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Dive into the research topics where Donald M. Okada is active.

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Featured researches published by Donald M. Okada.


American Journal of Obstetrics and Gynecology | 1979

Prenatal and intrapartum high-risk screening

Calvin J. Hobel; Marcia A. Hyvarinen; Donald M. Okada; William Oh

Abstract A high-risk pregnancy screening system based on a prospective analysis of prenatal, intrapartum, and neonatal factors in 738 pregnancies can predict perinatal morbidity and mortality. Factors were assigned with weighted values according to their assumed risk. Total scores for the prenatal, intrapartum, and neonatal period were dichotomized to simplify the scoring system by forming a low-risk group (scores


American Journal of Obstetrics and Gynecology | 1975

Hormones in human pregnancy. IV. Plasma progesterone.

Dan Tulchinsky; Donald M. Okada

The plasma concentration of progesterone (P) has been measured by radioimmunoassay in maternal peripheral vein (M.P.V.) at early pregnancy and in M.P.V. umbilical artery (U.A.) and umbilical vein (U.V.) at term pregnancy. In early preganacy marked hour-to-hour fluctuation of plasma progesterone was noted. At term pregnancy plasma P levels of U.V. were higher than those of U.A. and the umbilical venous arterial differences of plasma P did not differ between male and femal fetuses. Administration of hydrocortisone and ACTH to patients scheduled to undergo cesarean section had no effect on M.P.V., U.A., and U.V. plasma P concentration. On the basis of the differences between U.V. and U.A. plasma P concentrations and reported umbilical flow it was estimated that the secretion rate of P into the fetal circulation is approximately 23 mg. per 24 hr. and would amount to approximately 10 per cent of the reported total daily production rate of P at term pregnancy. The fraction of P which is unbound to the plasma proteins was estimeated by equilibrium dialysis at 37 degrees C. The per cent unbound P in M.P.V. plasma of pregnant patients at term was not different from that of nonpregnant patients but was 40 per cent lower than that in umbilical cord plasma (P LESS THAN 0.01), and the ratio between the concentrations of unbound P and estradiol in M.P.V. increased as pregnancy progressed. Plasma P in re-eclamptic patients who subsequently sustained intrauterine fetal death had no value in assessing placental function.


American Journal of Obstetrics and Gynecology | 1977

Neonatal scalp abscess and fetal monitoring: factors associated with infection.

Donald M. Okada; Anthony W. Chow; Virginia T. Bruce

Forty-two of 929 (4.5 per cent) newborn infants prospectively studied following continuous, direct fetal heart rate monitoring during labor developed a scalp abscess at the site of electrode application during the neonatal period. Factors associated with infection with the use of a multivariate analysis were duration of monitoring (p less than 0.01) and high-risk indications for monitoring (p less than 0.01). Of the 42 infected neonates, 33 had complete bacteriologic studies. Microorganisms were isolated from all the infection tended to be polymicrobial, most commonly containing both aerobes and anaerobes. Staphylococcus epidermidis, Streptococcus, Peptostreptococcus, and Peptococcus were the predominant isolates. These data indicate that scalp abscess complicating intrapartum fetal monitoring may be nosocomial importance, and infants monitored should be closely observed in order to prevent more serious infectious complications.


American Journal of Obstetrics and Gynecology | 1977

Serum progesterone and estradiol-17β levels in premature and term labor

L.M. Cousins; Calvin J. Hobel; R.J. Chang; Donald M. Okada; John R. Marshall

A total of 30 to 50 per cent of premature labors occur without identifiable predisposing conditions. To evaluate the hormonal status of these pregnancies, serum progesterone (P) and estradiol (E2) were measured by radioimmunoassay singly in 60 premature labor patients and serially in 19 normal pregnancies. Premature labor patients as a group have significantly lower P and E2 levels than controls. Pregnancies complcated by idiopathic premature labor (IPL) (p less than 0.01), premature labor secondary to abruptio-marginal separation (A-MS) (p less than 0.05), and premature rupture of membranes (PROM) (p less than 0.05) have significantly lower P levels than controls. Patients with IPL and A-MS have significantly lower P levels (p less than 0.01) than PROM patients. No significant change in P or E2 occurs immediately prior to normal term labor. Conclusions are that (1) premature labor patients have significantly lower Pand E2 levels than controls, (2) the degree of P depression varies according to the type of premature labor and (3) IPL is characterized by premature labor with no identifiable predisposing factors.


