Impact of stents on urological complications and health care expenditure in renal transplant recipients: results of a prospective, randomized clinical trial.

PURPOSE: We performed a randomized, prospective trial to compare the incidence of early urological complications and health care expenditures in renal transplant recipients with or without ureteral stenting. MATERIALS AND METHODS: Patients receiving a renal transplant at a single center were randomized preoperatively to undergo Double-J stent or no-stent ureterovesical anastomosis from November 1998 to October 2001. Early urological mechanical complications were recorded, including urinary leakage or obstruction, or urinary tract infections within 3 months of transplantation. Direct health care costs associated with stenting, urological complications and urinary tract infection management were also collected. RESULTS: A total of 201 patients were randomized to a stent (112) and a no-stent (89) group. In the no-stent group 11 patients received a stent due to intraoperative findings and were excluded from study. At 3 months there were significantly more cases of urinary leakage (8.9% vs 0.9%, p <0.008) and ureteral obstruction (7.7 % vs 0%, p <0.004) in the no-stent than in the stent group. Mean time of stent removal was 74.3 days. A significant increase in urinary tract infections was observed when stent was left greater than 30 days after transplantation compared to the rate in the no-stent group (p <0.02). An additional cost of 151 UK pounds per patient was incurred in the no-stent group vs the stent group. CONCLUSIONS: Using a ureteral stent at renal transplantation significantly decreases the early urinary complications of urine leakage and obstruction. However, there is a significant increase in urinary tract infections, primarily beyond 30 days after transplantation. Stent removal within 4 weeks of insertion appears advisable.

Long-term results of the antegrade continent enema procedure for constipation in adults.

OBJECTIVE: The aim of this study was to evaluate the long-term results of the Antegrade Continent Enema (ACE) procedure for treating severe constipation in adults. METHODS: Over 10 years 37 ACE conduits were created in 32 patients (median age 35 years, 26 women) with constipation caused by slow transit, obstructed defaecation or both. Conduits were created from the appendix (n = 20, 54%), ileum (n = 10, 27%), neoappendix caecostomy (n = 5, 14%) or colon (n = 2, 5%). Clinical records were retrospectively reviewed to determine outcome. RESULTS: After a median follow up of 36 (range 13-140) months, 28 (88%) required at least one further procedure on a primary conduit, including reversal in 19 (59%). Five patients had a second conduit fashioned, two successfully. Conduit type and constipation cause did not significantly influence the rates of ACE reversal or major revision. Ileal conduits were associated with fewer minor revision procedures for stenosis (1 in 7 patients) than appendix conduits (21 in 20 patients). There was one (3%) serious complication. Satisfactory ACE function was ultimately achieved in 47% of patients, at last follow up. After ACE reversal, 9 (28%) patients underwent formation of an end stoma and 3 patients had a colectomy. CONCLUSIONS: Revision procedures are common, but approximately half of patients can expect satisfactory long-term ACE function. ACE conduit reversal does not preclude subsequent alternative surgical strategies to treat this difficult condition.

Preperitoneal approach to parastomal hernia with coexistent large incisional hernia.

OBJECTIVE: To assess the outcome of preperitoneal mesh repair of complex incisional herniae incorporating a stoma and large parastomal hernia. METHODS: From 1994 to 1998, symptomatic patients who had repair of combined incisional hernia and parastomal hernia were reviewed. Body mass index, co-morbidity, length of hospital stay, patient satisfaction and outcomes were recorded. RESULTS: Ten patients (seven females and three males), mean age 62 (range 48-80) years underwent primary repair. All had significant comorbidities (ASA grade 3) and mean body mass index was 31.1 (range 20-49). Median hospital stay was 15 (range 8-150) days. Complications were of varying clinical significance (seroma, superficial infection, major respiratory tract infection and stomal necrosis). There were no recurrences after a mean follow up of 54 (range 22-69) months. CONCLUSION: The combination of a parastomal hernia and generalised wound dehiscence is an uncommon but difficult problem. The application of the principles of low-tension mesh repair can provide a satisfactory outcome and low recurrence rate. This must be tempered by recognition of the potential for significant major postoperative complication.

