Enhanced charge density wave coherence in a light-quenched, high-temperature superconductor

Superconductivity and charge density waves (CDWs) are competitive, yet coexisting, orders in cuprate superconductors. To understand their microscopic interdependence, a probe capable of discerning their interaction on its natural length and time scale is necessary. We use ultrafast resonant soft x-ray scattering to track the transient evolution of CDW correlations in YBa₂Cu₃O_6+x after the quench of superconductivity by an infrared laser pulse. We observe a nonthermal response of the CDW order characterized by a near doubling of the correlation length within ≈1 picosecond of the superconducting quench. Our results are consistent with a model in which the interaction between superconductivity and CDWs manifests inhomogeneously through disruption of spatial coherence, with superconductivity playing the dominant role in stabilizing CDW topological defects, such as discommensurations.

dfpk: An R-package for Bayesian dose-finding designs using pharmacokinetics (PK) for phase I clinical trials

BACKGROUND AND OBJECTIVE

Dose-finding, aiming at finding the maximum tolerated dose, and pharmacokinetics studies are the first in human studies in the development process of a new pharmacological treatment. In the literature, to date only few attempts have been made to combine pharmacokinetics and dose-finding and to our knowledge no software implementation is generally available. In previous papers, we proposed several Bayesian adaptive pharmacokinetics-based dose-finding designs in small populations. The objective of this work is to implement these dose-finding methods in an R package, called dfpk.

METHODS

All methods were developed in a sequential Bayesian setting and Bayesian parameter estimation is carried out using the rstan package. All available pharmacokinetics and toxicity data are used to suggest the dose of the next cohort with a constraint regarding the probability of toxicity. Stopping rules are also considered for each method. The ggplot2 package is used to create summary plots of toxicities or concentration curves.

RESULTS

For all implemented methods, dfpk provides a function (nextDose) to estimate the probability of efficacy and to suggest the dose to give to the next cohort, and a function to run trial simulations to design a trial (nsim). The sim.data function generates at each dose the toxicity value related to a pharmacokinetic measure of exposure, the AUC, with an underlying pharmacokinetic one compartmental model with linear absorption. It is included as an example since similar data-frames can be generated directly by the user and passed to nsim.

CONCLUSION

The developed user-friendly R package dfpk, available on the CRAN repository, supports the design of innovative dose-finding studies using PK information.

Rapid in situ X-ray position stabilization via extremum seeking feedback

X-ray beam stability is crucial for acquiring high-quality data at synchrotron beamline facilities. When the X-ray beam and defining apertures are of similar dimensions, small misalignments driven by position instabilities give rise to large intensity fluctuations. This problem is solved using extremum seeking feedback control (ESFC) for in situ vertical beam position stabilization. In this setup, the intensity spatial gradient required for ESFC is determined by phase comparison of intensity oscillations downstream from the sample with pre-existing vertical beam oscillations. This approach compensates for vertical position drift from all sources with position recovery times <6 s and intensity stability through a 5 µm aperture measured at 1.5% FWHM over a period of 8 hours.

A Bayesian Hybrid Adaptive Randomisation Design for Clinical Trials with Survival Outcomes

BACKGROUND

Response-adaptive randomisation designs have been proposed to improve the efficiency of phase III randomised clinical trials and improve the outcomes of the clinical trial population. In the setting of failure time outcomes, Zhang and Rosenberger (2007) developed a response-adaptive randomisation approach that targets an optimal allocation, based on a fixed sample size.

OBJECTIVES

The aim of this research is to propose a response-adaptive randomisation procedure for survival trials with an interim monitoring plan, based on the following optimal criterion: for fixed variance of the estimated log hazard ratio, what allocation minimizes the expected hazard of failure? We demonstrate the utility of the design by redesigning a clinical trial on multiple myeloma.

METHODS

To handle continuous monitoring of data, we propose a Bayesian response-adaptive randomisation procedure, where the log hazard ratio is the effect measure of interest. Combining the prior with the normal likelihood, the mean posterior estimate of the log hazard ratio allows derivation of the optimal target allocation. We perform a simulation study to assess and compare the performance of this proposed Bayesian hybrid adaptive design to those of fixed, sequential or adaptive - either frequentist or fully Bayesian - designs. Non informative normal priors of the log hazard ratio were used, as well as mixture of enthusiastic and skeptical priors. Stopping rules based on the posterior distribution of the log hazard ratio were computed. The method is then illustrated by redesigning a phase III randomised clinical trial of chemotherapy in patients with multiple myeloma, with mixture of normal priors elicited from experts.

