Sternalis muscle: topic for debate.
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Biomedical subjects
Publications and source records attributed to A Izumi.
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We encountered a fetus who exhibited transient (at most 30 s), repeated episodes of tachyarrhythmia (240 bpm). This female neonate was born at 36 weeks of gestation and showed a markedly prolonged QT interval and transient, repeated episodes of polymorphic ventricular tachycardia. Congenital long QT syndrome was diagnosed. Retrospective analysis of the videotape showing fetal cardiac movement revealed that atrio-ventricular dissociation was present prenatally and thus, the fetal tachyarrhythmia was due to ventricular tachycardia. To our knowledge, there are few reports of a fetus with the long QT syndrome who exhibited ventricular tachycardia in utero. In the presence of unexplained fetal tachyarrhythmia, long QT syndrome should be considered as a possible underlying cause disorder. The presence of atrio-ventricular dissociation may be useful in prenatal diagnosis of long QT syndrome.
AIM: The increased echogenicity of medullary pyramids in neonates and children is poorly understood. Hence we conducted a prospective ultrasound study of the kidneys of neonates and fetuses. Hence we conducted a prospective ultrasound study of the kidneys of neonates and fetuses. PATIENTS AND METHODS: Ultrasound images of kidneys in neonates and fetuses in late pregnancy were analysed. RESULTS: Thirteen percent of the studied neonates showed hyperechogenicity in the renal papillae that disappeared spontaneously within 1 week, although no hyperechoic papillae were seen in any of the fetuses. Urine volume of the neonates with hyperechogenicity was significantly less than that of those without it. CONCLUSION: The fact that no hyperechoic findings appeared before the 34th week of gestation suggests that maturation of renal tubules and ability to concentrate urinary substances were contributing factors. Because only the tips of the pyramids were hyperechogenic, however, the term hyperechoic papillae would seem more appropriate than hyperechoic pyramids, the term generally used today.
BACKGROUND/AIMS: Decreased antithrombin III (AT-III) activity and/or thrombocytopenia associated with an elevated serum level of aspartate aminotransferase in late pregnancy can threaten the lives of both the mother and the fetus. We investigated whether antenatal declines in AT-III activity and the platelet count occur in late twin pregnancy and whether reduced AT-III activity and/or thrombocytopenia precedes an increase in the serum level of aspartate aminotransferase. METHODS: The platelet count, AT-III activity, and the serum level of aspartate aminotransferase were determined weekly or biweekly in 237 women with twin pregnancies in a longitudinal and partly prospective study. RESULTS: Both AT-III activity and the platelet count decreased gradually in the last month of pregnancy, irrespective of the presence or absence of clinical signs of pre-eclampsia. A perinatal elevation in aspartate aminotransferase occurred in 36 (15%) of 237 women. The risk of a perinatal elevation in aspartate amino-transferase increased as the antenatal AT-III activity and/or the platelet count decreased. Pre-eclampsia developed in 60 women (25%). The relative risk of a perinatal aspartate aminotransferase elevation (95% confidence interval) for the 60 women with pre-eclampsia, the 60 women with a platelet count < or = the 25th percentile (164 x 10(9)/1), and the 60 women with AT-III activity < or = the 25th percentile (76% of normal) was 1.9 (1.0 to 3.4), 4.1 (2.3 to 7.5), and 5.9 (3.2 to 11.1), respectively, compared with the remaining 177 women. CONCLUSIONS: AT-III activity and platelet count gradually decreased in the last month of twin pregnancies. A perinatal aspartate aminotransferase elevation was preceded by marked decreases in these parameters in women with twin pregnancies. The monitoring of AT-III activity and platelet count in women who exhibit a gradual decline in these parameters may help to avoid the development of severe HELLP syndrome.
