Differences in obstetrical care and outcomes associated with the proportion of the obstetrician's shift completed

BACKGROUND

Understanding and improving obstetrical quality and safety is an important goal of professional societies, and many interventions such as checklists, safety bundles, educational interventions, or other culture changes have been implemented to improve the quality of care provided to obstetrical patients. Although many factors contribute to delivery decisions, a reduced workload has addressed how provider issues such as fatigue or behaviors surrounding impending shift changes may influence the delivery mode and outcomes.

OBJECTIVE

The objective was to assess whether intrapartum obstetrical interventions and adverse outcomes differ based on the temporal proximity of the delivery to the attending's shift change.

STUDY DESIGN

This was a secondary analysis from a multicenter obstetrical cohort in which all patients with cephalic, singleton gestations who attempted vaginal birth were eligible for inclusion. The primary exposure used to quantify the relationship between the proximity of the provider to their shift change and a delivery intervention was the ratio of time from the most recent attending shift change to vaginal delivery or decision for cesarean delivery to the total length of the shift. Ratios were used to represent the proportion of time completed in the shift by normalizing for varying shift lengths. A sensitivity analysis restricted to patients who were delivered by physicians working 12-hour shifts was performed. Outcomes chosen included cesarean delivery, episiotomy, third- or fourth-degree perineal laceration, 5-minute Apgar score of <4, and neonatal intensive care unit admission. Chi-squared tests were used to evaluate outcomes based on the proportion of the attending's shift completed. Adjusted and unadjusted logistic models fitting a cubic spline (when indicated) were used to determine whether the frequency of outcomes throughout the shift occurred in a statistically significant, nonlinear pattern RESULTS: Of the 82,851 patients eligible for inclusion, 47,262 (57%) had ratio data available and constituted the analyzable sample. Deliveries were evenly distributed throughout shifts, with 50.6% taking place in the first half of shifts. There were no statistically significant differences in the frequency of cesarean delivery, episiotomy, third- or fourth-degree perineal lacerations, or 5-minute Apgar scores of <4 based on the proportion of the shift completed. The findings were unchanged when evaluated with a cubic spline in unadjusted and adjusted logistic models. Sensitivity analyses performed on the 22.2% of patients who were delivered by a physician completing a 12-hour shift showed similar findings. There was a small increase in the frequency of neonatal intensive care unit admissions with a greater proportion of the shift completed (adjusted P=.009), but the findings did not persist in the sensitivity analysis.

CONCLUSION

Clinically significant differences in obstetrical interventions and outcomes do not seem to exist based on the temporal proximity to the attending physician's shift change. Future work should attempt to directly study unit culture and provider fatigue to further investigate opportunities to improve obstetrical quality of care, and additional studies are needed to corroborate these findings in community settings.

Assessment of the targeting specificity of a fluorescent albumin conceived as a preclinical agent of the liver function

In the context of increasing liver diseases, no contrast agent is currently available in Europe and the United States to directly assess the liver function. Only neolactosylated human serum albumin is being clinically used in Asia. In order to perform preclinical studies in the context of liver diseases, we conceived a fluorescent lactosylated albumin for the quantification of liver functional cells (l-Cyal). Precise characterization was achieved in order to determine the amounts of lactose and Cyanine 5 (Cy5) coupled to the albumin. In addition, potential aggregation was characterized by asymmetrical flow field-flow fractionation hyphenated to multi-angle light scattering (AF4-MALS). The optimal functionalized albumin exhibited a mass greater than 87 kDa which corresponds to the addition of 34 lactose moieties per protein and 1-2 Cy5 labels. Also, no significant formation of aggregates could be identified due to the modification of the native albumin. In healthy mice, the accumulation of l-Cyal in the liver and its selectivity for hepatocyte cells were shown by optical imaging and flow cytometry. Administration of l-Cyal to mice bearing liver metastases showed a reduced signal in the liver related to a decrease in the number of hepatocytes. The l-Cyal bioimaging contrast agent could be particularly useful for assessing the state of liver related diseases.

Neonatal outcomes of elective early-term births after demonstrated fetal lung maturity

BACKGROUND

Studies of early-term birth after demonstrated fetal lung maturity show that respiratory and other outcomes are worse with early-term birth (37⁰-38⁶ weeks) even after demonstrated fetal lung maturity when compared with full-term birth (39⁰-40⁶ weeks). However, these studies included medically indicated births and are therefore potentially limited by confounding by the indication for delivery. Thus, the increase in adverse outcomes might be due to the indication for early-term birth rather than the early-term birth itself.

OBJECTIVE

We examined the prevalence and risks of adverse neonatal outcomes associated with early-term birth after confirmed fetal lung maturity as compared with full-term birth in the absence of indications for early delivery.

STUDY DESIGN

This is a secondary analysis of an observational study of births to 115,502 women in 25 hospitals in the United States from 2008 through 2011. Singleton nonanomalous births at 37-40 weeks with no identifiable indication for delivery were included; early-term births after positive fetal lung maturity testing were compared with full-term births. The primary outcome was a composite of death, ventilator for ≥2 days, continuous positive airway pressure, proven sepsis, pneumonia or meningitis, treated hypoglycemia, hyperbilirubinemia (phototherapy), and 5-minute Apgar <7. Logistic regression and propensity score matching (both 1:1 and 1:2) were used.