Accumulation of calbindin in cortical pyramidal cells with ageing; a putative protective mechanism which fails in Alzheimer's disease.

There is considerable interest in the status of calbindin immunoreactive neurones in Alzheimer's disease (AD) but previous studies have produced widely differing results. Here we describe calbindin neurones in temporal neocortex from 18 severely demented patients with neuropathologically confirmed AD and 13 age and post-mortem delay matched, neurologically normal controls. Calbindin immunoreactive neurones were small and round in layers II-IV, and pyramidal in layers IIIc and V. There were significantly more calbindin positive neurones in controls than in AD (mean+/- SD, for each comparison P < 0.01): superior temporal lobe, AD = 3.32 +/- 2.24, Control (C) = 24.83 +/- 10.8; middle temporal lobe, AD = 3.6 +/- 4.94, C = 26.09 +/- 15.7; inferior temporal lobe, AD 3.69 +/- 3.6, C = 25.25 +/- 16.9. Furthermore, there was an age-related increase in immunopositive neurones in the superior (r2 = 0.37, P = 0.046) and inferior (r2 = 0.75, P = 0.01) temporal gyri in controls. In AD the number of calbindin positive neurones did not change with age. This is the first report of such an age-related increase in controls, and it suggests that this, rather than a decrease in AD, accounts for the overall difference between AD and controls. It is possible that an increase in intraneuronal calbindin protects these cells from degeneration and that failure of such a neuroprotective mechanism is a significant contributory factor in the pathogenesis of AD.

Expression of amyloid precursor protein in human astrocytes in vitro: isoform-specific increases following heat shock.

The beta-amyloid protein deposited in senile plaques and cerebral blood vessels in the Alzheimer's disease brain is derived from the larger transmembrane spanning amyloid precursor protein. The present study investigates the effects of heat shock on the expression and processing of amyloid precursor protein in a normal human fetal astrocytic cell line CC2565 using reverse transcription-polymerase chain reaction, in situ hybridization histochemistry and western blot analysis. Heat shock led to an increase in the messenger RNA encoding Kunitz protease inhibitor isoforms of amyloid precursor protein, which peaked at 4h post-heat shock. This increase was confined to the messenger RNA encoding amyloid precursor protein-751, with a decrease in amyloid precursor protein-770 and no change in amyloid precursor protein-695. This shift in splicing was accompanied by a significant decrease in secreted amyloid precursor protein and an increase in beta-secretase processing within the cell. These findings demonstrate that astrocytes in vitro demonstrate a striking response to heat shock. This is unlikely to be due to a direct action on the promoter region of the gene, since the response is specific for one splice variant; amyloid precursor protein-751 messenger RNA. This increase in expression is further accompanied by a decrease in secretion of amyloid precursor protein, implying a shift in processing towards an intracellular route, possibly via the actions of the beta-secretase enzyme, which is known to be potentially amyloidogenic. Such a mechanism may contribute to amyloidosis in the intact brain in response to cellular stress, such as head injury.

Dopexamine reduces the incidence of acute inflammation in the gut mucosa after abdominal surgery in high-risk patients.

