Endorsement by the primary care practitioner consistently improves participation in screening for colorectal cancer: a longitudinal analysis

OBJECTIVES

To investigate the effect of general practice (GP) and general practitioner (GPR) endorsement for faecal occult blood test (FOBT)-based screening on maintenance of participation in screening over four successive screening rounds.

SETTING

South Australian residents aged > or = 50 years.

METHODS

Random selection of four groups (n = 600 per group): one from the Commonwealth electoral roll (ER) and three from the combined patient lists of two collaborating GPs (GP1, GP2, GP3). Subjects were mailed offers to screen using a faecal immunochemical test over four successive rounds, spaced approximately 18 months apart. The GP1 and ER groups were invited to screen without any endorsement from a GPR or medical practice; GP2 invitees received an invitation indicating support for screening from their medical practice; and GP3 invitations were printed on practice letterhead and were signed by a GPR.

RESULTS

Multivariate analyses indicated that initial participation as well as re-participation over four successive rounds was significantly enhanced in the GP2 (39%, 42%, 45% and 44%) and GP3 groups (42%, 47%, 48% and 49%) relative to the ER group (33%, 37%, 40% and 36%). The analyses also indicated that 60-69 year olds were most likely to participate in all rounds (relative risk [RR] 1.49, 1.39, 1.43 and 1.25), and men were generally less likely to participate than women in all screening rounds (RR 0.86, 0.84, 0.80 and 0.83).

CONCLUSIONS

Associating a GPR or medical practice of recent contact with an invitation to screen achieves better participation and re-participation than does an invitation from a centralized screening unit. Furthermore, enhanced participation can be achieved by practice endorsement alone without requiring actual GPR involvement.

Array-CGH in a series of 30 patients with mental retardation, dysmorphic features, and congenital malformations detected an interstitial 1p22.2-p31.1 deletion in a patient with features overlapping the Goldenhar syndrome

Genosensor Array 300 (Abbott) is a multiplex platform for array-based comparative genomic hybridization that detects unbalanced genomic aberrations including whole chromosome gains/losses, microdeletions, duplications and unbalanced subtelomeric rearrangements. A series of 30 patients with unexplained mental retardation, dysmorphic features, congenital abnormalities and normal high resolution karyotype and FISH subtelomeric studies were analyzed using Genosensor Array 300 array-CGH. We identified a chromosomal aberration in one patient with an interstitial 1p31.1 deletion. FISH analysis with BACs specific probes of the 1p region confirmed the interstitial 1p22.2-p31.1 deletion. The patient was a 20-year-old man with short stature, facial dysmorphism including asymmetry, scoliosis, severe psychomotor delay and an epibulbar dermoid cyst. The phenotype was compatible with Goldenhar syndrome despite the absence of asymmetric ears. This observation is of interest since it could be a clue in the search for the genes responsible for Goldenhar syndrome. This study demonstrates the utility of the array-CGH technology in detecting interstitial deletions.

A titer plate-based polymer microfluidic platform for high throughput nucleic acid purification

A 96-well solid-phase reversible immobilization (SPRI) reactor plate was designed to demonstrate functional titer plate-based microfluidic platforms. Nickel, large area mold inserts were fabricated using an SU-8 based, UV-LIGA technique on 150 mm diameter silicon substrates. Prior to UV exposure, the prebaked SU-8 resist was flycut to reduce the total thickness variation to less than 5 mum. Excellent UV lithography results, with highly vertical sidewalls, were obtained in the SU-8 by using an UV filter to remove high absorbance wavelengths below 350 nm. Overplating of nickel in the SU-8 patterns produced high quality, high precision, metal mold inserts, which were used to replicate titer plate-based SPRI reactors using hot embossing of polycarbonate (PC). Optimized molding conditions yielded good feature replication fidelity and feature location integrity over the entire surface area. Thermal fusion bonding of the molded PC chips at 150 degrees C resulted in leak-free sealing, which was verified in leakage tests using a fluorescent dye. The assembled SPRI reactor was used for simple, fast purification of genomic DNA from whole cell lysates of several bacterial species, which was verified by PCR amplification of the purified genomic DNA.