American Journal of Obstetrics and Gynecology | 1987

Clinical and microbiologic risk evaluation for post—cesarean section endometritis by multivariate discriminant analysis: Role of intraoperative mycoplasma, aerobes, and anaerobes

Christine M. Williams; Donald M. Okada; John R. Marshall; Anthony W. Chow

The clinical and microbiologic risk factors for postpartum endometritis were studied prospectively in 77 patients undergoing cesarean section without antibiotic prophylaxis at Harbor-University of California at Los Angeles Medical Center. Intraoperative cultures were obtained from the amniotic fluid, lower uterine segment, and abdominal wound for isolation of genital mycoplasmas, aerobes, and anaerobes. Postsection endometritis developed in 21 (27%) patients and was significantly associated with presence of either high-virulence bacteria (predominantly, coliforms, streptococci, anaerobic cocci, and bacteroides) (35% to 60% versus 10% to 24%; p less than 0.05) or Ureaplasma urealyticum (15% to 42% versus 0% to 10%; p less than 0.05) at any site compared with afebrile women. Multivariate analysis identified primary cesarean section, younger maternal age, presence of ruptured membranes, and presence of Ureaplasma as significant risk factors independent of other confounding variables (p less than 0.01). It is suggested that genital mycoplasmas could play a primary role in some cases of postsection endometritis or that they are cofactors or markers for the presence of other high-virulence aerobic and anaerobic bacteria.


American Journal of Obstetrics and Gynecology | 1974

Plasma estrone, estradiol, estriol, progesterone, and cortisol in normal labor

Donald M. Okada; Dan Tulchinsky; Jim W. Ross; Calvin J. Hobel

Abstract The plasma concentrations of cortisol, progesterone, and unconjugated estrone (E 1 ), estradiol (E 2 ), and estriol (E 3 ) were measured by radioimmunoassay in six patients throughout normal labor induced by amniotomy. The mean plasma cortisol concentration of 199 ± 20 mg. per milliliter (S.E.M.) at the initiation of labor was not different from 175 ± 10 ng. per milliliter (S.E.M.) of 10 pregnant patients not in labor but it increased by 60 per cent throughout labor (P 1 and E 2 remained stable throughout labor. Plasma E 3 concentration did not change in four of six patients but it fluctuated significantly in one patient and fell significantly in another patient, who also sustained the highest plasma cortisol level. The mean plasma estriol of 13.8 ± 1.7 ng. per milliliter (S.E.M.) at the beginning of labor was not significantly different from 10.4 ± 1 ng. per milliliter (S.E.M.) at the end of labor (P > 0.05). The mean plasma progesterone remained unchanged throughout labor but individual patients showed occasional marked fluctuations of their plasma progesterone level. Whether or not any or all of these hormones or their changes during labor play a role in the control of parturition so far remains enigmatic.


American Journal of Obstetrics and Gynecology | 1977

Neonatal scalp abscess following intrapartum fetal monitoring: prospective comparison of two spiral electrodes.

Donald M. Okada; Anthony W. Chow

During a six-month period, 929 newborn infants had continuous, direct fetal heart rate monitoring during labor. Of these, 481 were monitored with the Berkeley Bio-Electronics spiral electrode and 448 were monitored with the Corometrics spiral electrode. The over-all incidence of scalp abscess complicating fetal monitoring was 4.5 per cent. In the group monitored with the Berkeley electrode, 25 newborn infants (5.2 per cent) developed a scalp abscess; in the group with the Corometrics electrode, 17 newborn infants (3.8 per cent) developed scalp abscess. The incidence of scalp abscess was not significantly different in the two groups.


The Journal of Infectious Diseases | 1978

Epidemiology of Group B Streptococcus: Longitudinal Observations during Pregnancy

Bascom F. Anthony; Donald M. Okada; Calvin J. Hobel


Annual Review of Medicine | 1977

THE EMERGENCE OF GROUP B STREPTOCOCCI IN INFECTIONS OF THE NEWBORN INFANT

Bascom F. Anthony; Donald M. Okada


The Journal of Clinical Endocrinology and Metabolism | 1976

Simultaneous Comparison of Δ5-3β-Hydroxysteroid Levels in the Fetoplacental Circulation of Normal Pregnancy in Labor and Not in Labor

R. Jeffrey Chang; John E. Buster; Jerry L. Blakely; Donald M. Okada; Calvin J. Hobel; Guy E. Abraham; John R. Marshall

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Calvin J. Hobel

Cedars-Sinai Medical Center

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John R. Marshall

Memorial Hospital of South Bend

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Dan Tulchinsky

Brigham and Women's Hospital

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Guy E. Abraham

University of Tennessee Health Science Center

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John E. Buster

Baylor College of Medicine

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