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Duration-discrimination thresholds of the silent interval (gap) between two successive tones (markers) were measured in four Japanese monkeys. The task was serial discrimination, and monkeys were required to release the lever when the gap duration decreased from 200 ms. Monkeys successfully acquired the task, and gap thresholds of monkeys were revealed to be larger than previous data with human subjects. Gap thresholds were not affected by marker frequency when the two markers were identical in frequency, though the thresholds increased when large frequency differences existed between markers. The effect of marker frequency disparity on gap thresholds in monkeys is discussed in terms of the difficulty in integrating information from discrete frequency channels.
OBJECTIVE: To assess the effects of uterine leiomyoma on obstetrical performance. METHODS: We reviewed the medical records of 102 women with singleton pregnancies who were found ultrasonographically to have uterine leiomyomas during the first half of their pregnancy and who gave birth at our hospital at > or = 22 weeks of gestation between January 1990 and December 1997. RESULTS: The 102 women gave birth to 101 healthy infants, weighing 2,974 +/- 579 g at 38.8 +/- 2.6 weeks of pregnancy. One woman experienced an unexplained antepartum fetal death at 24 weeks of gestation. Bleeding at the first trimester occurred in 16% of the women. Pain localized in the lower abdomen and requiring relief occurred in 28% of the women during the first or second trimester. Tocolytic treatment was required in 25% of the pregnancies, and preterm delivery occurred in 12% thereof. A cesarean section was performed in 39% of the pregnancies. Bleeding > or = 500 ml occurred at delivery in 48% of the cases. The largest fibroid, > 6 cm in diameter, which was seen in 51 women, was associated with higher frequencies of tocolytic treatment (41%), preterm delivery (24%), bleeding > or = 500 ml at delivery (59%), and cesarean delivery (51%). In 76 women (75%) who attempted vaginal delivery, the obstetrical outcome was comparable to that of 115 control women who were matched regarding age, parity, and gestational week. CONCLUSIONS: Although pain in the lower abdomen, the requirement of tocolytic treatment, preterm delivery, and cesarean delivery were common, the neonatal outcome was fairly good in women with uterine leiomyomas. The present data might be encouraging to pregnant women with uterine leiomyomas.
OBJECTIVE: To assess the relation between the preoperative serum level of C-reactive protein (CRP) and the WBC count and the efficacy of emergency cervical cerclage. STUDY DESIGN: We retrospectively reviewed the medical records of 17 women (16 singleton pregnancies and 1 twin pregnancy) who underwent emergency cervical cerclage (McDonald technique) between 21 and 26 weeks of gestation. The uterine cervix was dilated >/=3.0 cm and the intact (not ruptured) fetal membranes were visible or protruded into the vagina in all patients. The serum level of CRP and the WBC count were determined preoperatively and postoperatively. Emergency cervical cerclage was considered successful if delivery occurred >/=14 days after the procedure. RESULTS: Emergency cervical cerclage was successful in 12 women, including the woman with a twin pregnancy, but failed in 5 women. The preoperative serum level of CRP and the WBC count were significantly lower and dilatation of the cervix was significantly less in the success group than in the failure group. Cerclage was successful in all eight patients with cervical dilatation </=4.0 cm, but in only 4 of 9 patients with cervical dilatation >4.0 cm (p < 0. 05). Cerclage was successful in all 11 women with a preoperative serum level of CRP </=4.0 mg/dl and a WBC count </=14,000/ microl compared with 1 of 6 women with either a CRP level >4.0 mg/dl or a WBC count >14,000/ microl (p < 0.01). CONCLUSION: A preoperative CRP value </=4.0 mg/dl, a WBC count </=14,000/ microl, and cervical dilatation </=4.0 cm were significantly associated with prolongation of pregnancy after emergency cervical cerclage.
