Decreased neonatal tibial bone ultrasound velocity in term infants born after breech presentation.

OBJECTIVE: Fetuses found to be in the breech presentation have limited motion of their lower limbs. The aim of this study was to test the hypothesis that bone speed of sound (SOS) would be lower in infants born after breech presentation than in those born after vertex presentation. STUDY DESIGN: We studied 127 singleton, appropriate for gestational age, term infants delivered by a scheduled cesarean delivery at approximately 38 weeks of gestation because of breech presentation or repeat elective cesarean section with vertex presentation. We used the Sunlight Omnisense 7000p device to measure axially transmitted SOS of the right tibia within the first 96 h of life. RESULT: Fifty-three infants studied (42%) were born by cesarean section after breech presentation compared to 74 vertex controls. Bone SOS was significantly lower in the breech presentation group, even after taking into account the effect of gender and parity (as well as gestational age at birth and birth weight). CONCLUSION: Bone SOS is lower in infants born after breech presentation than in those born after vertex presentation. We speculate that limited motion of lower limbs in fetuses found to be in the breech presentation leads to a decrease in bone mineralization and strength.     

Spectral analysis of heart rate in vasovagal syncope: The autonomic nervous system in vasovagal syncope

Spectral analysis of heart rate fluctuations was used to investigate the role of the autonomic nervous system in the pathogenesis of vasovagal syncope. Nine adolescents with a history of at least three episodes of vasovagal syncope and nine age-matched healthy controls were studied. All subjects were tested in supine position and at a 60° inclination for 60 min or less if syncope developed. Blood pressure and heart rate were measured, while the ECG and respiration traces were recorded on magnetic tape for later spectral analysis.Baseline heart rate was lower in control subjects than in patients, increased with tilt in both groups, and remained lower in the control subjects throughout the experiment. Baseline systolic and diastolic blood pressure was similar in both groups. Diastolic blood pressure initially increased with tilt in all subjects and decreased significantly thereafter in patients. Pulse pressure was lower in patients throughout the experiment.The heart rate power spectra displayed a higher baseline level of low frequency fluctuations in the control group. The high frequency fluctuations component was similar in all subjects. The results of the test, regarding haemodynamic parameters and autonomic control of the heart rate, as expressed by low and high frequency fluctuations, are consistent with a reduced sympathetic reserve in the individuals with previous episodes of syncope.     

Lower whole blood ionized magnesium concentrations in hypocalcemic infants of gestational diabetic mothers.

Infants of insulin dependent (class B and above) diabetic mothers (IDM's) have a high rate of neonatal hypocalcemia (NHC) and hypomagnesemia. We carried out this study to test the hypotheses that: (1) infants of gestational diabetic (class A) mothers (IGDM's) are also at risk for NHC and (2) NHC in IGDM's relates to decreased whole blood Mg(2+) concentration. Thirty one term infants born to gestational diabetic mothers of classes A1 (diet controlled, n = 23) and A2 (requiring insulin, n = 8) of White's classification, were compared at 24 +/- 2 hours of age to 32 healthy, appropriate for gestational age controls, born after uncomplicated pregnancy, labor and delivery. Whole blood Mg(2+) and Ca(2+) were measured using an ion-specific electrode (Nova 8, Nova biomedical, Waltham, MA). The rate of NHC was higher in the IGDM group as compared to the control group (9 out of 31 [29%] vs. 1 out of 32 [3.1%] infants; p < 0.01). Whole blood Mg(2+) was lower in the IGDM group than in controls (p < 0.05). In multiple regression analysis, when Ca(2+) was used as the dependent variable and Mg(2+), diabetes class, gestational age, macrosomia and one minute Apgar scores were the independent variables, only Mg(2+) and diabetes class were significant (R2 = 0.4374; p < 0.01). Our results are consistent with the theory that Mg deficiency plays a role in NHC encountered in IGDM's, similar to what occurs in infants of insulin-dependent diabetic mothers.     

In-111-labeled white blood cell uptake in noninfected closed fracture in humans: prospective study

Since indium-111 white blood cell (In-111 WBC) scintigraphy is often used to evaluate for osteomyelitis in bone fractures, it is important to know if noninfected fractures have In-111 WBC uptake. Twenty-seven noninfected closed fracture sites in 19 patients were prospectively evaluated with technetium-99m methylene diphosphonate bone scintigraphy and In-111 WBC scintigraphy. In-111 WBC uptake was present in 41% of the 27 sites. In the 11 positive sites, the In-111 WBC uptake was 1+ (definite but minimal) in 55%, 2+ (moderate) in 36%, and 3+ (marked) in 9%. The visual intensity of the radioactive uptake on In-111 WBC scintigrams relative to that on bone scintigrams was less in 82%, equal in 9%, and greater in 9%. The visual size of the area of uptake on In-111 WBC scintigrams and bone scintigrams was smaller in 36%, equal in 55%, and greater in 9%. Factors that may help distinction of In-111 WBC uptake due to fracture alone from infection associated with fracture are discussed.     

Major malformations in infants of IDDM women. Vasculopathy and early first-trimester poor glycemic control

From animal and in vitro studies, it has been suggested that high environmental glucose, ketone, or insulin concentrations and low glucose or insulin concentrations may be etiologic factors for congenital malformations (CMs) in infants of diabetic mothers (IDMs). Transplacental passage of antibody-bound insulin has been demonstrated in humans. Controversy exists regarding the pathophysiology of CMs in human insulin-dependent diabetes mellitus (IDDM) pregnancies. We hypothesized that CMs in IDMs are associated with maternal vasculopathy, poor first-trimester glycemic control (i.e., hyper- and/or hypoglycemia), advanced White class, and high insulin requirements. We studied 165 first pregnancies of women with IDDM from 1978 to 1986. The goals of glucose control were a fasting blood glucose of less than 100 mg/dl and a 90-min postprandial blood glucose of less than 140 mg/dl. Insulin requirements, body weight, and pre- and postprandial blood glucose were recorded at weekly clinic visits. Maternal blood HbA1 was measured on entry and every 4 wk to confirm that adequate glycemic control was achieved. Women who enrolled in the project were interviewed during gestation by a geneticist/dysmorphologist who obtained genetic and environmental histories using a standard questionnaire. All live-born infants and stillbirths were examined. Each live-born infant was assessed systematically by two independent examiners, a neonatologist and a geneticist/dysmorphologist; examination with standardized checklists was performed in the newborn nursery as soon after birth as was practical. In first pregnancies in the study, there were 13 IDMs with major CMs (7.9%).(ABSTRACT TRUNCATED AT 250 WORDS)