Comparison of intermittent and continuous epidural analgesia on delivery and progression of labour.

In this study, 205 nulliparous parturients were enrolled to receive either intermittent (n = 101) or continuous (n = 104) type of epidural analgesia in labour. The primary outcome was rate of caesarean deliveries, whereas secondary outcomes included rate of fundal pressure manoeuvres, duration of labour from application of analgesia, dose of anaesthetic and short-term maternal and neonatal outcome between two groups. Rate of caesarean deliveries was significantly increased in the continuous group (15/104 vs 5/101, p = 0.02), as well as rate of fundal pressure manoeuvres (24/104 vs 11/101, p = 0.02) and dose of fentanyl (100 [100-300] vs 187.5 [125-450] µg, p < 0.001 and levobupivacaine (40 [40-60] vs 75 [50-90] ml, p < 0.001). Duration of labour from analgesia to delivery was not significantly different between the two groups (414 ±â€Š101 vs 432 ±â€Š94 min, p = 0.12).

Uterine anomalies and pregnancy outcome following resectoscope metroplasty.

OBJECTIVE: To compare reproductive outcome in women with uterine anomalies and women with a normal uterus, and evaluate the effect of resectoscope metroplasty. METHODS: The pregnancy outcomes, past and present, of 105 women with congenital uterine anomalies were compared with those of 182 women with a normally shaped uterus. The outcomes of 25 women with septate and bicornuate uteri before and after resectoscope metroplasty were also analyzed. The chi(2) and Mann-Whitney U test were used for statistical analysis, with P<0.05 considered statistically significant. RESULTS: Uterine anomalies were associated with higher rates of spontaneous abortion, preterm delivery, intrauterine growth retardation, breech presentation, and cesarean delivery (P<0.001). The highest incidence of early spontaneous abortion was noted among women with septate uteri, and the highest incidence of preterm labor was noted among women with arcuate or bicornuate uteri. Among women with arcuate uteri, significantly lower gestational age and birth-weight were observed compared with any other type of adverse outcome. Compared with their previous pregnancies, the abortion rates were lower and delivery rates were higher in women who conceived following hysteroscopic metroplasty (P<0.001). CONCLUSION: Resesctoscope metroplasty significantly improved pregnancy outcome in women with uterine anomalies.

The methylenetetrahydrofolate reductase 677 C-->T polymorphism and preeclampsia in two populations.

OBJECTIVE: The C677T polymorphism of the 5,10 methylenetetrahydrofolate reductase (MTHFR) gene is associated with decreased MTHFR activity and elevated plasma homocysteine levels with the result of an increased risk for vascular disease. Because thrombosis of the maternal spiral arteries can be one of the causative events in the disease, it has been suggested that the C677T polymorphism may also play a role in the pathogenesis of preeclampsia. Our case-control study investigated the prevalence of the 677T allele in two ethnically different populations and the potential association of the 677T allele with preeclampsia. Special attention was paid to the potential contribution of the fetal genotype to disease risk. METHODS: Blood samples were collected from 81 mothers and 61 newborns after preeclampsia and 99 mothers and 61 newborns with normal pregnancies. Genomic DNA was amplified by polymerase chain reaction with locus-specific primers, and presence of the polymorphism was determined by enzymatic digestion with HinfI and visualization on polyacrylamide gels. RESULTS: Genotypes carrying the MTHFR 677T allele were significantly more frequent in German-Croatians than in Indonesians in both patients and controls (P =.0033 in controls). In contrast, the prevalence of genotypes with the 677T allele was not increased among patients with preeclampsia compared with controls in both ethnic groups (P >.5 in all groups). In Germans, the frequency of 677T homozygotes among controls even exceeded that observed in preeclamptic patients (677T/T genotype frequency 0.20 in controls and 0.07 in patients). We did not find an increased prevalence of paternally inherited 677T alleles in preeclamptic fetuses relative to controls or other signs of maternal-fetal transmission distortion. CONCLUSION: In our study, the MTHFR C677T polymorphism was not associated with an increased risk for preeclampsia on the level of the maternal or fetal genotype. However, significant differences of the frequency of genotypes carrying the 677T allele between Middle-Europeans and Indonesians were identified.

Hospitalization vs. outpatient care in the management of triplet gestations.

