Confidence Limits In Parentheses Research Articles

Case-control study of PD-1, PD-L1 and B7-H3 expression in lung cancer (CA) patients (pts) with and without human immunodeficiency virus (HIV) infection.

11606 Background: PD-1, PD-L1 and B7-H3 are co-signaling molecules involved in CA immunology. There are limited data on expression of these molecules in HIV-infected (HIV+) lung CA pts and these pts are routinely excluded from immunotherapy trials. Methods: We reviewed archived lung CA tissue samples from HIV+ cases (n = 13) and HIV-uninfected controls (n = 13) from 2001-2015. Cases and controls were matched by histology and stage. Baseline demographics were collected for all pts. CD4 count and HIV RNA viral load (VL) were collected for HIV+ pts. Immunostained tumor sections were analyzed for percent of tumor cells expressing PD-L1 and B7-H3 (Abcam), and percent of tumor-infiltrating lymphocytes (TIL) expressing PD-1 and PD-L1 (Abcam). Positive expression was defined as > 5%. Statistical analysis was performed using the non-parametric Mann-Whitney test and the chi-square test. Proportions are specified as percentage with 95% confidence limits in parentheses. Results: Lung CA HIV+ case pts were predominantly male (62%), black race (100%), adenocarcinoma histology (77%), stage 4 disease (62%), and had a median age of 48 years. Of case pts with available data, mean CD4 count was 307 (range 37-617) and mean HIV VL was 29,400 (range 0-100,000). PD-L1 expression on tumor cells was positive in 23% (8%, 50%) of cases and 46% (23%, 71%) of controls. B7-H3 expression on tumor cells was positive in 92% (67%, 99%) of cases and 69% (42%, 87%) of controls. PD-1 expression on TIL was positive in 69% (42%, 87%) of cases and 54% (29%, 77%) of controls. PD-L1 expression on TIL was positive in 31% (13%, 58%) of cases and 69% (42%, 87%) of controls (p = 0.05). B7-H3 percent expression on tumor cells was significantly higher in cases vs controls (median 90% vs 20%, p = 0.005), but there were no significant differences in percent expression of PD-L1 on tumor cells, PD-1 on TIL or PD-L1 on TIL. Conclusions: HIV+ lung CA pts had significantly higher B7-H3 tumor percent expression compared to HIV-uninfected controls, with similar rates of PD-L1 tumor percent expression, PD-1 TIL percent expression and PD-L1 TIL percent expression. These results support inclusion of HIV+ lung CA pts in future immunotherapy trials.

Separate and Combined Effects of Mentha piperata and Mentha pulegium Essential Oils and a Pathogenic Fungus Lecanicillium muscarium Against Aphis gossypii (Hemiptera: Aphididae).

In the present study, the toxicity of essential oils of Mentha piperata L. and Mentha pulegium L. and pathogenicity of Lecanicillium muscarium (Zare & Gams) were studied in the melon aphid, Aphis gossypii Glover. Analyses of the essential oils by GC-MS indicated limonene (27.28%), menthol (24.71%), menthone (14.01%), and carvol (8.46%) in the M. piperata essential oil and pulegone (73.44%), piperitenone (5.49%), decane (4.99%), and limonene (3.07%) in the essential oil of M. pulegium as the main components. Both essential oils and the pathogenic fungus had useful toxicity against A. gossypii. Probit analysis indicated LC50 values (lethal concentrations to kill 50% of population; 95% confidence limits in parentheses) of M. piperata and M. pulegium essential oils as 15.25 (12.25-19.56) and 23.13 (19.27-28.42) µl/liter air, respectively. Susceptibility to the pathogenic fungus increased with exposure time. Aphid mortality also increased when the essential oils were combined with L. muscarium, although the phenomena was additive rather than synergistic. Mycelial growth inhibition of L. muscarium exposed to the essential oils was also very low. Based on our results, M. piperata and M. pulegium essential oils and the pathogenic fungus L. muscarium have some potential for management of A. gossypii.

Acute toxicity test using cyanide on Daphnia magna by flow-through system

This study describes the acute toxicity of sodium cyanide on the crustacean Daphnia magna (Cladocera). A new flow-through system was innovated in which the microorganism continuously exposure to the toxicity of sodium cyanide during the test. We used twelve different concentration of sodium cyanide from low values (0 mg CN/L) to high values (1 mg CN/L) on bioassay test. D. magna were exposed to the concentrations for 24, 48, 72 and 96 h at 20–25°C. We controlled the three important parameters such as temperature, pH and DO to meet the standard requirements. The LC50 values for 24, 48, 72 and 96 h (95% confidence limits in parentheses) were estimated statistically by the probit methods and were 0.171 (0.163–0.179), 0.12 (0.112–0.128), 0.07 (0.062–0.078) and 0.019 (0.011–0.027) mg/L respectively. Finally, we proposed two new values for SAR (safe application rate) and SAFE Coefficients.

