751
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Kirchmeier O, Weiss G, Kiermeier F. [The influence of different phosphates on the flow properties of processed cheeses (author's transl)]. ZEITSCHRIFT FUR LEBENSMITTEL-UNTERSUCHUNG UND -FORSCHUNG 1978; 166:212-20. [PMID: 676526 DOI: 10.1007/bf01126546] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Processed cheese was manufactured with different types of phosphates (P1 monophosphate to P4 tetrapolyphosphate) and by various techniques. The limiting viscosity numbers of sodium casein and the casein of processed cheese were determined and the axial ratio calculated. The axial ratio of processed cheese protein was a/b=20,0 and that of sodium casein 10,0 resp. We deduce that the apparent increase of the axial ratio is caused by the depolymerization of casein caused by emulsifying salts. The flow curves of processed cheese were analysed. There is good agreement with the power law of Ostwald tau=k.Dn. Therefore processed cheeses are characterized as pseudoplasts. The influence of melting salts on the flow properties can be described by a differing emulsifying effect (P1 less than or equal P4). Temperature, concentration and salt effects are discussed for the viewpoint of correlation between aggregation-desaggregation processes and dehydration and hydration of casein.
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752
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Hechtman L, Weiss G, Perlman T. Growth and cardiovascular measures in hyperactive individuals as young adults and in matched normal controls. CANADIAN MEDICAL ASSOCIATION JOURNAL 1978; 118:1247-50. [PMID: 647543 PMCID: PMC1818681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Height, weight, pulse rate and blood pressure were measured in 65 hyperactive individuals 17 to 24 years of age who had not taken stimulant medication during childhood and in 39 control subjects matched for age, sex, intelligence quotient and socioeconomic class. There were no significant differences in the physiologic measures between the two groups. Both the hyperactive and the control subjects seemed to have reached their growth plateau by the age of 17 to 24 years, though the exact time the plateau was reached was not determined. Hyperactive individuals who had taken phenothiazines during childhood were significantly taller (P less than 0.046) than those who had never taken medication. This finding may reflect stimulation of growth by phenothiazines at a critical period of growth, but more detailed reserach on this finding is necessary. The physiologic measures obtained in the hyperactive individuals who had never taken stimulant medication provide an important baseline against which to assess values in hyperactive individuals who have taken such medication.
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753
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O'Byrne EM, Flitcraft JF, Sawyer WK, Hochman J, Weiss G, Steinetz BG. Relaxin bioactivity and immunoactivity in human corpora lutea. Endocrinology 1978; 102:1641-4. [PMID: 744044 DOI: 10.1210/endo-102-5-1641] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Relaxin-like activity in extracts of corpora lutea (CL) from pregnant and non-pregnant women was determined by radioimmunoassay and by guinea pig pubic symphysis palpation assay. The biologically determined activity paralled the immunoactivity of extracts of CL of pregnancy. The relaxin content of CL of non-pregnant women was too low for detection by the bioassay.
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754
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Simberkoff MS, Moldover NH, Weiss G. Bactericidal and opsonic activity of cirrhotic ascites and nonascitic peritoneal fluid. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1978; 91:831-9. [PMID: 347014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BA and OA of sera and uninfected ascitic fluid from patients with alcoholic cirrhosis were assayed against gram-negative enteric bacilli. This was compared with BA and OA in normal serum and in peritoneal fluid obtained at laparoscopy or laparotomy from noncirrhotic patients. Cirrhotic sera showed significantly reduced BA and OA against one of the organisms tested, Serratia marcescens. It had reduced OA but normal BA against E. coli. Ascitic fluid was markedly deficient in BA and OA against all strains tested when compared to both cirrhotic sera and nonascitic peritoneal fluid. Immunoglobulin and complement concentrations in cirrhotic ascites were reduced. Ascites did not inhibit the BA or OA of normal serum. However, replacement experiments suggested that the diminished activity of ascites was largely the result of its reduced complement concentration. The demonstrated deficit in both BA and OA of ascites may be a factor in the frequency of spontaneous enteric bacillary peritonitis in the cirrhotic patient.