RESULTS

In all, 48,137 births met inclusion criteria; the prevalence of fetal lung maturity testing in the absence of medical or obstetric indications for early delivery was 0.52% (n = 249). There were 180 (0.37%) early-term births after confirmed pulmonary maturity and 47,957 full-term births. Women in the former group were more likely to be non-Hispanic white, smoke, have received antenatal steroids, have induction, and have a cesarean. Risks of the composite (16.1% vs 5.4%; adjusted odds ratio, 3.2; 95% confidence interval, 2.1-4.8 from logistic regression) were more frequent with elective early-term birth. Propensity scores matching confirmed the increased primary composite in elective early-term births: adjusted odds ratios, 4.3 (95% confidence interval, 1.8-10.5) for 1:1 and 3.5 (95% confidence interval, 1.8-6.5) for 1:2 matching. Among components of the primary outcome, CPAP use and hyperbilirubinemia requiring phototherapy were significantly increased. Transient tachypnea of the newborn, neonatal intensive care unit admission, and prolonged neonatal intensive care unit stay (>2 days) were also increased with early-term birth.

CONCLUSION

Even with confirmed pulmonary maturity, early-term birth in the absence of medical or obstetric indications is associated with worse neonatal respiratory and hepatic outcomes compared with full-term birth, suggesting relative immaturity of these organ systems in early-term births.

Preterm neonatal morbidity and mortality by gestational age: a contemporary cohort

BACKGROUND

Although preterm birth <37 weeks' gestation is the leading cause of neonatal morbidity and mortality in the United States, the majority of data regarding preterm neonatal outcomes come from older studies, and many reports have been limited to only very preterm neonates. Delineation of neonatal outcomes by delivery gestational age is needed to further clarify the continuum of mortality and morbidity frequencies among preterm neonates.

OBJECTIVE

We sought to describe the contemporary frequencies of neonatal death, neonatal morbidities, and neonatal length of stay across the spectrum of preterm gestational ages.

STUDY DESIGN

This was a secondary analysis of an obstetric cohort of 115,502 women and their neonates who were born in 25 hospitals nationwide, 2008 through 2011. All liveborn nonanomalous singleton preterm (23.0-36.9 weeks of gestation) neonates were included in this analysis. The frequency of neonatal death, major neonatal morbidity (intraventricular hemorrhage grade III/IV, seizures, hypoxic-ischemic encephalopathy, necrotizing enterocolitis stage II/III, bronchopulmonary dysplasia, persistent pulmonary hypertension), and minor neonatal morbidity (hypotension requiring treatment, intraventricular hemorrhage grade I/II, necrotizing enterocolitis stage I, respiratory distress syndrome, hyperbilirubinemia requiring treatment) were calculated by delivery gestational age; each neonate was classified once by the worst outcome for which criteria was met.

RESULTS

In all, 8334 deliveries met inclusion criteria. There were 119 (1.4%) neonatal deaths. In all, 657 (7.9%) neonates had major morbidity, 3136 (37.6%) had minor morbidity, and 4422 (53.1%) survived without any of the studied morbidities. Deaths declined rapidly with each advancing week of gestation. This decline in death was accompanied by an increase in major neonatal morbidity, which peaked at 54.8% at 25 weeks of gestation. As frequencies of death and major neonatal morbidity fell, minor neonatal morbidity increased, peaking at 81.7% at 31 weeks of gestation. The frequency of all morbidities fell >32 weeks. After 25 weeks, neonatal length of hospital stay decreased significantly with each additional completed week of pregnancy; among babies delivered from 26-32 weeks of gestation, each additional week in utero reduced the subsequent length of neonatal hospitalization by a minimum of 8 days. The median postmenstrual age at discharge nadired around 36 weeks' postmenstrual age for babies born at 31-35 weeks of gestation.

CONCLUSION

Our data show that there is a continuum of outcomes, with each additional week of gestation conferring survival benefit while reducing the length of initial hospitalization. These contemporary data can be useful for patient counseling regarding preterm outcomes.

Nonmedically indicated induction vs expectant treatment in term nulliparous women

OBJECTIVE

The purpose of this study was to compare maternal and neonatal outcomes in nulliparous women with nonmedically indicated inductions at term vs those expectantly treated.

STUDY DESIGN

Data were obtained from maternal and neonatal charts for all deliveries on randomly selected days across 25 US hospitals over a 3-year period. A low-risk subset of nulliparous women with vertex nonanomalous singleton gestations who delivered 38 0/7 to 41 6/7 weeks were selected. Maternal and neonatal outcomes for nonmedically indicated induction within each week were compared with women who did not undergo nonmedically indicated induction during that week. Multivariable analysis was used to adjust for hospital, maternal age, race/ethnicity, body mass index, cigarette use, and insurance status.

