Biofilm assemblage and activity on plastic in urban streams at a continental scale: Site characteristics are more important than substrate type

The fate of plastics in rivers is a key component of the global plastic cycle. Plastics entering freshwater ecosystems are colonized by microbial biofilms, and microbe-plastic interactions can influence ecosystem processes and plastic fate. While literature examining the role of geographic region on plastic biofilms is quickly expanding, research which covers large (i.e., continental) spatial scales and includes freshwater ecosystems is warranted. In addition, most research focuses on bacterial communities, while biofilm eukaryotes are less commonly studied. We assessed biofilm metabolism and community structure on plastic (foamed polystyrene and polyvinyl chloride; PVC) and natural substrates (unglazed ceramic tile) in urban streams spanning a nested geographic gradient in the continental United States. We measured biofilm biomass, community respiration, and chlorophyll a, in addition to assessing marker gene-based community diversity of bacterial, fungal, and algal assemblages. Results demonstrated some substrate-specific trends in biofilm characteristics, including higher biofilm biomass on polystyrene across sites, and lower diversity of bacterial assemblages on both types of plastic litter versus tile. However, there were no differences among substrates for chlorophyll, respiration, and the abundance and diversity of algal and fungal assemblages. Thus, we concluded that the primary driver of biofilm metabolism and community composition were site characteristics, rather than substrate type. Additional studies are needed to quantify which site-specific characteristics drive biofilm dynamics on plastic litter in streams (e.g., water chemistry, light, seasonality, hydrology). These results add to the growing literature on the biofilm 'plastisphere' in aquatic ecosystems, demonstrating that the factors which control the assembly and activity of biofilm communities on plastic substrates (including bacteria, algal, and fungal assemblages together) in urban streams are similar to those driving biofilm dynamics on natural substrates.

O7: APPARENT PATHOLOGICAL COMPLETE RESPONSE TO NEOADJUVANT THERAPY LEADS TO SELECTION OF TREATMENT RESISTANT CANCER STEM CELLS IN OESOPHAGEAL ADENOCARCINOMA

Introduction

In oesophageal adenocarcinoma with an apparent pathological complete response (pCR) to neoadjuvant therapy (NAT) there remains debate as to whether oesophagectomy is required. Single Cell RNA sequencing (scRNAseq) enables identification and characterisation of cell populations at higher resolution than diagnostic techniques.

Method

ScRNAseq was used to determine transcriptomic profiles of cell populations in 24 OAC tumours and 13 matched normal samples. Five were also analysed using bulk RNA sequencing and high-precision mass spectrometry proteomics. Immunohistochemistry (IHC) was used to validate pCR. Paired scRNAseq analysis of pre-and post-treatment specimens from three further patients was used to compare transcriptomic profiles before and after NAT. Cancer cells (CCs) were assigned a cancer stem cell (CSC) score curated from published gene sets.

Result

We analysed a total of 22,738 single cells forming 29 different cell phenotypes. In two samples with apparent pCR, IHC staining, bulk RNA sequencing and proteomics of post-treatment samples failed to identify CCs. ScRNAseq, conversely, revealed persistent CCs (12/978 and 45/774). Transcriptomic analysis identified upregulation of stem cell markers and high CSC scores in these cells.

Conclusion

We have shown that CCs persist beneath the lower detection limit of standard approaches in apparent pCR. These cells express marker genes and expression programs consistent with CSCs. CSCs are a critical subpopulation that drive tumour initiation, growth, invasion, metastasis and resistance to therapy. These gene expression programs are not enriched in non-responders and straight to surgery samples. Oesophagus sparing treatment algorithms in pCR may subject patients to unnecessary risk of progression.

Take-home message

Cancer cells remain within tumours after apparent complete pathological response. These cells express stem cell markers associated with resistance to therapy and cancer progression.

Microplastic in riverine fish is connected to species traits

Microplastic is a contaminant of concern worldwide. Rivers are implicated as major pathways of microplastic transport to marine and lake ecosystems, and microplastic ingestion by freshwater biota is a risk associated with microplastic contamination, but there is little research on microplastic ecology within freshwater ecosystems. Microplastic uptake by fish is likely affected by environmental microplastic abundance and aspects of fish ecology, but these relationships have rarely been addressed. We measured the abundance and composition of microplastic in fish and surface waters from 3 major tributaries of Lake Michigan, USA. Microplastic was detected in fish and surface waters from all 3 sites, but there was no correlation between microplastic concentrations in fish and surface waters. Rather, there was a significant effect of functional feeding group on microplastic concentration in fish. Neogobius melanostomus (round goby, a zoobenthivore) had the highest concentration of gut microplastic (19 particles fish^-1) compared to 10 other fish taxa measured, and had a positive linear relationship between body size and number of microplastic particles. Surface water microplastic concentrations were lowest in the most northern, forested watershed, and highest in the most southern, agriculturally dominated watershed. Results suggest microplastic pollution is common in river food webs and is connected to species feeding characteristics. Future research should focus on understanding the movement of microplastic from point-source and diffuse sources and into aquatic ecosystems, which will support pollution management efforts on inland waters.

The effect of neoadjuvant chemotherapy and chemoradiotherapy on exercise capacity and outcome following upper gastrointestinal cancer surgery: an observational cohort study

Background

In 2014 approximately 21,200 patients were diagnosed with oesophageal and gastric cancer in England and Wales, of whom 37 % underwent planned curative treatments. Potentially curative surgical resection is associated with significant morbidity and mortality. For operable locally advanced disease, neoadjuvant chemotherapy (NAC) improves survival over surgery alone. However, NAC carries the risk of toxicity and is associated with a decrease in physical fitness, which may in turn influence subsequent clinical outcome. Lower levels of physical fitness are associated with worse outcome following major surgery in general and Upper Gastrointestinal Surgery (UGI) surgery in particular. Cardiopulmonary exercise testing (CPET) provides an objective assessment of physical fitness. The aim of this study is to test the hypothesis that NAC prior to upper gastrointestinal cancer surgery is associated with a decrease in physical fitness and that the magnitude of the change in physical fitness will predict mortality 1 year following surgery.

