Monitoring of ovulation induction

The plasma hormonal patterns of the normal menstrual cycle have been reviewed. A consistent cyclic pattern of plasma hormone levels is observed in LH, FSH, estrogens, and progestins in the menstrual cycle. Other plasma hormones, such as ACTH, growth hormone, TSH, and PRL, as well as androgens and corticosteroids, fluctuate throughout the menstrual cycle without any consistent pattern during the ovulatory cycle. FSH, LH, E2, E1, P, T, and A levels during the induced ovulatory cycle are presneted for comparison. In the gonadotropin-induced ovulatory cycle most hormones behave in a manner similar to that in the normal ovulatory cycle, except for FSH levels, which rise continuously throughout the follicular phase of the cycle. Following ovulation in the gonadotropin-induced cycle, T rises above normal levels. Early in the clomiphene-induced ovulatory cycle, unlike the normal cycle, LH is distinctly elevated. Levels of both LH and FSH in the rest of the cycle simulate those in the normal cycle. However, T and A levels rise from the very beginning of clomiphene therapy and continue to rise throughout the clomiphene-induced ovulatory cycle. Levels of E and P are higher than in the normal ovulatory cycle, but a similar pattern is preserved. Because of the potential dangers of gonadotropin therapy, monitoring by frequent examination and laboratory tests is required. E monitoring is mandatory to evaluate follicular maturation, to time hCG administration, and to minimize hyperstimulation. Cervical mucus is an unreliable parameter for monitoring gonadotropin therapy alone. In addition to cervical mucus, plasma or urinary E should be monitored regularly. Clomiphene therapy is less dangerous than gonadotropin therapy. Because of its lesser risk, monitoring is rarely performed during clomiphene use. An active monitoring approach has been described. While this approach may not necessarily improve the outcome of clomiphene therapy, it may hasten the process of selecting the appropriate dose. Although other ovulation-inducing agents are available, their use is rarely associated with serious medical complications, and monitoring would seem unnecessary.

Removal of sodium channel inactivation in squid giant axons by n-bromoacetamide

The group-specific protein reagents, N-bromacetamide (NBA) and N-bromosuccinimide (NBS), modify sodium channel gating when perfused inside squid axons. The normal fast inactivation of sodium channels is irreversibly destroyed by 1 mM NBA or NBS near neutral pH. NBA apparently exhibits an all-or-none destruction of the inactivation process at the single channel level in a manner similar to internal perfusion of Pronase. Despite the complete removal of inactivation by NBA, the voltage-dependent activation of sodium channels remains unaltered as determined by (a) sodium current turn-on kinetics, (b) sodium tail current kinetics, (c) voltage dependence of steady-state activation, and (d) sensitivity of sodium channels to external calcium concentration. NBA and NBS, which can cleave peptide bonds only at tryptophan, tyrosine, or histidine residues and can oxidize sulfur-containing amino acids, were directly compared with regard to effects on sodium inactivation to several other reagents exhibiting overlapping protein reactivity spectra. N-acetylimidazole, a tyrosine-specific reagent, was the only other compound examined capable of partially mimicking NBA. Our results are consistent with recent models of sodium inactivation and support the involvement of a tyrosine residue in the inactivation gating structure of the sodium channel.

Plasma hormones in clomiphene citrate therapy

Daily plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrone (E1), estradiol-17beta (E2), progesterone (P), androstenedione (A), and testosterone (T) were measured in six clomiphene citrate (Clomid) treated cycles. Three patients ovulated and 1 of them conceived during the study cycle. Three other patients failed to ovulate in spite of some evidence of ovarian response to clomiphene treatment in 2 of them. Plasma gonadotropin levels, of LH in particular, rose during the clomiphene therapy and reached a peak during Day 5 to Day 7 of therapy. Levels of plasma estrogens, both E1 and E2, gradually rose, reflecting follicular maturation in the ovary. When E2 reached a critical level as in the normal ovulatory cycle, it triggered an LH surge which consequently initiated ovulation. When the E2 level was inadequate or excessive, ovulation failed in spite of an LH surge. Following ovulation, plasma P rose and fell in a manner similar to the normal ovulatory cycle, with occasional values that exceeded the normal range. Levels of androgens, both A and T, rose during clomiphene therapy in some cases and T seemed to fluctuate in correlation with LH level. The possible local inhibitory influence of high E2 and T levels on follicular maturation in the ovary during clomiphene therapy is suspected in some cycles in which ovarian response was evident, but ovulation failed to occur.

