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Biomedical subjects

J P Pirhonen

Publications and source records attributed to J P Pirhonen.

At least 19 recordsLinked to original sources
PubMed2003

Thermal response to submaximal exercise before, during and after pregnancy: a longitudinal study.

BACKGROUND: Heat stress in early pregnancy is known to have a teratogenic effect. Exercise produces excess heat and during pregnancy might therefore present a theoretical risk of malformations. Our aim was to assess the thermal response to exercise of healthy pregnant women in a longitudinal study. METHODS: Fourteen women were examined before pregnancy, and followed five times during, and twice after pregnancy, using a submaximal bicycle test with a target heart rate of 85% of the predicted age-adjusted maximum. The main aim was to present reference values. RESULTS: The temperature at submaximal work load declined continuously from preconception to postpartum levels (37.8 degrees C vs. 36.9 degrees C, p = 0.04). The difference between peak and basal core temperature fell from 0.6 degrees C to 0.05 degrees C at 29 and 36 weeks of gestation, reaching preconception levels at 24 weeks after delivery (0.8 degrees C lower). CONCLUSION: During submaximal exercise the temperature response seemed to provide thermal protection for the embryo and the fetus.

Adult↗
PubMed1999

Screening for endometrial cancer in asymptomatic postmenopausal women with conventional and colour Doppler sonography.

OBJECTIVE: To evaluate endometrial thickness and uterine arterial flow measurement as predictors of endometrial cancer. DESIGN: Prospective study among a cohort of women invited to age-adjusted, population-based breast cancer screening by mammography. SETTING: City of Turku, Finland. POPULATION: 1074 postmenopausal women aged 57-61 years (mean 59 years). METHODS: Conventional and colour Doppler sonography. Endometrial biopsy was taken when the endometrial thickness (double layer) was > or = 4.0 mm, if the uterine artery pulsatility index was < or = 1.0 or if there was a fluid accumulation in the endometrial cavity. MAIN OUTCOME MEASURES: Detection of endometrial cancer in endometrial biopsy. Record linkage with the files of the Finnish Cancer Registry three and a half years after the first ultrasound examination. Major statistical results are based on the analysis of variance and logistic regression models. RESULTS: An endometrial biopsy was taken from 291 women (27%). One woman had endometrial tuberculosis, three an endometrial polyp, 16 endometrial hyperplasia, three endometrial carcinoma (Stage Ib), and one had cervical carcinoma (Stage Ib). One woman was diagnosed as having endometrial cancer Stage Ib two and a half years after screening; she had refused further examination after a positive screen. A second endometrial cancer (Stage Ib) was diagnosed three years after a negative screening result. CONCLUSION: Transvaginal sonography is confirmed to have a very high sensitivity for the detection of early endometrial carcinoma, but the specificity remains low. If endometrial cancer is to be detected at an early stage, further examinations should be carried out when the endometrial thickness is > or = 4.0 mm, especially when the woman has risk factors such as obesity, late menopause or current use of hormonal replacement therapy. Doppler sonography does not improve the detection of premalignant and malignant endometrial lesions compared with normal ultrasound.

Biopsy↗
PubMed1998

Frequency of anal sphincter rupture at delivery in Sweden and Finland--result of difference in manual help to the baby's head.

