Novel chyme reinfusion device for gastrointestinal fistulas and stomas: feasibility study.

BACKGROUND: High-output enterostomies and enteroatmospheric fistulas are common causes of intestinal failure, and may necessitate parenteral nutrition and prolonged hospital stay. Reinfusing lost chyme into the distal gut is known to be beneficial, but implementation has been limited because manual reinfusion is unpleasant and labour-intensive, and no devices are available. A new device is presented for reinfusing chyme easily and efficiently, with first-in-human data. METHODS: The device comprises a compact centrifugal pump that fits inside a standard stoma appliance. The pump is connected to an intestinal feeding tube inserted into the distal intestinal limb. The pump is activated across the appliance by magnetic coupling to a hand-held driver unit, effecting intermittent bolus reinfusion while avoiding effluent contact. Safety, technical and clinical factors were evaluated. RESULTS: Following microbiological safety testing, the device was evaluated in ten patients (median duration of installation 39·5 days; total 740 days). Indications included remediation of high-output losses (8 patients), dependency on parenteral nutrition (5), and gut rehabilitation before surgery (10). Reinfusion was well tolerated with use of regular boluses of approximately 200 ml, and no device-related serious adverse events occurred. Clinical benefits included resumption of oral diet, cessation of parenteral nutrition (4 of 5 patients), correction of electrolytes and liver enzymes, and hospital discharge (6 of 10). Of seven patients with intestinal continuity restored, one experienced postoperative ileus. CONCLUSION: A novel chyme reinfusion device was developed and found to be safe, demonstrating potential benefits in remediating high-output losses, improving fluid and electrolyte balance, weaning off parenteral nutrition and improving surgical recovery. Pivotal trials and regulatory approvals are now in process.

ANTECEDENTES: Las ostomías y las fístulas entero-atmosféricas de alto débito son causas frecuentes de insuficiencia intestinal y pueden precisar nutrición parenteral (NP) y una hospitalización prolongada. Se sabe que la reinfusión del quimo perdido en el intestino distal es beneficiosa, pero su práctica se ha visto limitada porque la reinfusión manual es desagradable, laboriosa y no hay dispositivos disponibles. Se presenta un nuevo dispositivo para reinfundir el quimo de forma fácil y eficiente, junto con los primeros datos en humanos. MÉTODOS: El dispositivo constaba de una bomba centrífuga compacta que cabe dentro de una bolsa de ostomía estándar. Esta bomba iba conectada a una sonda intestinal colocada en el intestino distal. La bomba se activa manualmente mediante el acoplamiento magnético de una manivela, que evita el contacto con el efluente y permite efectuar la reinfusión de bolos discontinuos. Se evaluaron factores de seguridad, técnicos y clínicos. RESULTADOS: Después de las pruebas de seguridad microbiológica, se evaluó el dispositivo en 10 pacientes (mediana de tiempo de funcionamiento 39,5 días; total 740 días). Las indicaciones abarcaron la paliación de pérdidas cuantiosas (n = 8), la dependencia de NP (n = 5) y la rehabilitación intestinal antes de la cirugía (n = 10). La reinfusión se toleró bien utilizando bolos repetidos de ~200 ml, y no hubo efectos adversos graves relacionados con el dispositivo. Los beneficios clínicos incluyeron la reanudación de la dieta oral, el cese de la NP (4/5 pacientes), la corrección de trastornos electrolitos y de las enzimas hepáticas y el alta hospitalaria (6/10). De los 7 pacientes en los que se reconstruyó el tránsito digestivo, uno experimentó un íleo postoperatorio. CONCLUSIÓN: Se ha desarrollado un nuevo dispositivo de reinfusión de quimo que ha demostrado su seguridad y beneficios potenciales para paliar pérdidas cuantiosas, restaurar el equilibrio hidroelectrolítico, retirar la NP y mejorar la recuperación quirúrgica. Están en marcha los ensayos clínicos pivotales y el proceso para obtener los permisos reglamentarios.

Human adult neurogenesis across the ages: An immunohistochemical study.