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755
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Hechtman L, Weiss G, Metrakos K. Hyperactive individuals as young adults: current and longitudinal electroencephalographic evaluation and its relation to outcome. CANADIAN MEDICAL ASSOCIATION JOURNAL 1978; 118:919-21, 923. [PMID: 647563 PMCID: PMC1818222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In a 10-year follow-up study electroencephalograms (EEGs) of 31 hyperactive and 27 matched control subjects of mean ages 19.17 and 18.59 years respectively showed no significant differences in any of the features assessed. Sequential EEGs, available for only the hyperactive subjects, suggested that a much greater proportion were normal at the 10-year follow-up assessment than at the 5-year follow-up assessment and that the normalization tended to take place mainly in the second 5-year period. This supports the hypothesis that EEG abnormalities of hyperactive persons are those of an immature pattern that tends to normalize with age. Correlation between EEG findings at the 10-year follow-up assessment and global outcome measures was not significant. Initial and 5-year EEGs also failed to predict global outcome at the 10-year follow-up assessment.
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756
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Weiss G. Modular nursing means involvement. HEALTH CARE WEEK 1978; 1:10. [PMID: 10306845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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757
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Campbell SB, Schleifer M, Weiss G. Continuities in maternal reports and child behaviors over time in hyperactive and comparison groups. JOURNAL OF ABNORMAL CHILD PSYCHOLOGY 1978; 6:33-45. [PMID: 632458 DOI: 10.1007/bf00915780] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Maternal reports, observations of nursery and elementary school behavior, and teacher ratings of problems were available for hyperactive and control children who had participated in a longitudinal study. This paper examines consistencies in maternal reports and child behaviors over time, and their relationship to teacher ratings in elementary school. Maternal reports of infant sleep difficulties were related to maternal ratings of hyperactivity at 4 1/2 and 6 1/2 years. Maternal ratings of activity at 4 1/2 were predictive of 6 1/2-year ratings of hyperactivity and conduct problems. In addition, behavior in a research nursery at 4 1/2 predicted teacher ratings of problems and classroom behavior in grade two. Hyperactive preschoolers who left the table most during structured activities were more often out-of-seat and off-task in school. Controls who were more aggressive in the nursery were more disruptive in the classroom. These data indicate continuities in both maternal reports and child behaviors.
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758
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Hochman J, Weiss G, Steinetz BG, O'Byrne EM. Serum relaxin concentrations in prostaglandin- and oxytocin-induced labor in women. Am J Obstet Gynecol 1978; 130:473-4. [PMID: 629294 DOI: 10.1016/0002-9378(78)90292-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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759
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Beneking M, Schmidt H, Weiss G. Subcellular distribution of a factor inactivating tyrosine aminotransferase. Study of its mechanism and relationship to different forms of the enzyme. EUROPEAN JOURNAL OF BIOCHEMISTRY 1978; 82:235-43. [PMID: 23290 DOI: 10.1111/j.1432-1033.1978.tb12016.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The subcellular distribution of a tyrosine aminotransferase inactivating factor in rat liver has been investigated. Most of its activity is associated with plasma membranes, with minor amounts in mitochondria and endoplasmatic reticulum. The factor is also found in kidney and inactivates the enzyme reversibly in presence of cysteine, most likely by modification of -SH groups. ATP counteracts this inactivation only, when crude enzyme extracts are inactivated by purified subcellular fractions or when the purified enzyme is inactivated in presence of liver or kidney cortex homogenates. The relationship of this inactivation to reported different forms of the enzyme has been investigated. Form I of three different forms, that can be obtained by hydroxyl-apatite chromatography, is readily inactivated, form III can be partly converted to form I by incubation in presence of purified plasma membranes. The relationship of these findings to a possible multistep mechanism in the turnover of the enzyme discussed.
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760
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Goldsmith LT, Hochman JA, Weiss G. Effect of human placental lactogen upon the human corpus luteum of late pregnancy. Gynecol Obstet Invest 1978; 9:210-8. [PMID: 35449 DOI: 10.1159/000300986] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
To acertain whether human placental lactogen (HPL) functions as a luteotropin during pregnancy in humans, studies were performed to determine if receptors for HPL are present in cells of the human corpus luteum of late pregnancy. Preparations of 125I-HPL which demonstrated specific binding to late pregnant rabbit mammary gland cell homogenates showed specific binding of less than 2.5% to homogenates of human corpora lutea of late pregnancy. These studies indicate that HPL is not luteotropic at this stage of pregnancy in humans. The action of HPL upon the corpus luteum appears to vary considerably according to species.