BACKGROUND: Anal sphincter rupture is a serious complication of vaginal delivery and almost half the affected women have persistent defecatory symptoms despite adequate primary repair. During the past decade, the incidence of anal sphincter ruptures has been increasing in Sweden and is currently estimated to occur in 2.5% of vaginal deliveries. The aim of the study was to report the frequency of anal sphincter ruptures in two university hospitals in two Scandinavian countries, Malmö in Sweden and Turku in Finland, and analyze the potential determinants. METHODS: Retrospective analysis of a population of 30,933 deliveries (26,541 vaginal) during the years 1990 to 1994. RESULTS: The incidence of anal sphincter ruptures in Malmö, Sweden was 2.69%, and in Turku, Finland 0.36%. There were no significant population differences for the known risk factors (fetal weight, nulliparity or fetal head circumference). However, there is a difference in manual support given to the perineum and to the baby's head when crowning through the vaginal introitus between Malmö and Turku. The proportion of operative vaginal deliveries and abnormal presentations was significantly higher in Turku reflected in the lower Apgar score at 5 minutes and longer duration of second phase of labor. When high risk deliveries (operative vaginal delivery, abnormal presentation and newborns over 4,000 g) were excluded, the risk for anal sphincter ruptures was estimated to be 13 times higher in Malmö than in Turku. CONCLUSIONS: The difference in the incidence of anal sphincter rupture between Malmö, Sweden and Turku, Finland may be due to the difference in manual control of the baby's head when crowning.

Anal Canal↗
PubMed1997

Significance of a single CA 125 assay combined with ultrasound in the early detection of ovarian and endometrial cancer.

We evaluated the utility of a single CA 125 measurement in combination with transvaginal sonography for early detection of ovarian and endometrial cancer in asymptomatic postmenopausal women. A sample of peripheral blood was taken from 1291 apparently healthy postmenopausal women, who were examined by conventional and color Doppler ultrasound for early detection of ovarian and endometrial cancer. Serum CA 125 was determined in all samples 3 years later by the IMx CA 125 assay (Abbott Laboratories, Abbott Park, IL). The cutoff level based on the 99th percentile was 30 U/ml. Elevated values were controlled by repeat sonography and an additional determination of CA 125. Record linkage with the files of the Finnish Cancer Registry was performed 3 1/2 years after the primary sonographic screening. The mean CA 125 concentration was 8.1 U/ml (range 0-1410 U/ml). Fourteen of the 1291 women had a CA 125 level greater than 30 U/ml. None of these had signs of either endometrial or ovarian malignancy in the primary sonography screening. Among the other women three cases of endometrial carcinoma (all stage Ib) and one ovarian carcinoma (stage Ia with borderline malignancy) were detected by sonography. All these patients had a CA 125 value <30 U/ml, the mean value being 11.4 U/ml (range 7.5-16.7 U/ml). During follow-up of 3.5 years, one stage Ia ovarian carcinoma, one abdominal carcinomatosis, and two endometrial carcinomas (both stage Ib) were diagnosed. In these patients the mean value for CA 125 was 12.7 U/ml (range 2.5-30.9 U/ml) at the primary sonography screening. A single CA 125 measurement provides no advantage in the early detection of ovarian and endometrial cancer in asymptomatic postmenopausal women compared with transvaginal sonography. The vast majority of women with an elevated CA 125 value have some reason other than an ovarian or endometrial malignancy for this finding.

CA-125 Antigen↗
PubMed1996

Nitrous oxide inhalation: effects on maternal and fetal circulations at term.

OBJECTIVE: To evaluate the hemodynamic effects of nitrous oxide inhalation in normal term pregnancy. METHODS: Twenty healthy term pregnant women were given 30% nitrous oxide in pure oxygen for 2 minutes, and the hemodynamics were assessed by pulsed-wave color Doppler velocimetry of the uterine and internal carotid artery of the mother and the umbilical and middle cerebral artery of the fetus. Each vessel was assessed separately, allowing a 5-minute wash-out period between the inhalations. The measurements were continued for 2 minutes after the inhalation, and the pulsatility index (PI) was determined at 1-minute intervals. The maternal heart rate and blood pressure (BP) were recorded before and after inhalation; fetal well-being was confirmed with cardiotocography. Analysis of variance for repeated measurements and paired-sample t test were used for statistical analysis. RESULTS: A significant decrease in the PI of the maternal internal carotid artery was observed after 2-minutes of inhalation (from 0.83 +/- 0.22 to 0.71 +/- 0.20; P < .001). The uterine artery PI and maternal BP and heart rate were not affected by nitrous oxide. A significant decrease was evident even in the fetal middle cerebral artery PI (from 1.37 +/- 0.27 to 1.22 +/- 0.17; P = .02). The umbilical artery PI remained unchanged. CONCLUSION: Both maternal and fetal central vascular resistance were decreased by 30% nitrous oxide inhalation. So far, no adverse effects to mother or fetus have been demonstrated in clinical practice. However, preterm fetuses are susceptible to intracranial hemorrhage, and the cerebral hyperemia by nitrous oxide might increase the risk of hemorrhage in these fetuses. This hypothesis requires further investigation.