BACKGROUND: The effects of discrepancies in the birth weight and hemoglobin concentration ([Hb]) at the birth on infant outcome have not been fully investigated in monochorionic (MC) and dichorionic (DC) twins. METHODS: A retrospective study of 95 twin pregnancies. All 190 neonates (68 MC twins and 122 DC twins) were admitted to the neonatal intensive care unit, and the [Hb] was determined soon after birth. The [Hb] discordance represents the [Hb] of the smaller twin expressed as a percentage of the [Hb] of the larger twin. Infants were followed-up until 1 year of corrected age and their psychomotor development was evaluated between 12 and 18 months. RESULTS: One DC infant died by 1 year of age. Twelve MC infants and eight DC infants had disabilities by 1.5 year of age. In the MC group, 11 infants (28%) of 20 pairs with an intertwin [Hb] discordance >100 had disabilities compared with one (3.6%) of 14 pairs with an [Hb] discordance < or = 100 (p<0.05). A similar trend was observed in the DC group, but the difference was not significant. The incidence of disabled infants increased as the intertwin birth weight discordance increased in MC twins. CONCLUSIONS: An adverse outcome at 1 year of age in MC twins was associated with a greater birth weight discordance and an [Hb] disordance that indicated polycythemia in the smaller twin.
OBJECTIVE: To construct nomograms for birth weight in Japanese twins and to investigate the risk of early neonatal death (death within seven days of birth) in small-for-gestational-age (SGA) and large-for-gestational-age (LGA) twins as compared with appropriate-for-gestational-age (AGA) twins. STUDY DESIGN: Of 89,253 infants born at > or = 24 weeks of gestation to women with multifetal pregnancies (96% twins) between 1989 and 1993 in Japan, 1,804 were stillborn, and 891 died within seven days of birth (early neonatal death [END] group). The remaining 86,558 infants were defined as the normal group. We constructed growth curves for the normal and END groups and compared the incidence of early neonatal death among the SGA, AGA and LGA infants. RESULTS: Birth weights in the END group were similar to those in the normal group until 33 weeks of gestation, but was lower than the birth weights of the normal group after 33 weeks. Both SGA and LGA infants had an increased risk of death within 7 days of birth as compared with AGA infants throughout gestation. CONCLUSION: Both SGA and LGA twins were at increased risk of death as compared with AGA twins. We recommend the use of birth weight nomograms in the management of twin pregnancies.
The current progress in developmental biology suggests a genetically stable peripheral pathway formation. However, this may be incompatible with the variations or anomalies observed in the segmental origins of motor nerves in the mammals including the human. For the consideration of the causes raising this inconsistency, we examined the distribution of motoneurons for the serratus dorsalis cranialis muscle of the cat using a retrograde labeling method because this muscle consists of segmentally-arranged parts which receive segmental dual innervation. Consequently, the distribution of the labeled motoneurons for one part spread throughout the full extent of two spinal cord segments, while the distributions for the intercostal muscles in the cat and rat were segmental and in accordance with each spinal cord segment. This may indicate the more precise correspondence between the spinal nerve segments and the distribution of motoneurons projecting axons through them. We think, therefore, that segments of the spinal nerves supplying a given target exactly indicate the segmental levels of supplying motoneurons and suggest the segments of somites from which primordial cells of the target migrate.
We prospectively evaluated the antenatal changes in antithrombin-III (AT-III) activity and liver enzymes in a woman with a triplet pregnancy. A gradual decline in AT-III activity occurred in the absence of clinical signs of preeclampsia and preceded the onset of the typical HELLP syndrome in this patient. Monitoring of AT-III activity might help to avoid the development of severe HELLP syndrome.