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761
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Wan LS, Weiss G, Ganguly M. Pituitary response to LHRH stimulation in women on oral contraceptives. Contraception 1978; 17:1-7. [PMID: 342187 DOI: 10.1016/0010-7824(78)90054-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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762
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Weiss G, O'Byrne M, Hochman JA, Goldsmith LT, Rifkin I, Steinetz BG. Secretion of progesterone and relaxin by the humancorpus luteum at midpregnancy and at term. Obstet Gynecol 1977; 50:679-81. [PMID: 927758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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763
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Weiss G, Schmidt C, Kleinberg DL, Ganguly M. Positive feedback of oestrogen on LH secretion in women in neuroleptic drugs. Clin Endocrinol (Oxf) 1977; 7:423-7. [PMID: 338207 DOI: 10.1111/j.1365-2265.1977.tb03352.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The effect of a-adrenergic and dopaminergic blockade on the ability of pituitary-hypothalamic axis to produce an LH surge in response to oestrogen, was studied in eleven women treated with the neuroleptic agents haloperidol, fluphenazine or chlorpromazine. Seven women on no medication were controls. 6.6 mg of oestradiol benzoate (OB) was injected i.m. after control serum was obtained and daily serum samples were obtained for four additional days. Sera were assayed for total oestrogens, LH, FSH and prolactin. Six of seven women in the control group and eight of eleven women treated with neuroleptic agents had LH surges to OB challenge. The mean prolactin of the treated women was 33.1 +/- 3.6(SEM) ng/ml and the mean prolactin of the controls was 14.9 +/- 1.5(SEM) ng/ml, P less than 0.005). Elevated levels of circulating prolactin did not prevent an LH surge to OB challenge. These results indicate that even in subjects with catecholamine blockade, an LH surge can be induced. This contrasts to results obtained in rats and suggests that the control mechanism of LH surge production differs in rodents and humans.
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764
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Spurny KR, Baumert HP, Weiss G, Opiela H. [Investigations on the carcinogenic burden by air pollution in man. XVI. Formation of combined carbon black and benzo(a)pyrene aerosol (author's transl)]. ZENTRALBLATT FUR BAKTERIOLOGIE, PARASITENKUNDE, INFEKTIONSKRANKHEITEN UND HYGIENE. ERSTE ABTEILUNG ORIGINALE. REIHE B: HYGIENE, PRAVENTIVE MEDIZIN 1977; 165:139-73. [PMID: 595972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Two methods for the preparation of carbon black aerosols have been investigated: incomplete combustion of acetylene, acetylene + benzene and other hydrocarbons as well as a "resublimation" of amorphous carbon. The first method was developed for generating soot aerosols in animal experiments, but the latter method needs more basic investigation. Using radioactive acetylene and benzene the produced soot aerosol could be labelled by 14C. Benzo(a)pyrene aerosol was prepared by means of a vapour condensation and was also radioactive labelled. With a combination of both generators, a combined carbon black and benzo(a)pyrene aerosol was prepared. The benzo(a)pyrene amounts bound to the soot were in the range of from 1 ng to 50 microgram per 1 mg soot. Experiments dealing with adsorption and desorbtion of benzo(a)pyrene on soot in the gas phase have shown, that benzo(a)pyrene is relatively tightly adsorbed and cannot be easily or completely desorbed.
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765
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Kiermeier F, Weiss G, Behringer G, Miller M. [On the presence and the content of aflatoxin M in commercial cheese samples (author's transl)]. ZEITSCHRIFT FUR LEBENSMITTEL-UNTERSUCHUNG UND -FORSCHUNG 1977; 163:268-71. [PMID: 857498 DOI: 10.1007/bf02425358] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Between May 10 and August 9 1976, a total of 197 commercial cheese samples were tested on their aflatoxin M1 content; 136 samples (69%) were positive. The highest value was at 0.23 mug/kg, the average value of all positive samples was at 0.09 mug/kg. In more than half of the positive samples (54%), only traces of aflatoxin M1 could be detected, 21% contained up to 0.1 mug/kg and 14% more than 0.1 mug/kg. In soft cheese definitely less aflatoxin was found (57% positive samples) than in other cheese varieties (83--85% positive samples). Supplemental feeding of concentrates during spring season and pasture grazing of dairy cows resulted in more respectively less aflatoxin-positive cheese samples. This was especially true in soft cheese. The other cheeses with longer ripening periods showed the same effect, however, less pronounced with a clear lag phase. Inspite of many positive identity reactions on aflatoxin M1, a routine control of cheeses so far cannot be recommended because of the negative results on mass spectrometry.
