Ray transfer matrix for a spiral phase plate.

We present a ray transfer matrix for a spiral phase plate. Using this matrix we determine the stability of an optical resonator made of two spiral phase plates and trace stable ray orbits in the resonator. Our results should be relevant to laser physics, optical micromanipulation, quantum information, and optomechanics.

Transabdominal cervical cerclage in triplet pregnancies and risk of extreme prematurity and neonatal loss.

There are no reports indicating the effect of prophylactic transabdominal cerclage (TAC) on the prolongation of multifetal pregnancies. We report the use of TAC in triplets, which evolved over 20 years in one practice. A retrospective cohort study of triplet pregnancies was conducted. Obstetric and neonatal outcomes were compared among women who underwent a prophylactic TAC or transvaginal cerclage and no cerclage. Of the 141 women who delivered triplets, prophylactic TAC was associated with reduced incidence of extreme prematurity and improved incidence of neonatal/postnatal survival. With the exception of mode of conception, prepregnancy weight, and the use of home monitoring uterine activity monitor, procardia and terbutaline, no major differences were found in terms of patient characteristics and pregnancy and delivery management among the three groups. It was concluded that in triplet pregnancies, prophylactic placement of a TAC appears to lower the incidence of delivery before 28 weeks.

Melatonin dispensing among New Zealand children aged 0-18 years with autism: a nationwide cross-sectional study.

OBJECTIVE/BACKGROUND: Sleep problems in children on the autism spectrum are prevalent and persistent. Such problems are the result of a combination of biopsychosocial factors, including abnormal melatonin secretion. Exogenous melatonin is an empirically supported and popular treatment for sleep problems. However, we know little about rates of melatonin dispensing and associated variables. This study investigated rates of melatonin dispensing and the sociodemographic and child characteristics associated with its use in New Zealand. METHODS: This nationwide cross-sectional study used linked administrative health data obtained via the Integrated Data Infrastructure (IDI). Data were obtained for 11,202, 0-18 year old children on the autism spectrum. Descriptive data, and adjusted and unadjusted risk ratios, were calculated for sociodemographic and child characteristics. RESULTS: Melatonin is accessed by almost one quarter of children on the autism spectrum in New Zealand, with higher observed rates among females and those aged between 5 and 11 years, of European ethnicity, and presenting with co-occurring mental health conditions. CONCLUSIONS: Findings are largely consistent with research investigating both sleep disturbances and psychotropic drug use among children on the autism spectrum. High rates of melatonin use, age- and sex-related differences in its use, and the complexity associated with the presence of co-occurring conditions necessitates development of practice guidelines for melatonin dispensing. Further investigation into the duration of melatonin use and the interaction between child characteristics, co-occurring conditions, sociodemographic variables and melatonin dispensing is warranted.

Strategies for prevention of RSV nosocomial infection.

OBJECTIVE: To review the literature on respiratory syncytial virus (RSV) as a cause of nosocomial infections (NI) on neonatal intensive care units (NICUs) and pediatric wards, and the effectiveness of various containment strategies. STUDY DESIGN: We conducted a literature review to define characteristics of RSV NI, and to evaluate the relative effectiveness of various infection containment programs, including the use of palivizumab on the reported incidence of RSV NI on NICUs and pediatric wards. RESULT: Highly variable rates of RSV NI have not significantly changed since RSV was first identified. The evaluation of the effectiveness of containment strategies has relied on before/after study designs. Focus on rapid patient diagnosis, compliance of acceptable handwashing techniques and cohorting of patients and staff appears to form the backbone of most prevention and containment programs. When these or other measures have failed, the administration of palivizumab has been useful in halting the spread of RSV NI in children. CONCLUSION: RSV NI continues to be prevalent in the NICU despite adoption of infection control programs. Preventive measures should be employed to lower the risk of RSV NI and, if identified, appropriate containment strategies should be rapidly implemented.

Design, synthesis, and evaluation of metabolism-based analogues of haloperidol incapable of forming MPP+-like species.