Adult↗
PubMed1996

Endometrial fluid accumulation in asymptomatic postmenopausal women.

Postmenopausal endometrial fluid accumulation was considered in the past to be related to cancer of the genital organs. Our purpose was to evaluate its prevalence, and its association with cervical stricture, use of hormone replacement therapy and endometrial pathology. A group of 1074 asymptomatic postmenopausal women aged 57-61 (mean 59) years was examined by transvaginal sonography with color Doppler imaging. Women who had an endometrial fluid accumulation underwent endometrial biopsy. Statistical analysis was mainly based on analysis of variance. Endometrial fluid accumulation was found in 134 women (12%). Women using only estrogen as hormone replacement therapy had a relative risk of 3.5 of endometrial fluid accumulation. In 12 women (9%), a cervical stricture precluded endometrial sampling. Six abnormal histopathological samples were found (5%): two endometrial polyps, one cystic hyperplasia, two adenomatous hyperplasias but only one adenocarcinoma. One further patient with endometrial cancer was registered by the Finnish Cancer Registry 2.5 years later in a woman who had refused endometrial sampling. Endometrial fluid accumulation is quite a common finding on transvaginal sonography among asymptomatic postmenopausal women and the process may be multifactorial. Cervical stricture is not the most important etiological factor. The use of estrogen replacement therapy increases the risk of endometrial fluid accumulation; however, it is rarely a sign of malignancy.

Analysis of Variance↗
PubMed1995

Evaluation of ovarian findings in asymptomatic postmenopausal women with color Doppler ultrasound.

BACKGROUND: To evaluate the prevalence and significance of abnormal ovarian findings in asymptomatic postmenopausal women, screening for ovarian cancer with color Doppler ultrasound was performed. METHODS: One thousand three hundred sixty-four asymptomatic women aged 56-61 years (mean, 59 years) were examined by color Doppler sonography. Ninety-six percent of the examinations were transvaginal and 4% transabdominal. The criteria for abnormality were an ovarian volume 8 cm3 or greater, nonuniform echogenicity, and/or pulsatility index (PI) of the ovarian artery or tumor vessel, if present, 1.0 or less. Repeat sonograms were performed 1-3 months later on all patients with abnormal findings, and exploratory laparotomy was performed if a malignant tumor was suspected. RESULTS: Abnormal ovarian findings were detected in 160 women (12%). At the time of repeat sonogram there were 28 persisting abnormalities (2%). At that time, the ovary was regarded as normal if it still contained a small clear cyst with an unchanged greatest dimension of less than 20 mm. Three women had a low PI value but all had also abnormal ovarian sonographic morphology. Two ultrasound-guided cyst punctures were performed and three patients had surgery; one benign serous cyst, one benign serous cystadenoma, and one serous cystadenoma of borderline malignancy were detected. The remaining abnormal findings disappeared or remained unchanged during a minimum follow-up of 2 years. One case of Stage IA ovarian cancer has been reported 2 years after a negative screening and one abdominal carcinomatosis 2 1/2 years after a negative screening result. CONCLUSIONS: There is a high frequency of small ovarian cysts in asymptomatic postmenopausal women. A large percentage of these cysts regress spontaneously or remain unchanged. Transvaginal color Doppler ultrasound is an effective method for detecting these lesions. Color Doppler does not increase substantially the number of operations for benign reasons. However, as a primary screening modality, the conventional sonography seems to be quite sufficient.