Methods

This study is a multi-centre, prospective, blinded, observational cohort study of participants with oesophageal and gastric cancer scheduled for neoadjuvant cancer treatment (chemo- and chemoradiotherapy) and surgery. The primary endpoints are physical fitness (oxygen uptake at lactate threshold measured using CPET) and 1-year mortality following surgery; secondary endpoints include post-operative morbidity (Post-Operative Morbidity Survey (POMS)) 5 days after surgery and patient related quality of life (EQ-5D-5 L).

Discussion

The principal benefits of this study, if the underlying hypothesis is correct, will be to facilitate better selection of treatments (e.g. NAC, Surgery) in patients with oesophageal or gastric cancer. It may also be possible to develop new treatments to reduce the effects of neoadjuvant cancer treatment on physical fitness. These results will contribute to the design of a large, multi-centre trial to determine whether an in-hospital exercise-training programme that increases physical fitness leads to improved overall survival.

Trial registration

ClinicalTrials.gov NCT01325883 - 29^th March 2011.

A prospective comparison of totally minimally invasive versus open Ivor Lewis esophagectomy

The majority of esophagectomies in Western parts of the world are performed by a transthoracic approach reflecting the prevalence of adenocarcinoma of the lower esophagus or esophagogastric junction. Minimally invasive esophagectomy (MIE) has been reported in a variety of formats, but there are no series that directly compare totally minimally invasive thoracolaparoscopic 2 stage esophagectomy (MIE-2) with open Ivor Lewis (IVL). A prospective single-center cohort study of patients undergoing elective MIE-2 or IVL between January 2005 and November 2010 was performed. Short-term clinicopathologic outcomes were recorded using validated systems. One hundred and six patients (median age 66, range 36-85, 88 M : 18 F) underwent two-stage esophagectomy (53 MIE-2 and 53 IVL). Patient demographics (age, sex, body mass index, American Society of Anesthesiologists grade, tumor characteristics, neoadjuvant chemotherapy, and TNM stage) were comparable between the two groups. Outcomes for MIE-2 and IVL were comparable for anastomotic leak rates (5 [9%] vs. 2 [4%], P= 0.241), resection margin clearance (R0) (43 [81%] vs. 38 [72%], P= 0.253), median lymph node yield (19 vs. 18, P= 0.584), and median length of stay (12 [range 7-91] vs. 12 [range 7-101] days), respectively. Blood loss was significantly less for MIE-2 compared with IVL (median 300 [range 0-1250] mL vs. 400 [range 0-3000] mL, respectively, P= 0.021). MIE-2 in this series of selected patients supports its efficacy, when performed by an experienced minimally invasive surgical team. A well-designed multicenter trial addressing clinical effectiveness is now required.

Changes in the epidemiology of gastroenteritis in a paediatric short stay unit following the introduction of rotavirus immunisation

AIM

Acute gastroenteritis (AGE) has been a significant component of the clinical load in the short stay unit (SSU) at the Royal Children's Hospital (RCH) since its establishment in 2004. Since the introduction of routine rotavirus immunisation in Australia in 2007 there has been a clinical impression of a substantial reduction in AGE managed in the SSU. This study aimed to examine changes in the epidemiology of AGE in the SSU, and RCH overall, between 2005 and 2009 and explore whether this reflects a change specifically in AGE due to rotavirus.

METHODS

Discharge coding data for AGE from all inpatient wards, the SSU and emergency department (ED) at the RCH were examined. Stool virology results for the same period were analysed.

RESULTS

Since 2007 there has been a 58% reduction in AGE admissions to the SSU. The median age of patients admitted to the RCH with rotaviral enteritis has increased from 1.3 years to 3.8 years. Presentations to the ED for AGE have fallen from 53 to 34 cases per 1000 attendances between 2004 and 2009, and admission rates from the ED have fallen from 23 to 13% of AGE presentations. Detection rates of rotavirus fell from 13.1 to 6.7% between 2005 and 2009.

CONCLUSION

A marked decrease in AGE-related clinical activity and reduction in rotavirus detection at the RCH has occurred since the introduction of routine rotavirus immunisation in Australia. This has significant resource planning implications for units based on short stay models of care.

First probable Australian cases of human infection with Rickettsia felis (cat-flea typhus)

Human infection with Rickettsia felis has been reported in most parts of the world, and R. felis has recently been confirmed in cat fleas in Western Australia. The clinical presentations of R. typhi and R. felis are similar, and in the past, the incidence of R. felis infection may have been underestimated. We describe the first reported cases of probable human R. felis infection in Australia. Two adults and three children in Victoria contracted a rickettsial disease after exposure to fleas from kittens. Molecular testing of fleas demonstrated the presence of R. felis but not R. typhi.

Development of gap junctional intercellular communication within the lateral wall of the rat cochlea

Auditory function depends on gap junctional intercellular communication (GJIC) between fibrocytes within the cochlear spiral ligament, and basal cells and intermediate cells within stria vascularis. This communication within the lateral wall is hypothesized to support recirculation of K+ from perilymph to the intra-strial space, and thus is essential for the high [K+] measured within endolymph, and the generation of the endocochlear potential. In rats, the [K+] within endolymph reaches adult levels by postnatal day 7 (P7), several days before hearing onset, suggesting that GJIC matures before auditory responses are detectable. In this study we have mapped the postnatal development of GJIC within the cochlear lateral wall, to determine the stage at which direct communication first exists between the spiral ligament and stria vascularis. Connexin 30 immunofluorescence revealed a progressive increase of gap junction plaque numbers from P0 onwards, initially in the condensing mesenchyme behind strial marginal cells, and spreading throughout the lateral wall by P7-P8. Whole-cell patch clamp experiments revealed compartmentalized intercellular dye-coupling in the lateral wall between P2 and P5. There was extensive dye-coupling throughout the fibrocyte syncytium by P7. Also, by P7 dye introduced to fibrocytes could also be detected within strial basal cells and intermediate cells. These data suggest that lateral wall function matures several days in advance of hearing onset, and provide anatomical evidence of the existence of a putative K+ recirculation pathway within the cochlear lateral wall.

Reduction in rotavirus-associated acute gastroenteritis following introduction of rotavirus vaccine into Australia's National Childhood vaccine schedule

INTRODUCTION

: Rotavirus vaccines were introduced into the funded Australian National Immunization Program (NIP) in July 2007. Due to purchasing arrangements, individual states and territories chose either a 2-dose RV1 (Rotarix, GSK) regimen or 3-dose RV5 (Rotateq, Merck/CSL) regimen. This allowed comparison of both vaccines in similar populations with high infant vaccination coverage.