RESULTS

As expected, there was a reduction in the proportion of observed deaths in the adaptive vs. non-adaptive designs; this reduction was maximized using a Bayes mixture prior, with no clear-cut improvement by using a fully Bayesian procedure. The use of stopping rules allows a slight decrease in the observed proportion of deaths under the alternate hypothesis compared with the adaptive designs with no stopping rules.

CONCLUSIONS

Such Bayesian hybrid adaptive survival trials may be promising alternatives to traditional designs, reducing the duration of survival trials, as well as optimizing the ethical concerns for patients enrolled in the trial.

Abstract P4-14-12: Evaluation of the effect of pasireotide LAR administration in the lymphocele prevention after mastectomy with axillary lymph node dissection for breast cancer: results of a phase 2 randomized study

Background: Lymphocele is the principal post-operative morbidity following axillary node dissection. According to the literature, the incidence can vary from 4% to 89%. Encouraging results in terms of reducing postoperative lymphoceles as well as the volume and duration of drainage using octreotide LAR has been recently reported. Pasireotide LAR, a long acting drug designed to target multiple somatostatin receptors, was evaluated in this trial.

Trial design: A phase II, two centers, randomized, double-blind, non-comparative pilot study was carried out in order to evaluate efficacy and safety of a single injection of pasireotide LAR 60 mg administered 7–10 days before scheduled mastectomy with axillary dissection surgery. This study included a parallel placebo arm to assess the natural course of the disease.

Eligibility criteria: Adult female breast cancer patients planned to undergo a mastectomy (without reconstruction at the same time) and axillary node dissection.

Specific aims: To assess the efficacy and safety of a single injection of pasireotide LAR 60 mg or placebo prior to mastectomy with axillary lymph node dissection surgery in reducing symptomatic lymphocele development. Symptomatic lymphocele was evaluated and was defined as: 1. total lymphocele drainage/aspiration volume (unique or iterative) &gt;60 cc inclusive within the 28 days after surgery (excluding post-surgery drain) or; 2. a systematic aspiration volume at day 28 &gt; 120 cc.

Statistical methods: The statistical analysis was carried out sequentially after observing the absence of symptomatic lymphocele for each patient. It involves estimating the probability of a response in each group using a Bayesian design based on a beta-binomial model. The probability of response was considered random and its prior distribution was centered on 80% in the pasireotide group and 60% in the placebo group according to the investigators initial guesses. The distribution of the probability of response was updated after the observation of the patients included in the trial.

Results: A total of 90 patients were included over 18 months: 42 in the treatment group and 48 in the placebo group. In the treatment group, the posterior mean estimation of the response rate (i.e. patients who did not experience a symptomatic lymphocele) was 62.4% (95% CI: 48.6%–75.3%) and 50.2% in the placebo group (95% CI: 37.6%–62.8%%). In the treatment group, one serious adverse event occurred in a patient with known insulin dependent diabetes requiring hospitalization for hyperglycaemia.

Conclusion: A one time injection of pasireotide LAR to prevent symptomatic lymphocele development in women undergoing mastectomy with axillary dissection is promising. Further clinical studies are warranted.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-14-12.

Elemental and magnetic sensitive imaging using x-ray excited luminescence microscopy

We demonstrate the potential of x-ray excited luminescence microscopy for full-field elemental and magnetic sensitive imaging using a commercially available optical microscope, mounted on preexisting synchrotron radiation (SR) beamline end stations. The principal components of the instrument will be described. Bench top measurements indicate that a resolution of 1 μm or better is possible; this value was degraded in practice due to vibrations and/or drift in the end station and associated manipulator. X-ray energy dependent measurements performed on model solar cell materials and lithographically patterned magnetic thin film structures reveal clear elemental and magnetic signatures. The merits of the apparatus will be discussed in terms of conventional SR imaging techniques.

Risk factors for conversion and complications after unilateral laparoscopic adrenalectomy

BACKGROUND

Laparoscopic adrenalectomy (LA) is the procedure of choice for surgical management of most benign adrenal tumours, with a reported overall complication rate around 10 per cent. The aim of this study was to determine predictive factors for postoperative complications and conversion to open surgery after unilateral LA.

METHODS

From 1994 to 2009, consecutive patients undergoing unilateral LA by the lateral transabdominal approach were analysed from a prospectively maintained database. A mass larger than 12 cm in diameter and suspected primary adrenal carcinoma were considered contraindications to LA. Predictive factors for postoperative complications and conversion to open surgery were analysed.