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766
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Kiermeier F, Weiss G, Behringer G, Miller M, Ranfft K. [On the presence and the content of aflatoxin M1 in milk shipped to a dairy plant (author's transl)]. ZEITSCHRIFT FUR LEBENSMITTEL-UNTERSUCHUNG UND -FORSCHUNG 1977; 163:171-4. [PMID: 855496 DOI: 10.1007/bf01459851] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Between March 4 and April 15, 1976, the aflatoxin M1 content of milk shipped to a dairy plant was investigated. Out of 419 samples, 79 (19%) were positive. 33% of these samples showed values of 0.05--0.1 microng/1, 38% of more than 0.1 microng/1 and the highest value was at 0.54 microng/1. Other aflatoxins were not found. From samples of milk producers showing positive reactions, feed samples (n = 105) were taken, 45 of which (43%) were also positive. 40% of the positive samples contained up to 20 microng/kg, 36% were in the range between 20--50 microng/kg and the highest values were at 280 resp. 300 microng/kg, especially in mixed feed. Out of these samples, 47% (DLG Standard IV) resp. 36% (DLG Standard III) were higher than the tolerated maximum level of 20 microng/kg. There is a qualitative relationship between the aflatoxin M1 content in milk and the aflatoxin B1 content in feed. In 61 cases where milk samples were positive, in 41 feed samples (67%) aflatoxin B1 was detected.
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767
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Hitchcock PJ, Rutovitz IJ, Dando RV, Eathorne AJ, Weiss G. A multicentre trial of perhexiline maleate in the treatment of angina pectoris. CURRENT THERAPEUTIC RESEARCH 1977; 21:36-42. [PMID: 401710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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768
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Hochman J, Ganguly M, Weiss G. Induction of an LH surge with estradiol benzoate in a patient with incomplete testicular feminization syndrome. Obstet Gynecol 1977; 49:17-9. [PMID: 831170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A 31-year-old patient with incomplete testicular feminization syndrome characterized by a 46, XY karyotype in a phenotypic female with absent müllerian structures, marked clitoromegaly, testes and wolffian duct structures, partial labioscrotal fold fusion, and male levels of circulating androgens is described. She was challenged with estradiol benzoate (EB) to simulate the preovulatory surge of estradiol seen in cycling women. This EB challenge resulted in a negative feedback response for FSH but an LH surge similar to that induced with EB in cycling women. This suggests that in the incomplete testicular feminization syndrome there is hypothalamic or pituitary resistance to the blocking effects of androgens on LH surge production.
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769
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Abstract
Plasma samples from peripheral and ovarian veins were obtains from women at cesarean section. A peptide that immunologically cross-reacts with a specific antiserum to porcine relaxin is present in all samples. Its concentration is four times higher in the ovarian vein draining the ovary, which contains the corpus luteum of pregnancy, than in either the peripheral vein or the contralateral ovarian vein. Secretion of ovarian relaxin correlates with secretion of ovarian progesterone, thus providing another index of luteal function.