Dissipation and effects of chlortetracycline and tylosin in two agricultural soils: A field‐scale study in southern Denmark

Presently, there is a basic lack of information concerning the accumulation of antibacterial agent residues in agricultural soils. In this field study, performed in southern Denmark, we assess the dissipation of chlortetracycline (CTC), and tylosin A (TYL A) as a function of time. Field soils were classified as a sandy loam soil (field A) and a sandy soil (field B) and each field was sampled on six occasions during the 155-d experimental period from May to October 2000 for chemical analysis and counts of colony-forming units (CFU) detecting the level of aerobic bacteria surviving antibiotic exposure. Colony-forming units and TYL A were detected throughout the entire sampling period, with respective starting soil concentrations of 30 and 50 microg kg(-1) soil declining to 1 and 5 microg kg(-1) soil, on day 155. Compound half-lives (95% confidence limits in parentheses) were estimated for both fields and T1/2 for CTC was 25 d (20-34) and 34 d (28-42) in fields A and B, respectively, and T1/2 for TYL A was 67 d (54-86) and 49 d (40-64) in fields A and B, respectively. No significant difference was determined between compound half-lives on the two fields. The level of aerobic antibiotic-resistant bacteria in the soil over time and soil fauna community was assessed in relation to application of manure containing antibacterial agents to the agricultural fields. The level of both CTC- and TYL-resistant bacteria was affected in the soil by amendment of manure, but declined during the study to the same level as observed at the beginning.

Proton affinity of deuterated acetonitrile estimated by the kinetic method with full entropy analysis

Branching ratios for the dissociation of proton-bound dimers of selected alkyl nitriles, [R1CN⋯H+⋯NCR2], have been measured as a function of collision energy, using a triple quadrupole mass spectrometer. The system shows a small collision energy dependence consistent with small differences in entropy requirements for the competing fragmentation channels. The extended form of the kinetic method provides a value for the proton affinity and an approximate value for the relative entropy difference between the two dissociation channels (which corresponds approximately to the relative entropy of protonation of the two bases). A comparison is made between these results and those from earlier standard kinetic method data treatments. The proton affinity of d3-acetonitrile, estimated by the extended kinetic method, is 186.3 ± 1.2 (±1.4) kcal mol−1, where the standard deviation is given, followed by the 90% confidence limits in parentheses. The proton affinity of acetonitrile, estimated using the extended kinetic method as 188.2 ± 1.2 (±1.4) kcal mol−1, is statistically the same as that obtained for d3-acetonitrile. The relative entropies of protonation, Δ(ΔS), for d3-acetonitrile and acetonitrile, referenced to a series of alkyl nitriles, are 1.8 ± 0.3 (±0.3) and −1.1 ± 0.3 (±0.3) cal mol−1 K−1, respectively. Direct comparison of the isotopomers of acetonitrile using the standard and extended kinetic methods was employed to arrive at a more accurate value for the proton affinity difference between d3-acetonitrile and acetonitrile, and this method yielded a difference of ∼0.2 kcal mol−1. The direct comparison was also used to show that the proton affinity difference is a result of isotopic substitution. Normal secondary kinetic isotope effects were observed for the dissociation of the proton-bound dimer, CH3CN⋯H+⋯CD3CN. The branching ratio, kH/kD, was constant at 1.2 over the laboratory collision energy range of 5–50 eV.

Rapid Tracheal Intubation with Rocuronium: A Probability Approach to Determining Dose

