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Hall CE, Ayachi S. Dose-effect relationship in desoxycorticosterone hypertension: reduced sensitivity in adrenalectomized rats and its possible significance to the etiology of adrenal-regeneration hypertension. Can J Physiol Pharmacol 1971; 49:139-46. [PMID: 5569178 DOI: 10.1139/y71-020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Experiments were conducted to determine the smallest dose of DOCA which would cause saline polydipsia and induce hypertensive disease in unilaterally nephrectomized rats. This was found to be about 25 μg/day with the dosages used. This dose, and one five times as great, were then used to compare the sensitivity of adrenalectomized rats with that of animals having intact adrenals. Completely adrenalectomized animals were less responsive to the blood pressure effect at either dosage, whereas animals with regenerating or accessory adrenal glands were even more so. Adrenalectomized animals given either dosage of hormone had a lower serum protein concentration, red cell count, hematocrit, hemoglobin concentration, and red cell volume than did controls, but these parameters were within normal limits in animals found at necropsy to have residual or regenerating adrenal tissue. The hematologic characteristics appear to be useful criteria for distinguishing, during the course of experimentation, completely adrenalectomized rats from those having residual adrenal function. Clearly adrenal insufficiency diminishes the ability of DOCA to induce high blood pressure, and therefore it appears unlikely that adrenal-regeneration hypertension in the rat can be ascribed to heightened sensitivity to mineralocorticoid activity during the state of adrenal insufficiency.
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102
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Parsonson IM, Hall CE, Settergren I. A method for the collection of bovine seminal vesicle secretions for microbiologic examination. J Am Vet Med Assoc 1971; 158:175-7. [PMID: 4993552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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103
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Hall CE, Hall O, Ayachi S. Experimental hemorrhagic disease and hemarthrosis produced in the rat by dextran injections. J Transl Med 1971; 24:67-73. [PMID: 5544828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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104
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Hall CE, Cooney MK, Fox JP. The Seattle virus watch program. I. Infection and illness experience of virus watch families during a communitywide epidemic of echovirus type 30 aseptic meningitis. Am J Public Health Nations Health 1970; 60:1456-65. [PMID: 5465459 PMCID: PMC1349133 DOI: 10.2105/ajph.60.8.1456] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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105
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Ketler A, Hall CE, Fox JP, Elveback L, Cooney MK. The virus watch program: a continuing surveillance of viral infections in metropolitan New York families. 8. Am J Epidemiol 1969; 90:244-54. [PMID: 4309412 DOI: 10.1093/oxfordjournals.aje.a121067] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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106
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Hall CE, Hall O. Methylandrostenediol hypertension induced without salt excess: observations on organ changes and serum composition. Am J Pathol 1969; 54:489-505. [PMID: 5774267 PMCID: PMC2013481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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107
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Kogon A, Spigland I, Frothingham TE, Elveback L, Williams C, Hall CE, Fox JP. The virus watch program: a continuing surveillance of viral infections in metropolitan New York families. VII. Observations on viral excretion, seroimmunity, intrafamilial spread and illness association in coxsackie and echovirus infections. Am J Epidemiol 1969; 89:51-61. [PMID: 5762818 DOI: 10.1093/oxfordjournals.aje.a120915] [Citation(s) in RCA: 95] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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108
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Fox JP, Brandt CD, Wassermann FE, Hall CE, Spigland I, Kogon A, Elveback LR. The virus watch program: a continuing surveillance of viral infections in metropolitan New York families. VI. Observations of adenovirus infections: virus excretion patterns, antibody response, efficiency of surveillance, patterns of infections, and relation to illness. Am J Epidemiol 1969; 89:25-50. [PMID: 4303049 DOI: 10.1093/oxfordjournals.aje.a120913] [Citation(s) in RCA: 224] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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109
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Hall CE, Hall O. Interaction between desoxycorticosterone treatment, fluid intake, sodium consumption, blood pressure, and organ changes in rats drinking water, saline, or surcose solution. Can J Physiol Pharmacol 1969; 47:81-6. [PMID: 5761850 DOI: 10.1139/y69-013] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Intact control and DOCA-treated rats were allowed to drink distilled water, a 1% NaCl solution, or a 5% sucrose solution. Fluid intake, blood pressure changes, and organoleptic responses were evaluated. Control rats drank more sucrose solution than saline and more saline than water. Hormone treatment slightly increased water intake and greatly augmented saline consumption, but invariably depressed that of sucrose solution even though a considerable polydipsia remained in effect. Hypertension and cardiorenal enlargement characterized all groups given DOCA. Both were substantially more severe in those also given excess salt, and only in that group were cardiovascular–renal lesions grossly visible.