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770
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Weiss G, Butler WR, Dierschke DJ, Knobil E. Influence of suckling on gonadotropin secretion in the postpartum rhesus monkey. PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE. SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE (NEW YORK, N.Y.) 1976; 153:330-1. [PMID: 825871 DOI: 10.3181/00379727-153-39539] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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771
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Hechtman L, Weiss G, Finklestein J, Werner A, Benn R. Hyperactives as young adults: preliminary report. CANADIAN MEDICAL ASSOCIATION JOURNAL 1976; 115:625-30. [PMID: 974949 PMCID: PMC1878790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Thirty-five individuals aged 17 to 24 in whom severe chronic hyperactivity had been diagnosed 10 years before were studied together with 25 matched controls. There were no significant differences in mean height or weight or in electroencephalographic findings, but the mean pulse rate was significantly higher in the hyperactive group. Cognitive style tests indicated continued difficulty in reflection (resulting in more errors) but less impulsivity (longer reaction time) in the hyperactive individuals. Compared with controls, hyperactive subjects were continuing to have more scholastic difficulty, although this difference seemed to be less pronounced than 5 years before. Their adjustment in work situations and living arrangements did not differ significantly from that of the controls. Restlessness, both reported and observed, continued to be a problem for the hyperactive individuals, and socialization skills and sense of well-being continued to be poorer than in the controls. The hyperactive individuals did not show significantly more antisocial behaviour, nonmedical use of drugs or serious psychiatric disturbances.
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772
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Weiss G, Monder C, Bradlow HL. 17-Deoxygenation: a new pathway of cortisol metabolism. Isolation of 17-deoxycortolonic acids. J Clin Endocrinol Metab 1976; 43:696-9. [PMID: 956352 DOI: 10.1210/jcem-43-3-696] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The existence of a 17-deoxylation pathway in the metabolism of cortisol has been established by isolation of two 17-deoxy metabolites of cortisol. They have been identified as the 20alpha and 20beta-hydroxy isomers of 3alpha,20-dihydroxy, 11-oxo-5beta-pregnan-21-oic acids by comparison of the nuclear magnetic resonance spectra (nmr) and high resolution mass spectra of their methyl esters with authentic samples and confirmed by reverse isotope dilution.
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773
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Maurer HR, Weiss G, Laerum D. Starting procedures for the isolation and purification of granulocyte chalone activities. BLUT 1976; 33:161-70. [PMID: 134753 DOI: 10.1007/bf00995997] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Several starting materials and procedures for the extraction and purification of granulocyte chalone activities were tested and evaluated. Among others, leuko-adhesion of bovine blood granulocytes on nylon and cotton wool and direct extraction with polar organic solvents were found suitable. Following PVP-leukapheresis ascites fluids were collected from rats, purified by ultrafiltration and Sephadex G 25 chromatography to yield 2 inhibitors at Ve/Vo = 2.1 and 2.6 and one stimulator at 2.0 by the in vitro 3H-thymidine test. Fraction 2.1, which has met the criteria of a granulocyte chalone by the diffusion chamber and agar colony test, was found thermostabile and to contain several peptides. Yet evidence for the peptide nature of the inhibitor is not conclusive. Extracts from bovine blood granulocytes contained only the inhibitor at 2.1. Problems related to the in vitro test for chalone activity were discussed.
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774
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Weiss G, Rifkin I, Atkinson LE. Induction of ovulation in premenarchial rhesus monkeys with human gonadotropins. Biol Reprod 1976; 14:401-4. [PMID: 819046 DOI: 10.1095/biolreprod14.4.401] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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775
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Maurer HR, Weiss G, Laerum OD. Evaluation of a short term in vitro test for granulocyte chalone activity. VIRCHOWS ARCHIV. B, CELL PATHOLOGY 1976; 20:229-38. [PMID: 132006 DOI: 10.1007/bf02890342] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A short term in vitro test for granulocyte chalone activity eas examined for its specificity and reliability. The test used the inhibition, by granulocyte extracts, of 3H-thymidine (3H-Tdr) uptake in to the acid-insoluble material by rat bone marrow cells in vitro to measure possible chalone activity. Among the many possible 3H-Tdr artifacts pool size dilution by Tdr contained in the extracts was excluded using an E. coli mutant requiring thymine. Several amino acids and biogenic amines do not affect the test. However, continuous and pulse labelling of bone marrow cells with 3H-Tdr, viability tests and micro flow fluorometric measurements of the cell cycle distribution following colcemid treatment strongly suggests that the cells do not proliferate in vitro during short term incubation, since practically no cells enter the S-phase, cells in the S-phase die and few if any cells proceed through G2 and mitosis. Moreover, the test cannot exclude cytotoxicity. Thus, the in vitro test may only sceem for an unspecific S-phase inhibitor and must hence be supplemented by another assay to prove the chalone nature of an extract or fraction. The test per se fails to meet most of the requirements of a valid granulocyte chalone assay.
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