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G Betz

Publications and source records attributed to G Betz.

At least 37 records · Page 2Linked to original sources
PubMed1988

Physiological mechanisms associated with ovulation prediction using the CUE Ovulation Predictor.

It has been shown that monitoring of salivary electrical resistance (SR) enables prediction of ovulation several days in advance, since a peak in SR is seen 5-6 days before the LH peak. This paper explores physiological mechanisms that may account for this change. The pathway whereby oestrogen stimulates aldosterone (ALDO) secretion acting through the renin-angiotensin system was considered. It is shown that this mechanism would only result in increasing SR as oestrogen values rise during the follicular phase and therefore is not an explanation of the SR peak and declining SR 5-6 days before the LH peak. The reported trend of sodium in milk of ovulating women parallels that of SR. It is shown that these changes are most likely to be due to a similar change in aldosterone levels. A possible role for adrenocorticotrophic hormone (ACTH) in causing the changes in aldosterone is discussed and supported with data from other independent studies as well as with preliminary data obtained from two normally ovulating subjects. Peaks in ACTH, ALDO and SR were coincidental and occurred 6 days before the LH peak. The temporal relationship observed among these variables suggest that ACTH, by affecting ALDO, modifies salivary electrolytes and hence SR.

Adrenocorticotropic Hormone↗
PubMed1988

Ovulation prediction and detection with the CUE Ovulation Predictor.

Predicting ovulation is useful for managing the infertile patient and when done sufficiently in advance for fertility regulation by periodic abstinence. It has been reported that ovulation could be predicted by measurement of salivary and vaginal electrical resistance (SR and VR). These data from 32 menstrual cycles of 23 women were obtained to evaluate this technique. Data of 14 cycles were from subjects receiving clomiphene citrate (CC), while the others were from spontaneously ovulating subjects. A peak in SR was seen 5-7 days before the day of the LH peak in both natural and CC cycles. A correlation coefficient (r) of 0.94 was seen for the day of the SR peak and that of the LH peak. The SR trend was similar in both natural and CC cycles. VR in spontaneous cycles declined to a periovulatory nadir and then increased. The patterns of VR in CC cycles were similar except that values were initially depressed during and shortly after the end of CC therapy. Over 90% of VR increases were on the day of the LH peak and the day following. Results indicate that the method is useful for predicting ovulation in natural and CC cycles. Since the number of days by which ovulation is predicted exceeds the expected lifespan of spermatozoa in the female reproductive tract, the method also shows potential for use in natural family planning.

Electric Conductivity↗
PubMed1987

Prediction of ovulation with the use of oral and vaginal electrical measurements during treatment with clomiphene citrate.

This study was undertaken to evaluate the usefulness of measuring salivary and vaginal electrical resistance in monitoring ovulation induced by clomiphene citrate (CC). Data from 28 cycles of 12 women treated with CC were compared with those of 18 cycles of 13 women who were ovulating spontaneously. Patterns of salivary readings in CC and spontaneous cycles were similar and showed a preovulatory peak 6.2 (mean) days before the luteinizing hormone peak. The trend in vaginal readings for CC cycles differed from that of spontaneous ovulations in that the values were depressed during and shortly after CC therapy. Occurrence of the periovulatory nadir and subsequent rise was common to both groups. The rise in vaginal readings CC cycles occurred within 24 hours of the luteinizing hormone peak in 88% of cases. Retrospective analysis showed that, based on this method, artificial insemination would have been timed appropriately in 25 of 27 cycles or in every cycle, depending on the protocol used. The results indicate that the method is equally useful for predicting and confirming ovulation in cycles in which CC was used to induce ovulation as it is in spontaneous cycles.

Adult↗
PubMed1987

Steroidogenesis in adrenal tumor cells: influence of cell shape.