Female↗
PubMed1995

Effects of external radiotherapy on uterine blood flow in patients with advanced cervical carcinoma assessed by color Doppler ultrasonography.

BACKGROUND: This study was designed to evaluate radiation-induced changes in tumor blood flow by color Doppler ultrasonography. METHODS: Color Doppler examination was performed on 14 patients with advanced cervical carcinoma treated with external radiotherapy. The total dose of radiation varied from 30 to 65 Gy and was given as 1.9 Gy daily fractions, 5 days/week. Tumor vascularity and blood flow impedance were measured by one pretreatment and five follow-up examinations. RESULTS: At the baseline examination, 11 of 14 patients had very low tumor blood flow impedance (< 0.70). Radiotherapy caused a significant decrease in tumor vascularity (P = 0.0001) and in presence of very low blood flow impedance. The decrease of tumor vascularity during the treatment was associated with better outcome, whereas persistence of excessive vascularity or of vessels with low blood flow impedance at the end of radiation was associated with modest therapeutic response. Eight of 10 patients with increased tumor vascularity at the end of radiation needed further treatment or died of disease. Only one of four patients with normal vasculature at the end of radiotherapy needed further treatment and all four were clinically disease free during the follow-up (mean, 13 months; range, 6-26 months). CONCLUSIONS: These results suggest that color Doppler ultrasonography may be useful in early assessment of therapeutic response during radiotherapy and in for planning individualized treatment schedules.

Adenocarcinoma↗
PubMed1995

The hemodynamic effects of maternal hypo- and hyperoxygenation in healthy term pregnancies.

OBJECTIVE: To evaluate the hemodynamic effects of maternal hypo- and hyperoxygenation in normal term pregnancy. METHODS: Ten healthy women between 35-41 weeks' gestation were exposed to 10% oxygen in inspired air for 10 minutes and, after a 5-minute recovery period, to a stepwise increase in oxygenation with 50 and 100% oxygen for 10 minutes. Maternal ventilation, hemodynamics, and oxygenation were assessed noninvasively, and maternal and fetal vascular responses were assessed with pulsed-wave color Doppler velocimetry. Computerized cardiotocography was used for fetal heart rate (FHR) analysis. RESULTS: Substantial maternal hypoxia was achieved and accompanied by a statistically significant rise in the maternal heart rate (from 89 +/- 11 to 104 +/- 16 beats per minute) and systolic blood pressure (from 123 +/- 13 to 131 +/- 13 mmHg). Doppler measurements demonstrated a statistically significant decline in the pulsatility index (PI) of the maternal internal carotid artery (from 1.8 +/- 0.3 to 1.5 +/- 0.4) and an increase in the uterine artery PI (from 0.60 +/- 0.12 to 0.72 +/- 0.13). Baseline FHR, heart rate variability, and Doppler velocimetry in the umbilical artery and the middle cerebral artery showed no statistically significant changes. Hyperoxia did not cause changes in the maternal circulation, but the FHR decreased significantly (from 142 +/- 12 to 133 +/- 11 beats per minute). CONCLUSION: Acute short-term hypoxia modifies the maternal circulation, suggesting redistribution of maternal blood flow, but exerts no detectable effects on the healthy fetus. Maternal hyperoxygenation induces no apparent adverse effects.

Adult↗
PubMed1994

Does thermal stress decrease uterine blood flow in hypertensive pregnancies?

The aim of the study was to determine the acute effects of thermal stress on maternal and fetal circulatory responses in normal and hypertensive patients. Therefore we studied 14 healthy pregnant women and 12 women with compromised pregnancies during short-term heat stress using color Doppler ultrasound in addition to conventional follow-up methods. The uterine vascular resistance increased significantly during the exposure in the high-risk pregnancy group without change in the control group. The results of the present study give strong support to our earlier studies that short-term heat stress seems to be safe in uncomplicated pregnancies but may be detrimental in high-risk pregnancies.