RESULTS

We found 31,169 women who met our criteria. Neonatal complications were either less frequent with nonmedically indicated induction or no different between groups. Nonmedically indicated induction was associated with less frequent peripartum infections (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.16-0.98) at 38 weeks of gestation and less frequent third- and fourth-degree lacerations (OR, 0.60; 95% CI, 0.42-0.86) and less frequent peripartum infections (OR, 0.66; 95% CI, 0.49-0.90) at 39 weeks of gestation. Nonmedically indicated induction was associated with a longer admission-to-delivery time by approximately 3-4 hours and increased odds of cesarean delivery at 38 (OR, 1.50; 95% CI, 1.08-2.08) and 40 weeks (OR, 1.30; 95% CI, 1.15-1.46) of gestation.

CONCLUSION

At 39 weeks of gestation, nonmedically indicated induction is associated with lower maternal and neonatal morbidity than women who are expectantly treated.

CSF biomarkers in posterior cortical atrophy

OBJECTIVE

To describe CSF biomarker profiles in posterior cortical atrophy (PCA), which induces high-order visual deficits often associated with Alzheimer disease (AD) pathology, and relate these findings to clinical and neuropsychological assessment.

METHODS

This prospective observational study included 22 patients with PCA who underwent CSF biomarker analysis of total tau (t-tau), phosphorylated tau on amino acid 181 (p-tau181), and amyloid β (Aβ(42)). At group level, the CSF profiles of patients with PCA were compared to those of patients with typical AD and patients with other dementia (OD). Individually, the clinical presentation of patients with PCA was correlated to their CSF profile to assess the predictability of clinical features for diagnosis of underlying AD pathology.

RESULTS

At group level, the PCA biomarker profile was not different from that of the AD group, but very different from that of the OD group (p < 0.001). More than 90% of patients with PCA had CSF profiles consistent with AD. All patients with PCA with either isolated higher-order visual deficit (n = 8) or visual deficit associated with memory impairment (n = 11) had CSF profiles consistent with AD. Only one of the 3 patients with PCA with asymmetric motor signs fulfilled biological CSF criteria for AD.

CONCLUSIONS

PCA syndrome is usually associated with CSF biomarkers suggestive of AD, as shown by previous neuropathologic studies. This does not apply in case of motor signs suggesting associated corticobasal syndrome. CSF biomarkers help to discriminate AD from non-AD processes associated with this condition.

[Near a biological diagnosis of Alzheimer's disease and related disorders]

PURPOSE

To review the current concepts in the biological diagnosis of Alzheimer's disease (AD) and related disorders.

CURRENT KNOWLEDGE AND KEY POINTS

As new therapeutics specific of AD may be available soon, early diagnosis of AD in the context of mild cognitive impairment (MCI) or dementia appears to be challenging. The high amount of atypical clinical forms of AD leads to develop new tools allowing in vivo diagnosis. New CerebroSpinal Fluid (CSF) biomarkers seem to reflect specific aspects of deep neuropathological changes observed in AD, i.e. amyloid deposits and neurofibrillary tangles. Amyloid beta-peptide 1-42 (Abeta(1-42)) and hyperphosphorylated tubulin associated unit (tau) isoforms appear to be the most sensitive and specific CSF biomarkers, the combination of these biomarkers depicting the best diagnosis value for AD. These molecules are also efficient in the prediction of the conversion from the MCI state to the dementia state of AD. Combined to clinical and neuro-imaging information, CSF biomarkers appear thus to be highly relevant in improving the early etiological diagnosis of dementia.

FUTURE PROSPECTS AND PROJECTS

The current research focalises on the development of new molecules coming from Abeta and tau protein families, in the CSF and in the serum, as well as molecules reflecting other pathological metabolism changes, as alpha-synuclein in Lewy Body Disease. The diagnosis value of CSF biological markers is so promising that they have been recently included in the research diagnosis criteria of AD.

Optical imaging of luminescence for in vivo quantification of gene electrotransfer in mouse muscle and knee

BACKGROUND

Optical imaging is an attractive non-invasive way to evaluate the expression of a transferred DNA, mainly thanks to its lower cost and ease of realization. In this study optical imaging was evaluated for monitoring and quantification of the mouse knee joint and tibial cranial muscle electrotransfer of a luciferase encoding plasmid. Optical imaging was applied to study the kinetics of luciferase expression in both tissues.

RESULTS

The substrate of luciferase (luciferin) was injected either intraperitonealy (i.p.) or in situ into the muscle or the knee joint. Luminescence resulting from the luciferase-luciferin reaction was measured in vivo with a cooled CCD camera and/or in vitro on tissue lysate. Maximal luminescence of the knee joint and muscle after i.p. (2.5 mg) or local injection of luciferin (50 microg in the knee joint, 100 microg in the muscle) were highly correlated. With the local injection procedure adopted, in vivo and in vitro luminescences measured on the same muscles significantly correlated. Luminescence measurements were reproducible and the signal level was proportional to the amount of plasmid injected. In vivo luciferase activity in the electrotransfered knee joint was detected for two weeks. Intramuscular electrotransfer of 0.3 or 3 microg of plasmid led to stable luciferase expression for 62 days, whereas injecting 30 microg of plasmid resulted in a drop of luminescence three weeks after electrotransfer. These decreases were partially associated with the development of an immune response.