The long-term, irreversible, Parkinsonism-like side effects of haloperidol have been speculated to involve several mechanisms. More recently, it has been speculated that the metabolic transformation to MPP+-like species may contribute to the Parkinsonism-like side effects. Because BCPP+ and its reduced analogue have been shown to possess the potential to destroy dopamine receptors in the nigrostriatum, we have designed new analogues of haloperidol lacking the structural features necessary to form neurotoxic quaternary species but retaining their dopamine-binding capacity. The most potent agent at the D2 receptor, the homopiperidine analogue 11, was found to be equipotent to haloperidol. It was also of interest to identify analogues with DA binding profiles similar to that of clozapine at the dopamine receptor subtypes. Evaluation of the proposed agents shows that the ratio of D2 to D4 (2) binding of clozapine was mimicked by 7 [K(i)(D2) = 33, K(i)(D3) = 200, K(i)(D4) = 11 nM; K(i)(D2)/K(i)(D4) = 3] and 9 [K(i)(D2) = 44, K(i)(D3) = 170, K(i)(D4) = 24 nM; K(i)(D2)/K(i)(D4) = 2]. A preliminary in-vivo testing of compound 7 shows that its behavioral profile is similar to that of clozapine. This profile suggests that there is a need for further evaluation of these two synthetic agents and their enantiomers for efficacy and lack of catalepsy in animal models.

Differential transmission of adenovirus in a twin pregnancy.

BACKGROUND: Intrauterine adenovirus infection has been associated with nonimmune hydrops. We describe a twin pregnancy in which adenovirus was demonstrated by polymerase chain reaction in the amniotic fluid of one twin afflicted by hydrops. Adenovirus was absent in the amniotic fluid of the other twin. CASE: A 25-year-old, gravida 3, para 1, with twin gestation at 20 weeks' gestation was noted on ultrasound anomaly screen to have hydrops associated with twin B. Polymerase chain reaction analysis of amniotic fluid revealed adenovirus in twin B with none noted in twin A. At 26 weeks' gestation both infants died. CONCLUSION: This case demonstrates differential transmission of adenovirus in a twin pregnancy. One twin developed hydrops fetalis possibly secondary to adenovirus infection.

Multiple oral inoculations with Cryptosporidium parvum as a means of immunization for production of monoclonal antibodies.

Oral immunization of suckling mice with Cryptosporidium parvum results in a humoral response to a limited set of antigens. Six-day-old BALB/c mice were each inoculated orally with 1 x 10(6) viable oocysts and subsequently administered oral inoculations of 2 x 10(6) viable oocysts at 30 and 60 days following the primary infection. After 45 days, mice were boosted with 1 x 10(6) oocysts orally, plus soluble extracts equivalent to 2 x 10(6) and 1 x 10(6) oocysts given intravenously and intraperitoneally, respectively. Four days later, splenic lymphocytes were fused to Ag8 myeloma cells. Using this method, we have been able to select for monoclonal antibodies that predominantly recognize sporozoite surface and apical complex antigens.

Isolation and characterization of Borrelia parkeri in Ornithodoros parkeri (Ixodida: Argasidae) collected in Colorado.

This study describes the identification of Borrelia parkeri spirochetes in Colorado. Two isolates of B. parkeri (6230 and 6232) were recovered from Ornithodoros parkeri Cooley ticks collected at an inactive prairie dog town in Moffat County. Both isolates were partially characterized by sequencing and subsequent parsimony and neighbor-joining analyses of appropriate regions of the 16S ribosomal RNA, flagellin and P66 genes. Analyses of the 16S gene sequences from the Colorado isolates indicated that they were more closely related to B. parkeri and B. tucatae than to B. hermsii or the other species of Borrelia investigated in this study. Additional analyses of amino acid sequences for flagellin and P66, however, clearly demonstrated that isolates 6230 and 6232 were most closely related to B. parkeri. The possible significance of B. parkeri as an agent of human disease is discussed.

Prolongation of the latency period in preterm premature rupture of the membranes using prophylactic antibiotics and tocolysis.