Adult↗
PubMed1994

Vaginal and intracervical prostaglandin E2 for cervical ripening: a Doppler study of hemodynamic effects.

The hemodynamic effects of vaginally and intracervically administered prostaglandin E2 gel were evaluated by pulsed wave color Doppler ultrasound. Twenty term pregnant mothers were recruited. Mothers were randomized to receive either vaginal or intracervical prostaglandin E2 gel. The hemodynamics was assessed by repeated color Doppler velocimetry of the uterine artery and fetal umbilical and middle cerebral arteries; analysis of variance was used to test statistical significance. In the uterine artery a statistically significant rise (P < or = 0.001) of the pulsatility index (PI) was observed. A slightly higher rise of the PI was observed after intracervical administration, but the difference between the groups was not statistically significant (P = 0.4). The fetal PI remained unchanged both in the umbilical and cerebral vessels throughout the study. The rise in the uterine artery PI is probably caused by an increase in the uterine tone as prostaglandins of the E series usually cause vasodilation. No detectable fetal effects were evident.

Administration, Intravaginal↗
PubMed1993

Long-term effects of hormone replacement therapy on the uterus and on uterine circulation.

OBJECTIVE: Our purpose was to study the effects of postmenopausal hormone replacement therapy on the uterus and uterine circulation. STUDY DESIGN: The study population consisted of 432 women, 58 to 59 years of age. Color Doppler ultrasonography with a transvaginal probe was used to measure the size of the uterus and the uterine artery pulsatility index. RESULTS: The mean endometrial thickness in group 1 (controls without hormone replacement therapy) was significantly thinner compared with group 2 hormone replacement therapy and with group 3 after discontinuance of hormone replacement therapy. The mean uterine artery pulsatility index was lower both in group 2 and 3 compared with group 1. When hormone replacement therapy was initiated 2 to 10 years after menopause, the endometrial thickness did not differ from that among those who had started hormone replacement therapy earlier, but the pulsatility index was significantly higher. There was positive correlation between the size of the uterus and the pulsatility index in group 1, but the correlation was negative in group 2. In general, the duration of hormone replacement therapy had no effect on the pulsatility index. Estrogen users had a significantly thicker endometrium compared with estrogen-progestogen users. The pulsatility index was highest in the estrogen users with progestogen added every month. CONCLUSION: The duration, onset of treatment in relation to menopause, discontinuance of hormone replacement therapy, and mode of treatment modify both the normal postmenopausal endometrial thickness and the uterine vascular resistance.

Arteries↗
PubMed1993

Association of abnormal flow velocity waveforms in the uterine artery with frequency-specific fetal heart rate variability.

The aim of the study was to determine if abnormal flow velocity waveforms in the uterine artery are associated with altered frequency-specific fetal heart rate variability (HRV). Fetuses in the last third of gestation were studied. In seven fetuses the pulsatility index (PI) of the blood flow velocity waveform in the uterine artery was increased (Group II), and in ten fetuses the PI was normal (Group I). Frequency-specific HRV (0.025-0.07 Hz, 0.07-0.13 Hz, 0.13-1.0 Hz) was quantified by power spectral analysis and correlated with the PI in the uterine artery, umbilical artery and the middle cerebral artery. The slow variability dominated the fetal HRV. There was no difference between the groups in the mean frequency-specific variability. In Group II, an increase of the PI in the umbilical artery and a decrease in the middle cerebral artery correlated with an increase of HRV, the increase being greatest at the lowest frequency band.

Blood Flow Velocity↗
PubMed1992

Uterine and umbilical flow velocity waveforms in normotensive and hypertensive subjects during the angiotensin II sensitivity test.

