Cyanotic Congenital Heart Disease Modes of Presentation and Prenatal Detection

Prenatal detection of structural congenital heart disease (CHD) optimises cardiovascular stability pre-operatively and post-operative outcomes. We compared prenatal detection rates of critical CHD in units offering universal fetal anomaly scans with those offering imaging to selected women. One hundred and thirteen infants met inclusion criteria. The overall pre-natal detection rate for critical CHD was 57% of liveborn infants. It was 71% (57/80) in hospitals who offered a universal anomaly scan and 29% (9/31) in centres offering a limited service. Postnatal diagnosis was associated with PICU admission (p=0.016) and preoperative mechanical ventilation (p=0.001). One-year mortality was 10 fold higher in the postnatally diagnosed group 15% vs 1.55% (p=0.0066). There is a significant disparity between centres offering universal anomaly versus selective screening. Prenatal detection confers advantage in terms of pre-operative stability and one year survival. Failure to deliver an equitable service exposes infants with CHD to avoidable risk.

Practice and documentation of palliative sedation: a quality improvement initiative

BACKGROUND

Palliative sedation (ps), the continuous use of sedating doses of medication to intentionally reduce consciousness and relieve refractory symptoms at end of life, is ethically acceptable if administered according to standards of best practice. Procedural guidelines outlining the appropriate use of ps and the need for rigorous documentation have been developed. As a quality improvement strategy, we audited the practice and documentation of ps on our palliative care unit (pcu).

METHODS

A pharmacy database search of admissions in 2008 identified, for a subsequent chart review, patients who had received either a continuous infusion of midazolam (≥10 mg/24 h), regular parenteral dosing of methotrimeprazine (≥75 mg daily), or regular phenobarbital. Documentation of the decision-making process, consent, and medication use was collected using a data extraction form based on current international ps standards.

RESULTS

Interpretation and comparison of data were difficult because of an apparent lack of a consistent operational definition of ps. Patient records had no specific documentation in relation to ps initiation, to clearly identified refractory symptoms, and to informed consent in 60 (64.5%), 43 (46.2%), and 38 (40.9%) charts respectively. Variation in the medications used was marked: 54 patients (58%) were started on a single agent and 39 (42%), on multiple agents. The 40 patients (43%) started on midazolam alone received a mean daily dose of 21.4 mg (standard deviation: 24.6 mg).

CONCLUSIONS

The lack of documentation and standardized practice of ps on our pcu has resulted in a quality improvement program to address those gaps. They also highlight the importance of conducting research and developing clinical guidelines in this area.

A retrospective review of specialist palliative care involvement in motor neurone disease

The provision of specialist palliative care to Irish patients suffering from motor neurone disease has not been described in the literature. The purpose of this study was to characterize the care provided at a Dublin hospice. Consecutive referrals between 1st January 1999 and 31st December 2008 (n=72) were reviewed. At the time of data collection, 61 (84.7%) were deceased, 9 (12.5%) were alive and the status of 2 (2.7%) was unknown. At first assessment, 48 (66%) had bulbar symptoms and 35 (49%) had respiratory symptoms, 50 (70%) were receiving Riluzole, 25 (35%) had a feeding tube and 13 (18%) were using non-invasive positive pressure ventilation (NIPPV). Median survival from the point of referral was 7 months (95% CI 4.5-9.4). Of the 61 deceased patients, 22 (36%) died at home, 22 (36%) died in the inpatient unit, 9 (15%) died in hospital and 8 (13%) died in a nursing home.

The variations in symptom clusters related to well-being in palliative care patients during the final weeks of life

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Background: The purpose of this study was to determine whether the relationships between symptoms and well-being, as experienced by palliative care patients, changed as patients approached death. Methods: Data were extracted from a database that included Edmonton Symptom Assessment System scores collected from palliative care patients on Day 7 of Weeks 5 (n=123), 2 (n=115), and 1 (n=113) prior to death between 1995 and 2000. The model contained 18 effect parameters. Based on standard sample size requirements for structural equation modeling of 10 cases per indicator variable, the study was adequately powered for all three time points. The majority of patients had advanced cancer and were receiving care in either a tertiary palliative care or hospice setting. All participants had Folstein Mini- Mental Status Examination scores of 22 or higher at the time of original data collection. A causal model, based primarily on clinical discussions, linking pain, anxiety, nausea, shortness of breath, drowsiness, loss of appetite, tiredness, depression, and well-being was proposed. The model was tested against the data from all three time points, using LISREL, version 8.7.2s. Results: The model fit the data for all time points, but was revised slightly based on the modification indices. The final Goodness of Fit Test values were χ2= 4.2 (d.f.=8, p=.84), χ2= 13.3 (d.f.=9, p=.15), and χ2= 5.5 (d.f.=9, p=.79) respectively. With respect to tiredness, depression and well-being, the model explained at least 70% of the variance at Week 5, between 57% and 83% of the variance at Week 2, and 42% to 58% of the variance in Week 1. Nausea was unimportant in all of the models. The two strongest effects, persisting over all three time periods, were those linking anxiety to depression, and drowsiness to tiredness, reflecting strong stability in patient rankings even as health declined and treatment changed. Conclusions: The symptom clusters in this study changed over time, in disagreement with existing research that assumes the relationships between symptoms within symptom clusters remain stable. An improved understanding of alterations in symptom clusters may contribute to improved control of patient comfort, quality of life, and quality of death.