METHODS

: Admission and rotavirus identification data from the major pediatric hospitals in 3 states (2 using RV5, 1 RV1), together with state-based hospitalization and vaccination data from Queensland (RV5) were analyzed for the years before, and up to 30 months following rotavirus vaccine introduction. Emergency encounters and short-stay unit admissions for gastroenteritis are also described.

RESULTS

: Rotavirus vaccine coverage in Australia is high, with 87% of infants receiving at least 1 dose. Hospital admissions for both rotavirus gastroenteritis and nonrotavirus-coded gastroenteritis were reduced following vaccine introduction in all states, not only for the age group eligible for NIP rotavirus vaccination, but also for children born prior. RV5 vaccine efficacy in Queensland has been estimated at 89.3%. Marked reductions in acute gastroenteritis emergency presentations and short-stay unit admissions have also been observed.

CONCLUSIONS

: Early evidence from the NIP in Australia has demonstrated high rotavirus coverage with both RV1 and RV5. The introduction of both vaccines has been associated with a marked reduction in gastroenteritis admissions, supportive of both direct vaccine protection, as well as with indirect herd protection.

Measurements of the electric form factor of the neutron up to Q2=3.4 GeV2 using the reaction 3He(e,e'n)pp

The electric form factor of the neutron was determined from studies of the reaction 3He(e,e'n)pp in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q2 range over which it is known, we find G(E)(n)=0.0236±0.0017(stat)±0.0026(syst), 0.0208±0.0024±0.0019, and 0.0147±0.0020±0.0014 for Q(2)=1.72, 2.48, and 3.41 GeV2, respectively.

Onset of quark-hadron duality in pion electroproduction

A large data set of charged-pion (pi+/-) electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-->pion production mechanisms.

Insulin resistance and protein catabolism in non-diabetic hemodialysis patients

Chronic kidney disease (CKD) is associated with complex metabolic changes including insulin resistance. Siew et al. have highlighted an important relationship between insulin resistance and skeletal muscle protein turnover. If insulin resistance is implicated in sarcopenia of CKD, further research will be required to determine whether interventions that improve insulin sensitivity improve clinical outcomes and cardiovascular risk in CKD.

Postoperative sleep disturbance in pediatric patients using patient-controlled devices (PCA)

BACKGROUND

Sleep disturbance has not been well quantified in pediatric postoperative management, yet has broad implications in pain management as well as upon the physical and psychological well-being of the young patient admitted for surgery. We aimed to describe sleep disturbance in this population using patient-controlled analgesia (PCA) and then identify the predictors of disturbed sleep.

METHODS

A retrospective audit and analysis of sleep disturbance in postoperative pediatric patients using PCA devices were performed in a postoperative surgical ward population of a major tertiary referral center. PCA presses were used as a proxy measure of sleep. The description of the sleep disturbance included an unadjusted and adjusted analysis of the proposed predictors of sleep disturbance: age, sex, nature of presentation, operation type, PCA opioid type, presence of background infusion, postoperative night number, and adjuvant medication. All data were entered into an access database developed for the audit and analyzed using stata 8.0.

RESULTS

The first 126 children prescribed PCA devices in the year 2004 were audited. One-third of patients in the population prescribed PCA experienced sleep disturbance. Observed predictors of sleep disturbance include older children (OR: 0.86, P=0.001) and those receiving a background infusion (OR: 0.19, P=0.002). Other predictors were not significant.

CONCLUSIONS

Sleep disruption is common in children-prescribed PCA opioid analgesia. Older children and those receiving a background infusion were observed to experience less sleep. Other proposed predictors were not found to be reliable. Further investigation into the predictors of disturbed sleep in the postoperative patient is warranted.

Pharmacokinetics of levobupivacaine after caudal epidural administration in infants less than 3 months of age

BACKGROUND

There are few data describing levobupivacaine pharmacokinetics in infants (<3 months) after caudal administration.

METHODS

An open-label study was undertaken to examine the pharmacokinetics of levobupivacaine 2.5 mg ml(-1), 2 mg kg(-1) in children aged less than 3 months after single-shot caudal epidural administration. Plasma concentrations were determined at intervals from 0.5 to 4 h after injection. A population pharmacokinetic analysis of levobupivacaine time-concentration profiles (84 observations) from 22 infants with mean postnatal age (PNA) 2.0 (range 0.6-2.9) months was undertaken using non-linear mixed effects models (NONMEM). Time-concentration profiles were analysed using a one-compartment model with first-order input and first-order elimination. Estimates were standardized to a 70 kg adult using allometric size models.

RESULTS

Population parameter estimates (between-subject variability) for total levobupivacaine were clearance (CLt) 12.8 [coefficient of variation (CV) 50.6%] litre h(-1) 70 kg(-1), volume of distribution (Vt) 202 (CV 31.6%) litre 70 kg(-1), absorption half-life (Tabs) 0.323 (CV 18.6%) h 70 kg(-1). Estimates for the unbound drug were clearance (CLfree) 104 (CV 43.5%) litre h(-1) 70 kg(-1), volume of distribution (Vfree) 1700 (CV 44.9%) litre 70 kg(-1), absorption half-life (Tabsfree) 0.175 (CV 83.7%) h 70 kg(-1). There was no effect attributable to PNA on CL or V. Time to peak plasma concentration (Tmax) was 0.82 (CV 18%) h. Peak plasma concentration (Cmax) was 0.69 (CV 25%) microg ml(-1) for total levobupivacaine and 0.09 (CV 37%) microg ml(-1) for unbound levobupivacaine.

CONCLUSIONS

Clearance in infants is approximately half that described in adults, suggesting immaturity of P450 CYP3A4 and CYP1A2 enzyme isoforms that metabolize levobupivacaine in infants. This lower clearance delays Tmax, which was noted to occur approximately 50 min after administration of caudal epidural levobupivacaine.

