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King DJ, Griffiths K, Hall CE, Cooper NC, Morrison DJ. Effect of the CURB campaign on barbiturate prescribing in Northern Ireland. THE JOURNAL OF THE ROYAL COLLEGE OF GENERAL PRACTITIONERS 1980; 30:614-8. [PMID: 7452601 PMCID: PMC2159744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Barbiturate prescribing in general practice in Northern Ireland was monitored from computer data on prescription pricing for the years 1966 to 1979, and subjected to two methods of statistical analysis.Over the last decade a very marked decline in the prescribing of barbiturate hypnotics was accompanied by progressive decreases in barbiturate anti-epileptic and combination product utilization. During the 1975 to 1977 CURB campaign there was a statistically significant greater decrease in the total quantity of barbiturate hypnotics prescribed, but the downward trend in the numbers of prescriptions written was not significantly greater than before the campaign. The main effect of CURB, therefore, was to reduce the average quantity of barbiturate per prescription. The changes in barbiturate combination product prescribing between the CURB years were consistently large, whilst anti-epileptic barbiturate prescribing decreased less significantly towards the end of the campaign.
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Smith CB, Charette RP, Fox JP, Cooney MK, Hall CE. Lack of effect of oral ribavirin in naturally occurring influenza A virus (H1N1) infection. J Infect Dis 1980; 141:548-54. [PMID: 7373088 DOI: 10.1093/infdis/141.5.548] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
A double-blind placebo-controlled trial of ribavirin was conducted in 97 young adult males naturally infected with influenza virus similar to A/Brazil/11/78 (H1N1). Ribavirin was given orally at a dose of 1,000 mg/day for five days beginning within 24 or 48 hr after onset of clinical influenza. The clinical signs and symptoms of influenza and quantitative viral shedding were the same in ribavirin- and placebo-treated groups. Ribavirin treatment was associated with significantly fewer fourfold or greater rises in antibody to influenza A viral antigen by the complement-fixation test, while rises in hemagglutination-inhibiting antibody titers occurred with equal frequency in both groups. The ribavirin-treated group experienced significant increases in bilirubin and in reticulocyte counts after onset of therapy.
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Hall CE, Nasseth D. Factors affecting the acute pressor response to bolus cadmium injections. Physiol Behav 1980; 24:373-80. [PMID: 7375555 DOI: 10.1016/0031-9384(80)90101-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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54
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Hall CE, Gomez-Sanchez CE, Holland OB, Nasseth D. Influence of 19-nor-deoxycorticosterone on blood pressure, saline consumption, and serum electrolytes, corticosterone, and renin activity. Endocrinology 1979; 105:600-4. [PMID: 157270 DOI: 10.1210/endo-105-3-600] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Young, unilaterally nephrectomized, female Sprague-Dawley rats were given daily sc injections of 19-nor-deoxycorticosterone acetate (19-nor-DOCA) in oil at a dosage of 100 micrograms/day for 21 days and twice that amount for a further 11 days. One group drank distilled water and another drank 1% NaCl solution. Comparable control groups received oil injections. Another group received DOCA at the same steroid dosage and drank saline. Both 19-nor-DOCA-treated groups rapidly became hypertensive and developed cardiac hypertrophy, as did those given DOCA and saline. Saline consumption was greater in rats receiving 19-nor-DOCA, than in those given DOCA. Rats injected with 19-nor-DOCA and given water to drink showed enhanced growth and developed thymus enlargement and displayed hypokalemia and a reduction in both serum renin activity and corticosterone concentration. Plasma sodium concentration was not affected by any form of treatment. Clearly, 19-nor-DOCA is a potent mineralocorticoid and hypertensogenic agent. Since the parent steroid is known to be present abundantly in the urine of rats with regenerating adrenal glands, although circulating amounts have not yet been ascertained in that circumstance, it may be etiologically involved in adrenal regeneration hypertension, which such rats are prone to develop.