No significant financial relationships to disclose.

Laryngopharyngeal reflux in patients with symptoms of gastroesophageal reflux disease

Laryngopharyngeal reflux (LPR) has been extensively studied in patients with laryngeal signs and symptoms, gastroesophageal reflux being identified in approximately 50%. Few studies have investigated the incidence and significance of LPR in GERD patients. Two-hundred and seventy-six consecutive patients referred with symptoms of gastroesophageal reflux had dual probe 24 h pH, esophageal manometry, GERD and ENT questionnaires. LPR was defined as at least three pharyngeal reflux events less than pH 5.0 with corresponding esophageal reflux, but excluding meal periods. Fourty-two percent of patients were positive for LPR on 24 h pH monitoring and 91.3% corresponded with an abnormal esophageal acid score. Distal esophageal acid exposure was significantly greater (P < 0.001) in patients with LPR but symptoms of GERD and regurgitation scores showed no significant differences between patients with positive and negative LPR on 24 h pH. There was no significant difference between the incidence of LPR in patients with or without laryngeal symptoms. There is a high incidence of LPR in patients with GERD but its significance for laryngeal symptoms is tenuous. Fixed distance dual probe pH monitoring allows documentation of conventional esophageal reflux and LPR.

Intrapartum assessment of fetal well-being: any role for a fetal admission test?

OBJECTIVE

To determine whether the fetal admission test is predictive of intrapartum complications.

METHODS

We studied the fetal heart rate tracings of women in spontaneous labor at 37-42 weeks' gestation from 1 November 2001 to 31 March 2002. The study population was subdivided based on reactivity defined as > or = 15 beats/min for > or = 15 s, reactivity redefined as > or = 10 beats/min for > or = 10 s, variability, presence of late and/or variable decelerations, and reassuring fetal admission test; and compared for various labor outcome variables. Student's t test, the chi2 test and Fisher's exact test were used for analysis.

RESULTS

A total of 426 women met our inclusion criteria. There were no differences between groups when compared for maternal age, parity, gestational age, birth weight, labor analgesia and length of labor. Irrespective of the definition of reactivity, women with a non-reactive fetal admission test were more likely to be delivered by Cesarean section, to have fetal distress resulting in Cesarean section and to have a longer neonatal hospital stay. In addition, redefining reactivity improved the specificity, positive and negative predictive values, accuracy, relative risk and likelihood ratio with regard to development of fetal distress. Similar results were obtained when variability and decelerations were used as criteria for comparisons.

CONCLUSION

The fetal admission test is useful in predicting the absence of intrapartum fetal distress irrespective of the criterion used for evaluation. Redefined reactivity appears to be most predictive of intrapartum fetal distress.

Quantitative comparison of expression with adeno-associated virus (AAV-2) brain-specific gene cassettes

This study compared a range of mammalian CNS expression cassettes in recombinant adeno-associated virus (AAV-2) vectors using strong endogenous promoter sequences, with or without a strong post-regulatory element and polyadenylation signal. Changes in these elements led to transgene expression varying by over three orders of magnitude. In experiments conducted in primary cell culture and in >100 stereotactically injected rats, we observed highly efficient and stable (>15 months) gene expression in neurons and limited expression in glia; the highest expression occurred with endogenous, nonviral promoters such as neuron-specific enolase and beta-actin. The packaging size of AAV-2 was maximized at 5.7 kb without impairing gene expression, as judged by direct comparison with a number of smaller AAV-2 constructs. The genomic insert size and titer were confirmed by Southern blot and quantitative PCR, and infectivity was tested by particle titer using ELISA with a conformation-dependent epitope that requires the full intact capsid. A packaging and purification protocol we describe allows for high-titer, high-capacity AAV-2 vectors that can transduce over 2 x 10(5) neurons in vivo per microliter of vector, using the strongest expression cassette.