Recoil polarization for delta excitation in pion electroproduction

We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W = 1.23 GeV at Q(2) = 1.0 (GeV/c)(2), obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed for the first time. Dynamical models do not describe quantities governed by imaginary parts of interference products well, indicating the need for adjusting magnitudes and phases for nonresonant amplitudes. We performed a nearly model-independent multipole analysis and obtained values for Re (S(1+)/M(1+)) = -(6.84 +/- 0.15)% and Re (E(1+)/M(1+)) = -(2.91 +/- 0.19)% that are distinctly different from those from the traditional Legendre analysis based upon M1+ dominance and ll(pi) < or = 1 truncation.

Quasielastic 3He(e,e'p)2H reaction at Q2 = 1.5 GeV2 for recoil momenta up to 1 GeV/c

We have studied the quasielastic 3He(e,e(')p)2H reaction in perpendicular coplanar kinematics, with the energy and the momentum transferred by the electron fixed at 840 MeV and 1502 MeV/c, respectively. The 3He(e,e(')p)2H cross section was measured for missing momenta up to 1000 MeV/c, while the A(TL) asymmetry was extracted for missing momenta up to 660 MeV/c. For missing momenta up to 150 MeV/c, the cross section is described by variational calculations using modern 3He wave functions. For missing momenta from 150 to 750 MeV/c, strong final-state interaction effects are observed. Near 1000 MeV/c, the experimental cross section is more than an order of magnitude larger than predicted by available theories. The A(TL) asymmetry displays characteristic features of broken factorization with a structure that is similar to that generated by available models.

Measurement of the 3He(e,e'p)pn reaction at high missing energies and momenta

Results of the Jefferson Lab Hall A quasielastic 3He(e,e'p)pn measurements are presented. These measurements were performed at fixed transferred momentum and energy, q=1502 MeV/c and omega=840 MeV, respectively, for missing momenta p(m) up to 1 GeV/c and missing energies in the continuum region, up to pion threshold; this kinematic coverage is much more extensive than that of any previous experiment. The cross section data are presented along with the effective momentum density distribution and compared to theoretical models.

Use of a laparoscopic hand-assist device for accessory splenectomy

BACKGROUND

The use of a laparoscopic hand-assist device may aid in the identification of accessory spleens (ASs) and provide similar benefits to a conventional laparoscopic procedure. A patient with previous splenectomy for immune thrombocytopenic pupusa (ITP) and recurrent thrombocytopenia is reported.

METHOD

A computed tomography scan and RBC scan identified several nodules consistent with ASs. Initial laparoscopic exploration could not identify all the ASs seen on preoperative imaging. A hand-assist device was placed and a total of five nodules of splenic tissue were identified without conversion to laparotomy.

RESULTS

The patient had a brief and uncomplicated postoperative course with a return of platelet counts to 350,000 at 1-month follow-up.

CONCLUSION

We propose that in the scenario of recurrent ITP following laparoscopic splenectomy, repeat laparoscopy is the first step once an AS is identified by preoperative imaging. If the AS is not identified at laparoscopy, the insertion of a hand-assist device is an alternative to a full laparotomy.

Wide energy-window view on the density of states and hole mobility in poly(p-phenylene vinylene)

Using an electrochemically gated transistor, we achieved controlled and reversible doping of poly(p-phenylene vinylene) in a large concentration range. Our data open a wide energy-window view on the density of states (DOS) and show, for the first time, that the core of the DOS function is Gaussian, while the low-energy tail has a more complex structure. The hole mobility increases by more than 4 orders of magnitude when the electrochemical potential is scanned through the DOS.

Measurement of the generalized polarizabilities of the proton in virtual Compton scattering at Q2=0.92 and 1.76 GeV2

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.

Hand-assisted laparoscopic splenectomy in the setting of splenomegaly

BACKGROUND

Hand-assisted laparoscopic surgery (HALS) devices may be well suited to splenectomy in cases of splenomegaly.

METHODS

All cases of HALS for splenectomy between 1997 and 2001 were reviewed. Patient characteristics, operative details, and morbidity and mortality were analyzed.

RESULTS

HALS for splenectomy was performed in 54 patients. A total of 39 patients with massive splenomegaly (MS) (>600 g) were identified. The average weight of the MS group was 1285 +/- 505 g. There was one (3%) conversion. Operative time was 159 +/- 65 min, estimated blood loss was 257 +/- 240 ml, and length of hospital stay was 5.4 +/- 2.9 days. Morbidity was limited to 13 patients (24%), and there were two postoperative mortalities (5.1%).

CONCLUSIONS

HALS for splenectomy in the setting of splenomegaly is feasible and safe. For the surgeon considering a laparoscopic approach in the setting of splenomegaly, a hand-assisted technique is ideally suited for removal of the enlarged spleen.

Measurements of GnE/GnM from the 2H(e-->,en-->)1H Reaction to Q2=1.45 (GeV/c)2

We report new measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from the quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values of 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties of 7.6% and 8.4% at the two higher Q2 points, which points have never been achieved in polarization measurements.

Polarization transfer in the 4He(e-->,e'p-->)3H reaction up to Q2=2.6 (GeV/c)2

We have measured the proton recoil polarization in the 4He(e-->,e(')p-->)4H reaction at Q(2)=0.5, 1.0, 1.6, and 2.6 (GeV/c)(2). The measured ratio of polarization transfer coefficients differs from a fully relativistic calculation, favoring the inclusion of a medium modification of the proton form factors predicted by a quark-meson coupling model. In addition, the measured induced polarizations agree reasonably well with the fully relativistic calculation indicating that the treatment of final-state interactions is under control.

Laparoscopic management of complications following laparoscopic Roux-en-Y gastric bypass for morbid obesity

BACKGROUND

We reviewed our experience with complications following laparoscopic Roux-en-Y gastric bypass (LRYGB) that were managed laparoscopically.

METHODS

A total of 246 consecutive morbidly obese patients (mean body mass index, 50.9 kg/m2) underwent LRYGB by three surgeons at two institutions. All patients met National Institutes of Health criteria for surgical treatment of morbid obesity. Patients were followed prospectively.