Plasma hormones in human gonadotropin induced ovulation

Plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrone (E1), estradiol-17beta(E2), progesterone (P), androstenedione (A), and testosterone (T) were analyzed in daily plasma samples of seven cycles of human menopausal gonadotropin (hMG)-human chorionic gonadotropin (hCG) induced ovulation. Plasma FSH rose gradually and remained at a higher level (20 to 30 mlU/ml) during hMG injection while LH stayed at a low tonic level. The FSH/LH ratio of plasma gonadotropins was consistently higher than 1 in spite of injecting an hMG preparation with FSH/LH ratio of 1. A pharmacologically induced high RSH/LH ratio in the late follicular phase is contradictory to the low ratio seen in the normal ovulatory cycle. This may be one of the causes of multiple follicular maturation and ovulation frequently encountered in the hMG-hCG induced ovulation. Higher than normal levels of plasma progesterone commonly seen in the hMG-hCG induced cycle is attributed to the multiple ovulation. Plasma androgen levels, both A and T, in these therapy cycles stayed consistently within normal range. This is a strong contrast to the clomiphene induced cycle in which A and T were frequently elevated in parallel with elevated LH. No significant differences in plasma hormones were observed between the pregnant and nonpregnant patient following hMG-hCG induced ovulation. A consistent and similar ovarian response to hMG-hCG was noted in 1 individual who had 3 consecutive therapy cycles studied. The plasma hormone levels in the multiple ovulation did not show a significant difference from those in the single ovulation with the exception of a higher plasma P level in the former.

Dynamics of aminopyridine block of potassium channels in squid axon membrane

Aminopyridines (2-AP, 3-AP, and 4-AP) selectively block K channels of squid axon membranes in a manner dependent upon the membrane potential and the duration and frequency of voltage clamp pulses. They are effective when applied to either the internal or the external membrane surface. The steady-state block of K channels by aminopyridines is more complete for low depolarizations, and is gradually relieved at higher depolarizations. The K current in the presence of aminopyridines rises more slowly than in control, the change being more conspicuous in 3-AP and 4-AP than in 2-AP. Repetitive pulsing relieves the block in a manner dependent upon the duration and interval of pulses. The recovery from block during a given test pulse is enhanced by increasing the duration of a conditioning depolarizing prepulse. The time constant for this recovery is in the range of 10-20 ms in 3-AP and 4-AP, and shorter in 2-AP. Twin pulse experiments with variable pulse intervals have revealed that the time course for re-establishment of block is much slower in 3-AP and 4-AP than in 2-AP. These results suggest that 2-AP interacts with the K channel more rapidly than 3-AP and 4-AP. The more rapid interaction of 2-AP with K channels is reflected in the kinetics of K current which is faster than that observed in 3-AP or 4-AP, and in the pattern of frequency-dependent block which is different from that in 3-AP or 4-AP. The experimental observations are not satisfactorily described by alterations of Hodgkin-Huxley n-type gating units. Rather, the data are consistent with a simple binding scheme incorporating no changes in gating kinetics which conceives of aminopyridine molecules binding to closed K channels and being released from open channels in a voltage-dependent manner.

Free and protein-bound plasma estradiol-17 beta during the menstrual cycle

Methods are described for the measurement of the estradiol-binding capacity of TeBG and of the free, TeBG-bound, and non-specifically protein-bound fractions of plasma estradiol. Each determination used undiluted plasma at 37 C, and a total volume of less than 2.0 ml of plasma was required to complete all the assays. The measurement of the per cent of free estradiol was affected by changes in plasma dilution. The measurement of the other fractions of estradiol was not influenced by changes in either the dilution or the volume of plasma. The distribution of plasma estradiol was determined daily throughout 5 individual menstrual cycles. The per cent of free, the per cent of TeBG-bound, and the TeBG binding capacity of estradiol remained constant throughout the cycle with mean values of 2.21 +/- 0.04% (SE), 38.4 +/- 0.7%, and 16.6 +/- 0.43 ng/ml, respectively. The mean association constant of TeBG for estradiol was 6.58 +/- 0.25 x 10(7)M-1. The concentration of the free and non-specifically protein-bound fractions of estradiol paralleled the total plasma concentration of estradiol. The results show that biologic events related to normal cyclic changes of plasma estradiol may be attributed to fluctuations in the free estradiol and to estradiol which is bound with low affinity to non-specific plasma proteins.

Actions of trihexyphenidyl and benztropine on squid axon membranes

Trihexyphenidyl and benztropine have potent local anesthetic action on squid axon membranes. They suppress the peak transient sodium conductance with ED50 values equal to 1.75 X 10(-4) AND 0.78 X 10(-4) M, respectively, and shift the sodium condu-tance curve along the potential axis in the direction of depolarization by 2.3 and 8.7 mV, respectively. The time for the sodium current to attain its peak is shortened. Steady-state potassium conductance is also suppressed by these drugs and undergoes an inactivation which has a potential-dependence characteristic. The local anesthetic action combined with the anticholinergic action may warrant further study of these two drugs, especially trihexyphenidyl, as a potential antiarrhythmic agent.