Equianalgesic dose ratios for opioids. a critical review and proposals for long-term dosing

Clinicians involved in the opioid pharmacotherapy of cancer-related pain should be acquainted with a variety of opioids and be skilled in the selection of doses when the type of opioid or route of administration needs changing. The optimal dose should avoid under-dosing or overdosing, both associated with negative outcomes for the patient. Although equianalgesic dose tables are generally used to determine the new doses in these circumstances, the evidence to support the ratios indicated in these tables largely refers to the context of single dose administration. The applicability of these ratios to the setting of chronic opioid administration has been questioned. A systematic search of published literature from 1966 to September 1999 was conducted to critically appraise the emerging evidence on equianalgesic dose ratios derived from studies of chronic opioid administration. There were six major findings: 1) there exists a general paucity of data related to long-term dosing and studies are heterogeneous in nature; 2) the ratios exhibit extremely wide ranges; 3) methadone is more potent than previously appreciated; 4) the ratios related to methadone are highly correlated with the dose of the previous opioid; 5) the ratio may change according to the direction the opioid switch; and 6) discrepancies exist with respect to both oxycodone and fentanyl. Overall, these findings have important clinical implications for clinicians and warrant consideration in the potential revision of current tables. The complexity of the clinical context in which many switches occur must be recognized and also appreciated in the design of future studies.

c-Jun promotes neurite outgrowth and survival in PC12 cells

We investigated the function of c-Jun in PC12 cells by transfecting them with a plasmid containing a c-Jun cDNA transcription cassette. Transfected cells expressed high levels of c-Jun mRNA and protein and demonstrated an increase in both AP-1 DNA binding and gene activation. The c-Jun over-expressing cells showed marked neurite outgrowth but no evidence of spontaneous cell death. In fact, c-Jun over-expressing cells were more resistant to okadaic acid-induced apoptosis. The process outgrowth was not indicative of a full neuronal differentiation response as the transfected PC12 cells did not display action potentials when examined with whole-cell patch-clamping. The phosphorylation of c-Jun on serine 73 appears to be important for this neurite sprouting effect as mutagenesis at this site reduced sprouting whereas a serine 63 mutant tended to increase sprouting. Thus, in PC12 cells c-Jun expression does not induce apoptosis, but rather functions as a neurite outgrowth and neuronal survival signal.

The isolated hypertensive lower oesophageal sphincter: audit in a specialist unit

The hypertensive lower oesophageal sphincter (HLOS) is a distinct clinical entity defined by a lower oesophageal sphincter (LOS) pressure > or = 30mmHg and normal LOS relaxation and oesophageal peristalsis. The clinical, physiological, and radiological details of 27 patients with HLOS diagnosed in a 3-year period were reviewed. The reasons for referral included: gastro-oesophageal reflux disease (GORD) (33%), dysphagia (18.5%), epigastric discomfort (11%), non-cardiac chest pain (15%), globus (7.5%) and other (15%). All patients had manometric evidence of HLOS (Median LOS pressure 30 mmHg, range 25-50 mmHg) and 6 patients (20.7%) had abnormal pH studies. Less than 22% of contrast studies demonstrated an abnormality. There was no change in manometric findings following pharmacological treatment. Two patients underwent oesophagomyotomy and had normal manometry on follow up. We conclude that HLOS mimics a variety of upper gastrointestinal disorders and oesophageal manometry is the gold standard of diagnosis. There was an unexpectedly high incidence of GORD (22%) in this group. The significance and treatment of HLOS is discussed.

Scleral remodeling during the development of and recovery from axial myopia in the tree shrew

PURPOSE

Recent investigations have suggested that scleral thinning in mammalian eyes with axial myopia is a consequence of the loss of scleral tissue, rather than the redistribution of existing tissue as the eye enlarges. The present study investigated whether further changes in the distribution and metabolism of scleral tissue occur during the process of recovery from axial myopia. Scleral glycosaminoglycan (GAG) synthesis and content as well as scleral dry weight changes were monitored as indicators of remodeling in myopic and recovering tree shrew sclerae.

METHODS

Myopia was induced in tree shrews by monocularly depriving them of pattern vision. Some animals then had the occluder removed and were allowed to recover from the induced myopia for periods of 1, 3, 5, 7, and 9 days. Newly synthesized GAGs were radiolabeled in vivo with [(35)S]sulfate. Sulfate incorporation and total GAG content in the sclera was measured through selective precipitation of GAGs from proteinase K digests with alcian blue dye. Dry weights of the sclerae were also determined. Changes in ocular refraction and eye size were monitored using retinoscopy, keratometry, and ultrasonography.