OBJECTIVE: To evaluate the effect of dopexamine on the incidence of acute inflammation in the stomach/duodenum in patients undergoing abdominal surgery > or =1.5 hrs with a minimum of one high-risk criterion. DESIGN: Prospective, randomized, double-blind, placebo-controlled study. This study was conducted as a side arm to a multicenter, multinational study. SETTING: University hospital in an adult intensive care unit. PATIENTS: Thirty-eight patients. INTERVENTIONS: Patients were stabilized with fluid, blood products, and supplementary oxygen to achieve predetermined goals: cardiac index > 2.5 L/min/m2, mean arterial blood pressure of 70 mm Hg, pulmonary arterial occlusion pressure of 10 mm Hg, hemoglobin of 100 g/L, and arterial saturation of 94%. After stabilization, the study drug (either placebo [group A], dopexamine 0.5 microg/kg/min [group B], or dopexamine 2.0 microg/kg/min [group C]) was commenced. The study drug infusion was started 2 to 12 hrs before surgery and infused for 24 hrs after surgery. Estimation of upper gut blood flow was assessed using a gastric tonometer, and gastroscopy with biopsy was performed before surgery (after induction of anesthesia) and 72 hrs after surgery. Comparisons were made between endoscopic findings and histologic proof of acute inflammatory changes. In addition, biopsies were assessed for the presence in the mucosa of mast cells, myeloperoxidase activity, and inducible nitric oxide synthase. MEASUREMENTS AND MAIN RESULTS: Intramucosal pH decreased significantly with time in all three groups (p < .001), reaching the lowest point at the end of surgery. There was no difference among the groups. Endoscopy visualized acute inflammatory changes in 58.3% of group A patients, 46.2% of group B patients, and 53.90% of group C patients after hemodynamic optimization. At 72 hrs, dopexamine-treated patients compared with placebo-treated patients had a significantly lower incidence of gastric and duodenal acute inflammatory changes, as defined by myeloperoxidase activity (37.5% in groups B and C vs. 86% in group A; p < .05). CONCLUSION: Dopexamine in doses of 0.5 and 2.0 microg/kg/min affords significant histologic protection to the upper gastrointestinal tract mucosa 72 hrs after operation in high-risk surgical patients undergoing abdominal surgery.

Expression of mRNAs encoding flip isoforms of GluR1 and GluR2 glutamate receptors is increased in rat hippocampus in epilepsy induced by tetanus toxin.

The messenger RNAs encoding the flip and flop isoforms of the glutamate receptor subunits GluR1 and GluR2 were detected and quantified by in situ hybridization in the hippocampal formation of rats following intrahippocampal injection of tetanus on one side. The mRNAs encoding the flip isoforms of both GluR1 and GluR2 were significantly increased 4 weeks after injection. The GluR1 flip mRNA was significantly elevated only in the dentate gyrus, whereas significant increases in the GluR2 flip mRNA were seen in all hippocampal subfields examined. There were no significant changes in the mRNA encoding the flop isoforms of either GluR1 or GluR2. The significant changes in flip isoform mRNAs occurred on both sides.

Methods to uncover an antibody epitope in the KPI domain of Alzheimer's amyloid precursor protein for immunohistochemistry in human brain.

A novel polyclonal antibody (Ab993), specific for a KPI domain epitope of APP, was characterised for use in immunoprecipitation, Western blotting and immunohistochemistry. Conditioned medium from NTera2/D1 cells was used for immunoprecipitation and Western blots. Paraffin-embedded human brain sections were used for immunohistochemistry. The antibody recognised KPI-containing APP on Western blots after standard solubilisation but immunoprecipitation of soluble APP required reduction with 2-mercaptoethanol followed by alkylation of reduced sulphydryl bonds with sodium iodoacetate. Immunohistochemical staining of human brain sections was significantly enhanced by this pre-treatment. Microwaving of sections also increased immunolabelling, by a mechanism that was additive to reduction and alkylation. Incubation in 80% formic acid did not confer any enhancement of immunoreactivity. Ab993, applied with the methods reported here, is expected to be valuable in investigations of the pathogenesis of Alzheimer's disease to determine the source of the beta-amyloid peptide.

Metabolic and inflammatory responses after laparoscopic and open inguinal hernia repair.

A prospective comparison of metabolic and inflammatory responses after laparoscopic and open inguinal hernia operations was undertaken. There were 10 patients in each group. Plasma levels of cortisol, growth hormone, prolactin, C-reactive protein (CRP) and interleukin-6 (IL-6) were measured preoperatively and at fixed intervals up to 120 h postoperatively. In vitro, endotoxin stimulated whole blood tumour necrosis factor alpha (TNF alpha) was measured in preoperative and 24 h postoperative blood samples. Changes in the plasma levels of cortisol, growth hormone and prolactin showed no statistically significant difference between the groups. No significant change in IL-6 levels were recorded in any group. Changes in CRP levels were significantly higher (P < 0.006) in open hernia patients. Endotoxin stimulated TNF alpha production was suppressed in both groups. The degree of suppression in open hernia patients was significantly higher (P < 0.005). This study has shown that both these operations produce similar stress responses. However, open hernia operation results in a higher acute phase response and induces a greater endotoxin tolerance.