AIMS: Neurogenesis in the postnatal human brain occurs in two neurogenic niches; the subventricular zone (SVZ) in the wall of the lateral ventricles and the subgranular zone (SGZ) of the hippocampus. The extent to which this physiological process continues into adulthood is an area of ongoing research. This study aimed to characterize markers of cell proliferation and assess the efficacy of antibodies used to identify neurogenesis in both neurogenic niches of the human brain. METHODS: Cell proliferation and neurogenesis were simultaneously examined in the SVZ and SGZ of 23 individuals aged 0.2-59 years, using immunohistochemistry and immunofluorescence in combination with unbiased stereology. RESULTS: There was a marked decline in proliferating cells in both neurogenic niches in early infancy with levels reaching those seen in the adjacent parenchyma by 4 and 1 year of age, in the SVZ and SGZ, respectively. Furthermore, the phenotype of these proliferating cells in both niches changed with age. In infants, proliferating cells co-expressed neural progenitor (epidermal growth factor receptor), immature neuronal (doublecortin and beta III tubulin) and oligodendrocytic (Olig2) markers. However, after 3 years of age, microglia were the only proliferating cells found in either niche or in the adjacent parenchyma. CONCLUSIONS: This study demonstrates a marked decline in neurogenesis in both neurogenic niches in early childhood, and that the sparse proliferating cells in the adult brain are largely microglia.

Mid-gestational maternal cardiovascular profile in preterm and term pre-eclampsia: a prospective study.

OBJECTIVE: Pre-eclampsia (PE) is associated with maternal cardiac remodelling and biventricular diastolic dysfunction. Preterm PE alone can also be associated with severe left ventricular hypertrophy and biventricular systolic dysfunction. The aim of this study was to assess whether the maternal cardiovascular profile at mid-gestation in nulliparous normotensive women differs in women destined to develop preterm PE versus those who will develop PE at term. DESIGN: Prospective study. SETTING: Tertiary referral university centre. POPULATION: A total of 269 women, including 152 at increased risk of developing PE as determined by mid-gestational uterine artery Doppler assessment. METHODS: Women underwent blood pressure profiling, echocardiography, cardiac tissue Doppler and strain rate analysis at 20-23 weeks of gestation. MAIN OUTCOME MEASURES: Mid-gestational cardiovascular profile in women with normal pregnancy and those that subsequently developed preterm or term PE. RESULTS: Pre-eclampsia subsequently developed in 46 women, including 18 with preterm PE. Women who subsequently developed PE, irrespective of gestation, had evidence of left ventricular concentric remodelling (33%) which was not found in the control women (P < 0.0001). Only women who developed preterm PE exhibited a high resistance-low volume haemodynamic state at mid-gestation. The latter group also had evidence of left ventricular diastolic or systolic dysfunction (33%) and segmental impaired myocardial relaxation (72%). CONCLUSIONS: Asymptomatic cardiac diastolic dysfunction is evident at mid-gestation in women who subsequently develop preterm PE but not in those who develop term PE. These cardiac findings are useful in understanding the pathophysiology of PE and corroborate the concept that PE is not a single disorder, but a cluster of symptoms that have several different aetiologies.

Identification of the gene FMR2, associated with FRAXE mental retardation.

Five folate-sensitive fragile sites have been characterized at the molecular level (FRAXA, FRAXE, FRAXF, FRA16A and FRA11B). Three of them (FRAXA, FRAXE and FRA11B) are associated with clinical problems, and two of the genes (FMR1 in FRAXA and CBL2 in FRA11B) have been identified. All of these fragile sites are associated with (CCG)n/(CGG)n triplet expansions which are hypermethylated beyond a critical size. FRAXE is a rare folate sensitive fragile site only recently recognized. Its cytogenetic expression was found to involve the amplification of a (CCG)n repeat adjacent to a CpG island. Normal alleles vary from 6 to 25 copies. Expansions of greater than 200 copies were found in FRAXE expressing males and their FRAXE associated CpG island was fully methylated. An association of FRAXE expression with concurrent methylation of the CpG island and mild non-specific mental handicap in males has been reported by several groups. We now report the cloning and characterization of a gene (FMR2) adjacent to FRAXE. Elements of FMR2 were initially identified from sequences deleted from a developmentally delayed boy. We correlate loss of FMR2 expression with (CCG)n expansion at FRAXE, demonstrating that this is a gene associated with the CpG island adjacent to FRAXE and contributes for FRAXE-associated mild mental retardation.