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Dunn HO, McEntee K, Hall CE, Johnson RH, Stone WH. Cytogenetic and reproductive studies of bulls born co-twin with freemartins. JOURNAL OF REPRODUCTION AND FERTILITY 1979; 57:21-30. [PMID: 574547 DOI: 10.1530/jrf.0.0570021] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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56
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Hall CE, Nasseth D. Effect of cadmium on salt hypertension in rats. JOURNAL OF ENVIRONMENTAL PATHOLOGY AND TOXICOLOGY 1979; 2:789-97. [PMID: 422935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The suggestion that cadmium-induced hypertension in rats might be due to renal sodium retention, known to result from Cd treatment, was examined. Young female rats were given a regimen of intraperitoneal cadmium treatments reported to cause hypertension reliably within a month. They were sensitized to the development of salt hypertension by removal of one kidney and then given 1 percent saline solution to drink. Over a five-week period, experimental animals consistently drank more saline than controls, despite which fewer of them became hypertensive, with the result that the average systolic pressure of controls finally reached the hypertensive range, whereas the experimental group remained normotensive. Cadmium treatment had no detectable effect on growth, the hemogram, serum Na and K, or the weight of liver, kidney, heart, spleen, thymus, or adrenal glands. There was thus no evidence that cadmium caused any adverse constitutional or hemodynamic effects, but it appeared to retard the development of salt hypertension. The results do not support the suggestion that the hypertensive effects of cadmium are modulated by sodium-retaining influences on the kidney.
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57
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Hall CE, Nasseth D. Blood pressure in conscious and anesthetized adrenal-enucleated Sprague-Dawley and Wistar-Furth rats. Can J Physiol Pharmacol 1978; 56:1036-40. [PMID: 743620 DOI: 10.1139/y78-165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Systolic blood pressure was measured weekly in conscious and in anesthetized female Sprague-Dawley (SD) and Wistar-Furth (W/Fu) rats following adrenal enucleation, unilateral nephrectomy, and the imposition of a high salt intake. SD rats quickly developed adrenal-regeneration hypertension (ARH) which progressed rapidly, and was identifiable in both the conscious and the anesthetized state. W/Fu rats slowly developed mild ARH, which, with a single exception, was identifiable only in conscious animals; the arterial pressures were within the normotensive range under anesthesia. The depressor effect of ether was also greater in adrenal-enucleated W/Fu than in similarly prepared SD rats, and in hypertensives than in normotensives. It is concluded that blood pressure measurements taken under anesthesia may not be representative of the true resting blood pressures: this is likely to be a particularly crucial problem in identifying early hypertension under circumstances and in rat strains highly susceptible to the depressor effects of ether.
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Hall CE, Nasseth D, Hall O. Adrenal-regeneration hypertension in Wistar-Furth rats. Can J Physiol Pharmacol 1978; 56:591-5. [PMID: 688082 DOI: 10.1139/y78-094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The susceptibility of young virgin female Wistar-Furth (W/Fu) rats to adrenal-regeneration hypertension (ARH) was evaluated by comparing the blood pressure of adrenal-enucleated, mononephroadrenalectomized, salt-loaded rats with that of similarly treated rats having one intact adrenal over a period of 5 weeks. Hypertension began to appear in animals of the first group by the 3rd week, affected all of them by the 4th week, and increased in severity during the 5th week. Control rats remained normotensive during the study. Hypertensive rats developed marked enlargement of the heart and kidney, which frequently displaced myocardial scarring and nephrosclerosis, respectively. These studies do not support the contention that W/Fu rats display heightened resistance to ARH to which, in fact, they appear to be just as susceptible as are most other strains.
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Hall CE, Gomez-Sanchez CE, Holland OB, Nasseth D, Hall O. Experimental hypertension and other responses to 18-hydroxy-deoxycorticosterone treatment in the rat. Endocrinology 1978; 103:133-40. [PMID: 744064 DOI: 10.1210/endo-103-1-133] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Young female unilaterally nephrectomized, salt-loaded, Sprague-Dawley rats were treated with 200 microgram or 1 mg 18-hydroxy-deoxycorticosterone-21-acetate (18-OH-DOCA) in oil daily, and a group of kidney-intact animals on a normal salt intake was given 2 mg/day. The hormone was not found to increase saline consumption, increase urinary potassium or kallikrein excretion, or depress serum renin activity or potassium concentration. Slight hypertension did develop at 3 weeks in salt-loaded rats on the lowest dose, but this was neither increased by higher dosage or longer treatment, nor reflected by increased heart or kidney weight. The effect of 40-mg pellet implantation of DOCA and 18-OH-DOCA was then compared in unilaterally nephrectomized, salt-loaded, female Fischer 344 rats. The former caused increased saline consumption, hypertension, hypokalemia, and heart and kidney enlargement, whereas 18-OH-DOCA did not. Thus, the hypertensogenic potency of 18-OH-DOCA is, at best, a reflection of its known, very weak, mineralocorticoid activity.