Acellular dermal allograft for ventral hernia repair in the compromised surgical field

A ventral hernia and a contaminated surgical field are a difficult surgical combination. We hypothesize that acellular human dermis (AHD) can be a suitable biological tissue alternative in the repair of a ventral hernia. The study involved a retrospective review of the use of AHD in the repair of ventral hernia from 2001-2004. Inclusion criteria included a ventral hernia repair in a clean-contaminated (CC) or contaminated-dirty (CD) surgical field. The primary outcome of the study was wound infection and mesh removal. Patients were stratified into CC and CD, and management of a wound infection [medically managed (MM) or surgically managed (SM)]. Seventy-five patients met the study criteria. The most common comorbidity was hypertension (45.3%). There was one death in the study (from multiple organ dysfunction syndrome). The overall wound infection rate was 33.3 per cent: 11 MM (14.7%) and 14 SM (18.7%). The average length of stay was 16.7 days (+/-20.8) with a mean follow-up of 275 (+/-209) days. Subgroup analysis: CC (n = 64) had 9 wound infections that were MM (14.1%) and 12 wound infections that were SM (18.8%); CD (n = 11) had 2 wound infections that were MM (18.2%) and 2 wound infections that were SM (18.2%). Five of 14 SM (35.7%) wound infections required removal of the mesh. Wound infection in the contaminated surgical field occurred 33.3 per cent of the time. Some (18.7%) of the cases required SM management, and 35.7 per cent of these required removal of the AHD.

Acellular Dermal Allograft for Ventral Hernia Repair in the Compromised Surgical Field

A ventral hernia and a contaminated surgical field are a difficult surgical combination. We hypothesize that acellular human dermis (AHD) can be a suitable biological tissue alternative in the repair of a ventral hernia. The study involved a retrospective review of the use of AHD in the repair of ventral hernia from 2001–2004. Inclusion criteria included a ventral hernia repair in a clean-contaminated (CC) or contaminated-dirty (CD) surgical field. The primary outcome of the study was wound infection and mesh removal. Patients were stratified into CC and CD, and management of a wound infection [medically managed (MM) or surgically managed (SM)]. Seventy-five patients met the study criteria. The most common comorbidity was hypertension (45.3%). There was one death in the study (from multiple organ dysfunction syndrome). The overall wound infection rate was 33.3 per cent: 11 MM (14.7%) and 14 SM (18.7%). The average length of stay was 16.7 days (±20.8) with a mean follow-up of 275 (±209) days. Subgroup analysis: CC (n = 64) had 9 wound infections that were MM (14.1%) and 12 wound infections that were SM (18.8%); CD (n = 11) had 2 wound infections that were MM (18.2%) and 2 wound infections that were SM (18.2%). Five of 14 SM (35.7%) wound infections required removal of the mesh. Wound infection in the contaminated surgical field occurred 33.3 per cent of the time. Some (18.7%) of the cases required SM management, and 35.7 per cent of these required removal of the AHD.

High-energy particle acceleration in the shell of a supernova remnant

A significant fraction of the energy density of the interstellar medium is in the form of high-energy charged particles (cosmic rays). The origin of these particles remains uncertain. Although it is generally accepted that the only sources capable of supplying the energy required to accelerate the bulk of Galactic cosmic rays are supernova explosions, and even though the mechanism of particle acceleration in expanding supernova remnant (SNR) shocks is thought to be well understood theoretically, unequivocal evidence for the production of high-energy particles in supernova shells has proven remarkably hard to find. Here we report on observations of the SNR RX J1713.7 - 3946 (G347.3 - 0.5), which was discovered by ROSAT in the X-ray spectrum and later claimed as a source of high-energy gamma-rays of TeV energies (1 TeV = 10(12) eV). We present a TeV gamma-ray image of the SNR: the spatially resolved remnant has a shell morphology similar to that seen in X-rays, which demonstrates that very-high-energy particles are accelerated there. The energy spectrum indicates efficient acceleration of charged particles to energies beyond 100 TeV, consistent with current ideas of particle acceleration in young SNR shocks.

