Kenneth Campbell - Academia.edu (original) (raw)
Papers by Kenneth Campbell
Journal of Biological Chemistry, 1973
Proceedings of the National Academy of Sciences, 1980
The question of whether the two subunits of the glycoprotein hormone human chorionic gonadotropin... more The question of whether the two subunits of the glycoprotein hormone human chorionic gonadotropin (hCG) are handled separately or as a unit by target cells was addressed by using a dual-labeling procedure. The individual alpha and beta subunits of hCG were labeled with 131I or 125I, recombined, chromatographed, and injected intravenously into hormonally primed immature rats. The ovaries of these rats contained large numbers of antral follicles, the granulosa cells of which possess high concentrations of receptor for hCG. Comparisons of the distribution of the different radioisotopic labels in various tissues over time indicated the activity associated with the beta subunit was preferentially retained by the ovarian granulosa cells in a hormone-specific manner, while the activity associated with the alpha subunit was preferentially lost. This contrasted with other tissues, including other ovarian cells with receptor for hCG, in which both radiolabels were either handled nondifferenti...
Natural Human Fertility, 1988
This chapter is a preliminary attempt to characterise reproductive patterns in traditional, pre-i... more This chapter is a preliminary attempt to characterise reproductive patterns in traditional, pre-industrial societies, including huntergatherers, tribal horticulturalists and pastoralists and settled peasant agriculturalists. Assertions about the level of fertility in such societies have played a key role in the development of theoretical models in demography and anthropology and, more recently, in reproductive biology. In classic demographic transition theory, for example, it was assumed that pre-transitional societies were characterised by uniformly high fertility rates, which provided the starting point for the recent secular decline in fertility (Knodel, 1977). Most ecological anthropologists, in contrast, have come to believe that many traditional societies, especially un acculturated hunter-gatherers, have regulated their reproductive output at relatively low levels (Dumond, 1975; Peacock, 1986). It has even been suggested that there occurred an earlier, stone-age demographic transition toward higher birth and death rates associated with the emergence of settled village life during the Neolithic (Handwerker, 1983; Roth, 1985).1 Despite the theoretical importance of these assertions and generalisations, their empirical base is questionable. In this chapter we bring together the available evidence in an attempt to characterise the overall level of fertility in traditional societies, with special emphasis on interpopulation variation in the principal determinants of fertility. It might be asked whether this attempt is worth making, or whether the category 'traditional society' is such a catch all as to be useless. We believe this to be a legitimate question, and we will attempt to answer it in what follows. Many demographers use the phrase 'natural fertility populations' to refer to groups such as those dealt with here (e.g. Henry, 1979; Trussell, 1979). Technically, 'natural fertility' refers to the absence of deliberate, parity specific changes in reproductive behaviour intended to limit reproductive output in order to meet some preconceived target family size (Henry, 1961). The concept of natural fertility is controversial and difficult to apply, in part because it 39 P. Diggory et al. (eds.
Reproduction Abstracts, 2014
Author affiliations Organisms use protein hormones even when smaller molecules can trigger identi... more Author affiliations Organisms use protein hormones even when smaller molecules can trigger identical transduction paths. Why? Could residual peptides from hormone proteolysis extend the mechanisms of action of these hormones? Protein hormones are endocytosed by target cells and digested by cathepsins (A, B, C, D, F, H, L, O, X) acting sequentially as endosomes/lysosomes move centripetally. In silico prediction of multiple cathepsin action on each of 92 hormones usually leaves 3-24 residual peptides of 6-25 amino acids; post-translational modification maps suggest some predicted cleavages may be blocked in vivo so residual peptides may be even longer (the 30-residue hCGβ C-terminus may remain nearly intact).