MAL mRNA is induced during the differentiation of human embryonal carcinoma cells into neurons and is also localised within specific regions of the human brain.

We have found that the MAL gene, which encodes a membrane proteolipid expressed during the late stages of T-lymphocyte maturation, is also activated during neuronal differentiation of NTERA2 human embryonal carcinoma cells following induction with retinoic acid. An RT-PCR fragment with a sequence identical to MAL was found amongst 30 cloned DNA fragments corresponding to genes putatively activated during NTERA2 differentiation and isolated using a differential display PCR screen. PCR and Northern blot analysis with a cloned MAL cDNA as a probe confirmed that MAL is not expressed by undifferentiated NTERA2 EC cells, but is expressed, predominantly as a 1.1 kb transcript, within 7 days of retinoic acid-induced differentiation and later in the post-mitotic neurons arising in such cultures. MAL was not expressed in the non-neuronal lineages induced by treatment of NTERA2 cells with the gratuitous inducer hexamethylene bisacetamide. Analysis of cDNA libraries constructed from EC cells, purified neurons and a sub-population of non-neuronal cells (ME311+), confirmed that expression of the MAL gene is activated in the neural lineage of NTERA2 differentiation. Using in situ hybridisation we found that MAL is expressed in the human CNS and especially in grey matter of the cerebral cortex, with less in the cerebellum and the amygdala and little or none in subcortical white matter. In contrast to reports concerning the expression pattern of a rat MAL homologue, MAL was expressed in the human brain predominantly in cell bodies which include neurons, correlating with in vitro data from the NTERA2 line.

Selective loss of cholinergic receptors following unilateral intracortical injection of volkensin.

Experimental lesions and quantitative autoradiography were used to investigate the cellular distribution of neurotransmitter receptors in rats. Lesions were produced by intracortical injections of either volkensin or ricin. However, only the former is retrogradely transported and volkensin treatment causes significant loss of contralateral cortical pyramidal neurones. Binding of [3H]pirenzepine (muscarinic M1 receptors) and [3H]nicotine was reduced in contralateral cortex in volkensin compared with ricin and/or control (uninjected) animals. However, binding of [3H]8-hydroxy-2-(n-dipropylamino)tetralin (5-HT1A receptors), [3H]ketanserin (5-HT2A receptors), and [3H]1,3-dipropylcyclopentylxanthine (adenosine A1 receptors) was unchanged. The most likely explanation for these results is that M1 and nicotinic receptors are present in large numbers on those pyramidal neurones that are lost. The results are discussed in terms of the biology of cortical pyramidal neurones, drugs for Alzheimer's disease, and novel ligands for improving human brain scanning techniques.

Neuronal degeneration by suicide transport following injection of volkensin into rat cerebral cortex.

We have examined the time course of neurodegeneration in subcortical nuclei and other cortical areas known to project to the rat parietal cortex, following unilateral injection of the suicide transport agent, volkensin, into the cortex of one side. Degenerating neurons, visualized by Gallyas silver staining were most prominent 21 days after injection. At this time darkly staining neurons were present in nuclei and areas known to project to the injected cortical area but not in other sites. Affected subcortical nuclei included the ipsilateral ventral thalamus and intralaminar nuclei, the basal nucleus of Meynert and claustrum of the same side, and the dorsal median raphé nucleus of both sides. Within the cortex degenerating pyramidal neurons were visible in the contralateral parietal cortex and in the frontal cortex of the same side. The distribution of degenerating cells is in agreement with the conclusion that only neurons projecting to the injection site were affected. The time course of the appearance of the degeneration and its distribution are in keeping with axonal transport rather than spread by diffusion of the toxin. Neuronal counts in Nissl-stained sections of the contralateral SMI confirmed significant neuronal loss 28 days after injection. In situ hybridization studies using an oligonucleotide probe directed against GAD mRNA and counts of GAD mRNA-positive neurons in the contralateral cortex confirmed that this population of cortical interneurons, which do not project to the injection site, were unaffected.

Mitochondrial DNA mutations in Alzheimer's disease.