RESULTS

Eyes developing myopia showed a significant reduction in scleral GAG synthesis, particularly in the region of the posterior pole (-36% +/- 7%) compared with contralateral control eyes. Scleral dry weight was also significantly reduced in these eyes (-3.7% +/- 1.2%). In recovering eyes, significant changes in GAG synthesis were apparent after 24 hours of recovery. After 3 days of recovery, significantly elevated levels of GAG synthesis were found (+79% +/- 15%), returning to contralateral control eye values after 9 days of recovery. Interocular differences in scleral dry weight were shown to follow a similar pattern to that observed for GAG synthesis.

CONCLUSIONS

Active remodeling, resulting in either the loss or replacement of scleral tissue and not passive redistribution of scleral tissue, is associated with changes in eye size during both myopia development and recovery. Regulatory changes in scleral metabolism can be rapidly evoked by a change in visual conditions and the direction of regulation is related to the direction of change in eye size.

Symptoms are a poor indication of severity of reflux in Barrett's oesophagus

AIMS: Patients with Barrett's oesophagus have increased acid and duodenogastric reflux and impaired motility compared with non-Barrett's patients with reflux disease. Impaired sensitivity to acid infusion and distension have also been described, but the relationship of this visceral response to symptoms is unclear. A symptom index was used to compare Barrett's and non-Barrett's patients with reflux. METHODS: Patients with reflux (DeMeester score above 14) were studied with 24-h pH monitoring and manometry. An event marker recorded symptom events. An event was positive if it corresponded to a period greater than 10 s within 2 min either side of the drop in pH. The symptom index was calculated as the number of symptoms with pH less than 4/total number of symptoms x 100. RESULTS: Eighteen patients with Barrett's oesophagus were compared with 58 non-Barrett's patients with significant reflux. CONCLUSIONS: Patients with Barrett's oesophagus have a low symptom index compared with non-Barrett's patients with reflux disease. This occurs despite a near 100 per cent increase in acid exposure in the Barrett's group. Symptoms are thus no guide to the severity of reflux in patients with Barrett's oesophagus. Proof of efficacy of therapeutic modalities may need physiological rather than symptom-based confirmation.

Differentiation of mammalian vestibular hair cells from conditionally immortal, postnatal supporting cells

We provide evidence from a newly established, conditionally immortal cell line (UB/UE-1) that vestibular supporting cells from the mammalian inner ear can differentiate postnatally into more than one variant of hair cell. A clonal supporting cell line was established from pure utricular sensory epithelia of H2k(b)tsA58 transgenic mice 2 d after birth. Cell proliferation was dependent on conditional expression of the immortalizing gene, the "T" antigen from the SV40 virus. Proliferating cells expressed cytokeratins, and patch-clamp recordings revealed that they all expressed small membrane currents with little time-dependence. They stopped dividing within 2 d of being transferred to differentiating conditions, and within a week they formed three defined populations expressing membrane currents characteristic of supporting cells and two kinds of neonatal hair cell. The cells expressed several characteristic features of normal hair cells, including the transcription factor Brn3.1, a functional acetylcholine receptor composed of alpha9 subunits, and the cytoskeletal proteins myosin VI, myosin VIIa, and fimbrin. Immunofluorescence labeling and electron microscopy showed that the cells formed complex cytoskeletal arrays on their upper surfaces with structural features resembling those at the apices of normal hair cells. The cell line UB/UE-1 provides a valuable in vitro preparation in which the expression of numerous structural and physiological components can be initiated or upregulated during early stages of mammalian hair cell commitment and differentiation.

Immediate early gene transcription and synaptic modulation

Long-term changes in gene expression appear to be critical to the formation of memory, but little is known about its stimulus- transcription coupling. Numerous studies in the last decade, by focusing on unraveling this signal transduction pathway, have investigated the potential role of the immediate-early genes in this process. The krox family of immediate-early gene proteins are of particular interest because they may be involved in stabilizing the synaptic modifications that underlie hippocampal long-term potentiation (LTP). A potential upstream mediator of krox induction is cyclic AMP-responsive element binding protein (CREB), a posttranslationally activated transcription factor that has been implicated in numerous memory paradigms. In this study we investigated whether the activation of CREB by phosphorylation may have a role in the development of rat perforant- path-stimulated LTP and associated dentate granule cell krox-24 mRNA expression. Contrary to what was expected, we failed to show any difference in the levels of phosphorylated CREB after LTP or following endogenous synaptic facilitation stimulated by novelty. Using these same model systems we also investigated the protein levels of brain- derived neurotrophic factor (BDNF), another immediate-early gene that is induced following a durable form of LTP. However, BDNF protein was not induced within the hippocampus after LTP and was transiently decreased following novel environmental stimulation.