RESULTS

A total of 62 patients (25.2%) developed 64 complications, 34 of which (13.8%) required a surgical intervention. Twenty-seven of the 34 procedures were performed laparoscopically. Gastrojejunostomy stricture was the most common complication (8.9%), followed by intestinal obstruction (7.3%) and gastrointestinal bleeding (4%). The intestinal obstruction was secondary to adhesions (n = 6), internal hernia at the level of the transverse mesocolon (n = 3), jejunojejunostomy stricture (n = 3), and cicatrix around the Roux limb at the level of the transverse mesocolon (n = 3). Other complications included gastrojejunostomy leak (1.6%), symptomatic gallstone disease (2.8%), and gastric remnant perforation (0.8%). One patient underwent a negative laparoscopy to rule out anastomotic leak. There were 3 deaths in this series of patients, 2 attributable to anastomotic leak.

CONCLUSIONS

A variety of complications can present after LRYGB. Laparoscopy is an excellent technique to treat these complications.

Possible approaches to improving the international comparability of immigration and emigration statistics: an illustration of the Canadian situation

"This article seeks to highlight the extent of the lack of standardization which exists in the field of international migration statistics and, using statistics for Canada as an example, to illustrate how significant progress towards resolving this problem could be made if sufficient numbers of countries made their immigration and emigration statistics gradually comply more fully with the United Nations recommendations."

Macroporous germanium by electrochemical deposition

Germanium is electrodeposited in a template formed from a dried suspension of silica spheres. The germanium completely fills the pores of the silica matrix. The semiconductor, as deposited, is amorphous but can be crystallized by annealing. Selective dissolution of the silica template gives a macroporous germanium-air sphere matrix, which offers interesting possibilities for photonic applications.

Staircase in the electron mobility of a ZnO quantum dot assembly due to shell filling

Electron transport in an assembly of ZnO quantum dots has been studied using an electrochemically gated transistor. The electron mobility shows a stepwise increase as a function of the electron occupation per quantum dot. When the occupation number is below two, transport occurs by tunneling between the S orbitals. Transport becomes 3 times faster when the occupation number is between two and eight; tunneling now occurs between the P orbitals. Electron transport is thus critically determined by the quantum properties of the building blocks.

Measurement of G(E(p))/G(M(p)) in e(-->)p---> e(-->)p to Q(2) = 5.6 GeV(2)

The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).

Glucocorticoid-induced hypertension: from mouse to man

1. Adrenocorticotrophic hormone (ACTH) raises blood pressure in humans, sheep, rat and mouse. In rat and humans, but not sheep, the hypertension can be explained by glucocorticoid excess. 2. In both rat and humans, the hypertension is associated with a rise in cardiac output and renal vascular resistance. 3. In both rat and humans, the nitric oxide system is implicated in glucocorticoid hypertension. 4. In both rat and humans, hypertension due to naturally occurring glucocorticoids is not prevented by drugs that block classical glucocorticoid or mineralocorticoid receptors. 5. Abnormalities in glucocorticoid metabolism may contribute to some forms of 'essential' hypertension.

Cancer incidence in Alaska Natives thirty-year report 1969-1998

The Alaska Native Tumor Registry includes data from 1969 to the present. This report provides incidence rates over the thirty year period, 1969 through 1998, and compares trends over time for Alaska Natives (AN) with those of US Whites and Blacks. To examine current rates, average annual age-adjusted incidence rates for AN for 1984-98 are compared with US Whites. Data from the registry document numerous differences in rates of occurrence of specific cancers compared to US Whites and Blacks. Studies of these differences may provide clues to the causes and risk factors for the cancers. Most importantly, these data show that although cancer was considered a rare disease in the Alaska Native population as recently as the mid-twentieth century, the incidence rate for all cancers combined among Alaska Natives is now as high as that of US Whites, and even higher in women. On the other hand, despite relative differences in rates, the most frequently diagnosed cancers among Alaska Natives are the same as US Whites. Cancers of the lung, colon/rectum, breast, and prostate are most frequently diagnosed among Alaska Natives and in the U.S. These four cancers comprise over 50% of all diagnosed invasive cancers. Cancer of the lung is almost entirely preventable by eradication of tobacco use. Screening and early detection have been proven to reduce mortality for cancers of the colon/rectum and breast. Primary and secondary prevention of these cancers could markedly improve morbidity and mortality.

Dynamics of the 16O(e, e'p) reaction at high missing energies

We measured the cross section and response functions for the quasielastic 16O(e,e'p) reaction for missing energies 25< or =E(m)< or =120 MeV at missing momenta P(m)< or =340 MeV/c. For 25<E(m)<50 MeV and P(m) approximately 60 MeV/c, the reaction is dominated by a single 1s(1/2) proton knockout. At larger P(m), the single-particle aspects are increasingly masked by more complicated processes. Calculations which include pion exchange currents, isobar currents, and short-range correlations account for the shape and the transversity, but for only half of the magnitude of the measured cross section.

Hand-assisted laparoscopic surgery in the United States: an overview

Hand-assisted laparoscopic surgery (HALS) was developed to bridge the gap between open surgery and advanced laparoscopic surgery. Advantages of the hand in the abdomen include tactile feedback, the ability to palpate, blunt dissection, organ retraction, control of bleeding, and rapid organ removal. There are 3 commercially available devices in the United States, as well as a fourth in Europe and a fifth in Japan. Uses for HALS include procedures requiring intact specimen removal, complex laparoscopic procedures, preventing open conversion, and overcoming a technical obstacle. HALS procedures, such as esophagectomy, gastrectomy, hepatectomy, pancreatectomy, splenectomy, bariatric surgery, colectomy, nephrectomy, hysterectomy, and aortobifemoral bypass, have all been reported in the literature. Improvement in instrumentation, specifically with newer generation devices, will allow HALS to become more popular. We advocate the use of HALS specifically for laparoscopic colectomy, laparoscopic splenectomy for massive splenomegaly, and for living-related donor nephrectomy.

