Normal Physiological Variation Research Articles

Normal values and physiological variations of plasma iron and total iron-binding capacity in pigs.

Normal values and physiological variations of plasma iron and total iron-binding capacity in pigs.

Erythrocyte metabolism: interaction with oxygen transport.

Studies of the interactions between the metabolism and the function of the red cell have shown the importance of the red cell's metabolism in contributing to the maintenance of adequate oxygen delivery. Some of the phosphorylated intermediates of glycolysis, especially DPG, are now known to reduce the affinity of hemoglobin for oxygen. Current evidence indicates that this phenomenon is due to the effects of the binding of DPG to the , beta-chains of deoxyhemoglobin. It appears that increases in red cell concentrations of DPG commonly occur during hypoxia, and that these increases (as well as normal physiological variation) significantly enhance oxygen transport. Artificial manipulation of erythrocyte metabolism may soon prove to be of great clinical usefulness in the treatment of a great variety of disorders which limit oxygen transport.

Pharmacodynamics of dieldrin (HEOD). Ingestion by human subjects for 18 to 24 months, and postexposure for eight months.

The pharmacodynamics of HEOD (a compound in dieldrin) in adult males ingesting measured amounts daily for two years has been studied. No effects on the health of any of the subjects were found and any changes found were within the range of normal physiological variation. The relationship between the concentration of HEOD in the blood and the time of exposure is curvilinear and of the asymptotic type. Significant relationships have been found between the concentrations of HEOD in the blood and adipose tissue and the amount of HEOD ingested daily. The biological half-life of HEOD in man has been estimated. The experimental findings are consistent with a compartmental model of the type used to explain the kinetics of drugs, lipids, metallic ions, etc, in man.

Observations on Continuous Vascular Pulsative Phenomena in the Cerebral Cortex of Experimental Animals with Special Reference to the Effects of Closed vs. Opened Calvarium

Preliminary observations have been made on continuous recordings of change in optical density of the cerebral cortex and of the ipsilateral ear with vascular pulsation in anesthetized cats and in fully conscious monkeys with chronic implantation of transducers. The technique used employs fiber optic light guides implanted onto the surface of the cortex through openings in the skull and meninges. The calvarium is reclosed with dental cement. Light guides are attached to the ipsilateral ear by means of teflon receptacles sewn to opposing surfaces. Change in light intensity with change in optical density of tissue is converted by a photocell to a voltage for polygraphic recording. The electrocardiogram is recorded simultaneously. The data suggests that where changes in intracranial pressure occur within the range of normal physiologic variation, mechanisms regulating cerebrovascular distensibility provide remarkable stability. In this, integrity of the calvarium may have an important though limited role, since by allowing for establishment of intracranial pressures which can vary widely above and below atmospheric pressure, integrity of the calvarium may allow for finer adjustment in vascular transmural pressure as this affects vascular distensibility. At atmospheric pressure, decrease in propagation time and in vascular distensibility appears to have a lower limit. At this lower limit, introduction of a skull defect of significant size causes no further decrease in propagation time. It is suggested that under these circumstances other mechanisms—metabolic, mechanical, or both—become engaged even more prominently in preserving the stability of the system.

Pharmacodynamics of dieldrin (HEOD). I. Ingestion by human subjects for 18 months.

The pharmacodynamics of HEOD (a compound in dieldrin) in adult males ingesting measured amounts daily for two years has been studied. No effects on the health of any of the subjects were found and any changes found were within the range of normal physiological variation. The relationship between the concentration of HEOD in the blood and the time of exposure is curvilinear and of the asymptotic type. Significant relationships have been found between the concentrations of HEOD in the blood and adipose tissue and the amount of HEOD ingested daily. The biological half-life of HEOD in man has been estimated. The experimental findings are consistent with a compartmental model of the type used to explain the kinetics of drugs, lipids, metallic ions, etc, in man.

Normal value and Physiological Variation of Plasma Protein Fractions of the Japanese

Normal value and Physiological Variation of Plasma Protein Fractions of the Japanese

Prolapse of the Gastric Mucosa Through the Pylorus: Physiological or Abnormal?

Summary After a brief review of the literature and a discussion of the anatomy of the pyloric region, the results of X-ray examination of the stomach in 240 dyspeptic and 42 normal subjects are presented. Among the dyspeptics 44 exhibited prolapse (34 large prolapses, 10 a single fold through the pylorus), among the normals 21 (10 and 11). Accordingly, the authors interpret prolapse of the gastric mucosa through the pylorus as a normal physiological variation.

Dwarfism in healthy children; its possible relation to emotional, nutritional and endocrine disturbances.

CHILDREN in good health who are receiving an adequate diet tend to follow a relatively standard pattern of growth and maturation. Although moderate deviations from the average trend are commonly considered to be normal physiologic variations, extreme deviations suggest that some abnormality exists. In the past few years more than 100 abnormally short children have been encountered in the pediatric clinics of this hospital. In approximately 50 per cent of these patients the stunted growth could be related to a definite disturbance in the pulmonary, cardiovascular, gastrointestinal, renal, hepatic, skeletal or endocrinologic system. There remained, however, a group of 28 . . .

PIGMENTATION OF THE OPTIC NERVE

This article will deal mainly with the occurrence of uveal pigment, in the form of chromatophores in the lamina cribrosa, as a normal physiologic variation. The establishment of this fact will be considered a reason for anticipating in the disk any manifestations of pigment which are encountered in the uveal tract, and in this connection three cases of melanoma of the disk will be reported. Other forms of pigmentation will be discussed, including those arising from the pigmented epithelium, from hematogenous granules of pigment and from siderosis. Finally, several conditions simulating a pigmented disk will be mentioned. PIGMENTATION OF THE LAMINA CRIBROSA The external laminae, or laminae scleralis, are continuations of the scleral elements adjacent to the nerve, while the internal laminae, or laminae choroidalis, are continuations of the choroidal elements by way of the border tissue. These laminae usually contain no pigment cells, but in eyes in which