Y-1 adrenal tumor cells were grown on plastic, or plastic treated with poly(2-hydroxyethyl methacrylate) (polyHEMA) to produce concentration-dependent rounding (10(-5)-3 X 10(-4) M) of the cells or on plastic treated with poly-D-lysine (polylysine) to produce flat cells, in order to determine whether or not cell shape is correlated with steroid synthesis. The degree of rounding of cells was measured by determining mean cell height and longest cell diameter. Three measurements of steroid production were made: production of 20 alpha-dihydroprogesterone, transport of cholesterol to the inner mitochondrial membrane, and production of pregnenolone by isolated mitochondria. Cells grown on poly(HEMA) showed increase in mean cell height, decrease in longest diameter (i.e. rounding), and increase in all three measurements of steroidogenesis. In the case of synthesis of 20 alpha-dihydroprogesterone, the response was dependent on the concentration of poly(HEMA), being greater with higher concentrations (up to 10(-4) M), of this agent. Moreover the degree of rounding (cell height) was correlated with production of 20 alpha-dihydroprogesterone at three concentrations of poly(HEMA) (r = 0.93. ACTH at a supramaximal concentration produced increases in all of these responses to the poly(HEMA) surface. Polylysine produced flatter cells (lower mean height and greater longest diameter) than plastic and also inhibited all three steroidogenic responses to ACTH. (Bu)2cAMP exerted the same effects as ACTH. Growing cells on poly(HEMA) or polylysine did not affect production of cyclic AMP by the cells. Addition of poly(HEMA) or polylysine to the medium in which the cells were incubated, at the same concentrations as those used for influencing cell shape, was without effect on steroid synthesis or the response to ACTH. Cells grown on poly(HEMA) show decreased incorporation of [3H] thymidine into DNA. It is concluded that cell shape influences the delivery of cholesterol to inner mitochondrial membrane and in this way, increases the production of steroids by Y-1 cells and that the effects of poly(HEMA) on cell shape, cholesterol transport, and synthesis of DNA may involve microfilaments.

20-alpha-Dihydroprogesterone↗
PubMed1986

NADPH-cytochrome P-450 reductase from untreated rat testicular and liver microsomes: isolation and comparison.

NADPH-cytochrome P-450 reductase (EC 1.6.2.4), the enzyme involved in progesterone 17-hydroxylation, was purified to apparent homogeneity by detergent solubilization of the microsomal fractions of liver and testis from untreated rats. The enzymes from these two tissues were then compared with regard to several parameters. The liver and testicular reductases have the same subunit mol wt (79,000), determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and have similar specific activity for cytochrome c reduction (48.1 and 58.2 mumol min-1 mg-1, respectively). The absolute flavin absorption spectra of liver and testicular reductase were very similar. The spectra of native, reduced, and oxidized reductases were characteristic of flavoprotein with two flavin groups. The Km values for NADPH during cytochrome reduction were shown to be the same, within experimental error (5.29 +/- 0.46 microM-1 for liver and 4.37 +/- 0.53 microM-1 for testis). Monospecific antiserum was prepared against both rat liver and testicular reductases. There were no antigenic differences demonstrated by immunological tests using either antibody preparation. Antiliver reductase antiserum was shown to inhibit testicular microsomal progesterone 17-hydroxylase activity by 70%. Testicular cytochrome c reductase activity was inhibited by 94%, and liver cytochrome c reductase activity was inhibited by 85%. Peptide maps of both forms of reductase isolated from immunoprecipitates showed very similar patterns after enzymatic proteolysis. These results indicate that microsomal NADPH-cytochrome P-450 reductase involved in steroid hydroxylations in untreated rat liver and testis could not be distinguished from each other by these methods and, therefore, are probably the same protein.

Animals↗
PubMed1985

A new method for predicting and confirming ovulation.

Evaluation of a method for predicting and confirming ovulation by measurement of vaginal and salivary electrical resistance (VER and SER) was the purpose of this study. Eighteen menstrual cycles from 13 subjects were analyzed. A clearly defined nadir in VER at day 0, the day of the luteinizing hormone (LH) peak, followed by a pronounced increase the following day was observed. A peak in SER was consistently observed 5 to 6 days before day 0. The correlation coefficient (r) between the cycle day of the SER peak and cycle day of the LH peak was 0.94. After the peak in SER, values were low for several days but increased 1 to 2 days before the LH peak. Results indicate that monitoring of SER and VER may provide the basis for a simple method for predicting and confirming ovulation.