Mixed results have been obtained in several studies using tocolysis or antibiotics individually in the treatment of premature rupture of membranes (PROM). We compared the outcomes of a management protocol consisting of tocolysis, prophylactic antibiotic administration, and documentation of pulmonary maturity with a control group treated with passive expectant management for premature rupture of membranes. There were 55 women in the treatment group and 57 women in the control group. The mean latent phase (+/- SEM) in the treatment group was 7.34 (+/- 1.25) days compared with 1.86 (+/- .431) days in the control group (P less than .001). Eighteen of 55 patients (33%) in the treatment group were electively delivered after documentation of lung maturity, contributing to a falsely lowered mean latent phase in the treatment group. Twenty-four patients in the treatment group and 6 in the control group had a latent phase of 5 days or greater (P = .00018). There were 9 postpartum infections in the control group and 10 infections in the treatment group (P = NS). There was no difference in the length of latent phase of patients treated with ceftizoxime compared with the other antibiotics used (cefoxitin, cefazolin, ampicillin), although postpartum ceftizoxime was more effective in preventing postpartum infections (1 of 28 vs 9 of 27) (P = .005). There were fewer infected neonates in the study group, but this was not significant. It appears that treatment with this protocol significantly prolongs the latent phase in patients with preterm PROM without increasing infectious morbidity.

Thromboxane synthetase inhibition produces maternal and fetal vasodilation during ovine pregnancy-induced hypertension: a Doppler flow velocimetric study.

Changes in maternal and fetal umbilical arterial vasoreactivity during ovine pregnancy-induced hypertension and following intravenous administration of CGS 12970 [3-methyl-2-(3-pyridyl)-1-indoleoctanoic acid] were assessed. Continuous wave Doppler flow velocimetry was used to assess vascular reactivity during normotensive baseline, during ovine pregnancy-induced hypertension triggered by a 72-hour fast, and following thromboxane synthetase inhibition with CGS 12970. Uterine and umbilical arterial systolic/diastolic flow ratios increased significantly with the onset of sustained hypertension. After thromboxane synthetase inhibition, uterine and umbilical artery systolic/diastolic flow ratios were not different from baseline, and maternal blood pressure had returned to baseline values. These data indicate that thromboxane produces maternal and fetal vasoconstriction during ovine pregnancy-induced hypertension. Furthermore, these data provide strong evidence that thromboxane synthetase inhibition allows vasodilation, resulting in improved maternal and fetal condition.

Enterovesical fistula complicating pregnancy. A case report.

BACKGROUND: Enterovesical fistula is a rare cause of recurrent urinary tract infections. This condition is unusual in young people as common etiologies include diverticular disease and cancer. When an enterovesical fistula occurs in women of childbearing age, Crohn's disease is a likely cause. To our knowledge, enterovesical fistula complicating pregnancy has not been reported before. CASE: A pregnant woman with recurrent urinary tract infections was evaluated. Cystoscopy was suggestive of an enterovesical fistula, which was confirmed by charcoaluria following oral charcoal administration. The prenatal course was complicated by two episodes of hemorrhagic cystitis despite antibiotic prophylaxis. The patient had an uncomplicated term spontaneous vaginal delivery. An upper gastrointestinal series performed postpartum was suggestive of Crohn's disease and confirmed an enterovesical fistula. Surgical repair was successfully performed three months following delivery, revealing Crohn's disease. CONCLUSION: Enterovesical fistula may be an unusual cause of recurrent urinary tract infections in pregnancy. In this case, enterovesical fistula was the presenting symptom of Crohn's disease.

Active expectant management in very early gestations complicated by premature rupture of the fetal membranes.

Premature rupture of the membranes (PROM) in the previable gestation is frequently associated with fetal or neonatal death. Passive expectant management is successful in only a small minority of cases. Women presenting with PROM at < or = 27 weeks' gestation were treated with tocolysis and prophylactic antibiotics and delivered electively for lung maturity. The corrected perinatal survival was > 92%. The mean latency phase was 21.6 days (+/- 18.12 SD). Twenty-one percent of patients presented in labor; the mean latency phase for this subgroup was 14.4 (+/- 8.54) days. Nineteen patients (79%) had a latency phase > 7 days, and 14 (58%) had a latency phase > 14 days. Thirty-nine percent of infants required < 48 hours of mechanical ventilation. Six infants were delivered with intraventricular hemorrhage; in all cases it was grade 1 or 2. There were three (12.5%) postpartum infections and three septic neonates. Active expectant management using tocolysis and prophylactic antibiotics was associated with a prolonged latency phase, low infectious morbidity and good neonatal outcome.

Peripartum cardiomyopathy presenting as lower extremity arterial thromboembolism. A case report.