Gonadal steroids reduce the density of axospinous synapses in the developing rat arcuate nucleus: an electron microscopy analysis

The developing brain is exquisitely sensitive to gonadal steroid hormones, which permanently differentiate the neural substrate during a critical developmental period. One of the more striking sexual dimorphisms in the adult rat brain is synaptic patterning in the arcuate nucleus (ARC); females have twice the number of axospinous synapses as males (Matsumoto and Arai [1980] Brain Res. 190:238-242). Previously, we have demonstrated that a similar dimorphism in spine densities on ARC dendrites is present as early as early as postnatal day 2 (PN2) in Golgi-impregnated rat brains (Mong et al. [1999] J. Neurosci. 19:1464-1472). Males have 37% fewer dendritic spines than females. Moreover, these spine densities are sensitive to changes in the hormonal milieu such that males castrated on the day of birth have a significant increase in spine density, whereas females masculinized at birth by gonadal steroid exposure have a decreased dendritic spine density. One of the limitations of the Golgi technique is the inability to confirm the presence of synapses. The current study used quantitative electron microscopy and demonstrated that testosterone exposure dramatically reduced axospinous synapses in the ARC by PN 2. Males had 54% fewer and masculinized females had 77% fewer axospinous synapses than females (P < 0.05 and P < 0.01, respectively). We previously reported that gonadal steroids induce coincident changes in neuronal and astrocyte morphology in the neonatal ARC (Mong et al., 1999), and here confirm that these changes include an altered synaptic pattern that is strikingly similar to that observed in the adult (Matsumoto and Arai, 1980).

Search for quadrupole strength in the electroexcitation of the delta+(1232)

High-precision 1H(e,e'p)pi(0) measurements at Q2 = 0.126 (GeV/c)2 are reported, which allow the determination of quadrupole amplitudes in the gamma*N-->Delta transition; they simultaneously test the reliability of electroproduction models. The derived quadrupole-to-dipole ( I = 3/2) amplitude ratios, R(SM) = (-6.5+/-0.2(stat+sys)+/-2.5(mod))% and R(EM) = (-2.1+/-0.2(stat+sys)+/-2.0(mod))%, are dominated by model error. Previous R(SM) and R(EM) results should be reconsidered after the model uncertainties associated with the method of their extraction are taken into account.

Effects of oral L-arginine on plasma nitrate and blood pressure in cortisol-treated humans

OBJECTIVE

The aim of this study was to determine whether cortisol-induced hypertension can be reversed by co-administration of oral L-arginine.

STUDY DESIGN

Three studies were undertaken in healthy male human subjects. The first study addressed the effect of oral L-arginine loading on plasma arginine concentration. Study 2 addressed the effect of co-administration of cortisol with L-arginine on plasma L-arginine concentrations. Study 3 was a randomized placebo crossover control comparing the effects of cortisol 80 mg/day co-administered with a placebo to cortisol 80 mg/day co-administered with L-arginine 21 g/day.

METHODS

Blood pressure was measured by a random Hawksley sphygmomanometer. Plasma nitrate/nitrite concentrations were measured by a modified Greiss reaction. Plasma arginine and citrulline concentrations were measured by an automated amino acid analyser.

RESULTS

Plasma arginine concentrations were doubled by oral doses of 15 g/day and 21 g/day of L-arginine (study 1). Co-administration of cortisol did not alter plasma arginine concentrations in subjects taking 21 g of L-arginine per day (study 2). Co-administration of L-arginine 21 g/day with cortisol 80 mg/day did not prevent cortisol-induced increases in blood pressure or cortisol-induced falls in plasma nitrate/nitrite concentrations.

CONCLUSION

Cortisol-induced hypertension is accompanied by a fall in plasma nitrate/nitrite concentrations. Oral L-arginine administration does not prevent cortisol-induced falls in plasma nitrate/nitrite concentrations or increases in blood pressure. We propose that cortisol-induced reductions in nitrate/nitrite production occur at a point distal to L-arginine availability in the nitric oxide synthase pathway.

Prevalence and prognostic significance of malnutrition in chronic renal insufficiency

OBJECTIVE

Malnutrition is present in a significant proportion of patients commencing dialysis. However, the prevalence and prognostic significance of malnutrition within the chronic renal insufficiency (CRI) population before the initiation of dialysis is poorly characterized. The aim of this study was to determine the prevalence and prognostic significance of malnutrition in an unselected group of patients with CRI.

DESIGN

Cohort analytic study.

SETTING

Ambulatory care practice of a university teaching hospital.

PATIENTS

Fifty patients with CRI (serum creatinine concentration > or = 1.7 mg/dL) were enrolled. Patients with a recent acute illness, nephrotic syndrome, intercurrent steroid therapy, gastrointestinal disease, or other severe organ failure that may have independently influenced nutritional status were excluded.

INTERVENTION

At baseline, patients had a nutritional assessment consisting of subjective global assessment (SGA), measurement of body mass index (BMI), midarm circumference (MAC), serum albumin concentration, total lymphocyte count, and single frequency bioelectrical impedance analysis. Patients received standard medical care and were followed prospectively at quarterly intervals for 12 months.

RESULTS

At baseline assessment, 28% of patients had evidence of malnutrition by SGA criteria. The malnourished group of patients had a significantly lower creatinine clearance (18.9 +/- 9.8 v 36.5 +/- 14.0 mL/min/1.73 m(2), mean +/- SD, P <.001), glomerular filtration rate (20.7 +/- 10.9 v 28.5 +/- 12.5 mL/min/1.73 m(2), P =.04), BMI (22.7 +/- 2.9 v 29.0 +/- 5.0 kg/m(2)), and MAC (24.3 +/- 4.9 v 30.7 +/- 4.8 cm, P <.001), but there were no differences in serum albumin concentration or total lymphocyte count between the groups. At the 12-month follow-up, there was significantly increased mortality (21% v 3%, P =.04), composite endpoint of death or dialysis (50% v 11%, P =.02), and likelihood of acute hospitalization (78% v 23%, P =.001) in the malnourished group. A significant association was observed between baseline nutritional status and subsequent admission to hospital and baseline glomerular filtration rate and progression to end-stage renal failure.

CONCLUSION

These data suggest that SGA provides a useful means of assessing nutritional status and is helpful in identifying patients with increased risk of morbidity and mortality in the setting of CRI.

The effect of lower-extremity position on cerebrospinal fluid pressures

OBJECTIVE

To determine the effects of lower-extremity positioning on cerebrospinal fluid opening pressure (CSFp). The authors believed that during lumbar puncture (LP), CSFp does not meaningfully decrease when the lower extremities are extended from flexion, as is often suggested.

METHODS

In a convenience sample of adult patients who clinically required LP in an urban emergency department, three sequential CSFp measurements were obtained in either sequence A (knee, hip, and neck flexion [90 degrees ], then extension, then flexion) or sequence B (extension, flexion, then extension) prior to CSF withdrawal. The neck was flexed at 30 degrees when the lower extremities were flexed, while the thoracolumbar spine was kept in the neutral position for all measurements.