OBJECTIVE: To compare the course and outcome of triplet gestations under a preventive care strategy that includes hospitalization, surveillance, bed rest, and daily specialized care from the beginning of the second trimester, with pregnancies managed according to the Croatian standard outpatient care protocol for multiplets. METHODS: A retrospective study of 79 triplet pregnancies. Preventive hospitalization from the beginning of the second trimester, with complete bed rest and all necessary interventions, was chosen by 55 women (Group I). The remaining 24 women (Group II) elected the standard outpatient protocol for multiple pregnancies. Outpatient management with prophylactic bed rest was initiated at home as soon as the multiple pregnancy was diagnosed. After 28 weeks of gestation, all outpatients were hospitalized until delivery irrespective of symptoms. RESULTS: There was no difference between the groups regarding maternal age, race, pre-pregnancy weight and height, weight gain during the first 24 weeks of pregnancy, or the proportion of pregnancies achieved with assisted reproductive technology. Four out of 55 women (7.2%) from Group I and 4 out of 24 women (12.5%) from Group II had monochorionic triplet pregnancies (P=n.s.). Nulliparity was more frequent in Group I than in Group II (P=0.006). Elective cesarean delivery was significantly more frequent in Group I (46 out of 55 gestations, 72.7%) than in Group II (9 out of 24 gestations, 37.5%), P=0.024. Gestational age at delivery and mean birth weight were significantly higher in Group I than in Group II (P<0.001). Deliveries up to 28 weeks of pregnancy were infrequent in Group I (P=0.02). Thirty-three gestations in Group I (60%) and 6 (25%) in Group II had a duration of 33-36 weeks (P<0.001). Two out of 55 triplet gestations in Group I (3.6%) and 4 out of 24 in Group II (16.7%) ended in spontaneous abortion (P=0.053). The survival of the three triplets was more frequent in Group I than in Group II (P=0.048). For gestations reaching 24 weeks or more, the fetal and perinatal death rate was significantly lower in Group I (P<0.001). In Group I the intrauterine death rate for fetuses weighing 1500 g or less was also significantly lower (P=0.007), and the early neonatal death rate was almost half (15.8 vs. 28.9%, P=0.157). There were no differences in other pregnancy complications between the two groups except significantly more frequent preterm premature rupture of membranes and preterm labor requiring parenteral tocolysis in Group II (P=0.042 and 0.036, respectively), and significantly more frequent fetal growth retardation in Group I (P<0.001). CONCLUSION: Preventive hospitalization offers a better outcome for triplets even though prolonged hospitalization and all other procedures necessary to achieve optimal pregnancy outcome are also offered in the Croatian standard outpatient care protocol for multiplet pregnancies.

Antenatal predictors of the neurologic sequelae at 3 years of age: a multivariate analysis.

OBJECTIVE: To study the association between fetal blood flow abnormalities and the occurrence of long-term neurologic sequelae. STUDY DESIGN: Umbilical, aortic and middle cerebral artery blood flow parameters were obtained by Doppler examination and retrospectively analyzed in 128 high-risk singleton pregnancies, followed by neurologic examination of the surviving children at 3 years of age. Traditional parameters of neurologic outcome (Apgar scores, intrauterine growth retardation (IUGR), umbilical artery pH and base deficit, gestational age, birth weight, newborn encephalopathy, mode of delivery, fetal heart rate, neurosonographic examination) were included as possible confounding factors. Mann-Whitney U-test, Student's t-test, analysis of variance or Fisher's exact test, where applicable, were used for the univariate analysis. A stepwise logistic regression procedure was conducted to test the independent association of selected perinatal risk factors on neurological outcome. Statistical significance was assumed at P<0.05. RESULTS: Eighteen out of 114 surviving children suffered neurologic illness at 3 years of age. Four children had major neurologic dysfunction and the remaining 14 suffered minor or mild form of the disease. Although blood flow parameters and various perinatal parameters did not differ significantly between the group of children with major neurologic dysfunction and healthy children, aortic resistance index showed an independent association with occurrence of minor or mild neurologic disabilities. CONCLUSION: Antenatal evaluation of the aortic blood flow might be an important predictive variable for permanent neurologic disturbances.

Pregnancy outcome in renal transplant recipients.

