Successful treatment of peripartum cardiomyopathy with extracorporeal membrane oxygenation.

A 24-year-old female developed heart failure within four months of delivering her first child. Echocardiogram revealed a moderately dilated left ventricle with severely reduced systolic function. She continued to decompensate, requiring intubation and inotropic support. When the use of an intra-aortic balloon pump failed to stabilize the patient, the decision was made to place her on ECMO. The circuit consisted of a Quadrox D membrane oxygenator and a CentriMag centrifugal pump. After 11 days of support, the patient met the weaning criteria and was successfully removed from ECMO. She was discharged one month after her admission. The new technology available allows for ECMO to be considered as an earlier option for the treatment and management of these patients as a bridge to recovery.

The management of extremely premature infants and the perceptions of viability and parental counselling practices of Australian obstetricians.

The attitudes of Australian obstetricians to the resuscitation of extremely premature infants are reported. A structured questionnaire including questions regarding antenatal parent counselling, resuscitation practices, survival rates and personal attitudes about life support was distributed to obstetricians working in Australian hospitals with a Level 3 nursery Eighty-nine (48% response rate) replies were received from 12 units located in seven major cities. Obstetricians are more likely to discuss resuscitation with prospective parents with increasing gestation with a major shift occurring at 23-24 weeks' gestation. They strive for consensus with parents regarding resuscitation options and they act upon the opinion of both the prospective parents and their paediatric colleagues. Threat of litigation rarely influences the decision to limit resuscitation of an extremely preterm infant. Obstetricians may underestimate the prognosis for extremely preterm infants. The data presented offer useful insights into current attitudes and practice of tertiary hospital obstetricians.

Levels of knowledge of Down syndrome and Down syndrome testing in Australian women.

At their first hospital antenatal visit, 209 women were interviewed to explore their level of knowledge of Down syndrome and the available prenatal tests. Overall, the women had limited knowledge. Non-Caucasian women had less knowledge of Down syndrome, available prenatal tests and the association of Down syndrome with advanced maternal age than Caucasian women. Women with a history of a previous pregnancy and women over 35 years of age were not more aware of Down syndrome or the available tests than other women. These findings have significant implications for antenatal education and the implementation of screening programs for Down syndrome.

Women's knowledge of and attitudes to first and second trimester screening for Down's syndrome.

One hundred women were interviewed at their first hospital antenatal visit to assess their knowledge of, and attitudes to, first versus second trimester screening for Down's syndrome. Overall, the women had limited knowledge of Down's syndrome, and the prenatal screening and diagnostic tests that are available. However, when informed, the majority of women expressed a clear preference for first trimester screening tests for Down's syndrome, regardless of the rate of miscarriage of Down's syndrome pregnancies between 10 and 15 weeks of gestation. These findings have implications for the planning of prenatal Down's syndrome screening programmes.

The utilisation of nuchal translucency as a prenatal marker of Down syndrome, 1993-1999.

A sample of 6,038 obstetric ultrasound referrals and reports between January 1993 and June 1999 in a single Melbourne private ultrasound practice was reviewed to determine whether the referral and reporting pattern for nuchal translucency (NT) measurement has changed. The proportion of both 10-14 week ultrasound scans and mid trimester fetal anatomy scan referrals increased significantly over the study period (p < 0.001 and p < 0.001, respectively). There was also a significant increase in NT reporting and the number of specific referrals for an NT measurement over the study period (p = 0.01 and p < 0.001, respectively). If current trends continue it is likely that the 10-14 week scan for NT measurement will become a routine component of antenatal care. Therefore, as a matter of urgency, it is imperative that the best and most cost-effective screening strategy for Down syndrome in an Australian population is defined.

Urinary tract fistulas following gynaecological surgery.

Urinary tract fistulas are a relatively uncommon but important complication of gynaecological surgery. Between 1980 and 1995 we identified 17 patients who developed a urinary tract fistula after gynaecological surgery. Seven of the patients had surgery performed for neoplastic disease but none of these patients received adjuvant radiotherapy before the formation of the fistula. There were 12 vesicovaginal fistulas and five ureteric fistulas. Four of the vesicovaginal fistulas were repaired by the vaginal approach and five vesicovaginal fistulas were repaired by the abdominal route. Three vesicovaginal fistulas were treated by catheterisation alone. Two of the 17 patients took medicolegal action. Early recognition and repair of urinary tract fistulas is recommended. Repair of vesicovaginal fistulas by the vaginal approach is advised. The litigious nature of this distressing condition is lessened when early primary closure is successful.

Control of spatial orientation and lifetime of scroll rings in excitable media.