Proceedings of the National Academy of Sciences, 1979
Total ovarian granulosa cell proteins were labeled in vitro with [35S]methionine and analyzed by ... more Total ovarian granulosa cell proteins were labeled in vitro with [35S]methionine and analyzed by two-dimensional polyacrylamide gel electrophoresis. Of the 100-150 distinct proteins resolved by this method, 1-2% demonstrated an observable change in their synthesis during the early phases of luteinization after hormone administration. Two specific proteins first appeared as early as 30 min after treatment with human choriogonadotropin, while four additional new proteins became apparent at 3 hr. These changes in the synthesis of specific proteins occurred far in advance of the morphological changes associated with luteinization, which occur 24-72 hr later, and thus may play an important role in this process of hormonally induced cell differentiation in the rat ovary.
Hormones and Behavior, 1999
This study tested the hypothesis that implicit power motivation moderates individuals' testostero... more This study tested the hypothesis that implicit power motivation moderates individuals' testosterone responses to the anticipated success in and actual outcome of a dominance contest. Salivary testosterone levels were assessed in 42 male students at the beginning of the study, after they had imagined a success in an ensuing power contest, and immediately after the contest had taken place. Contest outcome (winning or losing against a competitor on a speed-based task) was varied experimentally. Participants' power motive was assessed with a picture-story exercise, in which an assertive, personalized (p Power) component was distinguished from an altruistic, socialized (s Power) component. In contrast to all other participants, individuals high only in p Power (a) had elevated testosterone after imagining a success in a subsequent dominance contest and (b) continued to have high testosterone levels after actually winning, but not after losing, the contest.
J Immunoass Immunochem, 2005
Our aim was to develop a statistical method to correct for non-parallelism in an estrone-3-glucur... more Our aim was to develop a statistical method to correct for non-parallelism in an estrone-3-glucuronide (E1G) enzyme immunoassay (EIA). Non-parallelism of serially diluted urine specimens with a calibration curve was demonstrated in an EIA for E1G. A linear mixed-effects analysis of 40 urine specimens was used to model the relationship of E1G concentration with urine volume and derive a statistical correction. The model was validated on an independent sample and applied to 30 menstrual cycles from American women. Specificity, detection limit, parallelism, recovery, correlation with serum estradiol, and imprecision of the assay were determined. Intra-and inter-assay CVs were less than 14% for high- and low-urine controls. Urinary E1G across the menstrual cycle was highly correlated with serum estradiol (r= 0.94). Non-parallelism produced decreasing E1G concentration with increase in urine volume (slope = -0.210, p < 0.0001). At 50% inhibition, the assay had 100% cross-reactivity with E1G and 83% with 17beta-estradiol 3-glucuronide. The dose-response curve of the latter did not parallel that of E1G and is a possible cause of the non-parallelism. The statistical correction adjusting E1G concentration to a standardized urine volume produced parallelism in 24 independent specimens (slope = -0.043+/-0.010), and improved the average CV of E1G concentration across dilutions from 19.5%+/-5.6% before correction to 10.3%+/-5.3% after correction. A statistical method based on linear mixed effects modeling is an expedient approach for correction of non-parallelism, particularly for hormone data that will be analyzed in aggregate.
Human Biology, Nov 1, 1987
Human biology, 1993
There have been few investigations of intrauterine mortality in non-Western populations that have... more There have been few investigations of intrauterine mortality in non-Western populations that have used techniques capable of detecting early pregnancy loss. We report here the initial results of a prospective study of fetal loss among the Turkana of northwest Kenya. Over 300 nomadic and settled women provided early morning urine samples for 3 consecutive days. Chorionic gonadotropin (hCG), a marker for pregnancy, and markers of ovarian cyclicity (LH, PdG) were determined with solid-phase enzyme immunoassays. Pregnancy was detected in 11% of nomadic women and in 22% of sedentary women of reproductive age. Follow-up surveys revealed that 45% of all pregnancies among settled women were lost; nearly 70% of pregnancies detected in the first trimester were lost. In contrast, none of the nomadic women experienced fetal loss. Because of the small sample sizes, these results must be interpreted cautiously. Nevertheless, even a conservative estimate of the fetal loss rate among the settled wo...