DNA sequence and analysis of human chromosome 9

Chromosome 9 is highly structurally polymorphic. It contains the largest autosomal block of heterochromatin, which is heteromorphic in 6-8% of humans, whereas pericentric inversions occur in more than 1% of the population. The finished euchromatic sequence of chromosome 9 comprises 109,044,351 base pairs and represents >99.6% of the region. Analysis of the sequence reveals many intra- and interchromosomal duplications, including segmental duplications adjacent to both the centromere and the large heterochromatic block. We have annotated 1,149 genes, including genes implicated in male-to-female sex reversal, cancer and neurodegenerative disease, and 426 pseudogenes. The chromosome contains the largest interferon gene cluster in the human genome. There is also a region of exceptionally high gene and G + C content including genes paralogous to those in the major histocompatibility complex. We have also detected recently duplicated genes that exhibit different rates of sequence divergence, presumably reflecting natural selection.

Repair of giant abdominal hernias: does the type of prosthesis matter?

Closure of the abdominal wall after trauma or major surgery may be difficult due to visceral edema or fascial weakness; thus, the risk of developing a ventral hernia (VH) is high. Commonly, these hernias are repaired using a prosthetic mesh. Complications following mesh repair can develop. We hypothesize that the type of prosthetic material affects outcome. This is a retrospective chart review of patients admitted from 1996 to 2002 undergoing VH (> or = 20 x 10 cm) repair with prosthetic mesh. Data collected included age, sex, and race. Patients were stratified by prosthetic material as follows: Gore-Tex (GR), Marlex + Gore-Tex (MG), Marlex (MR), and Marlex + Vicryl (MV). For the purpose of clinical analysis, the groups were collapsed into subgroups: Gore-Tex exposure (GT) or non-Gore-Tex exposure (NG). Outcome measures were hernia recurrence (HR), wound infection (WI), and fistula formation (FF). Statistical analysis utilized chi2 test and Fisher's exact test. There were 55 VH repairs in 37 patients. The mean age was 43.9 (+/- 16.3), males out-numbered females 22 (59.5%) to 15 (40.5%). The majority of the patients were Caucasian (29; 78.4%). There were 30 trauma patients (81.1%), and 7 general surgery patients (18.9%). The HR for the study (n = 55) was 20 (36.4%), the WI was 17 (30.9%), and the FF was 3 (5.5%). GR group (6; 66.7%) had a significant higher wound IF rate than MR group (8; 26.7%) (Chi P = 0.02, Fisher P = 0.047). All other group comparisons (HR, WI, and FF) were N.S. The Gore-Tex versus non-Gore-Tex subgroup comparison results were as follows: GT (n = 18) had a WI 8 (44.4%), HR 6 (33.3%), and FF 0 (0%). NG (n = 37) had a WI 9 (24.3%), HR 14 (37.8%), and a FF 3 (8.1%). There was a trend toward a higher wound infection in the GT versus NG, but it did not reach statistical significance. We conclude that 1) the wound infection rate was higher in the Gore-Tex versus the Marlex group (Chi P = 0.02, Fisher P = 0.047). Wound infection in the presence of Gore-Tex usually mandates the removal of the mesh resulting in a hernia recurrence. 2) There was a trend toward a higher wound infection in the GT (44.4%) versus NG (24.3%), but it did not reach statistical significance.

Drug errors: what role do nurses and pharmacists have in minimizing the risk?

A multi-professional project was carried out in order to identify the interventions that nurses and pharmacists make in relation to drug administration (an intervention refers to 'the process of querying a prescription with a prescriber'). The project highlights the importance of both these occupational groups in identifying prescribing errors and preventing them from being translated into actual medication errors. It also identifies the need for adequate training for nursing and medical staff, along with system changes, in order to minimize the risk of medication errors.

Are Five-View Plain Films of the Cervical Spine Unreliable? A Prospective Evaluation in Blunt Trauma Patients with Altered Mental Status

OBJECTIVES

Clearing the cervical spine in a time-sensitive fashion is difficult. We hypothesized that admission computed tomographic scan of the occiput to T1 (CTS) with multiplanar reformatted images will replace five-view (odontoid, anteroposterior, lateral, and oblique) plain films of the cervical spine (CSX) in the initial evaluation of blunt trauma patients with altered mental status.

METHODS

Between January and July 2001, all patients aged 16 years or older with altered mental status undergoing both CTS and CSX were prospectively entered into the study group. Attending physician interpretation defined the presence of cervical spine injury. Unstable fractures were defined as requiring surgical or halo stabilization.