RESULTS

Some 462 patients were analysed. There were no postoperative deaths. Postoperative complications occurred in 53 patients (11·5 per cent), medical complications in 28, and surgical complications in 33 patients. Six patients underwent reoperation for complications. Multivariable logistic regression analysis showed that conversion to open surgery (odds ratio (OR) 6·20, 95 per cent confidence interval 2·08 to 18·53; P = 0·001) and left-sided tumour (OR 1·89, 1·02 to 3·52; P = 0·044) were independent predictive factors for overall complications. Conversion to open surgery was the only independent predictive factor for medical complications (OR 12·88, 4·21 to 39·41; P = 0·001), and left-sided LA was the only predictive factor for surgical complications (OR 2·22, 1·01 to 4·89; P = 0·047). No factor was predictive of conversion to open surgery.

CONCLUSION

In this single-institution study, conversion to open surgery and left-sided tumours were independent predictive factors for overall complications, but none of the variables analysed was predictive of conversion.

Posterior maximization and averaging for Bayesian working model choice in the continual reassessment method

The continual reassessment method (CRM) is a method for estimating the maximum tolerated dose in a dose-finding study. Traditionally, use is made of a single working model or 'skeleton' idealizing an underlying true dose-toxicity relationship. This working model is chosen either by discussion with investigators or published data, before the beginning of the trial or simply on the basis of operating characteristics. To overcome the arbitrariness of the choice of such a single working model, Yin and Yuan (biJ. Am. Statist. Assoc. 2009; 104:954-968) propose a model averaging over a set of working models. Here, instead of averaging, we investigate some alternative Bayesian model criteria that maximize the posterior distribution. We propose three adaptive model-selecting CRMs using the Bayesian model selection criteria, in which we specify in advance a collection of candidate working models for the dose-toxicity relationship, especially initial guesses of toxicity probabilities, and adaptively select the only one working model among the candidates updated by using the original CRM for each working model, based on the posterior model probability, the posterior predictive loss or the deviance information criteria, during the course of the trial. These approaches were compared via a simulation study with the model averaging approach.

A compact apparatus for studies of element and phase-resolved ferromagnetic resonance

We present a compact sample holder equipped with electromagnets and high frequency transmission lines; the sample holder is intended for combined x-ray magnetic circular dichroism (XMCD) and ferromagnetic resonance measurements (FMR). Time-resolved measurements of resonant x-ray detected FMR during forced precession are enabled by use of a rf excitation that is phase-locked to the storage ring bunch clock. Several applications of the combined XMCD+FMR technique are presented, demonstrating the flexibility of the experimental design.

Long-term follow-up results after autologous haematopoietic stem cell transplantation for severe systemic sclerosis

OBJECTIVE

Systemic sclerosis (SSc) is a generalised autoimmune disease, causing morbidity and a reduced life expectancy, especially in patients with rapidly progressive diffuse cutaneous SSc. As no proven treatment exists, autologous haematopoietic stem cell transplantation (HSCT) is employed as a new therapeutic strategy in patients with a poor prognosis. This study reports the effects on survival, skin and major organ function of HSCT in patients with severe diffuse cutaneous SSc.

PATIENTS AND METHODS

A total of 26 patients were evaluated. Peripheral blood stem cells were collected using cyclophosphamide (4 g/m2) and rHu G-CSF (5 to 10 microg/kg/day) and were reinfused after positive CD34+ selection. For conditioning, cyclophosphamide 200 mg/kg was used.

RESULTS

After a median follow-up of 5.3 (1-7.5) years, 81% (n = 21/26) of the patients demonstrated a clinically beneficial response. The Kaplan-Meier estimated survival at 5 years was 96.2% (95% CI 89-100%) and at 7 years 84.8% (95% CI 70.2-100%) and event-free survival, defined as survival without mortality, relapse or progression of SSc, resulting in major organ dysfunction was 64.3% (95% CI 47.9-86%) at 5 years and 57.1% (95% CI 39.3-83%) at 7 years.

CONCLUSION

This study confirms that autologous HSCT in selected patients with severe diffuse cutaneous SSc results in sustained improvement of skin thickening and stabilisation of organ function up to 7 years after transplantation.