Interactions of aminopyridines with potassium channels of squid axon membranes

The effects of aminopyridines on ionic conductances of the squid giant axon membrane were examined using voltage clamp and internal perfusion techniques. 4-Aminopyridine (4-AP) reduced potassium currents, but had no effect upon transient sodium currents. The block of potassium channels by 4-AP was substantially less with (a) strong depolarization to positive membrane potentials, (b) increasing the duration of a given depolarizing step, and (c) increasing the frequency of step depolarizations. Experiments with high external potassium concentrations revealed that the effect of 4-AP was independent of the direction of potassium ion movement. Both 3- and 2-aminopyridine were indistinguishable from 4-AP except in potency. It is concluded that aminopyrimidines may be used as tools to block the potassium conductance in excitable membranes, but only within certain specific voltage and frequency limits.

Androgenic function of a granulosa cell tumor

Virilizing granulosa cell tumors are uncommon and have not been well studied hormonally. A hirsute woman with a cystic granulosa cell tumor of the ovary is presented. Plasma hormone levles obtained before and after surgery indicate testosterone production by the tumor with LH and FSH suppression. Plasma testosterone (T) and T-index returned to normal after tumor removal, and ovulation resumed.

Hydroxyl Radical Concentrations Measured in Ambient Air

Diurnal variations in the hydroxyl radical concentration of ambient air were measured for the first time by the technique of laser-induced fluorescence.

Plasma estrogen monitoring of ovulation induction

Eight hMG-hCG therapy cycles in 6 anovulatory infertile patients are presented. Daily plasma estrogen monitoring during the therapy contributed to success in inducing ovulation in all 6, 3 of whom established pregnancies and delivered healthy babies. The duration of hMG therapy required varies among individuals. Duration and dosage can be determined on the basis of daily plasma estrogen levels. Administration hCG is recommended to trigger ovulation when these levels reach 300 to 600 pg/ml. Although success in ovulation induction and pregnancy is achievable, multiple ovulation and multiple pregnancy cannot be predicted or prevented.

Human plasma triglyceride labeling after high sucrose feeding. II. Study on triglyceride kinetics and postheparin lipolytic activity

Kinetic studies of the very-low-density lipoprotein triglycerides (VLDL-TG) turnover by endogenous labeling with glycerol-2-3-H were performed in 13 patients in the postabsorptive state, first after 10-14 days on a low-sucrose high-starch diet, then again after 10-14 days of isocaloric high-sucrose low-starch diet (HSD). After HSD, a significant decrease in the fractional turnover rates of VLDL-TG was observed, as well as a modest but significant increase in its pool size, but the net turnover rates remained unchanged. Using Michaelis-Menten formulation, we have further calculated the Vmax and Km's of the removal system for VLDL-TG and found that the Vmax and Km's do not differ significantly between the two dietary periods. These results suggest that the removal mechanism for VLDL-TG has not changed after 10-14 days on the HSD, at least when the patients are studied in the postabsorptive state. Measurements of postheparin lipolytic acitivty under fed condition in 17 patients (including the 13 patients above) have shown a decrease after HSD. However, a defect in the removal of plasma-TG related to decreased activity of tissue-lipoprotein lipase in the fed state has not been conclusively uncovered by the kinetic studies performed in the postabsorptive state, and cannot contribute significantly to the expansion of VLDL-TG pool.

Hormonal changes associated with Danazol therapy

During a 6-month course of treatment of endometriosis with Danazol, a synthetic derivative of 17alpha-ethinyl testosterone, the following hormonal changes were found. Plasma LH remained essentially unchanged but FSH concentration was consistently in the low normal range. Plasma estradiol, especially after the fourth week of therapy, dropped to levels that did not exceed 30 pg/ml throughout the 6-month period of therapy. Plasma progesterone concentration was consistent with follicular phase levels. In the months after discontinuation of Danazol, all hormone parameters were strongly suggestive of normal ovulatory cycles. Danazol did not displace estradiol bound by endometrial cytosol.