RESULTS

One thousand six patients met study criteria. One hundred sixteen patients had 172 cervical spine injuries (CSIs) (fracture and subluxation). CSX missed 90 of 172 (52.3%) CSIs in 65 of 172 (56.0%) patients. Anatomically, CSX failed to identify 14 of 15 occipital fractures (93.3%), 17 of 36 (47.2%) C1-3 fractures, and 59 of 121 (48.8%) C4-T1 CSIs. CSX failed to identify 5 of 29 (17.2%) patients with unstable CSIs. CTS failed to diagnose 3 of 172 (1.7%) CSIs that were stable (spinous process fractures at C6-7). Two patients exhibited spinal cord injury without radiologic abnormality missed by both modalities. CTS had a sensitivity of 97.4%, a specificity of 100%, a prevalence of 11.5%, a positive predictive value of 100%, and a negative predictive value of 99.7%. CSX had a sensitivity of 44.0%, a specificity of 100%, a prevalence of 11.5%, a positive predictive value of 100%, and a negative predictive value of 93.2%.

CONCLUSION

CTS outperformed five-view CSX in a group of patients with altered mental status or distracting injuries. Five-view CSX failed to diagnose 52.3% of cervical spine fractures identified by CTS. Five-view CSX failed to diagnose five patients with unstable cervical fractures and failed to identify 93.3% of patients with occipital condyle fractures.

Noncontact Laser Doppler Imaging in Burn Depth Analysis of the Extremities

The purpose of this study was to determine the accuracy and practical utility of a noncontact laser Doppler imager (PIM-II, Lisca Development AB, Linköping, Sweden) in the estimation of burn depth in the upper and lower extremities. At 48 hours after burn injury, we performed scans of 35 burns in 22 patients and obtained histological samples for burn determination with hematoxylin and eosin and vimentin immunohistochemical staining. Additionally, sequential scans and tissue specimens were obtained on 10 burns at 24, 48, and 72 hours. A statistically significant inverse relationship was noted between burn depth and the laser Doppler perfusion index. Laser Doppler perfusion index values greater than 1.3 predicted a superficial dermal burn with 95% sensitivity and 94% specificity. Superficial dermal burns exhibited increased perfusion in the early burn period. Wounds showed a progressive decline in perfusion and a progressive increase in the depth of injury during a 72-hour period. This study demonstrates the advantage and accuracy of using a noncontact laser Doppler to differentiate deep dermal from superficial partial thickness burns in the extremities.

Managing patient demand: a qualitative study of appointment making in general practice

BACKGROUND

Managing patients' requests for appointments is an important general practice activity. No previous research has systematically observed how patients and receptionists negotiate appointments.

AIM

To observe appointment making and investigate patients' and professionals' experiences of appointment negotiations.

DESIGN OF STUDY

A qualitative study using participant observation.

SETTING

Three general practices on Tyneside; a single-handed practice, a practice comprising three doctors, and a seven-doctor practice.

METHOD

Participant observation sessions, consisting of 35 activity recordings and 34 periods of observation and 38 patient and 15 professional interviews, were set up. Seven groups of patients were selected for interview. These included patients attending an 'open access' surgery, patients who complained about making an appointment, and patients who complimented the receptionists.

RESULTS

Appointment making is a complex social process. Outcomes are dependent on the process of negotiation and factors, such as patients' expectations and appointment availability. Receptionists felt that patients in employment, patients allocated to the practice by the Health Authority, and patients who did not comply with practice appointment rules were most demanding. Appointment requests are legitimised by receptionists enforcing practice rules and requesting clinical information. Patients volunteer information to provide evidence that their complaint is appropriate and employ strategies, such as persistence, assertiveness, and threats, to try and persuade receptionists to grant appointments.

CONCLUSION

Appointment making is a complex social process where outcomes are negotiated. Receptionists have an important role in managing patient demand. Practices should be explicit about how appointments are allocated, including publishing practice criteria.