A phase I dose-finding and pharmacokinetic study of subcutaneous semisynthetic homoharringtonine (ssHHT) in patients with advanced acute myeloid leukaemia

To determine the maximum-tolerated dose (MTD), dose-limiting toxicities and pharmacokinetic of semisynthetic homoharringtonine (ssHHT), given as a twice daily subcutaneous (s.c.) injections for 9 days, in patients with advanced acute leukaemia, 18 patients with advanced acute myeloid leukaemia were included in this sequential Bayesian phase I dose-finding trial. A starting dose of 0.5 mg m⁻² day⁻¹ was explored with subsequent dose escalations of 1, 3, 5 and 6 mg m⁻² day⁻¹. Myelosuppression was constant. The MTD was estimated as the dose level of 5 mg m⁻² day⁻¹ for 9 consecutive days by s.c. route. Dose-limiting toxicities were hyperglycaemia with hyperosmolar coma at 3 mg m⁻², and (i) one anasarque and haematemesis, (ii) one life-threatening pulmonary aspergillosis, (iii) one skin rash and (iv) one scalp pain at dose level of 5 mg m⁻² day⁻¹. The mean half-life of ssHHT was 11.01±3.4 h, the volume of distribution at steady state was 2±1.4 l kg⁻¹ and the plasma clearance was 11.6±10.4 l h⁻¹. Eleven of the 12 patients with circulating leukaemic cells had blood blast clearance, two achieved complete remission and one with blast crisis of CMML returned in chronic phase. The recommended daily dose of ssHHT on the 9-day schedule is 5 mg m⁻² day⁻¹.

Experimental designs for phase I and phase I/II dose-finding studies

We review the rationale behind the statistical design of dose-finding studies as used in phase I and phase I/II clinical trials. We underline what the objectives of such dose-finding studies should be and why the widely used standard design fails to meet any of these objectives. The standard design is a "memoryless" design and we discuss how this impacts on practical behaviour. Designs introduced over the last two decades can be viewed as designs with memory and we discuss how these designs are superior to memoryless designs. By superior we mean that they require less patients overall, less patients to attain the maximum tolerated dose (MTD), and concentrate a higher percentage of patients at and near to the MTD. We reanalyse some recently published studies in order to provide support to our contention that markedly better results could have been achieved had a design with memory been used instead of a memoryless design.

The VAD chemotherapy regimen plus a G-CSF dose of 10 μg/kg is as effective and less toxic than high-dose cyclophosphamide plus a G-CSF dose of 5 μg/kg for progenitor cell mobilization: results from a monocentric study of 82 patients

A study was conducted to compare the efficiency and toxicity of two peripheral blood stem cell (PBSC) mobilization procedures for newly diagnosed patients with multiple myeloma. Patients from group 1 (n=51) were treated by high-dose cyclophosphamide (HD-CY) plus G-CSF (5 microg/kg/day), and the second group (n=31) by VAD regimen plus G-CSF administration (10 microg/kg/day). Successful mobilization, defined by a minimal count of 2.5 x 10(6) CD34(+) cells/kg collected, was achieved in 96 and 90% of patients in groups 1 and 2, respectively (P=0.15). The mean peripheral blood CD34(+) cells concentration and the mean CD34(+) cells/kg collected were higher in group 2 than in the group 1 (P=0.05). The mean number of leukaphereses necessary to collect a count of 2.5 x 10(6) CD34(+) cells/kg was reduced in group 2 compared to group 1. Adverse events, blood products consumption and time spent in the hospital were significantly greater after HD-CY. In conclusion, VAD plus a G-CSF dose of 10 microg/kg administration seems preferential to HD-CY plus a G-CSF dose of 5 microg/kg for PBSC collection because of equivalent or better efficiency in stem cell mobilization, strong favorable toxicity profile and reduced cost.

Dose-finding study of ibuprofen in patent ductus arteriosus using the continual reassessment method

OBJECTIVE

Intravenous ibuprofen (IBU) has been found to be as effective as indomethacin for the treatment of patent ductus arteriosus (PDA) in preterm infants and has been associated with fewer adverse effects in comparative phase III studies. The dose regimen used (10-5-5 mg/kg/day) was based on limited pharmacokinetic data and no phase II study was available to determine the optimal dose of IBU for this indication. The present study was designed to determine the minimum effective dose regimen (MEDR) of IBU (one course) required to close ductus arteriosus in preterm infants.

METHOD

A double-blind dose-finding study was conducted using the continual reassessment method, a Bayesian sequential design. Two distinct target closure rates were initially chosen according to postmenstrual age (PMA) at birth: 80% in infants with a PMA of 27-29 weeks, and 50% in infants with a PMA < 27 weeks. Forty neonates (20 in each PMA group) with PDA were treated between days 3 and 5 of life. Four different dose regimens were tested: loading doses of 5, 10, 15 or 20 mg/kg, followed by two doses (1/2 loading dose) at 24-h intervals. Efficacy was evaluated by echocardiography 24 h after the third infusion.