Excitable media, which range from autocatalytic chemical systems to biological cells and tissues, can maintain organized structures in the form of rotating spiral waves of excitation. The dynamics of spiral waves in two-dimensional systems have been shown to be susceptible to control by external fields (such as electric, thermal and optical). In three dimensions, the analogues of spiral waves are scroll waves. Here we show that an external field--a temperature gradient--can be used to control a particular class of scroll waves called scroll rings. The gradient allows scroll rings to be precisely oriented in space, and their spontaneous shrinkage to be accelerated, decelerated or even reversed (so that the ring expands). The temperature gradient also influences the lifetimes of the scroll rings. We suggest that these dynamics are likely to be generic to other types of field gradients and other excitable media.

Integration of oral habituation and gastric signals in decerebrate rat pups.

During a series of oral infusions of a sweet solution, the ingestive responses of young rat pups habituate; pups stop responding to the infusions even when their stomachs are empty and the infused diet is nonnutritive. The rate of this oral habituation is enhanced by the addition of gastric fill signals, even in decerebrate pups. In intact but not in decerebrate pups, prior deprivation gates out the influence of gastric fill on habituation. This oral habituation system, responsive to multiple ingestion-related signals, may serve as the elemental process that integrates physiological state with ongoing behavior to control ingestion.

Control of ingestion by oral habituation in rat pups.

The role of habituation of mouthing activity in the control of ingestion was investigated in 6-, 12-, and 18-day-old rat pups. In pups at all ages, oral habituation to a flavored diet inhibited ingestion of a continuous oral infusion of that same diet. Twelve-day-old pups that had orally habituated to a diet continued to consume less of a continuous oral infusion of that diet both 30 min and 3 hr later, and the duration of suppressed ingestion was shown to be dependent on the rate of stimulus presentation during habituation experience. These data suggest that oral habituation may be a diet-specific influence on both intra- and intermeal patterning.

Oral habituation in rat pups is in the brainstem.

We have previously demonstrated a decremental, oral, experienced-based control of ingestion in rat pups that is potent, diet-specific, and long lasting. This control of ingestion is revealed in the decreases in mouthing responses of rat pups to repeated oral stimulation, a phenomenon that is well described as oral habituation. The present study examined the neural basis for oral habituation by examining the responses of decerebrate 10-day-old rat pups to repeated, brief infusions of a sucrose solution. Like neurologically intact pups, decerebrate pups showed distinct decreases in mouthing responses following a series of oral infusions. Thus, oral habituation is present in the hindbrain. Although intact pups demonstrated sensitization by showing increased responding to the first few stimulus presentations, decerebrates failed to show a sensitization to the stimulation. These results suggest that while the brainstem alone is sufficient for the expression of oral habituation, the forebrain also influences oral responsivity in intact animals.

Habituation of oromotor responding to oral infusions in rat pups.

The influence of oromotor experience on the pattern of ingestion in rat pups and the relation of this influence to age and pups' physiological state were investigated using a procedure designed to mimic the sham-feeding preparation in adult rats. Six-, 12-, and 18-day-old pups received brief intra-oral infusions of sucrose solutions once every minute. Small infusion volumes minimized postoral effects. Pups' oromotor responsiveness was assessed by recording the pattern of mouthing behavior continuously during the test. Pups were tested after 24, 6 or 0 h deprivation. During testing, the mouthing behavior of all pups except 24-hr deprived 6-day olds showed a marked decline. The specificity of this decrement was demonstrated in a second experiment in which the decremented response was restored by a switch in solution flavor. Finally, the influence of postoral signals on the decline in responsiveness was evaluated by comparing the oral responsiveness of 18-day-old pups following intragastric, oral, or no infusions. Oral infusions suppressed subsequent oral responding, but intragastric infusions did not. These results provide evidence for a habituation-like role of oromotor experience in determining patterns of ingestive behavior within a feeding test. Here, major determinants of the pattern of decline were pups' physiological state and developmental age.

Analysis of 2-DG autoradiograms using image-averaging and image-differencing procedures for systems-level description of neurobehavioral function.

Computer assisted 2-deoxyglucose (2-DG) autoradiography has been used to provide functional maps of areas of altered neural activity related to changes in an animal's behavior or state. The standard procedure for comparison of autoradiograms between different treatment groups has been to take measurement samples from predefined neuroanatomical regions and to average these across brains to attain statistical sensitivity for detecting treatment effects. Unfortunately, when sampling is restricted to predefined areas, important topographic information is lost along with the ability to reveal an unexpected change in neural activity. To preserve the rich topographical detail of metabolic information and to enhance the capacity to uncover novel areas of altered metabolic activity, we have developed a system for averaging entire images from 2-DG autoradiograms and for comparing the average images from two experimental groups by creating an image of differences. This procedure does not rely on sampling only preselected regions, but still allows statistical comparisons between experimental groups. The procedures we describe can be readily and inexpensively adapted for use in individual laboratories and are based on modifications of preexisting image analysis software. We show that, when average and difference images are created using standardized protocols for sectioning brain tissue and editing section images, they are impressively resolved and realistic and can serve as effective topographic descriptions of group differences in neural activity of functional and behavioral relevance.