We prospectively studied 99 women with uncomplicated singleton pregnancies and 24 women with uncomplicated twin pregnancies to examine the effect of the location of the placenta on the pulsatility index (PI) in the uterine arteries in twin pregnancies and to compare singleton and twin pregnancies with regard to changes in the PI of uterine arteries over the course of the pregnancy. The flow velocity waveforms in both the right and left parametrial uterine arteries were recorded longitudinally at 2-week intervals from a gestational age of 19 weeks until delivery. The location of the placenta was determined by real-time ultrasonography at 18-20 weeks of gestation to determine which uterine artery was the ipsilateral artery. In both the ipsilateral and contralateral uterine arteries, the PI exhibited a steady decrease toward term in singleton pregnancies. In twin pregnancies, the PI exhibited a steady decrease until 27 weeks of gestation and remained unchanged thereafter. The PI in the ipsilateral artery was consistently lower than that in the contralateral artery in singleton as well as twin pregnancies. The mean values of PI of the ipsilateral and contralateral uterine arteries of twin pregnancies was consistently lower than that of singleton pregnancies at any gestational week. These results suggest that the ipsilateral uterine artery contributes more to placental perfusion than does the contralateral uterine artery in twin as well as in singleton pregnancies. Twin pregnancies differed from singleton pregnancies with respect to changes in PI in the uterine artery according to gestational age. The PI of uterine arteries declined more rapidly and reached a plateau earlier in twin than in singleton pregnancies.
OBJECTIVE: To define the clinical features of gestational thrombocytopenia and to determine its relationship to the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome). STUDY DESIGN: Retrospective cohort study. We reviewed the records of 24 women with gestational thrombocytopenia among 637 nonpreeclamptic women who had serial determinations of the platelet count during pregnancy between 1992 and 1995. Gestational thrombocytopenia was defined as an antenatal gradual decline in the platelet count to <150 x 10(9)/l in nonpreeclamptic women. The control group consisted of 213 nonpreeclamptic women whose platelet counts were > or = 150 x 10(9)/l at -3 to 0 days from delivery and in whom the perinatal serum level of aspartate transaminase (AST) had been determined. RESULTS: The platelet count decreased gradually, from 210+/-31 x 10(9)/l at < 13 weeks' gestation to 127+/-24 x 10(9)/l at -3 to 0 days from delivery, in the 24 women with gestational thrombocytopenia. The platelet count was 251+/-62 x 10(9)/l at -3 to 0 days from delivery in the 213 control women. The serum level of AST was elevated perinatally in 5 (21%) of 24 women with gestational thrombocytopenia compared with 6 (2.8%) of the 213 control subjects (p < 0.001). There had been 28 previous term or near-term pregnancies among 17 women with gestational thrombocytopenia, 14 of which were complicated by gestational thrombocytopenia or a decline in the platelet count by > 50 x 10(9)/l; 1 pregnancy was associated with the features typical of the HELLP syndrome. CONCLUSION: Gestational thrombocytopenia may be a risk factor for the development of the HELLP syndrome and is likely to recur in subsequent pregnancies.
Data on the prognosis of twins from tertiary institutions may not represent the general incidence of adverse infant outcomes. We retrospectively investigated the infant outcome in 32 twin gestations referred to us at 29.9 +/- 3.7 weeks of gestation (range, 21 to 38 weeks) (late referral group) and 237 twin gestations that had been monitored by us since < 20 weeks' gestation (control group). The physical and neurological status of infants was assessed at 1 year of corrected age. Delivery occurred 3.1 weeks earlier in the late referral group than in the control group (32.4 +/- 3.9 vs 35.5 +/- 2.4 weeks, p < 0.001). Deaths by 1 year of age and disabilities such as cerebral palsy, mental retardation, and epilepsy occurred in 16 (25%) of 64 infants in the late referral group compared with 24 (5.1%) of 474 infants in the control group (p < 0.001). Thus, the inclusion of data on women who were referred late increased the incidence of adverse infant outcomes in our tertiary hospital from 5.1% to 7.4% (40/538). It was not known whether an early referral to a tertiary hospital would have improved the outcome in the late referral group. These findings suggest that data from tertiary institutions on the prognosis of twins may be affected adversely by the inclusion of data on women who are referred because of complications.