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Buergelt CD, DeLisle G, Hall CE, Merkal RS, Duncan JR. In vitro lymphocyte transformation as a herd survey method for bovine paratuberculosis. Am J Vet Res 1978; 39:591-5. [PMID: 417649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The lymphocyte-transformation (LT) test was evaluated for its potential application as a field test for bovine paratuberculosis. Using a whole blood technique, samples from 3 consecutive collection periods were subjected to 3 mycobacterial antigens and to phytohemagglutinin. The results obtained from LT were compared with conventional serologic and cultural methods. A positive LT response to johnin purified-protein derivative (PPD) or avian PPD (or both) was noted in 40% to 60% of the animals tested. The complement-fixation test yielded 4% to 6.7% positive results, the immunodiffusion test between 1.2% and 1.4%, and the direct fecal culture between 2.4% and 6%. The mean of the stimulation indices of all positively responding animals was highest with johnin PPD. Specific stimulation to mammalian PPD occurred between 2.4% and 6% of the animals. The efficacy of the LT test for determining the incidence of infection with Mycobacterium paratuberculosis is discussed.
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Duncan JR, Hall CE, de Lisle C. Johne's disease and the practitioner. THE CORNELL VETERINARIAN 1978; 68 Suppl 7:179-88. [PMID: 630894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Mycobacterium paratuberculosis infections and the disease states resulting in cattle are defined as spectral in nature. There is a spectrum of immunological response which complicates tests based on this. It is recommended that initial diagnosis of suspicious clinical cases be confirmed by direct fecal smears and a serological test such as immunodiffusion. Herd evaluation requires the application of fecal cultures plus immunodiffusion. Control requires rigid management hygiene measures, surveillance of the herd status and post mortem confirmation of salvaged animals.
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Buergelt CD, Hall CE, Merkal RS, Whitlock RH, Duncan JR. Lymphocyte transformation: an aid in the diagnosis of paratuberculosis. Am J Vet Res 1977; 38:1709-15. [PMID: 412443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Hall CE, Nasseth D, Hall O. Evidence for variation in blood pressure during the day in normotensive and salt-hypertensive rats. Life Sci 1977; 21:199-203. [PMID: 886917 DOI: 10.1016/0024-3205(77)90302-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
The following findings were made from observations of adenovirus (AV) infections in Seattle VW families, 1965-1969, which extended the 1961-1965 New York VW studies: That infections are predominantly enteric, may be abortive or invasive and followed by persistent intermittent excretion was confirmed. That such excretion is most characteristic of types 1, 2, 3 and 5 viruses may explain why these types were usually endemic. However, since observed duration of excretion was not increased despite a longer average observation period, persistent excretion appears not to continue indefinitely and generation-to-generation transmission now seems improbable. Unilike New York, alternate cycling of types 1 and 2 viruses was not seen. Among homotypic susceptibles, infection rates for the endemic types were highest in infants (greater than 90% for types 1 and 2), decreased with age in older children but increased in parents, perhaps because of closer contact with infants. Development of serum neutralizing antibody was most frequent (about 90%) after types 1 and 2 infection; in all cases, titers decayed over time. While delayed virus spread related to persistent intermittent excretion did occur, spread closely following new or renewed (after larger than or equal to 3 months) excretion was more important. Sibling introducers were more effective spreaders than infants, and duration of excretion was more important than mode. These data indicate that homotypic immunity is 85% protective against infection. A protective effect of heterotypic immunity could not be shown. Illness (chiefly respiratory and often febrile) was associated with 49% of infections in susceptibles and with 65% when respiratory shedding occurred. The contribution of AV to all infectious illness, based on virus-positive infections only, was 5% in infants and 3% in the 2-4-year age group; for febrile illness, the corresponding contributions were about 10% and 5%. Inclusion of infections discovered only be serology (49% of all infections) would greatly increase the contribution of AV to illness.