Paediatric and Perinatal Epidemiology, 2006
Increasing interest in early preconception and periconception exposures and human developmental o... more Increasing interest in early preconception and periconception exposures and human developmental outcomes has led to studies that monitor subjects from before conception to gestation, birth and childhood. Monitoring ovulation, endometrial receptivity, fertilisation, implantation and gestation requires the non-invasive collection of biological information and samples, and the measurement of biochemical and biological markers (biomarkers) that are associated with the aforementioned physiological events. This paper describes some of the key features of biomarkers needed for epidemiological studies, identifies some existing and potential biomarkers and available measurement devices, and suggests some directions for identification and development of new biomarkers that might be employed in longitudinal studies involving the analysis of female reproductive function and of embryonic development.
Journal of Biosocial Science, 1985
SummaryThe Gainj of highland Papua New Guinea do not use contraception but have a total fertility... more SummaryThe Gainj of highland Papua New Guinea do not use contraception but have a total fertility rate of only 4·3 live births per woman, one of the lowest ever recorded in a natural fertility setting. From an analysis of cross-sectional demographic and endocrinological data, the causes of low reproductive output have been identified in women of this population as: late menarche and marriage, a long interval between marriage and first birth, a high probability of widowhood at later reproductive ages, low effective fecundability and prolonged lactational amenorrhoea. These are combined with near-universal marriage, a low prevalence of primary sterility and a pattern of onset of secondary sterility similar to that found in other populations. Of all the factors limiting fertility, by far the most important are those involved in birth spacing, especially lactational amenorrhoea.
Journal of Biosocial Science, 1985
SummaryThe effects of infant suckling patterns on the post-partum resumption of ovulation and on ... more SummaryThe effects of infant suckling patterns on the post-partum resumption of ovulation and on birth-spacing are investigated among the Gainj of highland New Guinea. Based on hormonal evidence, the median duration of lactational anovulation is 20·4 months, accounting for about 75% of the median interval between live birth and next successful conception (i.e. resulting in live birth). Throughout lactation, suckling episodes are short and frequent, the interval changing slowly over time, from 24 minutes in newborns to 80 minutes in 3-year olds. Maternal serum prolactin concentrations decline in parallel with the changes in suckling patterns, approaching the level observed in non-nursing women by about 24 months post-partum. A path analysis indicates that the interval between suckling episodes is the principal determinant of maternal prolactin concentration, with time since parturition affecting prolactin secretion only in so far as it affects suckling frequency. The extremely prolon...
Clinical Chemistry, 2003
Background: Monitoring of reproductive steroid hormones at the population level requires frequent... more Background: Monitoring of reproductive steroid hormones at the population level requires frequent measurements, hormones or metabolites that remain stable under less than ideal collection and storage conditions, a long-term supply of antibodies, and assays useful for a range of populations. We developed enzyme immunoassays for urinary pregnanediol 3-glucuronide (PDG) and estrone conjugates (E1Cs) that meet these criteria. Methods: Enzyme immunoassays based on monoclonal antibodies were evaluated for specificity, detection limit, parallelism, recovery, and imprecision. Paired urine and serum specimens were analyzed throughout menstrual cycles of 30 US women. Assay application in different populations was examined with 23 US and 42 Bangladeshi specimens. Metabolite stability in urine was evaluated for 0–8 days at room temperature and for 0–10 freeze-thaw cycles. Results: Recoveries were 108% for the PDG assay and 105% for the E1C assay. Serially diluted specimens exhibited parallelism...
Clinical Biochemistry, 1999
Clinica Chimica Acta, 1998
We describe simple modifications to the ICON II hCG (URINE) pregnancy test to provide a sensitive... more We describe simple modifications to the ICON II hCG (URINE) pregnancy test to provide a sensitive and specific urinary assay for hCG in field studies of fetal loss. The modified assay had a qualitative lower limit of detection of 0.30 IU/l, a 50% qualitative limit of 0.61 IU/l, a 100% qualitative limit of 1.16 IU/l, and a quantitative limit of 0.80 IU/l. Coefficients of variation ranged from 9.9% to 21.1%. Parallelism was observed among serially diluted subject samples. We used the assay in an 11-month prospective study of fetal loss in rural Bangladesh in which urine samples were collected twice-weekly from 494 women; 330 pregnancies and 93 fetal losses were detected. The median time to a positive pregnancy diagnosis was day 26 from last menses. The modified assay provided qualitative detection of early pregnancy comparable to laboratory assays, and appears to be well suited for use in epidemiologic or rural-population fetal loss studies.