CONCLUSION

A particular advantage of the i.p. injection of substrate is a widespread distribution at luciferase production sites. We have also highlighted advantages of local injection as a more sensitive detection method with reduced substrate consumption. Besides, this route of injection is relatively free of uncontrolled parameters, such as diffusion to the target organ, crossing of biological barriers and evidencing variations in local enzymatic kinetics, probably related to the reaction medium in the targeted organ. Optical imaging was shown to be a sensitive and relevant technique to quantify variations of luciferase activity in vivo. Further evaluation of the effective amount of luciferase in a given tissue by in vivo optical imaging relies on conditions of the enzymatic reaction and light absorption and presently requires in vitro calibration for each targeted organ.

Neutral Postgrafted Colloidal Particles for Gene Delivery

Surface modification of cationic lipoplexes has been carried out by means of a postgrafting reaction. The original lipoplexes described comprise a cationic lipid, a neutral lipid, poly(ethylene glycol)-cholesterol (with or without a targeting ligand) and DNA. Modifying their surface via a chemical, postgrafting reaction did not alter their size (approximately 100 nm) nor their ability to compact DNA, but did give a reduced zeta potential (approximately 0 mV) to afford surface neutral particles. With the modified lipoplexes nonspecific NIH3T3 cell surface binding in vitro was inhibited. Intravenous injection of the neutralized lipoplexes in mice showed decreased accumulation of the particles in the lung as compared to PEGylated cationic lipoplexes. Tumor targeting was also achieved in vivo by the addition of an RGD-PEG-Cholesterol as a lipid-ligand in the postgrafted lipoplex formulation.

Intramuscular plasmid DNA electrotransfer: biodistribution and degradation

We have studied radiolabelled plasmid DNA biodistribution and degradation in the muscle at different times after injection, with or without electrotransfer using previously defined conditions. Radiolabelled plasmid progressively left the muscle and was degraded as soon as 5 min after plasmid injection, with or without electrotransfer. Autoradiography showed that the major part of injected radioactivity was detected in the interfibrilar space of a large proportion of the muscle. Large zones of accumulation of radioactivity, which seems to be contained in some fibres (more than 20 microm), were identified as soon as 5 min after electrotransfer. Such structures were never observed on slices of non-electrotransferred muscles. However, these structures were not frequent and probably lesional. The surprising fact is that despite the amount of intact plasmid having been greatly reduced between 5 min and 3 h after injection, the level of transfection remains unchanged whether electric pulses were delivered 20 s or 3 h after injection. Such a behavior was similarly observed when injecting 0.3, 3 or 30 microg of plasmid DNA. Moreover, the transfection level was correlated to the amount of plasmid DNA injected. These results suggest that as soon as it is injected, plasmid DNA is proportionally partitioned between at least two compartments. While a major part of plasmid DNA is rapidly cleared and degraded, the electrotransferable pool of plasmid DNA represents a very small part of the amount injected and belongs to another compartment where it is protected from endogenous DNAses.

Conformation of bacteriochlorophyll molecules in photosynthetic proteins from purple bacteria

Fourier transform near-infrared resonance Raman spectroscopy can be used to obtain information on the bacteriochlorophyll a (BChl a) molecules responsible for the redmost absorption band in photosynthetic complexes from purple bacteria. This technique is able to distinguish distortions of the bacteriochlorin macrocycle as small as 0.02 A, and a systematic analysis of those vibrational modes sensitive to BChl a macrocycle conformational changes was recently published [Näveke et al. (1997) J. Raman Spectrosc. 28, 599-604]. The conformation of the two BChl a molecules constituting the primary electron donor in bacterial reaction centers, and of the 850 and 880 nm-absorbing BChl a molecules in the light-harvesting LH2 and LH1 proteins, has been investigated using this technique. From this study it can be concluded that both BChl a molecules of the primary electron donor in the photochemical reaction center are in a conformation close to the relaxed conformation observed for pentacoordinate BChl a in diethyl ether. In contrast, the BChl a molecules responsible for the long-wavelength absorption transition in both LH1 and LH2 antenna complexes are considerably distorted, and furthermore there are noticeable differences between the conformations of the BChl molecules bound to the alpha- and beta-apoproteins. The molecular conformations of the pigments are very similar in all the antenna complexes investigated.

Neonatal infrared axillary thermometry

The authors compared axillary skin temperatures (AT) measured with an infrared (IR) thermometer (Lightouch Neonate, Exergen Corp) with rectal temperatures (RT) in 16 newly born term infants under radiant warmers (RW) and in cribs. Twelve stable, growing premature infants in incubators were also studied. This new device may be useful because of safety and rapid results (1 second), but clinical accuracy is unknown. For term infants, mean (SD) RT-AT difference was 0.1 (0.48) degree C under RW and 0.25 (0.17) degree C 2 hours later in cribs. For premature infants in incubators the mean RT-AT difference was 0.09 (0.16) degree C. Axillary temperatures measured by IR thermometer approximate RT for newly born term infants in cribs and stable premature infants in incubators. For newly born term infants under RW, RT-AT differences vary more widely, limiting clinical usefulness in this setting. The device, the unique age of this population, and the RW environment may play a role.