Fragile X syndrome without CCG amplification has an FMR1 deletion.

We describe a patient with typical clinical features of the fragile X syndrome, but without cytogenetic expression of the fragile X or an amplified CCG trinucleotide repeat fragment. The patient has a previously uncharacterized submicroscopic deletion encompassing the CCG repeat, the entire FMR1 gene and about 2.5 megabases of flanking sequences. This finding confirms that the fragile X phenotype can exist, without amplification of the CCG repeat or cytogenetic expression of the fragile X, and that fragile X syndrome is a genetically homogeneous disorder involving FMR1. We also found random X-inactivation in the mother of the patient who was shown to be a carrier of this deletion.

A missense mutation in the neuronal nicotinic acetylcholine receptor alpha 4 subunit is associated with autosomal dominant nocturnal frontal lobe epilepsy.

Epilepsy affects at least 2% of the population at some time in their lives. The epilepsies are a heterogeneous group of disorders, many with an inherited component. Although specific genes have been identified in a few rare diseases causing seizures as part of a more diffuse brain disorder, the molecular pathology of the common idiopathic epilepsies is still unknown. Linkage has been reported for some generalised epilepsy syndromes, but only very recently for familial partial epilepsy syndromes. Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is a partial epilepsy causing frequent, violent, brief seizures at night, usually beginning in childhood. The gene for ADNFLE maps to chromosome 20q13.2-q13.3 in one large Australian kindred. The neuronal nicotinic acetylcholine receptor alpha 4 subunit (CHRNA4) maps to the same region of 20q (ref. 12) and the gene is expressed in all layers of the frontal cortex. We screened affected family members for mutations within CHRNA4 and found a missense mutation that replaces serine with phenylalanine at codon 248, a strongly conserved amino acid residue in the second transmembrane domain. The mutation is present in all 21 available affected family members and in four obligate carriers, but not in 333 healthy control subjects.

Localization of a gene for autosomal dominant nocturnal frontal lobe epilepsy to chromosome 20q 13.2.

The epilepsies comprise a group of syndromes that are divided into generalized and partial (focal) types. Familial occurrence has long been recognized but progress in mapping epilepsy genes has been slow except for rare cases where the inheritance is easily determined from classical genetic studies. Linkage is established for three generalized syndromes: the EBN1 and EBN2 genes for benign familial neonatal convulsions (BFNC) map to chromosomes 20q and 8q (refs 2-5), the EPM1 gene for Unverricht-Lundborg disease maps to 21q (ref. 6) and the gene for the northern epilepsy syndrome maps to 8p (ref. 7). A claim for linkage of the EJM1 gene for the common generalized syndrome of juvenile myoclonic epilepsy to 6p is currently in dispute. Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) was recently described in five families. We now report the chromosomal assignment, to 20q13.2, for the gene for ADNFLE in one large Australian kindred with 27 affected individuals spanning six generations.

Cloning of the sulphamidase gene and identification of mutations in Sanfilippo A syndrome.

Sanfilippo A syndrome is one of four recognised Sanfilippo sub-types (A, B, C and D) that result from deficiencies of different enzymes involved in the lysosomal degradation of heparan sulphate; patients suffer from severe neurological disorders. The Sanfilippo syndrome sub-types are also known as mucopolysaccharidosis (MPS) type III (MPS-IIIA, B, C and D), and are part of the large group of lysosomal storage disorders. Each of the MPS-III types is inherited as an autosomal recessive disorder with considerable variation in severity of clinical phenotype. The incidence of Sanfilippo syndrome has been estimated at 1:24,000 in The Netherlands with MPS IIIA (MIM #252900) the most common. MPS-IIIA is the predominant MPS-III in the United Kingdom, and has a similar high incidence to that found in The Netherlands (E. Wraith, personal communication). There is a particularly high incidence of a clinically severe form of MPS-IIIA in the Cayman Islands with a carrier frequency of 0.1 (ref. 4). Due to the mild somatic disease compared to other MPS disorders there is difficulty in diagnosing mild cases of MPS-III, hence Sanfilippo syndrome may be underdiagnosed, especially in patients with mild mental retardation. Here, we report the isolation, sequence and expression of cDNA clones encoding the enzyme sulphamidase (EC 3.10.1.1). In addition, we report the chromosomal localisation of the sulphamidase gene as being 17q25.3. An 11-bp deletion, present in sulphamidase cDNA from two unrelated Sanfilippo A patients, is described.