Cervix Mucus↗
PubMed1984

Steroid interactions with cytochrome P-450 from testis microsomes.

The cytochrome P-450 of gonadal microsomes is an integral component of the steroid converting enzymes, 17 alpha-hydroxylase and 17,20-lyase. Interaction of the steroid substrates with this cytochrome results in a shift in the Soret band as measured by difference spectroscopy. In these studies it is shown that in contrast to placental microsomal cytochrome P-450 which binds C19 steroids, testis microsomal cytochrome P-450 primarily binds C21 steroids. However, addition of a 17 alpha- methyl, 17 beta-acetate or a 17 beta-benzoate group to testosterone permits interaction. The addition of hydroxyl or methyl groups to other positions does not affect binding. The presence of multiple oxygen functions on C21 steroids, as in cortisol and corticosterone, precludes interaction. At least one oxygen function seems necessary for binding as 5 alpha- and 5 beta-pregnane do not bind whereas 20-deoxypregnenolone (5-pregnen-3 beta-ol) does bind. These findings indicate that factors in addition to hydrophobic interactions dictate the binding of steroid substrates to testis microsomal cytochrome P-450.

Animals↗
PubMed1984

Role of actin in the responses of adrenal cells to ACTH and cyclic AMP: inhibition by DNase I.

Erythrocyte ghosts were loaded with pancreatic DNase I and fused with Y-1 adrenal tumor cells to test the possibility that this enzyme might inhibit the steroidogenic responses of the cells to ACTH and cyclic AMP. Fusion of erythrocyte ghosts loaded with DNase I, but not those containing albumin, ovalbumin, boiled DNase I, or DNase I with excess G-actin, inhibited the increase in production of 20 alpha-dihydroprogesterone produced by ACTH and dibutyryl cyclic AMP; inhibition was concentration-dependent with 50% inhibition by 3 X 10(7) molecules of DNase I per cell. It was found that inhibition by DNase I was exerted at the step in the steroidogenic pathway at which cholesterol is transported to mitochondria where steroidogenesis begins. This was shown by measuring transport of cholesterol into the inner mitochondrial membrane, by measuring the production of pregnenolone by isolated mitochondria and by demonstrating that DNase I was without effect on the conversion of pregnenolone to 20 alpha-dihydroprogesterone (an end-product of steroid synthesis). The actin content of Y-1 cells was measured by two methods based upon inhibition of DNase I and by SDS gels following centrifugation. The cells were found to contain 2-3 X 10(7) molecules of actin per cell of which two-thirds is present as G-actin. Since DNase I is known to bind to G-actin to give a one to one complex, these and other findings suggest that at least some of the G-actin in the cells may be necessary for the steroidogenic responses to ACTH and cyclic AMP.

Actins↗
PubMed1983

Determination of steroid profiles in healthy and diseased states: identification and quantitation of a block of 17 alpha-hydroxylase.

The steroid metabolic profile on a patient with a suspected block in steroid biosynthesis was analyzed by gas chromatography and gas chromatography-mass spectrometry. The results of this work led to an interpretation of a block at the 17 alpha-hydroxylase step. Although the steroid metabolic profile was complex, we could not detect any steroids with a hydroxy moiety at position C-17. The use of gas chromatography-mass spectrometry, in this case, was the method of choice for a final diagnosis because of the confusion that resulted from other, more classical, forms of analysis. Data from our patient's sample are reported and compared to normals and to other cases where a block in 17 alpha-hydroxylase have been reported.

Adrenal Hyperplasia, Congenital↗
PubMed1983

Male pseudohermaphroditism due to 17 alpha-hydroxylase deficiency: diagnosis by gas chromatography--mass spectrometry.