Neonatal total parenteral nutrition ascites from liver erosion by umbilical vein catheters

BACKGROUND

A preterm infant was found to have total parenteral nutrition (TPN) ascites after infusion through a low umbilical vein catheter (UVC). Objective. To evaluate the clinical and imaging findings of neonates with TPN ascites after infusion through UVCs.

MATERIALS AND METHODS

Eight patients with TPN ascites were identified over three years. Charts were abstracted for clinical data. Plain-film, ultrasound (US), and contrast studies through the UVCs were examined to determine UVC placement, presence of liver injury, and confirmation of intraperitoneal extravasation from the UVC.

RESULTS

All eight patients with TPN ascites presented with hypotension and abdominal distension. All had UVCs overlying the liver on plain film. Catheters were in place a mean of 8.9 days prior to TPN extravasation. US in four patients showed hepatic parenchymal damage around the UVC tip. Contrast studies in six patients showed intraperitoneal spill.

CONCLUSION

While low UVC placement may sometimes be clinically unavoidable, TPN administered through abnormally positioned UVCs is not without risk.

Purification and immunological characterization of a recombinant trimethylflavonol 3'-O-methyltransferase

A flavonol O-methyltransferase cDNA clone (pF3'OMT) from Chrysosplenium americanum was expressed in Escherichia coli Top 10 and the recombinant protein was purified to near homogeneity by affinity chromatography on chelation resin and gel filtration on Superose 12 columns. The purified protein was enzymatically active as a 42 kDa monomer and exhibited strict specificity for position 3' of 3,7,4'-trimethylquercetin. In did not accept the mono- or dimethyl analogs, the parent aglycone quercetin or the phenylpropanoids, caffeic and 5-hydroxyferulic acids as substrates; thus indicating its involvement in the later steps of polymethylated flavonol synthesis in this plant. The K(m) values of the enzyme for 3,7,4'-trimethylquercetin as substrate and S-adenosyl-L-methionine as co-substrate were 7.2 and 20 microM, respectively. The enzyme activity was strongly inhibited by both Ni2+ and rho-chloromercuribenzoate and was restored by the addition of EDTA or beta-mercaptoethanol, respectively. Antibodies raised against the F3'OMT recombinant protein recognized a protein band migrating at the expected molecular mass of the enzyme on SDS-polyacrylamide gels of protein extracts prepared from various sources. This implies a high degree of structural similarity among these enzymes that is also corroborated by their hydropathy profiles.

Cardiac operations in octogenarians: perioperative risk factors for death and impaired autonomy

BACKGROUND

With the progressive aging of western populations, cardiac surgeons are increasingly faced with elderly patients.

METHODS

We reviewed the records of 191 consecutive patients aged 80 years or older (mean age, 83 +/- 2.4 years) who underwent a cardiac surgical procedure at our institution from 1991 through 1996.

RESULTS

Ninety-eight patients were men. Preoperatively, 32% of patients were in New York Heart Association class III or IV, and mean left ventricular ejection fraction was 0.55 +/- 0.02. One hundred ten patients (58%) underwent aortic valve replacement, 47 (25%) had coronary artery bypass grafting, 26 (14%) had combined aortic valve replacement and coronary artery bypass grafting, 5 (3%) underwent mitral valve replacement, and 3 (1.6%) had other procedures. Postoperative complications occurred in 69.1% of patients. The hospital mortality rate was 16.2%. Actuarial survival estimates at 1 year, 3 years, and 5 years were 79.2%, 74.9%, and 56.2%, respectively. Multivariate predictors (p < 0.05) of hospital death were preoperative pulmonary hypertension and lower left ventricular ejection fraction. Multivariate predictors of late death were combined aortic valve replacement and coronary artery bypass grafting and female sex. Sixty-four percent of long-term survivors were fully autonomous, and female sex was the only independent predictor of impaired autonomy. Eighty-three percent of survivors were satisfied with their present quality of life.

CONCLUSIONS

Cardiac operations can be performed in octogenarians with a favorable long-term outcome. Earlier referral and intervention is mandatory to improve results in this patient population.

Thermal equipment usage patterns in neonatal intensive care units: interunit variability and intraunit consistency

We conducted a survey and audit of thermal equipment use in very low-birth-weight infants in five Ohio neonatal intensive care units (NICUs) to document regional practice. The survey indicated a variety of thermal care styles. Two NICUs preferred to admit infants to incubators, the other three favoring radiant warmers. These three NICUs moved infants from radiant warmers into incubators at significantly different mean ages. The audit demonstrated inconsistent use of plastic covers, warming mattresses, and added humidity under radiant warmers, and discrepancies between survey responses and actual use within NICUs. Inter-NICU variability of thermal equipment use may complicate fluid management.