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110
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Hall CE. The Green Paper: a bird of paradise. Nurs Times 1968; 64:Suppl:193-4. [PMID: 5705607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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111
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Fox JP, Black FL, Elveback L, Kogon A, Hall CE, Turgeon L, Abruzzi W. Measles and readiness for reading and learning. 3. Wappingers Central School District study. Am J Epidemiol 1968; 88:345-50. [PMID: 4177267 DOI: 10.1093/oxfordjournals.aje.a120894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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112
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Abstract
Adrenal-regeneration hypertension developed uniformly in uninephroadrenalectomized, contralaterally adrenal-enucleated rats, but not in uninephroadrenalectomized controls, maintained on a high salt intake. Adrenal regeneration and the accompanying hypertension were both blocked by daily administration of 1 mg of corticosterone. One unit of ACTH gel given daily had no effect on either the blood pressure or the adrenal weight of rats with uncomplicated adrenal-regeneration hypertension or those in which blood pressure elevation was blocked with corticosterone. There were no significant differences in thymus weight between any of the foregoing groups. The daily administration of 4 units of ACTH permitted only slight enlargement of the adrenals of corticosterone-blocked, adrenal-enucleated rats, or of the hypertrophying adrenals of unilaterally adrenalectomized rats. Hypertension was fully restored to the former, but was not developed in the latter. Both groups displayed a degree of thymus involution. It would appear that full morphologic regeneration is not a prerequisite of adrenal-regeneration hypertension, but that adequate steroidogenesis to support the change can be elicited from an atrophied adrenal gland by adequate ACTH stimulation. The thymolytic effect of ACTH is analyzed for its possible relevance in respect to the secretory profile of adrenosteroids.
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Hall CE, Holland OB, Hall O. Hormonally maintained high blood pressure following adrenalectomy in rats with adrenal-regeneration hypertension and its possible significance in the etiology of that disorder. Can J Physiol Pharmacol 1968; 46:269-74. [PMID: 5660185 DOI: 10.1139/y68-043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Rats were caused to develop adrenal-regeneration hypertension, and attempts were made to reproduce in them after adrenalectomy the same rate of blood pressure rise as occurred in animals allowed to retain enucleated adrenals, by using aldosterone, corticosterone, or a mixture of the two. Corticosterone at 2.5 mg/day caused a somewhat greater rate of blood pressure increase than occurred in rats retaining regenerating glands, but whereas the latter did not manifest thymus involution, hormone-treated animals did. At 1 mg/day there was a drop in blood pressure following adrenalectomy in rats with adrenal-regeneration hypertension, although not always to normotensive levels, and the characteristic hypotension of adrenalectomized rats was prevented. Rats given 100 μg/day of aldosterone following adrenalectomy maintained a continued rise of blood pressure, the rate not differing significantly from that seen in rats with continuing adrenal-regeneration hypertension. Such rats did not display thymus involution, and the blood pressure response was no greater when 1 mg/day of corticosterone was added to the regimen. It is concluded that if the profile of hypertension and failure to cause thymus involution are valid criteria for establishing the identity of the hormone(s) which cause adrenal-regeneration hypertension, aldosterone appears to qualify. Some reasons for doubting the reliability of these criteria and some of the difficulties encountered in attempting to compare quantitatively the effects of endogenously secreted hormone with exogenously administered hormone are given.