RESULTS

In infants with a PMA of 27-29 weeks, the estimated MEDR was 10-5-5 mg/kg with a final estimated probability of success of 77% (95% credibility interval: 56-92%). The 15-7.5-7.5 mg/kg dose regimen had a better estimated probability of success (88%, 95% credibility interval: 68-97%), but resulted in more minor renal adverse effects. In contrast, in infants with a PMA < 27 weeks, the estimated MEDR was 20-10-10 mg/kg with an estimated probability of success of 54.8% (95% credibility interval: 22-84%), whereas the conventional dose regimen resulted in a low estimated probability of success (30.6%, 95% credibility interval: 13-56%). In these infants, compared with those with a PMA of 27-29 weeks, minor renal adverse effects were more frequent from the 10-5-5 mg/kg/day dose regimen and did not appear to be clearly dose related.

CONCLUSION

This study confirms that the currently recommended dose regimen (10-5-5 mg/kg) of IBU is associated with a high closure rate (80%) and few adverse effects in premature infants with a PMA of 27-29 weeks. The failure rate was much higher below 27 weeks. A higher dose regimen (20-10-10 mg/kg) might achieve a higher closure rate. However, tolerability and safety of this dose regimen should be assessed in a larger population before considering the use of these doses for ductus arteriosus closure.

Minimum effective dose of midazolam for sedation of mechanically ventilated neonates

OBJECTIVE

To determine the minimal effective dose (MED) of intravenous midazolam, required for appropriate sedation in 95% of patients, 1 h after drug administration.

METHODS

A double-blind dose-finding study using the continual reassessment method, a Bayesian sequential design. Twenty-three newborn infants hospitalized in intensive care unit participated. Inclusion criteria were: (i) post-natal age <28 days, (ii) gestational age >33 weeks, (iii) intubation and ventilatory support required for respiratory distress syndrome, (iv) need for sedation (i.e. one of the six following criteria: agitation or grimacing or crying facial expression before tracheal suctioning, agitation or grimacing or crying facial expression during tracheal suctioning). Each neonate was allocated to a loading dose, ranging from 75 to 200 microg/kg, and a maintenance dose ranging from 37.5 to 100 microg/kg/h.

RESULTS

The primary endpoint was the level of sedation 1 h after the onset of infusion. The sedation procedure was classified as a success if all the following clinical criteria were met: no agitation, no grimacing and no crying facial expression before as well as during tracheal suctioning. Based on the 23 patients, the final estimated probability of success was 76.9% (95% credibility interval: 56.6-91.4%) for the 200 microg/kg loading dose. no significant adverse effect was observed.

CONCLUSIONS

Continual reassessment is a new approach, suitable for dose-finding study in neonates. this method overcomes some of the ethical, statistical and practical problems associated with this population. Using this method, the MED was estimated to be the 200 mug/kg loading dose of midazolam.

Pregnancy outcome after laparoscopy or laparotomy in pregnancy

STUDY OBJECTIVE

To assess obstetric performance and fetal outcomes after laparoscopy or laparotomy performed during pregnancy.

DESIGN

Nationwide, multicenter, retrospective chart review (Canadian Task Force classification II-2).

SETTING

Seventeen hospitals throughout Israel: 12 university or university-affiliated hospitals and 5 general hospitals.

PATIENTS

Three hundred eighty-nine pregnant women.

INTERVENTION

Laparoscopy or laparotomy for various indications.

MEASUREMENTS AND MAIN RESULTS

Of 192 laparoscopies performed, 141 were during the first, 46 during the second, and 5 during the third trimester; respective figures for 197 laparotomies were 63, 110, and 24. No intraoperative complications were reported for either procedure. Six and 25 women had complications after laparoscopy and laparotomy, respectively. There was no significant difference in abortion rates between groups. Mean gestational age at delivery and mean birthweight were comparable between groups. No significant difference was found in frequency of fetal anomalies between groups or when compared with the Israel register of anomalies.

CONCLUSION

Operative laparoscopy seems to be as safe as laparotomy in pregnancy.