Neuronal death and survival in two models of hypoxic-ischemic brain damage

Two unilateral hypoxic-ischemia (HI) models (moderate and severe) in immature rat brain have been used to investigate the role of various transcription factors and related proteins in delayed neuronal death and survival. The moderate HI model results in an apoptotic-like neuronal death in selectively vulnerable regions of the brain while the more severe HI injury consistently produces widespread necrosis resulting in infarction, with some necrosis resistant cell populations showing evidence of an apoptotic type death. In susceptible regions undergoing an apoptotic-like death there was not only a prolonged induction of the immediate early genes, c-jun, c-fos and nur77, but also of possible target genes amyloid precursor protein (APP751) and CPP32. In contrast, increased levels of BDNF, phosphorylated CREB and PGHS-2 were found in cells resistant to the moderate HI insult suggesting that these proteins either alone or in combination may be of importance in the process of neuroprotection. An additional feature of both the moderate and severe brain insults was the rapid activation and/or proliferation of glial cells (microglia and astrocytes) in and around the site of damage. The glial response following HI was associated with an upregulation of both the CCAAT-enhancer binding protein alpha (microglia only) and NFkappaB transcription factors.

CCAAT-enhancer binding protein alpha is expressed in activated microglial cells after brain injury

Microglial cells play important roles in brain injury and repair and are implicated in diseases such as Alzheimer's disease, Creutzfeldt-Jacob disease, multiple sclerosis, the Aids Dementia Complex and stroke. Despite their importance in neuropathology, the underlying molecular basis for the activation of microglia after brain injury is not understood. We show, using RT-PCR, in situ hybridisation, immunocytochemistry, and electrophoretic mobility shift assay, that the CCAAT-enhancer binding protein alpha (C/EBP alpha), a sequence specific DNA-binding protein, is induced in microglial cells, but not astrocytes or neurons, after hypoxic-ischemic brain injury. These results suggest that C/EBP alpha might regulate gene expression and consequentially have a role in the activation and/or proliferation of microglia following brain injury.

Auditory hair cell precursors immortalized from the mammalian inner ear

Mammalian auditory hair cells are few in number, experimentally inaccessible, and do not proliferate postnatally or in vitro. Immortal cell lines with the potential to differentiate into auditory hair cells would substantially facilitate auditory research, drug development, and the isolation of critical molecules involved in hair cell biology. We have established two conditionally immortal cell lines that express at least five characteristic hair cell markers. These markers are the transcription factor Brn3.1, the alpha 9 subunit of the acetylcholine receptor, the stereociliary protein fimbrin and the myosins VI and VIIA. These hair cell precursors permit functional studies of cochlear genes and in the longer term they will provide the means to explore therapeutic methods of stimulating auditory hair cell regeneration.

Oesophageal motility and digestion of cream liqueurs in combination with common alcohol mixers

When acidic mixers are added to cream liqueur curdling occurs. Oesophageal motility was studied in normal volunteers during ingestion of this mixture and the effect of combining with gastric juice was assessed in a simulated physiological environment. Twenty-four h ambulatory manometry and pH (n = 22) and gastric studies (n = 7) were carried out. There was no detrimental effect on oesophageal motility. The precipitation is rapidly broken down by the digestive process in the stomach.

Subcutaneous clodronate: a study evaluating efficacy in hypercalcemia of malignancy and local toxicity

The logistics of administering intravenous bisphosphonates may be problematic in the care of advanced cancer patients, especially in the home setting. Hypodermoclysis is a convenient method of administering fluid via subcutaneous infusion, presently used in the domiciliary setting. Results of the administration of clodronate via this route are reported.

Dose ratio between morphine and hydromorphone in patients with cancer pain: a retrospective study

Morphine (M) and hydromorphone (HM) are commonly used opioid analgesics for cancer pain. Opioid rotation is often necessary in the event of toxicity and/or inadequate analgesia. Equianalgesic reference tables based on single dose comparisons are possibly inadequate for patients on chronic treatment and developing tolerance. This retrospective study of opioid rotation involving M and HM sought to determine the equianalgesic dose ratio for 91 rotations in 74 consecutively evaluable cancer pain patients. Only rotations involving subcutaneous (s.c.-s.c.) and oral (p.o.-p.o.) routes were evaluated. There were 44 rotations from M-HM (34: s.c.-s.c., 10: p.o.-p.o.) and 47 rotations from HM-M (35: s.c.-s.c., 12: p.o.-p.o.). Expressing all ratios as M/HM, the median dose ratios (lower-upper quartiles) for s.c. and p.o. rotations were 4.92 (4.1-5.9) vs. 5.76 (4.9-5.8) for M-HM (P = 0.28, NS) and 4.0 (3.1-4.8) vs. 3.45 (2.8-4.2) for HM-M (P = 0.4, NS), respectively. Pain intensity, as measured on a visual analogue scale (VASP), showed no significant difference between mean values pre- and post-rotation. A unified overall median dose ratio of 4.29 (3.3-5.3, lower-upper quartiles) was calculated by expressing all of the HM-M dose ratios as M/HM and combining them with the dose ratios for all of the M-HM rotations. This suggests a potency ratio of approximately 4.3:1 between M and HM. When expressed as M/HM for dose ratio comparison, the median dose ratio for all HM-M rotations was 3.7 (2.9-4.5, lower-upper quartiles) vs. 5 (4.2-5.9) for M-HM rotations (P = 0.0001), suggesting that the opioid to which rotation is taking place is more potent than our proposed unified overall median dose ratio of 4.29:1 would predict. Our data suggests that HM is 5 times more potent than M when given second (M-HM), but is only 3.7 times more potent when given first (HM-M). We therefore recommend a ratio of 5 for M/HM in rotating from M to HM and ratio of 3.7 for M/HM when rotating from HM to M in patients exposed to chronic dosing of these opioids. There was no correlation observed between M-HM and HM-M dose ratios and the level of previous opioid dose, in contrast to HM to methadone rotation where the dose ratio was higher in patients receiving higher doses of HM.