OBJECTIVE: To correlate pregnancy outcome with complications in pregnancy and transplantation-to-pregnancy interval in renal transplant recipients in Croatia. METHOD: Data on 23 pregnancies after prepregnancy stabilization of blood pressure and normalization of graft function were retrospectively analyzed. RESULT: The mean interval between transplantation and conception was 3.1 years. Primary renal disease was chronic glomerulonephritis in 7, chronic pyelonephritis in 7 and agenesis of right kidney and stenosis of left renal artery in 1 patient. There were 10 term and 5 preterm deliveries, 6 induced and 2 spontaneous abortions. The mean gestational age was 38.1 weeks and the mean newborn birthweight was 3015 g. The prematurity rate was 21.7%. Patients with arterial hypertension in pregnancy, elevated serum creatinine level and bacteriuria, as well as those with conception occurring less than 2 years after transplantation, had a higher rate of therapeutic and spontaneous abortions, preterm deliveries and low birth weight infants. CONCLUSION: The interval between transplantation and conception, as well as allograft function during pregnancy, seem to be of great importance for successful obstetric outcome in renal transplant patients.

HLA-G polymorphisms and molecule function--questions and more questions--a review.

Human leukocyte antigen (HLA)-G is a non-classical HLA-class I antigen which is predominantly expressed on invasive trophoblastic cells and is postulated to be a mediator of maternal-fetal tolerance. HLA-G interacts with NK cells, can present nonamer peptides and binds CD8 in an analogous manner to classical HLA-I. The HLA-G protein exists in soluble and membrane-bound isoforms generated through alternative splicing. Although initially considered to be non-polymorphic, variations of the HLA-G DNA sequence have been reported which led to the definition of a limited number of HLA-G alleles including the Null-allele G*0105N. Whereas the HLA-G DNA sequence shows a high degree of conservation in positions which are essential for classical HLA-I molecule functions, polymorphic sites in HLA-G are not congruent with sites of high nucleotide variability in classical HLA. The identification of two females with recurrent spontaneous abortions who are homozygous for the G*0105N Null-allele re-opens the discussion about the role of HLA-G in pregnancy and underlines the need of a systematic analysis of the different hypotheses of HLA-G function in vivo.

Pheochromocytoma with negative urinalysis in pregnancy.

We present a rare case of adrenal pheochromocytoma in pregnancy, with serial 24-h urine specimen collections showing normal concentrations of catecholamine metabolites. The diagnosis was based on clinical presentation, abdominal ultrasound, and magnetic resonance imaging, and was confirmed on post-operative pathohistological examination. Clinical suspicion of pheochromocytoma in pregnancy should be sufficient to implement adequate therapeutic measures, regardless of urine catecholamine concentrations.

Maternal neonatal outcome in quadruplet and quintuplet versus triplet gestations.

OBJECTIVE: Examination and comparison of the natural histories of triplet versus quadruplet and quintuplet gestations. STUDY DESIGN: A retrospective study of sixty-four multifetal pregnancies (fifty-two sets of triplets, nine sets of quadruplets and three sets of quintuplets) cared for during past 12 years in our department. Quintuplets and quadruplets were compared with triplet pregnancies according to gestational age, birthweight, pregnancy complications and perinatal outcome. Student's t-test, Fisher exact test and chi2 test were used for statistical analysis, considering P value of <0.05 as statistically significant. RESULTS: Although mean gestational age at delivery between triplets and higher order gestations was not significantly different, birthweight of quadruplets and quintuplets was significantly lower. Pregnancy complications, including intrauterine growth retardation, were equally distributed between the groups. Early neonatal and perinatal mortality were significantly higher in quadruplets and quintuplets than in triplets. Surprisingly, survival of growth retarded fetuses was better than survival of their eutrophic counterparts. The spontaneous loss rate was 11.5% for entire triplet gestation and 16.7% for quadru- and quintuplet pregnancies. CONCLUSIONS: As the spontaneous loss rate of triplets and higher order pregnancies observed in our study is quite similar to pregnancy loss rate caused by multifetal pregnancy reduction, conservative management of multifetal pregnancies in specialised tertiary centers seems to be a prudent solution.

The triple-marker test in predicting fetal aneuploidy: a compromise between sensitivity and specificity.