Background Rapid tracheal intubation with rocuronium has not been studied using a probability-based approach. The authors aimed to predict doses of rocuronium giving 90% and 95% probability of in intubation within 60 s and to estimate their durations of action. Methods After premedication with midazolam, 2 mg, anesthesia was induced in 80 subjects with fentanyl, 2 microg/kg, followed 3 min later by propofol, 2 mg/kg. Patients received randomly rocuronium, 0.0, 0.4, 0.8, or 1.2 mg/kg (n = 20/ dose). Laryngoscopy began 40 s later, aiming for intubation at 60 s, and conditions were graded perfect, acceptable, or unacceptable, with the first two conditions being successful intubation. Anesthesia was maintained with isoflurane 0.5-1.0% (end-tidal) and fentanyL Duration of action was time until reappearance of the first tactile train-of-four response. The dose versus fraction of patients with successful intubation was analyzed by logistic regression. Doses giving 90% and 95% (D90 and D95) probability of successful intubation were calculated. Results intubation was successful in 7, 11, 18, and 19 patients in the 0.0, 0.4, 0.8, and 1.2 mg/kg groups, respectively. The D90 and D95 doses (95% confidence limits in parentheses) were 0.83 (0.59-1.03) and 1.04 (0.76-1.36) mg/kg, respectively. Estimated time until first tactile train-of-four response after D90 and D95 doses was 32 and 46 min, respectively. Conclusions After induction with fentanyl and propofol, rocuronium, 1.04 mg/kg gives 95% probability of successful intubation at 60 s.

Evidence for partial agonist properties of daltroban (BM 13,505) at TP receptors in the anaesthetized open-chest rat.

We sought to determine whether the intrinsic pulmonary hypertensive activity of the purported thromboxane A2/prostanoid (TP) receptor antagonist, daltroban, was mediated by TP receptors, using the high efficacy TP receptor agonist, U-46619, and the silent TP receptor antagonist, SQ 29,548. In pentobarbitone-anesthetized, open-chest rats (n = 4-10 per group), non-cumulative injections of U-46619, dose-dependently increased mean pulmonary arterial pressure (MPAP) with an ED50 (geometric mean with 95% confidence limits in parentheses) of 1.4 (1.1-2.3) microg/kg i.v.. Daltroban increased MPAP in a bell-shaped manner, with an apparent ED50 [29 (21-35) microg/kg i.v.] being 21 fold less potent than that of U-46619. The maximal pulmonary hypertensive responses evoked by daltroban represented about half those induced by U-46619 (25.4+/-1.0 vs. 12.7+/-2 mmHg; P < 0.05 between groups). The TP receptor antagonist SQ 29,548 fully antagonized increases in MPAP evoked by equihypertensive doses of U-46619 (1.25 microg/kg) or daltroban (80 microg/kg). Further experiments were carried out to determine whether daltroban antagonized the pulmonary hypertensive responses evoked by the high efficacy agonist, U-46619, or by itself as receptor theory would predict for a partial agonist. Daltroban (10-2500 microg/kg) antagonized, although not fully, U-46619 (20 microg/kg)-evoked pulmonary hypertensive responses, since prominent intrinsic pulmonary hypertensive effects of daltroban were observed in the same range of doses. Furthermore, in contrast to U-46619 (1.25 microg/kg), daltroban (80 microg/kg) failed to evoke a second pulmonary hypertensive response following a previous injection, as would be expected for a partial agonist. Collectively, the results strongly suggest that daltroban behaves as a partial agonist at TP receptors in the pulmonary vascular bed of the rat in vivo.

CMV infection after allogeneic bone marrow transplantation is associated with the occurrence of various autoantibodies and monoclonal gammopathies.

Recent findings indicate that the kinetics of B-cell reconstitution after marrow transplantation mimic normal ontogeny. The early B-cell repertoire during ontogeny is characterized by a high degree of autoreactivity and interconnectivity. Therefore, in a prospective analysis, 95 consecutive recipients of an allogeneic marrow transplant were screened for the occurrence of various autoantibodies and 47 of these 95 were also screened for monoclonal gammopathies. None of the patients developed antibodies specific for systemic autoimmune disorders. In contrast, a high prevalence of natural antibodies (79/95) was found early post-transplant, with 58 of these 79 patients developing two or more autoantibodies. According to multiple regression, the mean number of natural antibodies (95% confidence limits in parentheses) depends significantly (P = 0.006) on the status of CMV infection: 0.9 (0.4; 1.6) CMV-negative: 2.0 (1.0; 3.3) asymptomatic CMV infection; 3.1 (1.7; 5.0) CMV disease. Sex, age, underlying disease, conditioning therapy, acute graft-versus-host disease and CMV serology of donor and recipient pretransplant did not affect the number of natural autoantibodies. Monoclonal gammopathies were detected in 12/47 patients with a predominance of the IgG-kappa subtype. All these 12 patients suffered from a viral infection (CMV, n = 11: influenza strain A, n = 1). The high degree of self-reactivity post-transplant further supports the hypothesis that B-cell reconstitution mimics ontogeny. Moreover, these data indicate nonspecific polyclonal, CMV-mediated, presumably T-cell independent B-cell stimulation and disturbed T-cell regulatory function following allogeneic BMT.