Closely related proteins MBD2 and MBD3 play distinctive but interacting roles in mouse development

MBD2 and MBD3 are closely related proteins with consensus methyl-CpG binding domains. MBD2 is a transcriptional repressor that specifically binds to methylated DNA and is a component of the MeCP1 protein complex. In contrast, MBD3 fails to bind methylated DNA in murine cells, and is a component of the Mi-2/NuRD corepressor complex. We show by gene targeting that the two proteins are not functionally redundant in mice, as Mbd3-/- mice die during early embryogenesis, whereas Mbd2-/- mice are viable and fertile. Maternal behavior of Mbd2-/- mice is however defective and, at the molecular level, Mbd2-/- mice lack a component of MeCP1. Mbd2-mutant cells fail to fully silence transcription from exogenous methylated templates, but inappropriate activation of endogenous imprinted genes or retroviral sequences was not detected. Despite their differences, Mbd3 and Mbd2 interact genetically suggesting a functional relationship. Genetic and biochemical data together favor the view that MBD3 is a key component of the Mi-2/NuRD corepressor complex, whereas MBD2 may be one of several factors that can recruit this complex to DNA.

A mouse Mecp2-null mutation causes neurological symptoms that mimic Rett syndrome

Rett syndrome (RTT) is an inherited neurodevelopmental disorder of females that occurs once in 10,000-15,000 births. Affected females develop normally for 6-18 months, but then lose voluntary movements, including speech and hand skills. Most RTT patients are heterozygous for mutations in the X-linked gene MECP2 (refs. 3-12), encoding a protein that binds to methylated sites in genomic DNA and facilitates gene silencing. Previous work with Mecp2-null embryonic stem cells indicated that MeCP2 is essential for mouse embryogenesis. Here we generate mice lacking Mecp2 using Cre-loxP technology. Both Mecp2-null mice and mice in which Mecp2 was deleted in brain showed severe neurological symptoms at approximately six weeks of age. Compensation for absence of MeCP2 in other tissues by MeCP1 (refs. 19,20) was not apparent in genetic or biochemical tests. After several months, heterozygous female mice also showed behavioral symptoms. The overlapping delay before symptom onset in humans and mice, despite their profoundly different rates of development, raises the possibility that stability of brain function, not brain development per se, is compromised by the absence of MeCP2.

New therapies for optic neuropathies: development in experimental models

Experimental models of human diseases have affected the design and direction of both basic and clinical research into understanding the pathogenesis and treatments of demyelinating disease, stroke, and hereditary disorders of the central nervous system. However, in spite of major advances in molecular research that have linked Leber Hereditary Optic Neuropathy to mutations in mitochondrial DNA, there has been relatively little focus in applying basic scientific methodologies to optic neuropathies other than glaucoma. The relative absence of detailed scientific knowledge about the basic mechanisms involved in the pathogenesis of optic nerve injury has contributed to the use of empiric therapies for neuro-ophthalmic optic neuropathies. Over the past decade major clinical trials, such as the Optic Neuritis Treatment Trial and Ischemic Optic Neuropathy Decompression Trial, have proven that currently available treatment options for demyelinating and ischemic optic neuropathies are ineffective and can even be harmful. Although the pathogenesis of visual failure in demyelinating, ischemic, and hereditary optic neuropathies appears diverse, a final common pathway for irreparable optic nerve injury may exist. This article reviews several models of experimental optic neuropathies that may aid in the development of novel treatments for neuro-ophthalmic disorders of the optic nerve during the 21st century.

Recombinant adeno-associated virus vector-based gene transfer for defects in oxidative metabolism

Defects in oxidative metabolism may be caused by mutations either in nuclear genes or in mitochondrial DNA (mtDNA). We tested the hypothesis that recombinant adeno-associated virus (rAAV) could be used to complement mtDNA mutations. AAV vector constructs were designed to express the reporter gene encoding green fluorescent protein (GFP), fused to a targeting presequence that directed GFP to be translocated into mitochondria. These vectors mediated expression of mitochondrial-localized GFP, as indicated by fluorescence microscopy and electron microscopy, in respiring human embryonic kidney 293 cells and nonrespiring mtDNA-deficient (rho 0) cells. However, when sequences encoding hydrophobic segments of proteins normally encoded by mtDNA were inserted between the presequence and GFP, mitochondrial import failed to occur. In similar experiments, a fusion was created between pyruvate dehydrogenase (PDH) E1 alpha subunit, a nuclear-encoded mitochondrial gene with its own targeting presequence, and GFP. With this construct, expression of GFP was observed in mitochondria in vitro and in vivo. We conclude that the hydrophobicity of mtDNA-encoded proteins limits their ability to be transported from the cytoplasm. However, rAAV-based gene therapy may hold promise for gene therapy of PDH deficiency, the most common biochemically proven cause of congenital lactic acidosis.