RESULTS

Nineteen patients were studied in each sequence. Although variable, overall within-patient changes between positions were not clinically meaningful. Mean and 95% confidence intervals (95% CIs) for the decrease in CSFp from position 1 to position 3 (same position) were 0.2 cm H(2)O (1.7%) and 0.9 to -0.6 cm H(2)O (6% to -2.7%), respectively. Changing from flexion to extension decreased pressure measurements by a mean of 0.9 cm H(2)O (2.5%) [95% CI = 2.1 to -0.1 cm H(2)O (7.6% to -2.4%)]. Changing from extension to flexion increased CSFp by a mean of 1.1 cm H(2)O (6.1%) [95% CI = 0.2 to 2.0 cm H(2)O (1.3% to 11.5%)], a statistically but not clinically meaningful change.

CONCLUSIONS

Changing lower-extremity position did not meaningfully change mean CSFp. These data do not support the common suggestion that extending the lower extremities during LP meaningfully decreases CSF opening pressures.

Follow-up program for emergency department patients with gonorrhea or chlamydia

OBJECTIVES

To study the performance of a centralized regional follow-up program organized by a municipal department of health (DH) for female patients presenting to the emergency department (ED) with Neisseria gonorrhoeae and/or Chlamydia trachomatis, who are not diagnosed or treated at the time of presentation.

METHODS

This was a retrospective observational study of female patients seen in the ED with positive cervical specimens, and their subsequent treatment and follow-up by the DH. Medical records were reviewed to determine the female patients seen in the ED who had positive specimens for N. gonorrhoeae or C. trachomatis. The DH followed up those not treated in the ED. Analysis of how long it took for these patients to be treated and the proportion lost to follow-up was performed.

RESULTS

Of 2,121 specimens, 342 were positive for N. gonorrhoeae or C. trachomatis. Of the 342, 154 (45%) were recognized and appropriately treated in the ED. One hundred fifty-nine of the 342 (46.5%) patients were discharged from the ED without treatment but were contacted by the DH and appropriate treatment was provided. The DH could not locate 23 (6.7%) patients, and four (1.2%) refused treatment. One died before treatment. Only 21 of the 159 were treated within nine days. Median time to treatment was 36 days.

CONCLUSIONS

Centralized laboratory analysis and follow-up by the DH for N. gonorrhoeae and C. trachomatis identified many female patients undiagnosed and untreated in the ED. The DH follow-up program provided appropriate treatment to most female patients.

Cushing, cortisol, and cardiovascular disease

Cushing's syndrome of glucocorticoid excess is named after the eminent Boston neurosurgeon Harvey W. Cushing (1869-1939). The recognition that glucocorticoid excess produces hypertension led to examination of the role of cortisol in essential hypertension, but it is only over the last decade that evidence has emerged to support the concept. Despite the widespread assumption that cortisol raises blood pressure as a consequence of renal sodium retention, there are few data consistent with the notion. Although it has a plethora of actions on brain, heart and blood vessels, kidney, and body fluid compartments, precisely how cortisol elevates blood pressure is unclear. Candidate mechanisms currently being examined include inhibition of the vasodilator nitric oxide system and increases in vasoconstrictor erythropoietin concentration.

High spatial resolution measurements of organ blood flow in small laboratory animals

With the use of a newly developed Imaging Cryomicrotome to determine the spatial location of fluorescent microspheres in organs, we validate and report our processing algorithms for measuring regional blood flow in small laboratory animals. Microspheres (15-microm diameter) of four different fluorescent colors and one radioactive label were simultaneously injected into the left ventricle of a pig. The heart and kidneys were dissected, and the numbers of fluorescent and radioactive microspheres were determined in 10 randomly selected pieces. All microsphere counts fell well within the 95% expected confidence limits as determined from the radioactive counts. Fluorescent microspheres (15-microm diameter) of four different colors were also injected into the tail vein of a rat and the left ventricle of a rabbit. After correction for Poisson noise, correlation coefficients between the colors were 0.99 +/- 0.02 (means +/- SD) for the rabbit heart and 0.99 +/- 0.02 for the rat lung. Mathematical dissection algorithms, statistics to analyze the spatial data, and methods to visualize blood flow distributions in small animal organs are presented.

Cortisol inhibits cholinergic vasodilation in the human forearm

Exogenous cortisol raises blood pressure (BP) in humans and there is accumulating evidence of abnormalities of glucocorticoid activity in essential hypertension. In this study we tested the hypothesis that exogenous cortisol attenuates the cholinergic dilator response in the forearm circulation. Fourteen healthy normotensive men were studied. Using bilateral forearm venous plethysmography, we examined forearm blood flow responses to intra-arterial acetylcholine (ACh) and sodium nitroprusside (SNP) pre- and post-NG-monomethyl-L-arginine (LNMMA) after 2 or 5 days of oral cortisol or placebo in a randomized, double-blind crossover study. Exogenous cortisol increased supine systolic (P < .05) and standing systolic (P < .05) BP and produced expected metabolic changes and suppressed serum cortisol concentration (P < .001). Baseline forearm blood flow did not differ between placebo and cortisol treatments at 2 or 5 days. Cholinergic vasodilatation was impaired after cortisol administration, reaching statistical significance at 5 days (P < .05). Cortisol did not affect responses to SNP. NG-monomethyl-L-arginine inhibited cholinergic vasodilatation in placebo-treated groups but had no additional effect in the presence of cortisol. These results support our hypothesis and suggest that the mechanism of impaired cholinergic dilatation in glucocorticoid-treated subjects involves abnormalities of the endothelial nitric oxide system.