Effect of having a functioning cadaveric renal transplant on cardiovascular mortality risk in patients on renal replacement therapy

Our aim was to estimate the effect of having a functioning cadaveric renal transplant on the risk of cardiovascular and total mortality in patients on renal replacement therapy (RRT). We retrospectively studied (by the Cox proportional hazards regression model) 195 subjects who began RRT with maintenance dialysis in our centre from 1 January 1978 to 31 December 1991. Out of this number, 76 patients received a cadaveric kidney transplant. Cardiovascular abnormalities at the onset of RRT were the principal independent determinant of both total and cardiovascular mortality risk. As compared to patients on dialysis with the same duration of RRT, patients with a functioning renal transplant for more than 1 year had a significantly lower total mortality risk (mean relative risk (RR): 0.48 (0.25-0.91) (95% confidence limits in parentheses), P = 0.03), an effect whose significance disappeared after adjustment for pretreatment conditions (RR = 0.62 (0.30-1.30), P > 0.3). However, the beneficial effect of a functioning renal transplant for more than 1 year on cardiovascular mortality risk was significant, both before (RR = 0.21 (0.06-0.74), P = 0.02) and after the adjustment for pretreatment conditions (RR = 0.32 (0.11-0.90), P = 0.035). During the first year after a successful transplantation the beneficial effect of having a functioning transplant on cardiovascular mortality risk was only weakly attenuated. During RRT a functioning cadaveric renal transplant decreases cardiovascular mortality risk partially independently of the better pretreatment status of the patients selected for transplantation.

Fractionation effects and repair kinetics in rat kidney

Rat kidneys were unilaterally irradiated with up to 40 fractions of X rays. Fractionation regimens were given either with long intervals of 6–24 hr between fractions, resulting in complete recovery from sublethal damage, or with 1-hr intervals, resulting in largely incomplete repair. The non-irradiated kidney was surgically removed 4 weeks after the last fraction. The development of radiation-induced kidney damage was monitored by regular assessment of three different parameters indicative of kidney function: serum urea, the total volume of urine excreted in 24 hr and urine osmolality. At the end of the observation period, 18 months after treatment, the kidney was removed. The hydroxyproline content was determined and a histopathological analysis was performed. Since the 20 and 40-fraction data indicated a higher effectiveness of these regimens than would be expected on the basis of the LQ model, the data were divided in two subsets, 2–10 fractions (high doses per fraction) and 10–40 fractions (low doses per fraction), and analyzed separately. The time course of α/β and T 1 2 values was determined for each functional parameter separately, and for the data from the three parameters combined. A complex pattern was found, with the values for α/β as well as T 1 2 differing between the two data subsets between about 20 and 40 weeks after treatment. For the lower doses per fraction the α/β values were generally higher and the repair half-times longer. After 40 weeks no significant differences were observed between the two data subsets. If the differences found earlier are ignored, overall α/β and T 1 2 values can be calculated. For early endpoints the α/β was 1.69 (1.45, 1.90) Gy (95% confidence limits in parentheses), for late endpoints it was 1.77 (1.56, 2.00) Gy. The corresponding T 1 2 values were 1.57 (1.44, 1.73) hr for early endpoints, and 2.10 (1.90, 2.34) hr for late endpoints. Hence, the α/β values do not alter in time, but the T 1 2 value for late damage might be higher than that for early damage.

Measurement of Stroke Volume with Three-dimensional Transesophageal Ultrasonic Scanning

The accuracy of measuring cardiac stroke volume with a new transesophageal phased array ultrasonic probe was investigated in 10 dogs. The method involved scanning the heart to obtain serial images covering the entire left ventricular cavity at end-expiration. An off-line computer analysis of the images was used to form three-dimensional reconstructions of the left ventricular cavity at end-diastole and end-systole, from which stroke volume was determined. Comparison with stroke volume determined by thermodilution during a wide range of hemodynamic conditions gave the following results for least-squares regression on 57 determinations (with the 95% confidence limits in parentheses): slope 0.95 (0.842-1.06), ordinate intercept 2.1 (2.0-2.2) ml, standard error of the estimate 4.1 ml, and correlation coefficient of 0.92 (0.87-0.95). Histologic examination of sections of esophagus surrounding the tip of the probe in nine dogs demonstrated minimal trauma to the esophageal wall, with eight specimens described as normal and one showing mild inflammation. The authors conclude that three-dimensional reconstruction of the left ventricular cavity from multiple transesophageal images offers a safe and accurate, although presently tedious, method for determining stroke volume.