Cholecystectomy-induced gastroesophageal reflux: is it reduced by the laparoscopic approach?

OBJECTIVE

The incidence of gastroesophageal reflux and esophagitis increases significantly following cholecystectomy. Laparoscopic technique minimizes the metabolic and mechanical disturbances of cholecystectomy, but there has been no study of its effects on gastroesophageal reflux. The aim of this study was to examine the effect of laparoscopic cholecystectomy on the indices of gastroesophageal reflux.

METHODS

A prospective study was carried out on patients scheduled for cholecystectomy. Informed consent was obtained. Preoperative 24-h pH studies and manometry were performed. Studies were repeated 3 months after surgery. Pathological acid reflux was defined in terms of the DeMeester acid score.

RESULTS

Pre- and postoperative studies were carried out on 28 patients who had open cholecystectomy and on 22 patients who had laparoscopic cholecystectomy. The mean (SEM) DeMeester acid score increased from 14.8 (2.4) to 34.0 (6.7) following open cholecystectomy (p = 0.006) and from 13.9 (2.5) to 28.9 (4.3) following laparoscopic cholecystectomy (p = 0.002). Decrease in mean lower esophageal sphincter pressure in both groups was not significant.

CONCLUSIONS

A significant increase in the incidence of gastroesophageal reflux occurred within 3 months after surgery in both study groups. Despite the less invasive nature of laparoscopic cholecystectomy, the type of surgery did not influence the degree of esophageal dysfunction.

Apoptosis, neurotrophic factors and neurodegeneration

Apoptosis is an active process of cell death characterized by distinct morphological features, and is often the end result of a genetic programme of events, i.e. programmed cell death (PCD). There is growing evidence supporting a role for apoptosis in some neurodegenerative diseases. This conclusion is based on DNA fragmentation studies and findings of increased levels of pro-apoptotic genes in human brain and in in vivo and in vitro model systems. Additionally, there is some evidence for a loss of neurotrophin support in neurodegenerative diseases. In Alzheimer's disease, in particular, there is strong evidence from human brain studies, transgenic models and in vitro models to suggest that the mode of nerve cell death is apoptotic. In this review we describe the evidence implicating apoptosis in neurodegenerative diseases with a particular emphasis on Alzheimer's disease.

Severe opioid toxicity and somatization of psychosocial distress in a cancer patient with a background of chemical dependence

A case of severe opioid toxicity is described in a 52-year-old cancer patient. The patient presented with classical clinical features of central hyperexcitability associated with opioid toxicity: delirium, myoclonus, hallucinations, hyperalgesia, and a possible seizure. This patient had a background of severe psychosocial distress and somatization in addition to a history of benzodiazepine dependence and alcohol abuse. The occurrence of opioid toxicity in this patient highlights the risks of a unidimensional approach to cancer pain, which ignores the non-organic components of pain, such as psychosocial distress, which will not respond to escalating doses of opioid medication.

TrkB expression in dentate granule cells is associated with a late phase of long-term potentiation

Recent studies have demonstrated that the neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are induced in hippocampal neurons following the induction of long-term potentiation (LTP), a model of memory, and that BDNF and NT-3 (but not NGF) can induce LTP-like increases in synaptic efficacy. Receptors for these neurotrophins have been cloned and characterized and we investigated whether LTP alters the expression of two neurotrophin receptors, trkB (BDNF receptor) and trkC (NT-3 receptor) in dentate granule neurons of the hippocampus using in situ hybridization analysis. Results show that trkB is strongly induced in these neurons in an N-methyl-D-aspartate (NMDA) receptor-dependent manner. Moreover, the induction of trkB and trkC mRNAs was attenuated by sodium pentobarbital, which interferes with the durability of LTP. Low-frequency stimulation of the perforant path had no effect on trkB mRNA levels but significantly reduced trkC mRNA in dentate granule cells. Thus, both BDNF and its receptor trkB are induced in granule cells by stimulation that produces durable LTP, suggesting that this neurotrophin and its receptor play an important role in memory formation and may be suitable targets for the development of cognitive-enhancing drugs in the treatment of diseases, such as Alzheimer's.