Effects of nicotinic acid on insulin sensitivity and blood pressure in healthy subjects

Insulin resistance and hyperinsulinaemia are associated with hypertension although a causative relationship has not been established. The aim of this study was to determine whether a short term reduction in insulin sensitivity induced by nicotinic acid treatment (NA) would alter blood pressure. The study was a double-blind randomised placebo-controlled cross-over study. Seven healthy volunteers, three males and four females were randomised to placebo or NA 500 mg daily for 7 days then 1 g daily for a further 7 days. Hyperinsulinaemic euglycaemic clamp, indirect calorimetry, 24-h ambulatory blood pressure monitoring (ABPM) and forearm blood flow measurement (FABF) were performed at day 14 of each treatment phase. NA significantly reduced the glucose infusion rate required to maintain euglycaemia in all subjects (placebo vs NA; 31.5+/-4.2 vs. 26.2+/-4.6 micromol/kg/min, P = 0.002) associated with a decrease in non-oxidative glucose disposal. NA did not significantly alter 24-h mean systolic or diastolic blood pressure. Fasting glucose, insulin and non-esterified free fatty acid (NEFA) levels remained unchanged, energy expenditure and substrate oxidation were not altered by NA. These results suggest a short term reduction in insulin sensitivity with NA is not accompanied by a change in blood pressure. This may relate to the short duration of treatment, to a dissociation between insulin resistance and hypertension or to other homeostatic mechanisms which prevent blood pressure rising in subjects not predisposed to hypertension.

The feasibility and accuracy of diagnostic laparoscopy in the septic ICU patient

BACKGROUND

Systemic inflammatory response syndrome (SIRS) and sepsis of unknown origin are common complications of critically ill patients in the ICU. These patients frequently have unreliable clinical exams and are candidates for exploratory laparotomy. Although abdominal CT is commonly used because it is less invasive than laparotomy, it is often unreliable or unobtainable. Bedside laparoscopy is an alternative technique that may be more accurate than CT in selected patients and less invasive than laparotomy.

METHODS

We performed diagnostic laparoscopy (DL) in a series of ICU patients with SIRS/septic state of unknown origin between May 1997 and June 1998. All patients were unstable and required significant respiratory and hemodynamic support. Laparoscopy was either performed in the ICU at the patient's bedside or in the operating room. CT scan of the abdomen had been performed on most of the patients who were stable enough to transport. Confirmation of diagnosis was obtained either by laparotomy, autopsy, or clinical recovery.

RESULTS

Among the 17 eligible patients, 16 underwent successful DL. Insufflation was impossible in one patient because of high intraabdominal pressure. Bedside evaluations were performed in 14 of the 17 patients. There were no complications from the laparoscopy. Six patients were identified as positive (four intestinal ischemia, two cholecystitis); the other 10 had negative explorations. Follow-up on two patients with negative laparoscopy was incomplete due to denied postmortem. Laparoscopic diagnoses were confirmed in the remaining 14 patients by laparotomy (six cases), postmortem (three cases), or recovery (five cases), with an accuracy of 100%. The overall accuracy of abdominal CT obtained in nine of the 14 patients was 33%.

CONCLUSIONS

DL in a select group of critical ICU patients is safe and accurate, whereas CT scan tends to be inaccurate and is often unobtainable due to patient instability. Performing the procedure at the bedside can expedite the diagnosis, eliminate the burden for transfer, and save on anesthesia and operating room charges.

Hand-assisted laparoscopic aortobifemoral bypass grafting

OBJECTIVE

Aortobifemoral bypass grafting is a durable operation for arterial reconstruction in patients with symptomatic aortoiliac occlusive disease. In several small laparoscopic series technically demanding aortic operations have been described that have not gained widespread acceptance or applicability. To simplify the laparoscopic approach to the aorta, we have developed a technique of aortobifemoral bypass grafting that uses hand-assisted laparoscopic surgery (HALS) to minimize the complexity of aortic dissection and reconstruction.

METHODS

Five patients with symptomatic aortoiliac occlusive disease underwent successful HALS aortobifemoral bypass grafting. With the use of a specialized sleeve device (Hand-Port), an operative hand was introduced into the laparoscopic field while pneumoperitoneum was maintained. Laparoscopic dissection of the infrarenal aorta was then performed with retraction provided by the operative hand. Proximal aortic anastomosis was performed with an open technique through the same 7.5-cm Hand-Port incision, and femoral anastomoses were performed in the standard fashion.

RESULTS

Five hand-assisted laparoscopic aortobifemoral bypass grafts were performed (two end-to-end, three end-to-side proximal anastomoses). Mean operative time was 231 minutes. Mean blood loss was 440 mL. All patients underwent extubation immediately after surgery, were ambulatory on postoperative day (POD) 1, and were tolerating their diet by POD 3. The mean length of hospital stay was 3.8 days. One patient was discharged on POD 5 and started a clear liquid diet after a self-limiting postoperative ileus. All patients were asymptomatic and back to full activity/work by 14.6 days postoperatively, on average (range, 11-20 days).

CONCLUSION

The HALS offers the advantages of tactile feedback, flexible retraction, and the introduction of conventional surgical instruments, all of which extend laparoscopic surgery and its established benefits to a wide array of more complex surgical problems, including major vascular surgery. Ease of performance, shorter hospital stays, and faster recovery times all suggest that HALS may become a valuable adjunct to conventional aortobifemoral bypass grafting.

The drug epidemic: effects on newborn infants and health resource consumption at a tertiary perinatal centre

OBJECTIVES

Illicit drug taking in Australia, with its attendant social and medical consequences, is increasing and the effects extend to maternity hospitals where infants born to addicted mothers have more health problems in the neonatal period. The aims of this study were to evaluate (1) the patterns of illness of such infants and (2) the burden imposed on the neonatal department of a large tertiary maternity centre.

METHODOLOGY

An audit was conducted of all Chemical Dependency Unit (CDU) mothers and babies delivered at the Royal Women's Hospital, Melbourne, Australia during 1997. Data were compared with those from a concurrent control group of mothers and babies randomly generated from the hospital's obstetric database.

RESULTS

Ninety-six infants born to CDU mothers were compared with a control group of 200 infant/mother pairs. The majority of women in the CDU clinic were treated for narcotic addiction with methadone (90%) but most continued to use heroin during pregnancy (68%). Infants born to CDU mothers were significantly less mature and lighter than control infants. Fifty-three (55%) CDU infants required admission to the Special Care Nursery either because of neonatal abstinence syndrome (n = 29) or other medical reasons (n = 24). The median length of hospital stay was significantly longer in CDU compared with control infants (8 vs 3 days, P < 0.01).

CONCLUSIONS

Infants born to drug dependent mothers have more neonatal problems requiring specialized medical and nursing expertise, compared with control infants. These infants are large consumers of scarce health resources.