Separation of hemodynamic signals from GCaMP fluorescence measured with wide-field imaging.

Wide-field calcium imaging is often used to measure brain dynamics in behaving mice. With a large field of view and a high sampling rate, wide-field imaging can monitor activity from several distant cortical areas simultaneously, revealing cortical interactions. Interpretation of wide-field images is complicated, however, by the absorption of light by hemoglobin, which can substantially affect the measured fluorescence. One approach to separating hemodynamics and calcium signals is to use multiwavelength backscatter recordings to measure light absorption by hemoglobin. Following this approach, we develop a spatially detailed regression-based method to estimate hemodynamics. This Spatial Model is based on a linear form of the Beer-Lambert relationship but is fit at every pixel in the image and does not rely on the estimation of physical parameters. In awake mice of three transgenic lines, the Spatial Model offers improved separation of hemodynamics and changes in GCaMP fluorescence. The improvement is pronounced near blood vessels and, in contrast with the Beer-Lambert equations, can remove vascular artifacts along the sagittal midline and in general permits more accurate fluorescence-based determination of neuronal activity across the cortex.NEW & NOTEWORTHY This paper addresses a well-known and strong source of contamination in wide-field calcium-imaging data: hemodynamics. To guide researchers toward the best method to separate calcium signals from hemodynamics, we compare the performance of several methods in three commonly used mouse lines and present a novel regression model that outperforms the other techniques we consider.

Cesarean scar pregnancy: imaging and treatment with conservative surgery.

BACKGROUND: Pregnancy in a cesarean scar represents a rare type of secondary abdominal pregnancy. Early diagnosis can be challenging and optimal treatment is unknown. CASE: A 21-year-old woman presented for an abortion at 8 weeks' gestation. A cesarean delivery had been performed 5 months earlier. Suspecting a cervical pregnancy, her physician referred her to us, and an 8-week cesarean scar gestation was diagnosed and then confirmed by serial sonograms, cystoscopy, and magnetic resonance imaging. The patient elected pregnancy termination, which was accomplished by hysterotomy with uterine preservation followed by intramuscular methotrexate. CONCLUSION: We report a case of cesarean scar pregnancy treated surgically with uterine preservation. This approach should be considered when cesarean scar ectopic pregnancy is diagnosed.

Infertility. A clinical guide for the internist.

Infertility is a common condition that internists practicing primary care may increasingly encounter. Abnormal male semen parameters, ovulation disorders, and tubal dysfunction account for most cases of infertility. By performing a complete initial evaluation and through appropriate and timely referral, internists can contribute to the care and improve outcomes for couples with this condition (Table 9).

Midtrimester pregnancy termination for fetal malformations. Use of intravaginal prostaglandin E2.

OBJECTIVE: To compare outcome differences and responses to treatment in pregnancies complicated by either major fetal malformations or previous fetal death in the second trimester. STUDY DESIGN: Data were analyzed from a computerized perinatal database and individual hospital records for singleton gestations between 14 and 23 weeks undergoing labor induction with prostaglandin E2 (PGE2) suppositories (20 mg intravaginally every three to five hours). RESULTS: Between January 1993 and June 1995, 65 pregnancies underwent induction of labor for either a lethal fetal malformation (38) or death (27). As compared with the fetal death group, the malformation group required more suppositories (median 4, range 1-10, versus median 3, range 1-6; P < .05) and needed a greater total dosage (77.5 +/- 38.5 mg versus 61.8 +/- 37.8 mg, P < .05). The mean time from initiation of treatment until delivery was two hours longer in the malformation group. There were no significant differences between the two treatment groups in incidence of maternal side effects or of retained placentas requiring operative intervention. CONCLUSION: Patients who undergo second-trimester induction of labor for major fetal malformations using intravaginal PGE2 should be counseled that the dosage of the drug is greater and that labor may last longer than in pregnancies complicated by a previous fetal death.

PIP: The capability to identify major fetal malformations in the middle trimester of pregnancy has increased the number of requests for late pregnancy termination. This retrospective study compared the use of prostaglandin E2 (PGE2) suppositories in 38 pregnancies undergoing induction of labor before 23 weeks of gestation after confirmation of 1 or more major fetal malformations and a control group of 27 pregnancies undergoing induction because of fetal death. Both groups were identified through a perinatal database of all pregnancies delivered at an Oklahoma City, Oklahoma, hospital in a 30-month period during 1992-94. The most frequent fetal malformations were cystic hygroma, spina bifida, hydrocephalus, and anencephaly. The median number of 20 mg PGE2 doses required was greater in the fetal malformation group (4, range 1-10) than the fetal death group (3, range 1-6). The total dosage was also greater for the malformation group (77.5 +or- 38.5 mg) than for the fetal death group (61.8 +or- 37.8 mg). Mean time until delivery was 2 hours less in the fetal death group, but the percentage of women delivering within 24 hours was similar in both groups (81.6% in the fetal malformation group and 85.2% in the fetal death group). All malformed fetuses were delivered stillborn. The frequencies of maternal side effects such as fever, vomiting, and diarrhea were somewhat greater in the fetal malformation group, presumably because of the higher dosage of PGE2. Although women undergoing second-trimester PGE2-induced labor for fetal malformations should be counseled that labor may last longer and a higher drug dosage may be required than in pregnancies complicated by fetal death, the method seems to be highly effective in both situations.