Biology of Reproduction, 1979
Chemical treatments previously shown to disrupt gap junctions were applied to rat ovaries with an... more Chemical treatments previously shown to disrupt gap junctions were applied to rat ovaries with antral follicles prior to expressing the granulosa cells with a blunt spatula. Exposure of the ovaries to 6.8 mM EGTA lethyleneglycol-bis-13-aminoethyl ether)-N,N'-tetracetic acid I and 0.5 M sucrose either by perfusion in situ or incubation in vitro generated monodisperse suspensions of granulosa cells with improved integrity as evaluated by several criteria. Similar numbers of granulosa cells (7-8 X 106 per ovary) were obtained either by direct physical expression or by pretreatment of the ovaries followed by physical expression. However, the ability of the granulosa cells to exdude trypan blue dye was consistently improved 2-3-fold by pretreatment with EGTA and hypertonic sucrose (from 25% to 40-80%). Likewise, in vitro synthetic capacities for protein, RNA and DNA were enhanced 2-6-fold, 5-10-fold and 10-20-fold, respectively. A qualitative one-to-one correspondence between protein synthesis and vital dye exdusion was demonstrable but the quantitative relationship between dye exclusion and macromolecular precursor incorporation appeared to be nonlinear. Cells obtained using the chemical pretreatments also demonstrated better survival in minimal medium for at least the first 12 h of culture The enhancements observed could not be obtained by reversing the order of the chemical treatments or by treating granulosa cells after physical removal from ovarian follicles. Pretreatment of ovaries with EGTA and hypertonic sucrose appears to be a reliable procedure for improving the yield of monodisperse, viable, biochemically intact granulosa cells for use in in vitro examinations of follicular physiology and function.
Journal of Biological Chemistry, 1973
Proceedings of the National Academy of Sciences, 1980
The question of whether the two subunits of the glycoprotein hormone human chorionic gonadotropin... more The question of whether the two subunits of the glycoprotein hormone human chorionic gonadotropin (hCG) are handled separately or as a unit by target cells was addressed by using a dual-labeling procedure. The individual alpha and beta subunits of hCG were labeled with 131I or 125I, recombined, chromatographed, and injected intravenously into hormonally primed immature rats. The ovaries of these rats contained large numbers of antral follicles, the granulosa cells of which possess high concentrations of receptor for hCG. Comparisons of the distribution of the different radioisotopic labels in various tissues over time indicated the activity associated with the beta subunit was preferentially retained by the ovarian granulosa cells in a hormone-specific manner, while the activity associated with the alpha subunit was preferentially lost. This contrasted with other tissues, including other ovarian cells with receptor for hCG, in which both radiolabels were either handled nondifferenti...
Natural Human Fertility, 1988
This chapter is a preliminary attempt to characterise reproductive patterns in traditional, pre-i... more This chapter is a preliminary attempt to characterise reproductive patterns in traditional, pre-industrial societies, including huntergatherers, tribal horticulturalists and pastoralists and settled peasant agriculturalists. Assertions about the level of fertility in such societies have played a key role in the development of theoretical models in demography and anthropology and, more recently, in reproductive biology. In classic demographic transition theory, for example, it was assumed that pre-transitional societies were characterised by uniformly high fertility rates, which provided the starting point for the recent secular decline in fertility (Knodel, 1977). Most ecological anthropologists, in contrast, have come to believe that many traditional societies, especially un acculturated hunter-gatherers, have regulated their reproductive output at relatively low levels (Dumond, 1975; Peacock, 1986). It has even been suggested that there occurred an earlier, stone-age demographic transition toward higher birth and death rates associated with the emergence of settled village life during the Neolithic (Handwerker, 1983; Roth, 1985).1 Despite the theoretical importance of these assertions and generalisations, their empirical base is questionable. In this chapter we bring together the available evidence in an attempt to characterise the overall level of fertility in traditional societies, with special emphasis on interpopulation variation in the principal determinants of fertility. It might be asked whether this attempt is worth making, or whether the category 'traditional society' is such a catch all as to be useless. We believe this to be a legitimate question, and we will attempt to answer it in what follows. Many demographers use the phrase 'natural fertility populations' to refer to groups such as those dealt with here (e.g. Henry, 1979; Trussell, 1979). Technically, 'natural fertility' refers to the absence of deliberate, parity specific changes in reproductive behaviour intended to limit reproductive output in order to meet some preconceived target family size (Henry, 1961). The concept of natural fertility is controversial and difficult to apply, in part because it 39 P. Diggory et al. (eds.