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Hall CE, Ayachi S, Hall O. Delayed onset and reduced severity of adrenal-compression hypertension in rats treated with digitoxin. CLINICAL SCIENCE AND MOLECULAR MEDICINE. SUPPLEMENT 1976; 3:159s-162s. [PMID: 1071596 DOI: 10.1042/cs051159s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
1. Bilateral compression of adrenal glands combined with unilateral nephrectomy and followed by imposition of a high sodium chloride intake caused severe hypertension in all rats, accompanied by enlargement of the heart, kidneys and adrenal glands, atrophy of the thymus and severe nephrosclerosis. 2. Digitoxin treatment delayed the onset, reduced the incidence and ameliorated the magnitude of the hypertensive response in such rats; it also reduced the degree of cardiac hypertrophy, the severity of nephrosclerosis and completely prevented enlargement of the adrenals and kidneys or atrophy of the thymus.
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Hall CE, Hall O. Comparative serum potassium and sodium concentrations of rat blood obtained by different methods. PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE. SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE (NEW YORK, N.Y.) 1976; 153:233-5. [PMID: 995952 DOI: 10.3181/00379727-153-39517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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68
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Fox JP, Rainey HS, Hall CE, Ray CG, Patterson MJ. Rubella vaccine in postpubertal women. Experience in Western Washington State. JAMA 1976; 236:837-43. [PMID: 947264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Nearly two thousand nonimmune, postpubertal females given rubella vaccine in western Washington state in 1970 to 1974 were followed up for acute reactions, inadvertent pregnancy onset, and (776 women) seroresponse. Low-level prevaccination immunity appears to explain most of the apparent vaccine failure (11.6%). The 27 vaccine-complicated pregnancies identified resulted in 17 apparently normal infants (nine from nonimmune mothers). The remaining ten were terminated by abortion (four in nonimmune women), but no abortus yielded rubella virus. Frequency of post-vaccination complaints (largely joint-related) varied with age (higher in those over 25 years), with vaccine (higher after HPV-77-DE-5 than after Cendehill strain virus), with stage of menstrual cycle when vaccine was given, and with method of contraception.
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Gomez-Sanchez C, Holland OB, Hall CE, Ayachi S. On the mineralocorticoid and hypertensogenic properties of 16beta-hydroxy-dehydroepiandrosterone. EXPERIENTIA 1976; 32:1067-9. [PMID: 182526 DOI: 10.1007/bf01933976] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Dosages of either 1 or 2 mg daily of 16beta-hydroxy-dehydroepiandrosterone, given to mononephrectomized, salt-loaded female rats, had no detectable effect upon saline consumption, blood pressure, kallikrein excretion or heart and kidney weight. Its alleged mineralocorticoid properties, as judged by these criteria, were not demonstrable.
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Hall CE, Ayachi S, Hall O. Sodium excretory response to acute salt loading and induction of adrenal-regeneration hypertension in Fischer 344 rats. Life Sci 1976; 19:175-82. [PMID: 957864 DOI: 10.1016/0024-3205(76)90388-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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McDonald TJ, Foote RH, Drost M, Lu L, Patrascu M, Hall CE. Preparation of teaser bulls and steriods-implanted steers and their effectiveness in detecting estrus. Theriogenology 1976; 6:51-60. [PMID: 976588 DOI: 10.1016/0093-691x(76)90188-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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72
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Corbeil LB, Hall CE, Lein D, Corbeil RR, Duncan JR. Immunoglobulin classes in genital secretions of mycoplasma-infected and normal heifers. Infect Immun 1976; 13:1595-600. [PMID: 971941 PMCID: PMC420806 DOI: 10.1128/iai.13.6.1595-1600.1976] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Immunoglobulin levels were studied in the genital secretions of seven heifers which had been bred to a bull infected with Mycoplasma agalactiae var. bovis and three heifers bred to a noninfected bull. The median immunoglobulin G (IgG)/IgA ratio ratio for vaginal secretions was 0.7, for cervical secretions 21.9, and for uterine secretions 13.0. This indicated that IgA was the mahor immunoglobilin class in the most superficial portion of the reproductive tract and that IgG was the major class in secretions of the deeper tract. The response to infection was studied by comparing animals infected with mycoplasma and noninfected controls. The IgG/IgA ratios were significantly lower in infected animals than in controls, apparently due to high IgA values in infected animals. Low mycoplasmal agglutinin titers were detected in secretions of three of the infected animals, but there appeared to be no relationship between agglutinin titers and histopathological lesions or between agglutinin titers and IgG/IgA ratios in this group of animals.