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Hall CE, Holland OB, Hall O. Influence of hydrochlorothiazide on fluid consumption, blood pressure, and organ changes in rats subjected to hypersalimentation or augmented hypersalimentation. J Transl Med 1968; 18:232-9. [PMID: 5648567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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116
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Fawzy KY, Fox JP, Ketler A, Brandt CD, Hall CE, Haraway AW. The virus watch program: a continuing surveillance of viral infection in metropolitan New York families. V. Observations in employed adults on etiology of acute upper respiratory disease and heterologous antibody response to rhinovirus. Am J Epidemiol 1967; 86:653-72. [PMID: 4295282 DOI: 10.1093/oxfordjournals.aje.a120774] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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117
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118
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O'Steen WK, Hall CE, Hall OS. Hypertension induced with hormones and 5-hydroxytryptophan. Arch Pathol 1967; 84:168-177. [PMID: 21936119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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119
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Hall CE, Holland OB, Hall O. Benign and malignant hypertension after adrenal enucleation in the rat. Relationship to salt intake, response to hydrochlorothiazide, and similarity to essential hypertension. J Exp Med 1967; 126:35-52. [PMID: 6027646 PMCID: PMC2138308 DOI: 10.1084/jem.126.1.35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Adrenal-enucleated, mononephrectomized rats given a high salt diet rapidly develop malignant hypertension, characterized by the presence of necrotizing vascular lesions in a number of organs and tissues. If a normal salt intake is provided, or if hydrochlorothiazide is given together with a high salt diet, there is, instead, the delayed onset of benign hypertension which either stabilizes or increases in intensity extremely slowly; Such animals display few, if any, pathologic vascular changes other than occasional focal glomerular hyalinization, show insignificant cardiac enlargement, and do not exhibit alterations in the serum sodium or potassium. Occasional animals behave atypically and develop malignant hypertension despite normal salt consumption, demonstrating that in susceptible rats excess salt is not essential to this disorder. Hydrochlorothiazide given to rats that imbibed distilled water postoperatively prevented hypertension entirely for 97 days, when one of eight rats developed mild hypertension and some others reached what is regarded as a prehypertensive range. It is concluded that adrenal regeneration provides a physiological milieu favorable to the development of benign hypertension, which is not, as a rule, manifest until regeneration is complete. Salt excess converts the response into one in which malignant hypertension begins during regeneration and worsens rapidly thereafter until death. The course and findings are compared with those of the benign and malignant phases of clinical essential hypertension, and the implications of the similarities are discussed.
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120
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Abstract
The antihypertensive activity of diazoxide was evaluated in rats with regenerating adrenal glands. The drug was given chronically in the drinking fluid, and also by subcutaneous injection at two intervals during the experiment. For a brief period diazoxide in the drinking fluid was replaced by hydrochlorothiazide. Diazoxide caused detectable sodium retention, despite which it reduced the intensity of hypertension and reduced the incidence, severity, and extent of the accompanying vascular lesions. The substitution of hydrochlorothiazide for diazoxide, or the subcutaneous administration of diazoxide to rats that were then consuming it in the drinking fluid, usually further depressed the blood pressure. It may thus be concluded that maximal blood pressure lowering effects of diazoxide were not achieved by oral ingestion, and that while the drug does afford a significant degree of protection against adrenal-regeneration hypertension it is less effective in this respect than hydrochlorothiazide, possibly because diazoxide causes sodium retention whereas hydrochlorothiazide promotes saluresis.