Reproduction Abstracts, 2014
Author affiliations Organisms use protein hormones even when smaller molecules can trigger identi... more Author affiliations Organisms use protein hormones even when smaller molecules can trigger identical transduction paths. Why? Could residual peptides from hormone proteolysis extend the mechanisms of action of these hormones? Protein hormones are endocytosed by target cells and digested by cathepsins (A, B, C, D, F, H, L, O, X) acting sequentially as endosomes/lysosomes move centripetally. In silico prediction of multiple cathepsin action on each of 92 hormones usually leaves 3-24 residual peptides of 6-25 amino acids; post-translational modification maps suggest some predicted cleavages may be blocked in vivo so residual peptides may be even longer (the 30-residue hCGβ C-terminus may remain nearly intact).
Proceedings of the National Academy of Sciences, 1979
Total ovarian granulosa cell proteins were labeled in vitro with [35S]methionine and analyzed by ... more Total ovarian granulosa cell proteins were labeled in vitro with [35S]methionine and analyzed by two-dimensional polyacrylamide gel electrophoresis. Of the 100-150 distinct proteins resolved by this method, 1-2% demonstrated an observable change in their synthesis during the early phases of luteinization after hormone administration. Two specific proteins first appeared as early as 30 min after treatment with human choriogonadotropin, while four additional new proteins became apparent at 3 hr. These changes in the synthesis of specific proteins occurred far in advance of the morphological changes associated with luteinization, which occur 24-72 hr later, and thus may play an important role in this process of hormonally induced cell differentiation in the rat ovary.
Hormones and Behavior, 1999
This study tested the hypothesis that implicit power motivation moderates individuals' testostero... more This study tested the hypothesis that implicit power motivation moderates individuals' testosterone responses to the anticipated success in and actual outcome of a dominance contest. Salivary testosterone levels were assessed in 42 male students at the beginning of the study, after they had imagined a success in an ensuing power contest, and immediately after the contest had taken place. Contest outcome (winning or losing against a competitor on a speed-based task) was varied experimentally. Participants' power motive was assessed with a picture-story exercise, in which an assertive, personalized (p Power) component was distinguished from an altruistic, socialized (s Power) component. In contrast to all other participants, individuals high only in p Power (a) had elevated testosterone after imagining a success in a subsequent dominance contest and (b) continued to have high testosterone levels after actually winning, but not after losing, the contest.