Genomic sequence and transcriptional profile of the boundary between pericentromeric satellites and genes on human chromosome arm 10q

The organization of centromeric heterochromatin has been established in a number of eucaryotes but remains poorly defined in human. Here we present 1025 kb of contiguous human genomic sequence which links pericentromeric satellites to the RET proto-oncogene in 10q11.2 and is presumed to span the transition from centric heterochromatin to euchromatin on this chromosome arm. Two distinct domains can be defined within the sequence. The proximal approximately 240 kb consists of arrays of satellites and other tandem repeats separated by tracts of complex sequence which have evolved by pericentromeric-directed duplication. Analysis of 32 human paralogues of these sequences indicates that most terminate at or within repeat arrays, implicating these repeats in the interchromosomal duplication process. Corroborative PCR-based analyses establish a genome-wide correlation between the distribution of these paralogues and the distribution of satellite families present in 10q11. In contrast, the distal approximately 780 kb contains few tandem repeats and is largely chromosome specific. However, a minimum of three independent intrachromosomal duplication events have resulted in >370 kb of this sequence sharing >90% identity with sequences on 10p. Using computer-based analyses and RT-PCR we confirm the presence of three genes within the sequence, ZNF11/33B, KIAA0187 and RET, in addition to five transcripts of unknown structure. All of these transcribed sequences map distal to the satellite arrays. The boundary between satellite-rich interchromosomally duplicated DNA and chromosome-specific DNA therefore appears to define a transition from pericentromeric heterochromatin to euchromatin on the long arm of this chromosome.

Adenoviral gene therapy with catalase suppresses experimental optic neuritis

OBJECTIVE

To determine if adenoviral-mediated transfer of the gene for catalase (CAT), the reactive oxygen species scavenger, suppresses experimental optic neuritis.

CLINICAL RELEVANCE

Gene therapy with CAT delivered by an adeno-associated viral vector was previously shown to suppress experimental optic neuritis. Because the transduction of protein expression with recombinant adeno-associated viral vector is relatively slow, taking weeks to reach full levels, we studied the effects of replication-deficient adenovirus containing CAT in suppressing experimental optic neuritis. Transduction with adenovirus occurs within days of inoculation, thus, it may be more applicable for the treatment of patients with acute optic neuritis.

MATERIALS AND METHODS

Replication-deficient adenovirus containing CAT was injected above the right optic nerve heads of SJL/J mice that were simultaneously sensitized for experimental allergic encephalomyelitis. For controls, the left eyes were injected with the replication-deficient adenovirus without CAT or no virus. The histological effects of CAT on the lesions of experimental allergic encephalomyelitis were measured by computerized analysis of the myelin sheath area (for demyelination), optic disc area (for optic nerve head swelling), the extent of the cellular infiltrate, extravasated serum albumin labeled with immunogold (for disruption of the blood-brain barrier), and the in vivo hydrogen peroxide reaction product.

RESULTS

After 1 month, cell-specific catalase activity, evaluated by the quantitation of catalase immunogold, was increased about 2-fold each in endothelia, oligodendroglia, astrocytes, and axons of the CAT-inoculated right optic nerves compared with the control left optic nerves. The increased cellular levels of catalase reduced demyelination by 30%, optic nerve head swelling by 25%, cellular infiltration by 26%, disruption of the blood-brain barrier by 61%, and in vivo levels of hydrogen peroxide by 81%.

CONCLUSIONS

Adenoviral-mediated gene transfer increased catalase levels in all optic nerve cell types, and it persisted for 1 month after inoculation. The increased cellular levels of catalase suppressed demyelination and blood-brain barrier disruption at the foci in the optic nerve where prior magnetic resonance imaging and histopathologic studies have demonstrated the demyelinating inflammation of experimental and human optic neuritis. Together, they suggest that gene therapy with CAT may be helpful in the treatment of patients with optic neuritis.