OBJECTIVE: to review the contribution of unconjugated estriol in Down's syndrome detection, and influence of maternal age, cut-off choice, and population specificity on the balance between triple-marker test sensitivity and specificity. STUDY DESIGN: Prenatal karyotyping was performed in 2833 pregnant women, 73% of them over the age of 34. Duration of gestation was determined by ultrasound in 98% of women. Prior to amniocentesis, the serum levels of alpha-fetoprotein, human chorionic gonadotropin and unconjugated estriol were evaluated and corrected for weight. The risk of trisomy 21 was calculated for the first 986 subjects using default medians, and for 1847 by our population-specific medians. The cut-off was initially 1:300 at term, but the 1:100 and 1:200 risks were also tested. Down syndrome risk was calculated with alpha-fetoprotein and human chorionic gonadotropin combination as well. Linear logistic regression model was performed to test the ability of aneuploidy markers to classify patients into normal and trisomic groups. RESULTS: There were twelve cases of Down's syndrome, seven of trisomy 18, four of trisomy 13, and one trisomy 22. Four cases of aneuploidy (16.7%) referred to women younger than 35. With the cut-off risk of 1:300, detection rate was 87.5% and specificity 63.3%, and with 1:100, 66.7% and 79.5%, respectively. The sensitivity for Down's syndrome was from 75% for cut-off=1:100 to 92% for cut-off=1:300, while detection of other trisomies was less successful (58% and 83%, respectively). Exclusion of unconjugated estriol MoM from the risk calculations reduced detection rate by 33% and improved specificity by 4% independently of cut-off choice. Linear logistic regression analysis showed that only unconjugated estriol was able to correctly classify patients between normal and trisomy 21 (p=0.011, odds ratio=1.445), and normal and trisomy 18 (p=0.0023, odds ratio=1.96) groups. CONCLUSIONS: The unconjugated estriol significantly contributes in Down's syndrome detection with cost of slightly reduced specificity. The 1:300 risk caused an unfavorable compromise between sensitivity and specificity. A higher cut-off, 1:100, would indicate performance of amniocentesis in women aged 39 years and older, and in those aged 35-39 only after the screen-positive result.

Effects of tamoxifen on steroid hormone receptors and hormone concentration and the results of DNA analysis by flow cytometry in endometrial carcinoma.

OBJECTIVES: Tamoxifen is a nonsteroidal triphenylethylene derivate with a predominant antiestrogen activity, used in the endocrine treatment of breast and endometrial cancer. It is not known which endometrial carcinomas will respond favorably to tamoxifen and which ones will not. The aim of this study was to find out whether tamoxifen has an effect on hormone steroid receptors, hormone concentration, DNA content, and proliferative activity in endometrial cancer and to correlate the tamoxifen-induced changes with pathologic parameters such as clinical stage, tumor differentiation, depth of invasion, and histologic type. METHODS: Thirty postmenopausal women with endometrial carcinoma were treated with 30 mg of tamoxifen daily for 7-10 days after curettage. Steroid hormone receptors (estrogen and progesterone receptors), levels of follicle-stimulating hormone, luteinizing hormone, prolactin, estradiol, progesterone, testosterone, dehydroepiandrosterone sulfate, sex hormone binding globulin, and DNA ploidy and proliferative activity were determined before and after therapy. The patients were also divided into favorable and unfavorable prognosis groups according to classical histological parameters. The patients in the favorable group consisted of patients with stage I disease, well and moderately differentiated tumors, favorable histologic type, and a depth of myometrial invasion of less than (1/3). The patients with only one of the unfavorable parameters (clinical stage II or III, poorly differentiated tumors, unfavorable histologic types, and deeper invasion of myometrium) were included in the unfavorable prognosis group. RESULTS: After the treatment, there was a net increase in the progesterone receptors and sex hormone binding globulin and a significant decrease in the estrogen receptors. The increase in progesterone receptors and decrease in estrogen receptors occurred in the patient group with favorable prognosis regarding histologic type, degree of differentiation, and clinical stage, but also in the unfavorable prognosis group regarding the depth of myometrial invasion. Statistically significant decrease in the follicle-stimulating hormone concentration was observed in the groups with favorable prognosis regarding histologic type, depth of myometrial invasion, and grade of differentiation. Concentration of sex hormone binding globulin was significantly increased in groups with favorable prognosis if histologic type and grade of differentiation were taken into account. On the other hand, there was a significant decrease in the concentration of luteinizing hormone in the group with unfavorable histologic type and also a decrease in progesterone concentration in patients with unfavorable prognosis regarding the grade of differentiation. There was no statistical significance either in the concentrations of other hormones measured or in the DNA analysis by flow cytometry. CONCLUSIONS: Our results revealed that tamoxifen can increase progesterone receptors and decrease estrogen receptors in endometrial cancer. The effect was most pronounced in tumors with favorable clinicopathologic parameters. We conclude that tamoxifen therapy can induce progesterone receptor synthesis even in tumors with low initial progesterone receptor levels, making such tumors potentially responsive to additional hormonal therapy with progesterone.