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Ayachi S, Hall CE, Holland OB, Gomez-Sanchez C. Effect of deoxycorticosterone acetate and 16beta-hydroxy-dehydroepiandrosterone on blood pressure and plasma renin activity of rats. Exp Biol Med (Maywood) 1976; 152:218-20. [PMID: 132667 DOI: 10.3181/00379727-152-39364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Intact female Sprague-Dawley rats were given daily injections of either 3.125 mg of deoxycorticosterone or 5.0 mg of 16beta-hydroxy-dehydroepiandrosterone, calculated from the activities reported for each to be equivalent mineralocorticoid dosages. The former caused hypertension, cardiorenal enlargement, increased urine output and depressed PRA. Treatment with 16beta-OH-DHEA had no such effect, raising questions regarding its classification as a mineralocorticoid.
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Ayachi S, Hall CE. Protective effect of digitoxin in adrenal-compression hypertension. Exp Biol Med (Maywood) 1976; 152:242-5. [PMID: 132668 DOI: 10.3181/00379727-152-39370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bilateral compression of the adrenal glands combined in mononephrectomy and followed by the imposition of a high NaC1 intake resulted in severe hypertension in all rats so treated. It was accompanied by enlargement of the heart, kidneys, and adrenal glands, atrophy of the thymus, and the occurrence of severe nephrosclerosis. Digitoxin treatment delayed the onset, reduced the incidence, and ameliorated the magnitude of the hypertensive response in such animals; it also reduced the degree of cardiac hypertrophy and the severity of nephrosclerosis and completely prevented enlargement of the adrenals and kidneys and atrophy of the thymus.
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75
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Gartland P, Schiavo J, Hall CE, Foote RH, Scott NR. Detection of estrus in dairy cows by electrical measurements of vaginal mucus and by milk progesterone. J Dairy Sci 1976; 59:982-5. [PMID: 1270655 DOI: 10.3168/jds.s0022-0302(76)84307-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Electrical resistance (ohms) of mucus were analyzed in 20 postpartum Holstein cows by use of a probe inserted into the anterior vagina every other day for 30 days. Composite milk samples were taken on the same day, and progesterone was determined by radioimmunoassay. Cows were observed twice daily for standing estrus and reproductive organs palpated weekly per rectum (rectal palpation). Fifteen cows which were cycling showed increasing progesterone 6 to 7 days after the onset of estrus with values of 8.1 to 10.0 ng progesterone/ml milk on days 10 to 17. Concentrations had declined rapidly 2 days before onset of the next estrus. Progesterone in milk was affected by cow and by day of the cycle. Electrical resistance followed a similar cyclical pattern, but variability was large and only cows differed. The correlation between milk progesterone and mucus resistance was .22. Progesterone concentrations for four cows with follicular cysts fluctuated randomly with a mean of 2.6 ng/ml. Mean resistance of vaginal mucus was 44 omega for both cycling and cystic cows, indicating that a single measurement of electrical resistance every 2nd day was unreliable in distinguishing physiological states. One cow had high progesterone in milk on days 19 to 25 and was diagnosed pregnant by rectal palpation 3 wk later. Cows were not seen in estrus 28% of the time when milk progesterone and rectal palpation indicated they were in the follicular phase of the estrous cycle and were cycling.
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