Loss of Ref-1 protein expression precedes DNA fragmentation in apoptotic neurons

Ref-1 is a bifunctional protein that has been implicated in the transcriptional regulation of AP-1 elements and in DNA repair. To investigate whether Ref-1 is involved in programmed cell death its expression was measured in the 21-day-old rat brain at various time-points following a moderate unilateral hypoxic-ischemic (HI) insult. The CA1 pyramidal cells, which are selectively vulnerable to HI injury, showed a significant decrease in Ref-1 immunoreactivity 48 h-7 days post-insult. This loss of Ref-1 immunoreactivity may contribute to a decrease in endogenous repair activity and the development of apoptosis in the CA1 pyramidal cells.

Cancer pain management

Pain occurs in more than 80% of cancer patients before death. Because of the increase in the frequency of cancer deaths worldwide, it is imperative to address cancer pain as a public health problem. Until recently, educational efforts were focused on treatment issues rather than adequate assessment. The approach to pain intensity as a multidimensional construct has helped in focusing treatments and identifying prognostic factors. Valid tools have been developed that allow multidisciplinary assessment of these prognostic factors and their complex interrelationship with the analgesic response. As a result of increased opioid exposure, patients are currently developing newer toxicities, mostly central excitability including delirium, myoclonus, grand mal seizures, and hyperalgesia. The observation that more than 80% of patients will require alternate routes for opioid delivery before death led to the development of a number of novel and effective alternate routes for delivery. Finally, in recent years it has become evident that some specific pain syndromes need to be addressed using specific assessment and management techniques. Incidental pain, somatization, neuropathic pain, and cancer pain in patients with alcoholism and drug addiction are some of these syndromes.

Trk receptor alterations in Alzheimer's disease

The expression of trk receptors in postmortem normal, Huntington's disease and Alzheimer's disease human brains was investigated using immunohistochemistry, in-situ hybridisation and Western blotting. Alzheimer's disease hippocampi displayed an increase in trkA receptor levels in astrocytes in the CA1 region, some of which were associated with beta-amyloid-positive plaques. Truncated trkB receptors were found in high levels in senile plaques, while the full-length receptor was expressed in glial-like cells in the hippocampus of Alzheimer's disease brains. In-situ hybridisation studies indicated that trk receptor mRNA was also elevated in Alzheimer's. The appearance of trkA and trkB receptors in astrocytes and plaques in Alzheimer's disease might be related to beta-amyloid deposition and could be implicated in the development of Alzheimer's disease.

Temporal relationship between the expression of fos, jun and krox-24 in the guinea pig vestibular nuclei during the development of vestibular compensation for unilateral vestibular deafferentation

Immediately following unilateral vestibular deafferentation (UVD), expression of the c-fos protein increased in both vestibular nucleus complexes (VNCs). By 10 h post-UVD, c-fos proteins were more evident in the bilateral medial vestibular nuclei (MVN), but their expression had decreased in the bilateral superior vestibular nuclei (SVN) and lateral vestibular nuclei (LVN) compared to immediately post-UVD. At 50 h post-UVD, c-fos protein expression was still evident in the bilateral VNC, but had decreased relative to immediately post-UVD. Immediately post-UVD, c-jun protein expression increased in the bilateral VNC, but was more noticeable at 10 h post-UVD. By 50 h post-UVD, c-jun protein expression had decreased markedly throughout the bilateral VNC. The krox-24 protein could not be seen anywhere in the immediate post-UVD condition. However, it was expressed at a low level in the bilateral MVN at 10 h post-UVD; by 50 h post-UVD, this expression had decreased. No evidence of apoptosis was observed following UVD.

Clusterin accumulates in dying neurons following status epilepticus

Clusterin is a protein that has been implicated in cell death and remodelling in a number of different tissues. To further investigate the role of clusterin in nerve cell death its expression was measured in the rat brain at various times after status epilepticus (SE) induced by 1 h of hippocampal stimulation, by using in situ hybridization, immunocytochemistry, and immunoblotting. SE lead to a dramatic time-dependent increase in clusterin mRNA in non-nerve cells resembling astrocytes in the hippocampus beginning after 24 h. There was also an earlier induction of clusterin mRNA in dentate granule cells, that survive SE. Only a low mRNA signal was observed over the CA1 pyramidal cells, which die after SE. In contrast to these mRNA results, massive clusterin-like immunoreactivity was observed in CA1 pyramidal cells and dentate hilar neurons (and both of these neuronal populations die after SE), but not in dentate granule cells. We speculate that astrocytes produce clusterin after SE and that the clusterin is then secreted and taken up by hippocampal neurons destined to die. Thus, the role of clusterin in nerve cell death/ regeneration warrants further investigation.