A case of male pseudohermaphroditism associated with 17 alpha-hydroxylase deficiency is reported in which the diagnosis was firmly established by gas chromatography-mass spectrometry. The patient was a 20-year-old genotypic male, phenotypic female who presented with primary amenorrhea, absence of body hair, and no breast development. She was hypertensive. Corticosterone and progesterone levels were very high and sex steroids were virtually absent. Gonadotropins were in the menopausal range. The results of radioimmunoassay were not diagnostic. Analysis of urine using gas chromatography-mass spectrometry revealed a striking absence of steroids with 17-oxygen function-nor were there any 18 or 19 carbon steroids. These results clearly establish a total deficiency of 17 alpha-hydroxylase activity.

Adrenal Hyperplasia, Congenital↗
PubMed1983

Isolated gonadotropin deficiency in three sisters.

Three female siblings with isolated gonadotropin deficiency were studied. None demonstrated hyposmia or craniofacial abnormalities. Single doses of luteinizing hormone-releasing hormone and thyrotropin-releasing hormone (TRH) produced markedly different responses within the kindred. Following administration of TRH, one subject displayed a sharp rise in prolactin, but thyrotropin did not change.

Adolescent↗
PubMed1981

Actions of danazol in vivo on cytochrome P-450 and steroidogenic enzymes in rat testis and liver microsomal preparations.

The mechanism of action of danazol has not been established and the drug may act at multiple loci. Effects suggesting inhibition of pituitary gonadotropin release have been described while some in vitro studies have demonstrated competitive inhibition of steroidogenic enzymes. In addition, destruction of cytochrome P-450 by the acetylenic moiety of danazol is a possible mechanism. Following 14 days of danazol treatment (10 mg/kg/day), the specific content of rat testis microsomal cytochrome P-450 and the serum testosterone were decreased, in spite of no significant change in serum luteinizing hormone. Furthermore, simultaneous administration of human chorionic gonadotropin with danazol still resulted in a decrease in cytochrome. The activities of two testicular microsomal steroid-converting enzymes (17 alpha-hydroxylase and 17,20-lyase) were not altered when based on cytochrome P-450 content but were markedly depressed when based on microsomal protein. In liver, danazol showed a similar but less marked dimunition of the cytochrome. Surprisingly, steroid 17 alpha-hydroxylase activity in liver was significantly increased while other cytochrome P-450 dependent enzyme activities were not altered.

Aniline Hydroxylase↗
PubMed1980

Tuboplasty--comparison of the methodology.

A number of innovations have recently been made in the area of tubal surgery. This report summarizes our experience with these techniques. Microtechniques improved our results markedly with tubal anastomosis. Pregnancy rates were over 50% in reversal of fimbriectomy, but much lower with undilated tubes closed by inflammatory processes. Use of low molecular weight dextran was without benefit in improving pregnancy rates. Salpingolysis without steroids or hydrotubation resulted in a pregnancy rate of 69%.

Dextrans↗
PubMed1980

Reconstitution of steroid 17,20-lyase activity after separation and purification of cytochrome P-450 and its reductase from rat testis microsomes.

The testicular enzyme, 17,20-lyase, catalyzes the removal of the C-17 side chain from steroids in the synthesis of androgens. This activity employs cytochrome P-450 as an oxygen donor. Attempts to purify the cytochrome and its reductase from testis microsomes have previously been unsuccessful due to the low concentrations of these components (2--5% that of liver). The cytochrome and reductase were solubilized from rat testis microsomes using a mixture of sodium cholate and Emulgen 913. The components were then separated by DEAE chromatography. The cytochrome was further purified by chromatography using hydroxylapatite for an 8.5-fold enrichment. The reductase was further purified by hydroxylapatite and affinity chromatography. An 84-fold enrichment was achieved. 17,20-Lyase activity could be partially restored by mixing the cytochrome and reductase in the presence of phospholipid.

Aldehyde-Lyases↗