The continual reassessment method: comparison of Bayesian stopping rules for dose-ranging studies

The continual reassessment method (CRM) provides a Bayesian estimation of the maximum tolerated dose (MTD) in phase I clinical trials and is also used to estimate the minimal efficacy dose (MED) in phase II clinical trials. In this paper we propose Bayesian stopping rules for the CRM, based on either posterior or predictive probability distributions that can be applied sequentially during the trial. These rules aim at early detection of either the mis-choice of dose range or a prefixed gain in the point estimate or accuracy of estimated probability of response associated with the MTD (or MED). They were compared through a simulation study under six situations that could represent the underlying unknown dose-response (either toxicity or failure) relationship, in terms of sample size, probability of correct selection and bias of the response probability associated to the MTD (or MED). Our results show that the stopping rules act correctly, with early stopping by using the two first rules based on the posterior distribution when the actual underlying dose-response relationship is far from that initially supposed, while the rules based on predictive gain functions provide a discontinuation of inclusions whatever the actual dose-response curve after 20 patients on average, that is, depending mostly on the accumulated data. The stopping rules were then applied to a data set from a dose-ranging phase II clinical trial aiming at estimating the MED dose of midazolam in the sedation of infants during cardiac catheterization. All these findings suggest the early use of the two first rules to detect a mis-choice of dose range, while they confirm the requirement of including at least 20 patients at the same dose to reach an accurate estimate of MTD (MED). A two-stage design is under study.

Acute mastoiditis--the antibiotic era: a multicenter study

OBJECTIVES

To evaluate the clinical course and identify the causative organisms of acute mastoiditis in a community where most of the patients who develop acute otitis media are treated with antibiotics.

METHODS

A multicenter retrospective review of a series of 223 consecutive cases of acute mastoiditis.

SETTING

Nine secondary or tertiary academic or non-academic referral centers.

RESULTS

Prior to the diagnosis of acute mastoiditis, 121 of the patients (54.3%) had been receiving oral antibiotic treatment for acute otitis media for periods ranging from 1 to 21 days (mean 5.3 days). Samples for bacterial culture were obtained from 152 patients. Cultures were negative in 60 patients. The organisms isolated in the 92 positive cultures were: Streptococcus pneumoniae (15 patients), Streptococcus pyogenes (14 patients), Staphylococcus aureus (13 patients), Staphylococcus coagulase negative (three patients), Pseudomonas aeruginosa (eight patients), Haemophilus influenzae (four patients), Proteus mirabilis (two patients), Escherichia coli (two patients), Klebsiella pneumoniae (one patient), Enterobacter (one patient), Acinetobacter (one patient), anaerobic gram-negative bacilli (one patient), and fungi (two patients). Ten patients had mixed flora. Sixteen patients presented with complications (cerebellar abscess, perisinus empyema, subdural abscess or empyema, extradural abscess, cavernous sinus thrombosis, lateral sinus thrombosis, bacterial meningitis, labyrinthitis, petrositis, or facial nerve palsy).

CONCLUSIONS

Antibiotic treatment cannot be considered an absolute safeguard against the development of acute mastoiditis. Early myringotomy for acute otitis media seems to decrease the incidence of complications. The distribution of causative organisms in acute mastoiditis differs from that in acute otitis media. Intracranial complications in acute mastoiditis are not rare. Because of the diversity of causative organisms in acute mastoiditis and the growing resistance of bacteria to the various antibiotics, all means to obtain a sample for culture prior to antibiotic treatment, including general anesthesia.

Hypnotic effect of i.v. thiopentone is enhanced by i.m. administration of either lignocaine or bupivacaine

We have compared the hypnotic requirements for i.v. thiopentone alone and in combination with i.m. lignocaine or bupivacaine. Ninety women, ASA I-II, undergoing minor gynaecological surgery were allocated randomly to nine groups of 10 patients to receive thiopentone combined with i.m. lignocaine, bupivacaine or saline, respectively. Thiopentone was administered in bolus doses of 0.5 mg kg-1 every 30 s until loss of response to verbal command. Lignocaine and bupivacaine significantly enhanced the hypnotic effect of thiopentone in a dose-dependent manner. The maximum doses tested (lignocaine 3.0 mg kg-1 and bupivacaine 1.0 mg kg-1) reduced the hypnotic dose of thiopentone by 39% and 48%, respectively. We conclude that if lignocaine or bupivacaine are injected into soft tissue before induction of anaesthesia by thiopentone, the i.v. dose of the latter should be modified accordingly.

Sex differences in mortality of Japanese macaques: twenty-one years of data from the Arashiyama West population

Theorists argue that mortality in male mammals should be higher than that of females, and many studies of primates followed across the life course have found this to be the case. This study examines mortality patterns in the rapidly expanding Arashiyama West (Texas) population of Japanese macaques (Macaca fuscata) and finds that males have a significantly lower median survival age (12.2 years) in comparison to females (20.5 years). Males and females are born in equal proportions, but by adulthood there are 2-5 females to every male. Males are at higher risk of falling victim to infectious diseases and human-related causes of death, and they are more likely to "disappear" from the population, which is inferred to result largely from emigration. There are no significant sex differences in the risks of dying from predation, non-infectious illnesses, neonatal defect, or social stress. Males become more susceptible to mortality than females once they reach sexual maturity, and they remain at greater risk than females until their old age. There is no evidence that one sex or the other is at greater risk of dying as infants, or as juveniles. Comparing males of different age classes, adolescent and adult males are more likely to die and to disappear than are juvenile males. These findings support the "high-risk, high-gain" hypothesis that males are mainly lost to the population because of their risk-taking behaviors after sexual maturity, rather than the "fragile male" hypothesis that males are more vulnerable to mortality during the period of growth and development.