Febrile seizures and generalized epilepsy associated with a mutation in the Na+-channel beta1 subunit gene SCN1B.

Febrile seizures affect approximately 3% of all children under six years of age and are by far the most common seizure disorder. A small proportion of children with febrile seizures later develop ongoing epilepsy with afebrile seizures. Segregation analysis suggests the majority of cases have complex inheritance but rare families show apparent autosomal dominant inheritance. Two putative loci have been mapped (FEB1 and FEB2), but specific genes have not yet been identified. We recently described a clinical subset, termed generalized epilepsy with febrile seizures plus (GEFS+), in which many family members have seizures with fever that may persist beyond six years of age or be associated with afebrile generalized seizures. We now report linkage, in another large GEFS+ family, to chromosome region 19q13.1 and identification of a mutation in the voltage-gated sodium (Na+)-channel beta1 subunit gene (SCN1B). The mutation changes a conserved cysteine residue disrupting a putative disulfide bridge which normally maintains an extracellular immunoglobulin-like fold. Co-expression of the mutant beta1 subunit with a brain Na+-channel alpha subunit in Xenopus laevis oocytes demonstrates that the mutation interferes with the ability of the subunit to modulate channel-gating kinetics consistent with a loss-of-function allele. This observation develops the theme that idiopathic epilepsies are a family of channelopathies and raises the possibility of involvement of other Na+-channel subunit genes in febrile seizures and generalized epilepsies with complex inheritance patterns.

Mutant GABA(A) receptor gamma2-subunit in childhood absence epilepsy and febrile seizures.

Epilepsies affect at least 2% of the population at some time in life, and many forms have genetic determinants. We have found a mutation in a gene encoding a GABA(A) receptor subunit in a large family with epilepsy. The two main phenotypes were childhood absence epilepsy (CAE) and febrile seizures (FS). There is a recognized genetic relationship between FS and CAE, yet the two syndromes have different ages of onset, and the physiology of absences and convulsions is distinct. This suggests the mutation has age-dependent effects on different neuronal networks that influence the expression of these clinically distinct, but genetically related, epilepsy phenotypes. We found that the mutation in GABRG2 (encoding the gamma2-subunit) abolished in vitro sensitivity to diazepam, raising the possibility that endozepines do in fact exist and have a physiological role in preventing seizures.

Altered activity of pain processing brain regions in association with hip osteoarthritis.

Hip osteoarthritis (OA) is characterized by chronic pain, but there remains a mismatch between symptoms and radiological findings. Recently, brain connectivity has been implicated in the modulation of chronic peripheral pain, however its association with perceived pain in hip OA is not understood. We used resting-state functional magnetic resonance imaging (fMRI) to examine functional connectivity associated with pain in hip OA patients. Thirty participants with hip OA and 10 non-OA controls were recruited. Using the visual analogue scale (VAS), pain scores were obtained before and after performing a painful hip activity. All participants underwent 3.0 T resting-state fMRI, and functional connectivity of brain regions associated with pain was determined and compared between participants, and before and after hip activity. Relative to controls, functional connectivity between the secondary somatosensory cortex and left posterior insula was increased, and functional connectivity between the bilateral posterior insula and motor cortices was significantly decreased in hip OA participants. In response to painful hip activity, functional connectivity increased between the thalamus, periaqueductal grey matter and brainstem. Functional connections between brain regions associated with pain are altered in hip OA patients, and several connections are modulated by performing painful activity. Unique lateralization of left posterior insula and linked brain functional connectivity patterns allows assessment of pain perception in hip OA providing an unbiased method to evaluate pain perception and pain modulation strategies.

Prevalence of maternal cardiac defects in women with high-resistance uterine artery Doppler indices.