Toxicity of methyl parathion and fensulfothion to the fish Mystus cavasius

The 96-h LC 50 values of methyl parathion and fensulfothion (with the 95% confidence limits in parentheses), to the freshwater fish Mystus cavasius were, respectively, 5·9 (5·4 to 6·5) and 16·5 (14·8 to 17·8) ppm. Both the pesticides induced severe morpho-anatomical deformities and behavioural changes in the exposed fish. Methyl parathion caused bloating of the stomach and softening of the ventral side. Exposure to fensulfothion resulted in lateral bending of the body. Both pesticides, at higher concentrations, affected the oxygen uptake of M. cavasius, with a progressive reduction of the oxygen consumption with increasing concentration of the pesticide. The highest concentration of methyl parathion that caused irreversible damage during the period of the respiratory experiment (i.e. 15 ppm) induced stressed and excited swimming and increased the oxygen uptake. The present paper is the first published work on the toxicity of fensulfothion to fish.

One-year drinking history and mortality

The one-year drinking history of 94 men was recorded by recurrent interviews (mean: 20 per person). The cohort was followed for 18.3 years; during that time, 13 men died. Cox's proportional hazards survival models including age and social class as confounders, indicated that mortality was significantly associated with total annual alcohol consumption, frequency of drinking, and frequency of intoxicating drinking. Estimates of risk of death for various consumption levels are presented: For having 10 drinks (each containing 12 grams of pure ethanol) a week vs one drink a week, the estimated relative risk of death (95% confidence limits in parentheses) was 2.3 (1.6-3.3). For being intoxicated once a week vs no intoxications at all during one year the respective risk was 2.1 (1.3-3.1). The risk estimates for the frequency of intoxication were found to be higher than those in an earlier study using single interview data on drinking. This suggests that more accurate measurement of alcohol consumption may yield higher risk of death estimates than found in studies based on single interview data on alcohol.

Toxicity of fenitrothion to the fish Mystus cavasius and Labeo rohita

The 96-h LC 50 values (with the 95% confidence limits in parentheses) of fenitrothion for the freshwater fish, Mystus cavasius and three size groups of Labeo rohita (3 to 4·4 cm, 4·5 to 5·9 cm and 6 to 8 cm in length) were respectively 3·3 (3 to 3·5), 2·8 (2·6 to 3), 4·1 (4 to 4·2) and 4·6 (4·5 to 4·7) ppm. There was a decrease in the toxicity of the compound with increase in size, and a significant negative correlation between increasing concentrations of fenitrothion and the oxygen uptake of L. rohita. Although it is less toxic to mammals than the closely related methyl parathion, fenitrothion seems to be more toxic to fish.

Use of plaque assays to study thyroglobulin autoantibody synthesis by human peripheral blood lymphocytes.

Plaque assays have been used to study thyroglobulin autoantibody synthesis and total immunoglobulin production by cultures of peripheral blood lymphocytes from patients with Hashimoto's thyroiditis. Freshly isolated Hashimoto or normal lymphocytes contained small numbers (7-1300) of total IgG plaque-forming cells (PFC) and total IgM PFC, but specific thyroglobulin antibody PFC was undetectable. After 5-8 days' culture with pokeweek mitogen (PWM), total IgG and IgM PFC were markedly increased to a geometric mean of 10,140 (8414-12,220) IgG PFC and 3450 (163-7534) IgM PFC per 10(6) cultured lymphocytes (95% confidence limits in parentheses). Furthermore, a mean of 63 (22-287) specific IgG thyroglobulin antibody PFC per 10(6) lymphocytes were detectable in cultures of Hashimoto lymphocytes. The IgG thyroglobulin antibody PFC were stimulated by Epstein-Barr virus (EBV) infection, suggesting that EBV infection may be useful in obtaining monoclonal thyroid autoantibodies.

Acute and Chronic Effects of Kepone and Mirex on the Fathead Minnow

Abstract Acute and chronic toxicity studies were conducted with fathead minnows (Pimephales promelas) and the organochlorine insecticides Kepone and mirex. Kepone was highly toxic to fathead minnows under acute conditions; 96-hour LC50's (median lethal concentrations; 95% confidence limits in parentheses) were as low as 340 (289–400) μg/liter and 96-hour EC50's (median effective concentrations; 95% confidence limits in parentheses) were as low as 18 (15–22) μg/liter. The observed effect, upon which the EC50 calculations were based, was an extensive hemorrhage associated with an apparent fracture or dislocation of the vertebral column in the region of the dorsal fin. Mirex was not acutely toxic to fathead minnows, even at concentrations that exceeded its maximum water solubility. Chronic toxicity testing indicated that the maximum acceptable toxicant concentration for fathead minnows exposed to Kepone was between 1.2 and 3.1 μg/liter. Adverse chronic effects of mirex were limited to a possible impairment o...