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121
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Hall CE, Holland OB, Hall O. Evolution of adrenal regeneration hypertension in rats with actively regenerating or fully regenerated glands. J Transl Med 1967; 16:488-95. [PMID: 6023791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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122
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Hall CE, Hall O. The comparative hypertensive activities of the acetates of D-aldosterone and deoxycorticosterone. Acta Endocrinol (Copenh) 1967; 54:399-410. [PMID: 6071361 DOI: 10.1530/acta.0.0540399] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
ABSTRACT
The hypertensive effect of the acetates of d-aldosterone and deoxycorticosterone was compared by injecting 0.125 mg of each twice daily in oil subcutaneously into unilaterally nephrectomized rats given 1% saline solution to drink. The two hormones had entirely comparable activity in respect to the enhancement of saline consumption, the development of hypertension and the magnitude of cardiac enlargement induced. Aldosterone treatment caused a much greater degree of renal hypertrophy and far more severe vascular lesions in the heart and kidney. It is suggested that both of these effects may reflect the superior ability of aldosterone to cause potassium excretion and therefore a more severe hypokaliaemia. Only aldosterone caused thymic involution, believed to be an indirect response, and impairment of body growth.
Under the circumstances of this experiment the hypertensive potency of aldosterone was at least as great as that of deoxycorticosterone, and the ability to bring about vascular damage far greater. Although it is recognized that this relationship might not obtain at all dose levels of the two steroids, it is suggested that the lesser activity usually ascribed to aldosterone as compared with DCA when the two are given in dosages calculated to cause an equivalent degree of sodium retention, may reflect the operation of variables such as absorption rate, enzymatic inactivation rate and hence the respective quantities in the circulation at any given time, rather than differences in the inherent potency.
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123
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Hall CE, Warin JF. Cervical Cytology. West J Med 1967. [DOI: 10.1136/bmj.1.5536.365-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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124
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Hall CE. Some contributions of Anton T. Boisen (1876-1965) to understanding psychiatry and religion. Bull Menninger Clin 1967; 31:42-53. [PMID: 5343177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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125
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Hall CE, Hall O. Hypertension following subcutaneous and intraperitoneal injections of polyvinyl alcohol and the effect of aldosterone. Can J Physiol Pharmacol 1967; 45:161-8. [PMID: 6030393 DOI: 10.1139/y67-016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Rats given subcutaneous or intraperitoneal injections of polyvinyl alcohol (PVA) for a month developed hypertension after discontinuance of injections. Aldosterone given for a week terminally to severely hypertensive animals neither exacerbated hypertension nor induced the eclamptic manifestations previously noted to occur after more prolonged subcutaneous PVA administration. It is concluded that eclamptic manifestations are not due to increased levels of endogenous salt-retaining steroids. Possible reasons are considered for the customary inability of rats given PVA intraperitoneally to develop hypertension during the course of injections although they readily do so thereafter.Intraperitoneal PVA administration caused the formation of medial and intimal foam cells in cardiac arteries, and an abundant display of giant cells in various organs and tissues. In contradistinction to the earlier findings in animals killed immediately after a course of injections, there was in this study, in which the rats were killed only when a considerable time had elapsed after PVA treatment, no substantial difference in the severity of hepatosplenomegaly between intraperitoneally and subcutaneously injected rats.
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126
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Hall CE, Hall O. Comparative effectiveness of glucose and sucrose in enhancement of hypersalimentation and salt hypertension. Proc Soc Exp Biol Med 1966; 123:370-4. [PMID: 5924472 DOI: 10.3181/00379727-123-31491] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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127
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Hall CE, Hall O. Effects of dextran on blood pressure, saline consumption, and organ structure of control and deoxycorticosterone acetate-treated rats. J Transl Med 1966; 15:1174-86. [PMID: 5947066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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128
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Hall CE, Hall O. Comparative ability of certain sugars and honey to enhance saline polydipsia and salt hypertension. Proc Soc Exp Biol Med 1966; 122:362-5. [PMID: 5980537 DOI: 10.3181/00379727-122-31135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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129
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Elveback LR, Fox JP, Ketler A, Brandt CD, Wassermann FE, Hall CE. The Virus Watch program: a continuing surveillance of viral infections in metropolitan New York families. 3. Preliminary report on association of infections with disease. Am J Epidemiol 1966; 83:436-54. [PMID: 4286697 DOI: 10.1093/oxfordjournals.aje.a120596] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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130
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Hall CE, Hall O. Hypertension and hypersalimentation. II. Deoxycorticosterone Hypertension. J Transl Med 1965; 14:1727-35. [PMID: 5842379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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131
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Abstract
Inactive four-ribosome polyribosomes, insensitive to ribonuclease, have the form of tight symmetrical squares and appear in feather cells during the early and intermediate periods of development. When, on the 13th day of incubation, the inactive polyribosomes become sensitive to ribonuclease and can then synthesize protein, the squares open up so that the four-ribosome polysomes are strung out in the configuration characteristic of functioning polysomes.