BACKGROUND: Although venous thromboembolism has been associated with peripartum cardiomyopathy, there have been no prior reports of lower extremity arterial thromboembolism complicating cardiac failure. CASE: A 38-year-old woman, gradiva 5, para 5, presented on postpartum day 9 with left pedal parasthesia. Lower extremity angiography found acute thrombotic emboli in the left popliteal artery, right tibial artery and right peroneal artery. When respiratory decompensation ensued, a transthoracic echocardiogram revealed global hypokinesis and a left ventricular ejection fraction of 30%. The patient had an uneventful recovery after treatment with digoxin, furosemide and intravenous heparin. CONCLUSION: Lower extremity arterial thromboembolism may be the initial manifestation of peripartum cardiomyopathy.

Successful pregnancy outcome in a woman with a gain-of-function mutation of the calcium-sensing receptor. A case report.

BACKGROUND: Gain-of-function mutations of the calcium-sensing receptor gene have recently been identified as a cause of familial hypercalciuric hypocalcemia. There have been no earlier reported cases of pregnancy among patients with this disorder. CASE: A 26-year-old woman, gravida 1, para 0, was diagnosed at age 18 as being a heterozygous carrier of a mutation in the calcium-sensing receptor gene. Stable maternal hypocalcemia was achieved during pregnancy with high-dose calcium and 1,25-dihydroxyvitamin D3 therapy. Prenatal diagnosis was accomplished via amniocentesis at 16 weeks' gestation. The patient underwent cesarean delivery at 35 5/7 weeks' gestation after developing the HELLP syndrome. CONCLUSION: Patients with mutations of the calcium-sensing receptor may have a successful pregnancy outcome. This abnormality may be transmitted to the fetus via an autosomal dominant pattern.

Alternatives to blood as a source of DNA for large-scale scanning studies of canine genome linkages.

Participation and compliance are critical to the success of any large-scale study of canine disease using DNA markers. Most canine genetic studies rely upon DNA extracted from peripheral blood samples. We assessed the utility of buccal swab epithelial cells and toe nails as a source of DNA for use in genomic screening studies. Using eight multiplexed canine microsatellite markers, amplified DNA obtained from peripheral blood, and from freshly extracted buccal epithelial cells, and buccal swab DNA extracted and stored at 20 degrees C for 27 months or extracted from toe nails were compared for three dogs. The accuracy of the genotyping at each locus was identical for each preparation. Buccal swab DNA samples were readily and uniformly amplified and could be stored for years without loss of integrity. Each buccal swab provided sufficient DNA for more than 200 individual PCR reactions. Toe nails provided ample DNA for thousands of PCR reactions and had the added advantage of ease of storage of the original tissues. These studies demonstrate the potential utility of DNA derived from buccal swabs or nails in large-scale genomic scanning and marker linkage studies.

Saccharomyces cerevisiae samples stained with FUN-1 dye can be stored at -20 degrees C for later observation.

FUN-1, a fluorescent vital dye, has been observed to form cylindrical intravacuolar structures within the vacuoles of metabolically active yeast cells. FUN-1 staining, which begins as a diffuse pool of fluorescent cytoplasmic stain, uses an unknown endogenous biochemical processing mechanism to compact and form orange-red cylindrical intravacuolar structures within the cell vacuole. In the clinical setting, FUN-1 is primarily used for identification of fungal infection. FUN-1 is utilized in the laboratory to distinguish between metabolically active and dead fungal cells. Although this stain is useful for distinguishing between live and dead fungal dead cells, few studies have utilized this chemical. This lack of use in the scientific community may be due to the requirement that cells are visualized directly after staining. Thus, it would be of interest to be able to stain cells and store them for later use. Our lab examined the longevity of cylindrical intravacuolar structures in two strains of Saccharomyces cerevisiae stained with FUN-1 and stored at -20 degrees C. We found that cylindrical intravacuolar structures could be reliably observed and imaged utilizing differential interference contrast microscopy and fluorescence microscopy for 21 days. We also observed that cells stained with FUN-1 would resume propagation on yeast extract, peptone, dextrose (YPD) plates after being frozen at -20 degrees C for 21 days. These modifications to the published procedure for FUN-1 dye staining should allow for a more prevalent and less time sensitive use of this important biological tool.