J Immunoass Immunochem, 2005
Our aim was to develop a statistical method to correct for non-parallelism in an estrone-3-glucur... more Our aim was to develop a statistical method to correct for non-parallelism in an estrone-3-glucuronide (E1G) enzyme immunoassay (EIA). Non-parallelism of serially diluted urine specimens with a calibration curve was demonstrated in an EIA for E1G. A linear mixed-effects analysis of 40 urine specimens was used to model the relationship of E1G concentration with urine volume and derive a statistical correction. The model was validated on an independent sample and applied to 30 menstrual cycles from American women. Specificity, detection limit, parallelism, recovery, correlation with serum estradiol, and imprecision of the assay were determined. Intra-and inter-assay CVs were less than 14% for high- and low-urine controls. Urinary E1G across the menstrual cycle was highly correlated with serum estradiol (r= 0.94). Non-parallelism produced decreasing E1G concentration with increase in urine volume (slope = -0.210, p < 0.0001). At 50% inhibition, the assay had 100% cross-reactivity with E1G and 83% with 17beta-estradiol 3-glucuronide. The dose-response curve of the latter did not parallel that of E1G and is a possible cause of the non-parallelism. The statistical correction adjusting E1G concentration to a standardized urine volume produced parallelism in 24 independent specimens (slope = -0.043+/-0.010), and improved the average CV of E1G concentration across dilutions from 19.5%+/-5.6% before correction to 10.3%+/-5.3% after correction. A statistical method based on linear mixed effects modeling is an expedient approach for correction of non-parallelism, particularly for hormone data that will be analyzed in aggregate.
Human Biology, Nov 1, 1987
Human biology, 1993
There have been few investigations of intrauterine mortality in non-Western populations that have... more There have been few investigations of intrauterine mortality in non-Western populations that have used techniques capable of detecting early pregnancy loss. We report here the initial results of a prospective study of fetal loss among the Turkana of northwest Kenya. Over 300 nomadic and settled women provided early morning urine samples for 3 consecutive days. Chorionic gonadotropin (hCG), a marker for pregnancy, and markers of ovarian cyclicity (LH, PdG) were determined with solid-phase enzyme immunoassays. Pregnancy was detected in 11% of nomadic women and in 22% of sedentary women of reproductive age. Follow-up surveys revealed that 45% of all pregnancies among settled women were lost; nearly 70% of pregnancies detected in the first trimester were lost. In contrast, none of the nomadic women experienced fetal loss. Because of the small sample sizes, these results must be interpreted cautiously. Nevertheless, even a conservative estimate of the fetal loss rate among the settled wo...
Paediatric and Perinatal Epidemiology, 2006
Increasing interest in early preconception and periconception exposures and human developmental o... more Increasing interest in early preconception and periconception exposures and human developmental outcomes has led to studies that monitor subjects from before conception to gestation, birth and childhood. Monitoring ovulation, endometrial receptivity, fertilisation, implantation and gestation requires the non-invasive collection of biological information and samples, and the measurement of biochemical and biological markers (biomarkers) that are associated with the aforementioned physiological events. This paper describes some of the key features of biomarkers needed for epidemiological studies, identifies some existing and potential biomarkers and available measurement devices, and suggests some directions for identification and development of new biomarkers that might be employed in longitudinal studies involving the analysis of female reproductive function and of embryonic development.
Journal of Biosocial Science, 1985
SummaryThe Gainj of highland Papua New Guinea do not use contraception but have a total fertility... more SummaryThe Gainj of highland Papua New Guinea do not use contraception but have a total fertility rate of only 4·3 live births per woman, one of the lowest ever recorded in a natural fertility setting. From an analysis of cross-sectional demographic and endocrinological data, the causes of low reproductive output have been identified in women of this population as: late menarche and marriage, a long interval between marriage and first birth, a high probability of widowhood at later reproductive ages, low effective fecundability and prolonged lactational amenorrhoea. These are combined with near-universal marriage, a low prevalence of primary sterility and a pattern of onset of secondary sterility similar to that found in other populations. Of all the factors limiting fertility, by far the most important are those involved in birth spacing, especially lactational amenorrhoea.
Journal of Biosocial Science, 1985
SummaryThe effects of infant suckling patterns on the post-partum resumption of ovulation and on ... more SummaryThe effects of infant suckling patterns on the post-partum resumption of ovulation and on birth-spacing are investigated among the Gainj of highland New Guinea. Based on hormonal evidence, the median duration of lactational anovulation is 20·4 months, accounting for about 75% of the median interval between live birth and next successful conception (i.e. resulting in live birth). Throughout lactation, suckling episodes are short and frequent, the interval changing slowly over time, from 24 minutes in newborns to 80 minutes in 3-year olds. Maternal serum prolactin concentrations decline in parallel with the changes in suckling patterns, approaching the level observed in non-nursing women by about 24 months post-partum. A path analysis indicates that the interval between suckling episodes is the principal determinant of maternal prolactin concentration, with time since parturition affecting prolactin secretion only in so far as it affects suckling frequency. The extremely prolon...