CA-125 is elevated in viable pregnancies destined to be miscarried: a prospective longitudinal study

OBJECTIVE

To assess the predictive value of E2, hCG, CA-125, and morphometric parameters in early pregnancies with demonstrable fetal heartbeat, complicated by bleeding.

DESIGN

Prospective longitudinal follow-up.

SETTING

The emergency service of the Department of Obstetrics and Gynecology, "Rebecca Sieff" Hospital, Safed, Israel.

PATIENTS

Twenty-five consecutive patients with vaginal bleeding during weeks 7 to 12 of pregnancy who had demonstrable fetal heartbeat. Ten women with normal pregnancies, serving as controls.

MAIN OUTCOME MEASURE

The serum levels and the morphometric parameters were related to the outcome of pregnancy as revealed by future hospitalization, delivery, or telephone questioning.

RESULTS

In the five patients who eventually aborted, the values of CA-125 were > 125 U/mL, whereas none of the successful pregnancies had a value > 93 U/mL. The mean values were 133 +/- 4.85 versus 36.95 +/- 23.1 U/mL for miscarriages and successful pregnancies, respectively. In normal pregnancies the respective value was 32.3 +/- 4.3 U/mL. Although mean E2 levels were lower in the serum of women who eventually aborted, there was a significant overlap of values with the successful pregnancies. All the other parameters measured had no correlation to the outcome of these pregnancies.

CONCLUSION

CA-125 may serve as an accurate predictor of the outcome in early pregnancies with demonstrable fetal heartbeat, which are complicated by bleeding.

Fertility, miscarriage and pregnancy after vertical banded gastroplasty operation for morbid obesity

Vertical banded gastroplasty (VBG) is today the most widely performed bariatric operation. The procedures used previously for the same purpose resulted in metabolic derangements and other pathologies during pregnancy. In a retrospective study we compared the reproductive performance of nine women prior to VBG and after it. Of eighteen pregnancies prior to the operation, seven ended with miscarriage, while only one of fourteen pregnancies conceived after the operation was aborted. The rate of spontaneous conception was greatly increased after the operation and there were fewer complications in the course of the pregnancies. From the obstetrician and gynecologist's point of view VBG seems to be a good treatment for morbid obesity.

Spectral window of the acousto-optic folded spectrum analyzer

I derive here the spectral window of the acousto-optic folded spectrum analyzer proposed by [K. Wagner and D. Psaltis, Proc. Soc. Photo-Opt. Instrum. Eng. 564, 209-223 (1985)]. This window function turns out to be quite informative. It clarifies important characteristics that distinguish this system from the more conventional digital spectrum analyzers, and it clarifies the relationships between various system design parameters and helps guide their selection. The spectral window of one specific implementation of a finer-resolution version of this analyzer (the super-fine-resolution variant suggested in the above reference) is also determined. Analysis shows that for certain narrow-frequency ranges this window has two main lobes separated by a large number of super-fine frequency-resolution bins. This characteristic makes it unacceptable in many applications.

[Pregnancy and delivery in women with coarctation of the aorta]

We report 2 cases of aortic coarctation in women aged 18.5 and 24 years, respectively. In 1 the malformation was found during gestation, while the other became pregnant after the diagnosis was made. Both had uneventful pregnancies and delivered healthy babies. Coarctation of the aorta is found in approximately 7% of those with congenital heart disease. The clinical diagnosis is made from the absence of femoral artery pulsations and low arterial pressure in arteries originating distal to the coarctation and hypertension in those proximal to it. Since it occurs mainly in males and is usually corrected during infancy, its incidence in pregnancy is low. Maternal morbidity may be high, since pregnancy increases the risk of aortic rupture or dissection, as well as of cerebral hemorrhage from rupture of an aneurysm of the circle of Willis. Surgical repair before conception reduces the risk of aortic complications during pregnancy, and also decreases the incidence of fetal complications, such as IUGR or congenital heart disease. The outcome of pregnancy is also influenced by coexistence of other malformations, such as bicuspid aortic valve which leads to infective endocarditis. In uncomplicated coarctation, pregnancy and delivery are usually uneventful. Cesarean section is done mainly for obstetric indications.