Anxiety, antisocial behavior, and heart rate regulation in adolescent males

We explored relationships between anxiety and antisocial behavior and autonomic heart rate regulation in a homogenous sample (N = 175) of 15-year-old males. Measures of anxiety and antisocial behavior were obtained at yearly intervals over a period of 4-6 years. Components of heart rate variability associated with postural (sympathetic) and respiratory (vagal) change and transfer of respiratory to heart rate variability were estimated at age 15 using spectral analytic techniques. Anxiety and antisocial behavior were predictably related to enhanced and diminished levels of mean heart rate, respectively. Anxiety was also predictably related to enhanced sympathetic mediation of phasic postural effects on heart rate. Antisocial behavior was unexpectedly related to disruption of vagally mediated, phasic respiratory effects on heart rate. Anxiety and antisocial behavior showed distinct relationships to heart rate, and to the autonomically mediated components of heart rate variability from postural and respiratory sources. Spectral analytic techniques helped elucidate these unique regulatory patterns, suggesting utility for future research in this area.

High frequency-induced upregulation of human cardiac calcium currents

BACKGROUND

In mammalian heart cells, Ca2+ influx through voltage-gated L-type Ca2+ channels can be upregulated by high rates of stimulation. We have investigated this important adaptive regulation in human cardiomyocytes.

METHODS AND RESULTS

Using the whole-cell patch-clamp technique, we found a high frequency-induced upregulation (HFIUR) of the dihydropyridine-sensitive L-type Ca2+ current (ICa) in human cardiomyocytes. ICa was potentiated in a graded manner with increasing rates of stimulation between 0.3 and 5 Hz. Both moderate increase of ICa peak amplitude and marked slowing of current decay contributed to large increases of Ca2+ influx (up to 80%). The maximal potentiation of ICa was reached rapidly after the change in the rate of stimulation (no more than a few seconds). Beta-Adrenergic stimulation of the cells by isoproterenol (1 micromol/L), which is well known to induce a slow (approximately 1 minute) cAMP-mediated potentiation of ICa, could enhance (when present) or promote (when absent) the HFIUR of ICa. As a consequence, the increasing effect of isoproterenol on Ca2+ influx through Ca2+ channels was dependent on the rate of stimulation. HFIUR of ICa was altered in patients with ejection fraction lower than 40% and in patients pretreated with Ca2+ antagonists or beta-blockers.

CONCLUSIONS

Upregulation of Ca2+ entry through voltage-gated Ca2+ channels by high rates of beating may be involved in the frequency-dependent regulation of contractility (Bowditch "staircase") of the human heart. This process, which is highly sensitive to beta-adrenergic stimulation, may be crucial in adaptation to exercise and stress.

Inherited antithrombin III deficiency in the neonate

OBJECTIVE

To describe two cases of inherited antithrombin III (AT-III) deficiency presenting at less than or equal to 28 days of age, and to review other neonatal reports.

RESEARCH DESIGN

Clinical descriptions of two patients and literature review of known references to the neonatal presentation of this disorder.

SETTING

Academic neonatal intensive care unit.

PATIENTS

Case reports--two patients with thrombosis and family history of AT-III deficiency. Literature review--neonatal patients with thrombosis and diagnosis of AT-III deficiency or parental diagnosis of AT-III deficiency or diagnosis of AT-III deficiency alone.

SELECTION PROCEDURES

Random observation (case reports) and literature search for cases of AT-III deficiency diagnosed in the neonatal period or presenting with thrombosis and a positive family history of the disorder.

INTERVENTIONS

Fresh frozen plasma, heparin, and AT-III concentrate were employed in the current case reports. The cases from the literature used combinations of the above or no intervention.

MEASUREMENTS/MAIN RESULTS

Twenty-three cases, including the current reports, of suspected or proved AT-III deficiency were found, with at least 11 cases of thrombosis and at least 10 deaths.

CONCLUSIONS

Significant morbidity and mortality from inherited AT-III deficiency can occur in the neonatal period, and the incidence of affected neonatal patients is probably underestimated. Careful family history, early recognition, diagnosis, and specific treatment are important for management of this disorder.

Passive stiffness of the lumbar torso in flexion, extension, lateral bending, and axial rotation. Effect of belt wearing and breath holding

This work investigated the passive bending properties of the intact human torso about its three principal axes of flexion: extension, lateral bending, and axial rotation. Additionally, the effects of wearing an abdominal belt and holding the breath (full inhalation) on trunk stiffness was investigated. The torsos of 22 males and 15 females were subjected to bending moments while "floating" in a frictionless jig with isolated torso bending measured with a magnetic device. Belts and breath holding appear to stiffen the torso about the lateral bending and axial rotation axes but not in flexion or extension. Torsos are stiffer in lateral bending and capable of storing greater elastic energy. Regression equations were formulated to define stiffness and energy stored for input to biomechanical models that examine low back function and for bioengineers designing hardware for stabilization and bracing or investigation of traumatic events such as automobile collision.