Genetic control of enzyme induction in the -ketoadipate pathway of Pseudomonas putida: two-point crosses with a regulatory mutant strain

Several mutant strains of Pseudomonas putida, selected on the basis of their inability to grow at the expense of benzoate, have been shown to be unable to form inducibly both muconate lactonizing enzyme and muconolactone isomerase. A secondary mutant strain derived from one of these pleiotropically negative strains forms these two enzymes and, in addition, catechol oxygenase in the absence of inducer. This constitutive mutant strain was used as a donor in transductionally mediated two-point crosses to determine the order of point mutations within the structural genes for muconate lactonizing enzyme and muconolactone isomerase (the catB and catC genes, respectively). The gene order conformed precisely with the one that has been established by deletion mapping.

Stimulation of Enterotoxin B Production II. Synthetic Medium for Staphylococcal Growth and Enterotoxin B Production

A relatively large amount of enterotoxin B (125 μg/ml) was produced in a synthetic medium composed of amino acids, inorganic salts, and vitamins. This medium was prepared on the basis of the utilization of the various amino acids by Staphylococcus aureus strain S-6 throughout the growth cycle. Arginine appeared to be essential for enterotoxin production. The pattern of enterotoxin production in the synthetic media appeared to differ from that in complex media.

Stimulation of Enterotoxin B Production I. Stimulation by Fractions from a Pancreatic Digest of Casein

Chromatography on Dowex 50-X2 of Protein Hydrolysate Powder (Mead Johnson International, Evansville, Ind.), a pancreatic digest of casein, yielded 18 fractions. Five fractions stimulated enterotoxin production in greater amounts than were produced in the basal medium when it contained Protein Hydrolysate Powder. The stimulatory effect was due to the presence of peptides in the fractions. Many of these peptides contained large amounts of proline. Apparently, the primary structure of the peptides was important in the stimulation effect.

In vitro oestrogen biosynthesis in foetal organs of midpregnancy

Foetal organs; namely adrenal, gastrointestinal tract, kidney, liver, lung, skin and testis of midpregnancy were incubated individually with radio-active dehydroepiandrosterone (DHA) and the free and conjugated oestrogens were analyzed. Free oestriol was isolated in the gastrointestinal tract, liver and skin incubates. Oestrone and oestriol glucuronides were found in the gastrointestinal tract and liver incubates respectively. In the gastrointestinal tract incubate oestrone sulphate was found in the highest concentration while sulphates of oestradiol and oestriol were shown in the liver incubate. Conversion rates were small, ranging from 0.009% to 0.121%. These studies suggest that although certain foetal organs are able to aromatize steroids, their contribution to the high levels of oestrogen produced by the foeto-placental unit may be negligible.

Radioimmunoassay of estrone and estradiol

Antibodies to estradiol were produced by immunization of sheep with 17β-estradiol-succinyl-BSA. The antiserum cross reacted readily with estrone and was used for radioimmunoassay of plasma estrone and estradiol. The method includes ether extraction, separation of estrone and estradiol by Sephadex LH-20 column chromatography and radio-immunoassay using a mixture of polymerized estradiol antibodies and tracer 3H-estradiol. Separation of the free and protein bound radio-activity was effected by centrifugation. The water blank of the method is 11 ± 1 picogram (pg). The lower limit of sensitivity is 50 pg. The coefficient of variation was 8–18% for estrone and 4–17% for estradiol. Analysis of plasma estrone and estradiol in 5 ovulatory menstrual cycles revealed a midcycle peak of estradiol in each subject.

A rat pancreas-small gut preparation for the study of intestinal factor(s) and insulin release

A technic for in situ perfusion of rat pancreas alone or with a small intestine preparation, which is suitable for studying insulin and/or glucagon secretion and the role intestinal factor(s) has upon it, is described. Krebs- Ringer bicarbonate buffer, containing 4.0 per cent bovine albumin and 80 mg. per 100 ml. glucose with pH adjusted to 7.4, was used as perfusate.

When the pancreas was perfused with a nonrecirculated buffer there was no significant change in the levels of glucose or insulin in the perfusate, while with recirculated buffer, there was a decrease in both measurements.

When additional glucose was added to the perfusate, there was an increase of insulin levels, more marked in the pancreas perfusion with recirculated buffer (possibly pancreatic glucagon plus glucose effect) than in nonrecirculated ones (glucose effect).

In pancreas-intestine perfusion with recirculated buffer, there was a decrease of the levels of insulin and glucose, and when additional glucose was added to the perfusate, there was an increase of the levels of insulin and glucose (possibly pancreatic glucagon and glucose effect).

When glucose was passed through the intestine, there was a marked increase of the levels of insulin which was significantly higher than the previous group studied, probably due to the effects of glucose, pancreatic glucagon and intestinal factors.

It may be possible by the results obtained to separate the effects of the three factors on the release of insulin: glucose, glucagon and intestinal factor(s).