Several reports have indicated that point mutations of the mitochondrial DNA (mtDNA) contribute to the pathogenesis of Alzheimer's disease (AD). However, other groups have failed to find similar associations between these mutations and AD. A recent report described a set of mutations in the mtDNA encoded cytochrome oxidase genes which may account for 20% of all AD cases. We screened brain tissue from 65 AD patients for each of these previously reported mtDNA mutations but were unable to find an increased incidence of any of them in our AD sample. However, one patient with a mutation in the APP gene did harbour a novel mtDNA mutation (G to C at position 5705 in the tRNAAsn gene) that might have contributed to the very early onset of dementia in this individual. The role of mtDNA mutations in the pathogenesis of AD remains unclear, but they do not appear to be primary causes but may contribute to the onset of the disease.

Amyloid precursor protein mRNAs in Alzheimer's disease.

Hybridization studies of mRNA link genetic with neurochemical and neuropathological approaches to Alzheimer's disease (AD). Here we review the distribution and abundance of amyloid precursor protein mRNAs in normal and AD-afflicted brains. The expression of apolipoprotein E and presenilin mRNAs are also discussed.

Cortical connections and the pathology of Alzheimer's disease.

The hypothesis that the distribution of neurodegeneration in Alzheimer's disease results from the spread of the pathology via anatomical connections is reviewed in the light of recent advances in knowledge of the connectivity of the cerebral cortex. Current understanding of cortical connections allows a more detailed examination of the distribution of pathology, particularly neurofibrillary tangles, in relation to this hypothesis. In particular, quantitative assessment of corticocortical pathways opens up the possibility of specific testing of the hypothesis. Theoretical considerations are discussed, and a predicted spread of pathology beginning in the olfactory centres of the medial temporal lobe and spreading retrogradely via known pathways is presented.

Individuals with schizophrenia have an increased incidence of the H2R649G allele for the histamine H2 receptor gene.

We have previously described an allelic variant of the human H2R, nominated the H2R649G allele. This allele contains an adenine-->guanidine substitution at base 649, which introduces an additional TaqI restriction endonuclease site into the gene. With this in mind, we have investigated allelic polymorphism of this receptor and its association with schizophrenia. H2R DNA from 47 schizophrenic patients and 46 control subjects was amplified by the polymerase chain reaction (PCR). These PCR products were analyzed by observing TaqI cleavage patterns and single-stranded conformational polymorphisms. It was found that the H2R649G allele was 1.8 times more frequent in the schizophrenic population (chi 2 test P < 0.01). In addition, schizophrenic individuals were 2.8 times more likely to be homozygous for the H2R649G allele than the control population, (chi 2 test P < 0.05). These data place the attributable fraction for possession of the H2R649G allele at 28.4%.

Alteration in brain presenilin 1 mRNA expression in early onset familial Alzheimer's disease.

The expression of the presenilin 1 (PS-1) gene has been investigated by in situ hybridization in early onset familial Alzheimer's disease (FAD), late onset Alzheimer's disease (AD) and normal control brain. Mutations in this gene are responsible for chromosome 14-linked FAD. We have found that presenilin 1 mRNA is present throughout the human brain with a distribution consistent with both a glial and neuronal localization. The in situ hybridization pattern was similar for the controls, the early onset FAD cases and the late onset AD cases. However, one of the two forms of the mRNA for PS-1, the long form (which contains a sequence encoding a four amino acid (VRSQ) insert at its 5' end) was significantly reduced in early onset FAD brain compared with late onset AD. We suggest that this long transcript may alter the normal pathway for processing of amyloid precursor protein, the protein which appears to be central in the pathogenesis of AD.

Allelic variations of the human histamine H2 receptor gene.

The gene encoding the human histamine H2 receptor (H2R) has previously been cloned and sequenced from gastric cDNA. Following PCR amplification of a fragment of the H2R gene from total human DNA, three single nucleotide base substitutions were observed and confirmed when compared with the previously published sequence. One of these base changes introduces an additional TaqI restriction endonuclease site in the coding portion of the gene. PCR amplification of human H2R gene fragments followed by cleavage with TaqI demonstrated the existence of allelic variation of the human H2R gene.