High density lipoprotein concentration is increased during the ovulatory phase of the menstrual cycle in healthy young women

This study aimed to examine the relation between sex steroid hormone fluctuations during the menstrual cycle and serum lipoproteins and their constituents. Serum was obtained in the early follicular, preovulatory, and midluteal phases from 18 young women. Ovulation was confirmed by estrogen and progesterone assays. High density lipoprotein cholesterol (HDL-C) was found to increase by 16% in the preovulatory phase, in comparison to the early follicular phase. Serum apolipoprotein-AI (Apo-AI) was elevated in the preovulatory and mid-luteal phases (14% and 19%, respectively) in comparison to the early follicular phase. Total cholesterol, triglycerides, very low, and low density lipoprotein-cholesterol (VLDL-C and LDL-C) and apolipoprotein-B (Apo-B) serum levels did not change throughout the cycle. In the mid-luteal phase, the Apo-AI/HDL-C ratio was higher than in the other two phases, suggesting altered HDL composition during this phase. These results suggest that endogenous progesterone, unlike some synthetic progestogens, does not negate the beneficial effect of estrogen on serum lipoproteins.

Axillary vein thrombosis during pregnancy: a case report

A 32-year-old multiparous woman had progressive swelling of the right arm at 32 weeks' gestation, accompanied by cyanosis and a preserved radial pulse. Phlebography demonstrated a 5-cm thrombus in the axillary vein. No known etiologic factors were found. Intravenous heparin administration resulted in rapid resolution of the clinical findings. Subcutaneous heparin 10,000 U/day was administered for secondary prophylaxis until cesarean at 39 weeks, during which a full dose was administered without complications. Axillary vein thrombosis during pregnancy may be diagnosed by either phlebography or duplex scanning, and preferably should be treated by heparin. Thrombolytic therapy is justified mainly for life-threatening complications such as pulmonary embolism.

Sudden dysphonia due to parathyroid apoplexy: a rare case of recurrent laryngeal nerve palsy

A case is presented of sudden onset dysphonia in a 59-year-old man caused by acute vocal cord paralysis due to bleeding within a hyperplastic lower right parathyroid gland. There were no laboratory findings of hyperparathyroidism nor coagulation disorder. Acute onset of vocal cord paralysis is rarely associated with benign processes; the current case is the first associated with parathyroid hyperplasia.

Midazolam acts synergistically with fentanyl for induction of anaesthesia

The induction dose-response of midazolam was compared with the dose-response of its combination with fentanyl and with that of fentanyl alone in three groups of 60 unpremedicated, ASA physical status I or II women undergoing minor gynaecological surgery. The end-point of induction of anaesthesia was inability to open eyes upon command. Dose-response curves were determined for each group with a probit procedure and compared with an isobolographic analysis. Midazolam was found to act in synergism with fentanyl for induction of anaesthesia. Twenty-five percent of the ED50 of fentanyl was required in combination with 23% of the ED50 for midazolam to achieve the ED50 of the combination. This degree of synergism may explain mutual potentiation between opioids and benzodiazepines reported previously.

[Epistaxis caused by leeches]

Among the conditions which can cause epistaxis are intranasal or nasopharyngeal foreign bodies. A living foreign body, or parasite, in the nose or nasopharynx is rare in western countries, but in other parts of the world is a fairly common cause of epistaxis. In the past 5 years 17 cases of epistaxis due to infestation with leeches were treated in our 2 departments. In 14 patients, 9-27 years old, the complaint was of recurrent episodes of mild epistaxis and blood-spitting several days before admission. 3 patients were admitted hemorrhaging profusely from the nose and mouth. Examination showed a green-brown mass protruding from the nasopharynx behind the soft palate, which is every case was a blood-engorged leech. Treatment consisted of removing the leech by applying a forceps to the middle of the leech's body and giving a quick pull. Bleeding ceased immediately after removal of the leech. All the patients had drunk water from brooks, streams or fresh water lakes. Therefore, in areas in which leeches are present only boiled or filtered water should be drunk.

Quadruplets following cessation of clomiphene citrate. A case of sustained effect

We report a case of quadruplet birth in a young oligomenorrheic woman, who had been prescribed clomiphene citrate for two consecutive cycles. She conceived following cessation of treatment and an intervening menstruation. Ultrasonic follow-up which concurred with the last menstrual period dating indicated multiple ovulation as a sustained effect of clomiphene citrate medication.