The systemic and uterine circulatory effects of angiotensin II infusion in five normotensive and 10 hypertensive subjects at the end of the third trimester of gestation were studied. Color Doppler ultrasonography was used for investigating the systolic/diastolic ratios on flow velocity waveforms in the uterine and umbilical arteries. A significant increase was observed in the systolic/diastolic ratio in the uterine artery in both groups. In normotensive subjects a differential effect of angiotensin II on the systemic diastolic blood pressure and on the systolic/diastolic ratio was observed; the uterine circulation had a slower response and a faster recovery than the maternal diastolic blood pressure. In hypertensive subjects this relative refractoriness to angiotensin II was less marked; the increase in uterine vascular resistance was faster and the recovery slower than in the normotensive group. No changes in the systolic/diastolic ratio in the umbilical artery were observed in either group. These results indicate that the uterine circulation of normotensive subjects is remarkably more refractory to angiotensin II than the circulation of hypertensive subjects.

Adult↗
PubMed1992

Flow velocity waveforms in uterine and umbilical arteries during submaximal bicycle exercise in normal pregnancy.

Eight healthy women who were not conditioned athletes, at 35-38 weeks' gestation, performed a submaximal bicycle exercise test three times for 4 minutes each with stepwise increases (73 +/- 27, 114 +/- 29, and 161 +/- 16 W) of the work load. The target heart rate at the end of the last load was 170 beats per minute. The systolic-diastolic ratios (S/Ds) of flow velocity waveforms were measured with pulsed color Doppler ultrasound in the uterine and umbilical arteries immediately after each work load and during recovery. The heart rates at the end of each load (133 +/- 3, 156 +/- 3, and 173 +/- 7 beats per minute) corresponded to an average of 70, 83, and 92% of the calculated maximum heart rate. With the subject in the sitting position on the ergometer before exercise, the S/D in the uterine artery was 1.49 +/- 0.09, increasing gradually and significantly during the exercise to the maximum of 2.04 +/- 0.06 at 1 minute of recovery. Heart rate and S/D in the uterine artery correlated significantly (r = 0.58, P less than .01). Although the mean arterial pressure increased significantly during exercise from 92 +/- 6 to 109 +/- 10 mmHg, the significant decrease of the ratio of the mean arterial blood pressure and S/D suggests that the flow in the main uterine artery may decrease during intense exercise. No changes occurred in the S/D of the umbilical artery flow velocity, but the fetal heart rate increased significantly.

Adult↗
PubMed1991

Single dose of labetalol in normotensive pregnancy: effects on maternal hemodynamics and uterine and fetal flow velocity waveforms.

The short-term effect of 0.8 mg/kg of intravenous bolus of labetalol upon maternal and fetal hemodynamics was investigated in 10 healthy women at 38 weeks of gestation admitted to the hospital for elective cesarean section. The maximum effect occurred within 35 min after labetalol. At that point, the mean arterial pressure had decreased by 16%, and a slight decrease was observed in maternal heart rate. As to the flow velocity waveforms, no significant change was found in mean systolic/diastolic (S/D) ratio of uterine artery, umbilical artery or fetal middle cerebral artery. However, in 2 subjects with a large decrease in blood pressure also the uterine artery S/D ratio decreased.

Adult↗
PubMed1991

Single dose of labetalol in hypertensive pregnancy: effects on maternal hemodynamics and uterine and fetal flow velocity waveforms.

The short-term effect of 0.8 mg/kg of an intravenous bolus of labetalol on maternal and fetal hemodynamics was investigated in ten women with pregnancy-induced hypertension. The maximum effect occurred within 35 minutes after labetalol administration. At that point, the mean arterial pressure had decreased by 18% and there was a slight decrease in maternal heart rate. As to flow velocity waveforms, no significant change was found in mean systolic/diastolic (S/D) ratio of the uterine artery, umbilical artery or fetal middle cerebral artery. However, in two subjects with a marked reduction in blood pressure also the uterine artery S/D ratio decreased.

Adult↗