OBJECTIVES: To compare the prevalence of previously undiagnosed cardiac structural abnormalities in pregnant women with normal- and high-resistance midtrimester uterine artery Doppler indices. METHODS: Maternal transthoracic echocardiography was undertaken in asymptomatic pregnant women after uterine artery Doppler screening for pre-eclampsia at 21-23 weeks' gestation. Women with a mean uterine artery pulsatility index above the 90(th) centile (1.25) for the local population (multiethnic, socially diverse and migrant) were considered to have high-resistance uteroplacental blood flow indices. The prevalence of newly diagnosed cardiac structural defects in these women was recorded. RESULTS: A total of 491 women underwent echocardiography, of whom 205 had high-resistance uterine artery blood flow indices. There were nine previously undiagnosed, functionally significant cardiac defects in the high-resistance uterine artery blood flow group and only one, functionally insignificant cardiac defect in the normal-resistance group (P = 0.005; relative risk = 12.6, 95% confidence interval, 1.60-98.34). Multiple regression analysis demonstrated that both uterine artery Doppler indices (P = 0.024) and ethnicity (P = 0.048) contributed independently towards a higher prevalence of cardiac defects. CONCLUSIONS: The prevalence of previously undiagnosed maternal cardiac structural abnormalities is significantly increased in women with high midtrimester uterine artery Doppler resistance indices. This observation has important consequences for the current and long-term medical care provided to these patients. Detailed maternal cardiac assessment with echocardiography may be required in migrant women with high uterine artery Doppler indices.

Comparing the needs of health professional and peer cancer support group facilitators in an Australian context.

This study explored the perceived needs of health professional and peer facilitators of cancer support groups. Participants were facilitators of support groups affiliated with The Cancer Council Victoria (Australia). Facilitators completed questionnaires assessing their experience of support group facilitation, including training and support needs. Data from health professional and peer facilitators (n= 74) were analysed in this paper. The majority of facilitators (88%) were female; 57% had run their group for more than 3 years, and 47% reported between 11 and 20 people attended each group. Although results showed the characteristics of support groups are broadly similar for peers and professionals, there were some distinct differences in perceived needs. Health professional facilitators were more likely than peers to regard training as valuable and beneficial to their role. In addition, health professionals more frequently reported needing debriefing as well as more difficulty accessing debriefing than cancer peers. This study builds on the small body of literature exploring the experiences of cancer support group facilitators. Given the experiences and needs of health professional and peer facilitators may differ, it may be relevant to tailor training and support so that it meets the needs of both health professionals and cancer peers.

Fragile sites on human chromosomes: demonstration of their dependence on the type of tissue culture medium.

The observation of heritable fragile sites on human chromosomes prepared for lymphocyte cultures has been shown to depend on the type of tissue culture medium in which the lymphocytes are grown. The sites are observed at a much greater frequency when medium 199 is used than when RPMI 1640, Ham's F10, Eagle's (basal), and CMRL 1969 are used. One site on the X chromosome is of clinical significance in that it is a marker for X-linked mental retardation.

Fragile sites in chromosomes: possible model for the study of spontaneous chromosome breakage.

The tissue culture condition that is required for the type of chromosome breakage seen at most fragile sites, namely, the absence of folic acid and thymidine in the medium, greatly enhanced micronucleus formation in proliferating lymphocyte cultures from normal individuals. This suggests that chromosome breakage at fragile sites and the apparently spontaneous damage that gives rise to micronuclei are controlled by the same mechanism.

Genetic length of a human chromosomal segment measured by recombination between two fragile sites.

Two families were studied in which the same homolog of chromosome pair 10 expressed both the fragile sites on the long (q) arm at 10q23 and 10q25. Recombination between the fragile sites was observed in 3 of the 27 offspring in whom it could occur. The genetic length of chromosome between the fragile sites was 11 female centimorgans within a 95 percent probability interval of 4 to 28 centimorgans. This estimate of genetic length is comparable to those obtained with other methods.

Fragile sites at 16q22 are not at the breakpoint of the chromosomal rearrangement in AMMoL.

There is much speculation about fragile sites on human chromosomes predisposing to specific chromosome rearrangements seen in cancer. Acute myelomonocytic leukemia is characterized by neoplastic chromosome rearrangements involving band 16q22 in patients who carry the rare fragile site at 16q22. This specific leukemic breakpoint is within the metallothionein gene cluster, which is here shown to be proximal to the rare fragile site (FRA16B) and to a common fragile site (FRA16C) in this region. Hence neither of these fragile sites are at the breakpoint in this leukemic chromosomal rearrangement.