HLA-G polymorphisms: ethnic differences and implications for potential molecule function.

PROBLEM: Human leukocyte antigen (HLA)-G is uniquely expressed on extravillous cytotrophoblasts of the placenta and is postulated to be a mediator of maternal immune tolerance. Although it was originally considered to be nonpolymorphic, variations of the HLA-G DNA sequence have been reported, and a limited number of HLA-G alleles been defined. METHOD OF STUDY: The HLA-G wild-type sequence was compared with HLA-A2 with regard to the conservation of functionally essential parts of classical HLA-I molecules. HLA-G polymorphisms were analyzed under the aspect of ethnic differences, site, and consequences for postulated molecule functions. RESULTS: HLA-G exhibits a high degree of conservation relative to HLA-A2 in functionally relevant sites of HLA-class I molecules. However, polymorphic sites in HLA-G and classical HLA loci are not congruent. CONCLUSION: The type and localization of HLA-G polymorphisms suggest that different parts of HLA-G molecule underlie different selective constraints.

HLA-G polymorphisms and allele frequencies in Caucasians.

HLA-G, a nonclassical class I MHC molecule, is uniquely expressed on extravillous cytotrophoblasts of the maternal-fetal interface and is suggested to be essential for establishment of maternal-fetal immune tolerance. Although the level of polymorphism in HLA-G has originally been considered low, number, nature and site of polymorphisms seem to vary between different ethnic populations. We investigated HLA-G polymorphisms in a population of German and Croatian origin by SSCP-analysis and direct sequencing as well as RFLP analysis for presence of the 1597delC mutation. HLA-A alleles associated with the different HLA-G alleles were determined by SSP PCR-typing. In Caucasians, HLA-G exhibits a low degree of polymorphism on the amino-acid level and only slightly higher variability on the nucleotide level. In 264 independent chromosomes, 4 HLA-G alleles on the level of amino acid polymorphisms and an additional 6 variations of nucleotide sequences could be identified. The null-allele G*0105N was present at an allele frequency of 2.3%, which is higher than initially suggested for Caucasians but lower than in Hispanics and African-Americans. Furthermore, some HLA-G alleles exhibit strong linkage disequilibrium with HLA-A.

Possible influence of expatriation on perinatal outcome.

BACKGROUND: In order to test the hypothesis of possible influence of environmental stress on the length of gestation the data on deliveries in the Maternity Unit, Zagreb University School of Medicine in three six months periods; May-October 1991 (active war in Croatia), May-October 1990 (pre-war period), and the same period in 1992 are analysed. METHODS: Deliveries of 7845 women from free areas of Croatia (non-displaced population) and deliveries from 712 women from occupied areas of Croatia, as well of 593 Croatian refugees from Bosnia and Herzegovina and Serbia (expatriated population) were compared. The duration of pregnancy, fetal weight, immediate neonatal condition, mode of delivery and perinatal outcome in non-displaced and expatriated population were compared using chi-square test in statistical analysis. RESULTS: During 1992 and 1991, there was a slight increase in total number of deliveries in comparison to 1990. The number of deliveries by displaced women more than doubled. The incidence of major pregnancy complications was almost the same for both groups in all three time periods. The two populations were comparable regarding their age, parity and previous obstetric history. Slight increase in preterm delivery rate (7.7% in l990, 8.7% in 1991 and 9.4% in 1992), and a subsequent slight decrease in birth weight was found in all women. There was no significant change in the proportion of growth-retarded newborns. Expatriated women both in 1990 and in 1991 delivered twice as often prematurely in comparison to non-displaced women (17.5% and l4.3% deliveries), respectively. Birth weight of their infants was significantly more often under 2500 grams. Slight increase in overall perinatal mortality was observed. Perinatal mortality in the experiated population was significantly higher than in the non-displaced population. Increase in perinatal mortality could be attributed exclusively to increase in prematurity rate. CONCLUSION: Our results support the concept of possible influence of stress, fear, exile and inadequate antenatal surveillance on the length of gestation.