We investigated the relation between an alteration in calcium (Ca) excretion in early pregnancy and the risk of preeclampsia in 1,147 pregnant women. We measured Ca and creatinine (Cr) concentrations in spot urine samples obtained at 12 weeks or less of gestation. Seventy-one (6.2%) had hypertension alone, nine (0.8%) developed superimposed preeclampsia, 39 (3.4%) developed proteinuria alone, and 13 (1.1%) developed preeclampsia; 1,015 women did not develop hypertension or proteinuria. The Ca/Cr ratio was significantly reduced in the 39 women who eventually developed proteinuria (0.116 +/- .103) and 13 who developed preeclampsia (0.121 +/- .063) compared with 1,015 women who had neither hypertension nor proteinuria (0.158 +/- .239). The relative risk of development of preeclampsia, proteinuria, or superimposed preeclampsia was 1.98 (95% confidence interval, 1.22 to 3.22) for women with a Ca/Cr ratio less than the 30th percentile (0.082) compared with women with a Ca/Cr ratio greater than the 30th percentile. These results suggest that preeclampsia may be related, in part, to a relative Ca intake deficiency. Determination of the Ca/Cr ratio in spot urine samples in the first trimester is of only limited clinical value for identifying women with an increased risk of preeclampsia.
OBJECTIVE: To evaluate the accuracy of a new pulse oximeter in estimating the oxyhemoglobin (O2Hb) concentration in fetal arterial blood (SaO2) with either a high concentration of hemoglobin F (HbF) or a low concentration of O2Hb during labor. PATIENTS AND METHODS: Fetal forehead arterial oxygenation was determined in 44 fetuses by reflectance pulse oximeter (SpO2) during labor and was compared with SaO2 determined immediately after birth. Because HbF has little or no known effect on pulse oximetry, but does affect the laboratory multiwavelength "CO-oximeter" type reading, the SaO2 was corrected by HbF concentration. SpO2 and SaO2 were simultaneously measured in five hypoxic adult volunteers achieved by inhaling 11% oxygen. RESULTS: A gradual decline in HbF concentration was seen during weeks 37 to 40 of gestation. HbF concentration varied near term, ranging between 53 and 88% of the fetal hemoglobin concentration (mean +/- SD = 74.6 +/- 6.3%). This alteration produced a lower %O2Hb percent by 4% at the most. The corrected SaO2 in cord blood correlated with fetal SpO2 (y = 0.974, x -7.279, r = 0.90). In five adults, SpO2 reflected well SaO2 with a mean +/- SD of bias of -1.1 +/- 2.9%. CONCLUSIONS: SpO2 determined by a new reflectance pulse oximeter at the end of labor correlated with an immediate post-natal cord arterial blood sample before the first breath, with a mean and SD of bias of 8.5 +/- 6.2%. Reflectance pulse oximetry is a useful tool for continuous noninvasive monitoring of the fetal oxygen status during labor.
To determine the relationship between abnormal fetal heart rate (FHR) patterns, fetal oxygen content by reflectance pulse oximetry, and the effects of maternal oxygen administration, 158 intrapartum women consisting of 120 women with normal FHR patterns, and 38 women with varying degrees of variable FHR decelerations were examined. A new reflectance pulse oximetry probe was attached to the fetal forehead to continuously monitor fetal oxygen saturation (SpO2) during labor. Oxygen was administered for 30 min at 5 liters/min by nasal canula in 32 women. No significant change in fetal SpO2 was seen in women with normal FHR patterns, but a significant decline in SpO2 was observed shortly before births. FHR decelerations less than 90 bpm occurred prior to the decline in fetal SpO2. Maternal oxygen administration was effective in increasing fetal SpO2 in fetuses with decreased SpO2 (SpO2 < 50%), but not in fetuses with high SpO2 (SpO2 > 60%). It is concluded that fetal SpO2 exhibits no change during normal labor but significantly declines shortly before birth, that relatively severe variable decelerations (<90 bpm) can decrease fetal SpO2, and that maternal oxygen treatment at 5 liters/min is effective in augmenting fetal oxygen tension in fetuses with decreased oxygen tension.