard to the cross-sectional area of the spinal canal; however, the differences between the two groups were significant with regard to mean sagittal and transverse diameters of the spinal canal. The sagittal diameters of the spinal canal of the control group were significantly larger than those of the spinal cord-injured group. Conversely, the transverse diameters of the spinal canal of the spinal cord-injured group were significantly larger than those of the control group. These findings suggest that certain patients may be predisposed to spinal cord injury, given sufficient trauma. It is not the total volume of space in the spinal canal that is the critical factor; rather, it is the shape. An index of shape is the ratio of the sagittal to the transverse diameter. The difference between the two groups, based on the ratio of sagittal to transverse diameter, was highly significant. Because this measure is a ratio, there is no need to evaluate an individual on the basis of measurements of absolute values.

Adolescent↗