Umbilical arterial catheter use: report of an audit conducted by the Study Group for Complications of Perinatal Care

The Study Group for Complications of Perinatal Care through 13 of its participating neonatal intensive care units conducted an audit of umbilical artery catheter (UAC) use over 3 months. Of 1941 patient admissions, 582 (30%) had a UAC inserted and left in place for a mean of 4.9 days. The mean supplemental oxygen concentration (FIO2) at removal was 0.35 with over 55% of UACs remaining in place until FIO2 was less than 0.26. Institutional practices varied widely for positioning the catheter tip, use of heparin, and types of infusates, as did the frequency of adverse events that prompted removal of the UAC. Most institutions with multiple physicians found less consistency in practice patterns within their own units than presumed prior to the audit. Just two institutions preferred catheter placement in the abdominal aorta (low) with the others selecting a low site only after detecting a malposition below the initially sought thoracic level. All but one group routinely used heparin, although in varying concentrations and total doses. Patient weight and catheter duration were inversely correlated, with smaller patients having catheters left in place for significantly longer periods (P < 0.01). Similarly, smaller patients had a higher likelihood of catheter removal because of an adverse event; the adverse events were not necessarily related to longer duration. A significant relationship existed between positioning a catheter tip in the abdominal aorta and removal for adverse events (P < 0.05).

Umbilical venous catheterizations: audit by the Study Group for Complications of Perinatal Care

The Study Group for Complications of Perinatal Care, through 13 of its participating neonatal intensive care units, conducted a prospective audit to describe contemporary use of umbilical venous catheters (UVCs) over 3 months in 1951 admissions. Frequency of UVC attempts was 15.5% for all patients and greatest (50%) in patients of 1000 g or less birthweight (BW), with a wide range of frequency by institution and by BW grouping. Institutions with more 1500 g or less BW infants tended to use UVCs more frequently. The most common reason for placement was general intravascular access. A variety of fluids were infused, and in most cases heparin was employed. Mean duration of use was 4.4 days for all patients and longest (5.5 days) in infants in the 1001 to 1500 g BW group. The most common reason for UVC removal was lack of further need. UVCs appear to be used more commonly and for a longer duration than is currently recommended. There is a need for a prospective, randomized trial to assess the risks properly and maximize the benefits of UVC usage.

Static morphometric bases for CT identification and evaluation of the outflow chamber of the left ventricle. Preliminary study in formalin-fixed heart

A static morphometric study of the outflow chamber of the left ventricle (OCLV) was investigated in a series of 10 formalin-fixed hearts. A spatial reconstruction of the shape and the volume of the OCLV was carried out by means of a Somaton Plus TR4 Tomodensitometer (Siemens). The technic allows evaluation of the surface of the aortic and the mitral orifices and visualization of the three-dimensional OCLV and LV morphology, as well as calculation of their volumes. The limits of the technic in the dynamic study of the OCLV are presented.

Effects of transcutaneous monitor electrode heat on skin servo-controlled environments

This study tested the hypotheses that (1) the heat generated by a transcutaneous monitor electrode is sufficient to decrease skin servo-controlled radiant warmer heat output when it is positioned next to the operating skin servo-thermistor, and (2) the decrease in radiant warmer heat output is enough to lower body temperatures or cause a heat-conserving response in a baby. Seventeen newborns less than or equal to 5 days old, gestational age 29 to 40 weeks, cared for under radiant warmers were studied before and for 30 minutes after juxtaposition of the transcutaneous monitor electrode and the skin servo-controlled thermistor. Mean radiant warmer heat output, measured as watt-hours/5 minute periods, decreased for the first 15 minutes after movement, mainly in the infants cared for under an older model radiant warmer. Mean skin temperature and foot temperature decreased, and esophageal-foot temperature gradient increased for those under the older model radiant warmer. Despite differences in the gestational age of the infants under the older compared with the newer model radiant warmer, multiple regression analysis indicated a significant effect of the model of radiant warmer on the results. Many factors can influence the proper functioning of servo-controlled heating systems, including the type of electronic logic and extraneous sources of heat. These factors require more study, and should be considered in the evaluation of thermal control problems.

Biosynthesis of White Lupin Isoflavonoids from [U-C]l-Phenylalanine and Their Release into the Culture Medium

Pulse-labeling experiments of white lupin (Lupinus albus L.) cell cultures with [U-(14)C]l-phenylalanine for 72 h resulted in the incorporation of the radioactivity into the isoflavone aglucones, glucosides, and prenylated derivatives. Both the aglucones genistein and 2'-hydroxygenistein and their 7-O-glucosides accounted for 85% of the total isoflavonoids identified in the cultured cells and contained 35% of the radioactivity, whereas the prenylated derivatives comprised 15 and 65%, respectively. Almost 20% of the labeled isoflavones of the cellular pool was recovered from the culture medium, 90% of which were monoprenylated and diprenylated derivatives containing 80% of the radioactivity. These results clearly demonstrate the release into the culture medium of a substantial amount of the endogenously synthesized isoflavonoids, especially the prenylated derivatives.