Clinical Chemistry, 2003
Background: Monitoring of reproductive steroid hormones at the population level requires frequent... more Background: Monitoring of reproductive steroid hormones at the population level requires frequent measurements, hormones or metabolites that remain stable under less than ideal collection and storage conditions, a long-term supply of antibodies, and assays useful for a range of populations. We developed enzyme immunoassays for urinary pregnanediol 3-glucuronide (PDG) and estrone conjugates (E1Cs) that meet these criteria. Methods: Enzyme immunoassays based on monoclonal antibodies were evaluated for specificity, detection limit, parallelism, recovery, and imprecision. Paired urine and serum specimens were analyzed throughout menstrual cycles of 30 US women. Assay application in different populations was examined with 23 US and 42 Bangladeshi specimens. Metabolite stability in urine was evaluated for 0–8 days at room temperature and for 0–10 freeze-thaw cycles. Results: Recoveries were 108% for the PDG assay and 105% for the E1C assay. Serially diluted specimens exhibited parallelism...
Clinical Biochemistry, 1999
Clinica Chimica Acta, 1998
We describe simple modifications to the ICON II hCG (URINE) pregnancy test to provide a sensitive... more We describe simple modifications to the ICON II hCG (URINE) pregnancy test to provide a sensitive and specific urinary assay for hCG in field studies of fetal loss. The modified assay had a qualitative lower limit of detection of 0.30 IU/l, a 50% qualitative limit of 0.61 IU/l, a 100% qualitative limit of 1.16 IU/l, and a quantitative limit of 0.80 IU/l. Coefficients of variation ranged from 9.9% to 21.1%. Parallelism was observed among serially diluted subject samples. We used the assay in an 11-month prospective study of fetal loss in rural Bangladesh in which urine samples were collected twice-weekly from 494 women; 330 pregnancies and 93 fetal losses were detected. The median time to a positive pregnancy diagnosis was day 26 from last menses. The modified assay provided qualitative detection of early pregnancy comparable to laboratory assays, and appears to be well suited for use in epidemiologic or rural-population fetal loss studies.
Biology of Reproduction, 1979
Chemical treatments previously shown to disrupt gap junctions were applied to rat ovaries with an... more Chemical treatments previously shown to disrupt gap junctions were applied to rat ovaries with antral follicles prior to expressing the granulosa cells with a blunt spatula. Exposure of the ovaries to 6.8 mM EGTA lethyleneglycol-bis-13-aminoethyl ether)-N,N'-tetracetic acid I and 0.5 M sucrose either by perfusion in situ or incubation in vitro generated monodisperse suspensions of granulosa cells with improved integrity as evaluated by several criteria. Similar numbers of granulosa cells (7-8 X 106 per ovary) were obtained either by direct physical expression or by pretreatment of the ovaries followed by physical expression. However, the ability of the granulosa cells to exdude trypan blue dye was consistently improved 2-3-fold by pretreatment with EGTA and hypertonic sucrose (from 25% to 40-80%). Likewise, in vitro synthetic capacities for protein, RNA and DNA were enhanced 2-6-fold, 5-10-fold and 10-20-fold, respectively. A qualitative one-to-one correspondence between protein synthesis and vital dye exdusion was demonstrable but the quantitative relationship between dye exclusion and macromolecular precursor incorporation appeared to be nonlinear. Cells obtained using the chemical pretreatments also demonstrated better survival in minimal medium for at least the first 12 h of culture The enhancements observed could not be obtained by reversing the order of the chemical treatments or by treating granulosa cells after physical removal from ovarian follicles. Pretreatment of ovaries with EGTA and hypertonic sucrose appears to be a reliable procedure for improving the yield of monodisperse, viable, biochemically intact granulosa cells for use in in vitro examinations of follicular physiology and function.