Microwave optical double resonance and reanalysis of the CaF A2Π r- X2Σ band system

A laser excitation spectrum of the (0,0) and (1,1) bands of the CaF A 2Π- X 2Σ system has been recorded and all 12 rotational branches assigned on the basis of laser induced fluorescence measurements. Microwave optical double resonance (MODR) measurements were also made on several low- J transitions to obtain precise spectroscopic constants of the X 2Σ state. The present set of molecular constants for both the A 2Π and X 2Σ states represent a vast improvement in precision over previously reported values because of the larger number of line position measurements and the use of a more reasonable Hamiltonian. The excellent agreement between the rotational constants derived from the optical and microwave measurements fully validates the assignments. Important derived constants are listed below (in cm −1) with 95% confidence limits in parentheses.

Acute oral toxicity of ethylidene gyromitrin in rabbits, rats and chickens

The acute oral toxicity of ethylidene gyromitrin (acetaldehyde N-methyl- N-formylhydrazone), the toxic compound in false morels, Gyromitra esculenta, was determined in rabbits, rats and chickens, the LD 50 values (with 95% confidence limits in parentheses) in these three species being 70 (67–74), 320 (210–494) and >400 mg/kg, respectively. Clonic-tonic convulsions, hypersensitivity, loss of activity, lack of appetite and severe weight loss accompanied intoxication in rabbits and rats. Haemoglobinuria, proteinuria, bilirubinuria and a decrease in urinary pH were evident in affected rabbits and concentrations of creatine, bilirubin and activities of aspartate and alanine aminotransferases were abnormally high in the serum. Rabbits that died showed extensive fatty degeneration of the liver, but this effect was much less severe in rats. Rabbits excreted at least part of the administered ethylidene gyromitrin unchanged in the urine. No toxic effects were detected in chickens given a dose of 400 mg/kg.

A radioimmunoassay method for simultaneous determination of pregnenolone, pregnenolone sulfate, dehydroepiandrosterone and dehydroepiandrosterone sulfate in human plasma (author's transl)

A radioimmunoassay method has been developed for the simultaneous determination of pregnenolone, pregnenolone sulfate, dehydroepiandrosterone(DHA) and dehydroepiandrosterone sulfate (DHA sulfate). The method consists of the following procedures: 1) ether extraction of unconjugated compounds, 2) extraction of sulfates fromaqueous residue with ethyl acetate, 3) solvolysis with sulfuric acid at 40 degree C for 60 minutes, 4) celite column chromatography to separate individual compounds, 5) radioimmunoassay. Efficiencies of solvolysis for pregnenolone sulfate and DHA sulfate are 94 and 80%, Precision and accuracy studies have shown that the assays of sulfates as well as unconjugates are reproducible and accurate. Specificity was ascertained by parallelism and linearity studies. No interfering substance was detected in appreciable quantity. Plasma levels of these four compounds were determined in specimens obtained from 15 normally ovulating women. To represent the whole menstrual cycle, samples were taken 8 days before LH peak (LH-8), the day of LH peak (LH = O) and 8 days after LG peak (LH+8). Plasma contents of these compounds (geometric mean in ng/ml and 95% confidence limits in parentheses) are as follows: pregnenolone, LH-8: 1.33 (1.02-1.74), LH = 0: 1.45 (1.22-1.72), LH+8: 1.88(1.70-2.21); pregnenolone sulfate, LH-8: 70.0 (55.9-89.2), LH = 0 57.5 (40.0-82.7), LH+8: 102 (81.5-129); DHA, LH-8: 5.38 (3.90-7.43), LH = 0: 4.90 (3.58-6.79), LH+8: 4.58 (3.12-6.83), DHA sulfate, LH-8: 1480 (1110-1980), LH = 0: 1570 (1150-2140), LH+8: 1590 (1150-2190). Both pregnenolone and pregnenolone sulfate levels of 8 days after LH peak are significantly higher than those of other two days. Conversely, plasma DHA and DHA sulfate levels fluctuate over wide range with no consistent trend.