Serotonin increases calcium current in human atrial myocytes via the newly described 5-hydroxytryptamine4 receptors

In various species, including humans, 5-hydroxytryptamine (5-HT) has been shown to exert positive chronotropic and inotropic cardiac effects through different types of receptors. The goal of the present study was to investigate the regulation by 5-HT of voltage-gated Ca2+ channels in human atrial myocytes and to characterize the receptor involved. Cardiomyocytes isolated enzymatically and mechanically were voltage-clamped using the whole-cell configuration of the patch-clamp technique. Extracellular perfusion of 5-HT increased Ca2+ current (ICa) amplitude with a EC50 (0.1 microM) similar to that observed with isoprenaline. The effects of 5-HT were blocked by the addition of protein kinase A inhibitor in the pipette. In addition, the effects of 5-HT, isoprenaline, and intracellular cAMP on ICa were not additive. These results support the hypothesis that the inotropic effect of 5-HT in human atrial myocytes is related to an increase of ICa via an elevation of intracellular cAMP levels and stimulation of cAMP-dependent protein kinase. The effects of 5-HT were not blocked by antagonists of 5-HT1 (methiothepin), 5-HT2 (ketanserin), or 5-HT3 (ICS 205-930 at a low concentration) receptors. The benzamide derivatives renzapride and zacopride and the azabicyclobenzimidazolone derivative BIMU 8 increased ICa, but less efficiently than did 5-HT or 5-methoxytryptamine. Moreover, ICS 205-930 at high concentrations (greater than 1 microM) completely antagonized the effects of 5-HT. Thus, the pharmacology of the 5-HT receptor involved in an increase of ICa in human atrial myocytes resembles that recently described for the 5-HT4 receptor. In atrial myocytes dissociated from rat, rabbit, guinea pig, or frog, 5-HT at high concentrations had no effect on Ca2+ currents, suggesting that the distribution of 5-HT4 receptors in cardiac tissues is species dependent.

Constitutive production of interleukin-6 and immunologic features in cardiac myxomas

The constitutive production of interleukin-6 (IL-6), a potent hepatocyte-stimulating factor and B cell-differentiating factor, was demonstrated in 3 patients with cardiac myxomas. Tumor cells from the only patient who presented with immunologic features produced 14-23-fold higher levels of IL-6 than those from the 2 patients who lacked such features. A significant serum IL-6 level (56 pg/ml), greater than that observed in patients with active rheumatoid arthritis, was also observed only in this patient, with a subsequent return to an undetectable level after surgical removal of the tumor. This was associated with a regression of the immunologic features. This same patient was observed to have an IL-6-dependent, proliferative polyclonal plasmacytosis of the bone marrow. These observations demonstrate that an overproduction of IL-6 by cardiac myxoma cells, in association with a systemic passage of this IL-6, may be responsible for the immunologic features similar to those observed in true autoimmune diseases such as rheumatoid arthritis.

Alcohol withdrawal concealing symptoms of subdural hematoma--a caveat

Symptoms of significant medical illnesses, in this case subdural hematoma, is easily overlooked in midst of alcohol withdrawal. Unusual symptoms must be regarded with caution.

Electrophysiological effects of penticainide (CM 7857) in isolated human atrial and ventricular fibers

The intracellular electrophysiological properties of a new antiarrhythmic agent, penticainide (5 x 10(-6) to 5 x 10(-5) M) were studied in isolated driven human right atrial appendage and papillary muscle superfused with oxygenated Tyrode's solution. In atrial fibers, penticainide decreased the amplitude, maximum rate of rise (dV/dtmax), plateau amplitude, and duration (APD) of action potentials (AP). In ventricular fibers, the main AP modification induced by penticainide was a dV/dtmax diminution. All those effects were frequency and concentration dependent. Penticainide decreased resting potential at 5 x 10(-5) M only. Ventricular APD variations were relatively weak: in most of the cases, 5 x 10(-6) M decreased APD and 5 x 10(-5) M shortened long APD (greater than 300 ms) and lengthened short APD (less than 300 ms). The class I antiarrhythmic property (dV/dtmax decrease) of penticainide was rate dependent in both human fibers and was obtained at lower drug concentrations than those used in other species. The relatively rapid rate of onset and the rather slow recovery kinetics of dV/dtmax block suggest a common mechanism of action of penticainide on sodium channels in human heart and others mammals.

Intramyocardial distribution of hydroquinidine in the dog

Hydroquinidine concentrations were measured simultaneously in the plasma and in right atrial and ventricular biopsy samples of four dogs in the steady state after eight days of oral sustained release hydroquinidine administration. The right ventricular concentrations were greater than the plasma concentrations in all samples (ratio 5.02(2.2)). In necropsy samples the ventricular concentrations were higher than the atrial concentrations, (ratio 1.54(0.36); p less than 0.01) and than the concentration in the sinus node region (7.72(1.85) ng.g-1 vs 4.21(2.6) ng.g-1). This study shows that intramyocardial pharmacokinetic measurements are possible and may help towards a better understanding of antiarrhythmic agents, particularly those with cumulative myocardial effect.

[Surgery of coronary revascularization in patients over 70. Apropos of 40 cases]

40 of the 900 patients operated upon for aorto-coronary bypass grafting between January 1980 and October 1984, were over 70 years old (mean 71.1; range: 70-76 years old). 25 had severe angina pectoris (class III or IV) and 15 of them had emergency surgery. An average of 2 grafts per patient was performed with 3 deaths and 3 myocardial infarcts in the peri-operative period. Patients had an average of 21 months follow-up (range 5 years, 3 months); in that period 2 deaths due to myocardial infarction, 3 persistent angina pectoris (class II) and 32 asymptomatic patients were observed. These results illustrate advances in cardiac surgery, anesthesia and postoperative management. Coronary surgery may therefore be performed in patients over 70 years old with an acceptable operative risk and satisfactory longterm results.