Antenatal fetal demise in multiple gestation--the outcome of surviving fetus at one to four years of age.

The outcome of 26 multifetal pregnancies with single fetal demise after 12 weeks of pregnancy cared for at the University Medical School of Zagreb from 1986 to 1991 is presented. Growth retardation of dead and surviving infant and pathohistological findings consistent with reduced uterine blood flow to cotyledonary space was the most frequent complication, irrespective of the type of placentation. Perinatal infection was the most frequent neonatal complication. Neonatal asphyxia was observed in only one infant. The outcome at 1-4 years of age was perfect in 14 out of 15 surviving infants for whom data are available. An early diagnosis of multifetal pregnancy, based essentially on ultrasonography and appropriate monitoring of the mother and the survivor, with cesarean delivery carried out at first signs of imminent asphyxia, is the best guarantee for a favorable outcome.

[The effect of chronic kidney disease on the course and outcome of pregnancy]. / Utjecaj kronicnih bubreznih bolesti na tijek i ishod trudnoce.

In order to estimate the effect of renal disease on the pregnancy, and the effect of pregnancy on the natural course of renal disease, the course and outcome of the 37 pregnancies was analyzed in gravidas with chronic renal disease. The women were cared for between 1978 and 1990 at the Department of Obstetrics, School of Medicine University of Zagreb. Analysis of the results in this article is retrospective. Thirty-six pregnancies finished by vaginal or cesarean delivery or by abortion, while one pregnancy was ectopic and ended by laparotomy during the 20th week. There were 31 live births from 36 fetuses (86.1%), 5 stillbirths (13.19%), of which 2 pregnancies ended in fetal death (abortion). In addition, there were 6 instances of neonatal death (8.3%). Twenty-five percent of pregnancies finished before 37 weeks of gestation. In 6 of 34 (17.6%) deliveries amniotic fluid was meconium stained, and 5 of 31 (16.1%) infants were born hypoxic. There were 29 percent of growth retarded liveborn fetuses. Perinatal mortality was 167/1000. Renal insufficiency was noted in 12 of 37 (32.4%) pregnancies, 54% of pregnant women had hypertension, 8.1% hyperkalemia, 78.4% were anemic, 27% had significant bacteriuria and 21.6% overt pyelonephritis. There was one case of acute deterioration in renal function that required hemodialysis, and one case of preeclampsia. Renal insufficiency or hypertension reduce drastically the chances for a successful outcome of pregnancy in gravidas with kidney disorders. However renal insufficiency in the presence of hypertension, carries even poorer prognosis, with perinatal mortality of 428/1000.

[Pregnancy and labor associated with encephalopathy in neonates during the early neonatal period]. / Trudnoca i porod u novorodencadi s encefalopatijom u ranom neonatalnom razdoblju.

Pregnancy complications, drugs and surgical interventions during pregnancy, fetal growth, medications and interventions during labor, labor complications as well as fetal heart activity during labor in a group of 114 term infants without malformations, but with signs of central nervous system (CNS) damage throughout early neonatal period are compared with paired group of term healthy infants born in the same presentation and mode of delivery. Among prelabor factors only maternal hypertension (found in 16.7% of encephalopathy children versus 0.8% in a control group) was significantly correlated with CNS damage. Fetal growth retardation and long term ritodrine administration were found more frequent in encephalopathy than in healthy group of infants, although statistical significance between the groups could not be demonstrated. A prolonged second stage of labor, high oxytocin dosage, too frequent uterine contractions and vacuum extractions were found significantly correlated with neonatal encephalopathy. CTG pattern during labor was normal in only 28.9% of children, with encepalopathy prepathologic in 46.4% and pathologic in 24.7%. The respective percentages for healthy newborns were: 82.5%, 16.25% and 1.2%. All differences between the groups were statistically significant. Mean duration of prepathologic CTG score in the group of infants with encephalopathy (78.8 minutes) as well as of pathologic score (51.7 minutes) was significantly longer than in healthy infants (23.7 minutes prepathologic and 7 minutes pathologic).(ABSTRACT TRUNCATED AT 250 WORDS)