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132
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Hall CE. Electron Microscopy: Quantitative Techniques. Science 1964; 145:1467-9. [PMID: 17838709 DOI: 10.1126/science.145.3639.1467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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133
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Abstract
Hematologic studies of parabiotic rats indicate that in addition to pairs in which one twin exhibits anemia and the partner hyperemia (parabiosis intoxication), there are pairs in which an anemic or a hyperemic rat has a normal co-twin. The hematologic status of parabionts cannot accurately be deduced from their coloration, and hence visual categorization of pairs as normal or ‘intoxicated’ is unreliable. Death of one of the partners always causes a fatal anemia to develop in the previously normal twin in healthy pairs, and usually produces the same condition in the previously erythremic partner in intoxicated pairs. The findings are interpreted to mean that the hematologic inequalities of intoxicated pairs represents the effect of unequal transfusion, with one partner gaining blood at the expense of the other; and are thought to be inconsistent with the contention that the anemia of parabiosis intoxication is hemolytic in nature and the erythremia a sludging of erythrocytes resulting in interference with their negotiation of the capillary anastomosis.
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135
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Ogden E, Hall CE. Peripheral Circulation. Annu Rev Physiol 1949; 11:435-68. [DOI: 10.1146/annurev.ph.11.030149.002251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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136
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137
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Hall CE, Hauser EA, leBeau DS, Schmitt FO, Talalay P. Natural and Synthetic Rubber Fibers. Electron Microscope Studies. Rubber Chemistry and Technology 1944. [DOI: 10.5254/1.3546703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
Hevea rubber fibers suitable for observation in the electron microscope were prepared from thin films produced by spreading rubber solutions and dispersions on a water surface. Fibers of guayule, Cryptostegia, Neoprene, and Buna-S were prepared in a similar manner and studied with the electron microscope. Unvulcanized Hevea rubber was separated into sol and gel fractions. Electron micrographs of the sol fraction show fibers bearing many large nodules along their lengths. The spherical shape of many of the nodules is strongly suggestive of fluid properties. The gel fraction shows practically no nodules, but tends to form closely branched networks. The smallest fibers have a characteristically beaded appearance which may be related to the state of aggregation of the isoprene chains. When pale crepe or smoked sheet is worked on the mill, cross-linked networks of the gel fraction disappear, and the milled material takes on the appearance typical of the sol. Vulcanization of milled rubber in solution has the effect of producing cross-linked networks of fine fibers similar to those from the gel fraction. Unvulcanized and vulcanized compounds containing carbon black were examined. From the location and distribution of the carbon in rubber particles, films, and fibers, suggestions are offered concerning the nature of the reënforcement phenomena.
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Affiliation(s)
- C. E. Hall
- 1Massachusetts Institute of Technology, Cambridge, Mass
| | - E. A. Hauser
- 1Massachusetts Institute of Technology, Cambridge, Mass
| | - D. S. leBeau
- 1Massachusetts Institute of Technology, Cambridge, Mass
| | - F. O. Schmitt
- 1Massachusetts Institute of Technology, Cambridge, Mass
| | - P. Talalay
- 1Massachusetts Institute of Technology, Cambridge, Mass
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Selye H, Hall CE, Rowley EM. Malignant Hypertension Produced by Treatment with Desoxycorticosterone Acetate and Sodium Chloride. Can Med Assoc J 1943; 49:88-92. [PMID: 20322846 PMCID: PMC1827836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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140
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