In situ evidence for DNA fragmentation in Huntington's disease striatum and Alzheimer's disease temporal lobes

To test the hypothesis that apoptosis is involved in human brain neurodegenerative disorders, we investigated whether DNA fragmentation occurs in Alzheimer's disease (AD). Huntington's disease (HD) and Parkinson's disease, as well as in temporal lobe epilepsy, using neurologically normal post-mortem human brain tissue as a control. Using in situ end labelling of DNA, we found evidence of DNA fragmentation in cells in temporal cortex and hippocampus from patients with AD and in striatum from those with HD. In contrast, only scattered DNA fragmentation positive cells were detected in the pial surfaces of some of the neurologically normal human brains. Thus, cells in the HD striatum and AD temporal cortex exhibited DNA fragmentation, suggesting that apoptosis may be involved in these disorders.

Ambulatory oesophageal bile reflux monitoring in Barrett's oesophagus

Bile reflux has been implicated in the pathogenesis of Barrett's oesophagus but evaluation remains difficult. Bilitec 2000 is an ambulatory system that detects bilirubin based on its spectrophotometric properties. Oesophageal bile exposure was evaluated in three groups of patients. Group 1 (n = 11) were normal controls, group 2 (n = 13) were patients with uncomplicated gastro-oesophageal reflux and group 3 (n = 12) were patients with Barrett's oesophagus. Bile reflux was greater in patients with Barrett's mucosa than in controls or those with uncomplicated reflux. This difference was seen in the supine and interdigestive periods. The percentage of time at which gastric pH was greater than 4 and oesophageal pH was above 7 did not differ between the groups. Bilitec 2000 detects greater bile reflux in patients with Barrett's oesophagus. No corresponding gastric or oesophageal alkaline shift is found. This ambulatory bile reflux monitoring system may be a useful tool in clinical practice.

Krox20 may play a key role in the stabilization of long-term potentiation

Long-term potentiation-inducing stimulation of the perforant path was followed in dentate gyrus granule cells by a dramatic increase of mRNA and protein for Krox20, a zinc-finger-containing transcription factor. Induction of Krox20 required stimulation sufficient to induce LTP and was prevented by NMDA antagonists CPP and MK-801, which block LTP induction. Krox20 protein increased within 20 min of tetanization, was maximal between 1 and 8 h, and was still significantly elevated at 24 h after LTP induction. This prolonged appearance is in striking contrast with the more transient induction of the related molecule, Krox24. The elevation in the mRNA for Krox20 and Krox24 was of similar duration, suggesting that the Krox20 protein has a greater stability and may play a key role in the stabilization of long-term potentiation.

Immediate early gene expression associated with the persistence of heterosynaptic long-term depression in the hippocampus

Long-term depression (LTD) of synaptic efficacy is likely to be as important in memory processing as the more well-known long-term potentiation (LTP). The case for LTD serving as a memory mechanism, however, requires that it be shown to persist across days or weeks at least. Here we examined the persistence of heterosynaptic LTD in the medial and lateral perforant path inputs to the dentate gyrus in awake rats and correlated this persistence with the degree of immediate early gene expression as assessed immunohistochemically. Rats were chronically implanted with separate stimulating electrodes in the medial and lateral perforant paths and an extracellular field potential recording electrode in the dentate hilus. After recovery from surgery, either the medial or the lateral perforant path was tetanized with 400-Hz trains, and homosynaptic LTP and heterosynaptic LTD were followed across time. Heterosynaptic LTD was shown to occur readily in awake animals and to persist across days or weeks, depending on the stimulation protocol. The persistence of LTD and LTP was highly correlated within animals. Additional animals, given the same tetanization protocols, showed that the greatest immediate early gene expression occurred following that protocol which consistently gave the longest-lasting LTP and LTD. These data support the proposed role of LTD in memory processing but question whether immediate early genes are important for the persistence of LTP, LTD, or both.

c-fos antisense reduces expression of Krox 24 in rat caudate and neocortex

1. The aim of this study was to investigate the neurochemical effects and measure the anatomical spread of infusion of c-fos antisense (AS) DNA into the striatum. 2. Rats were anesthetized and infused in opposing striata with c-fos AS and c-fos sense (S) DNA. Ten hours later they were injected with apomorphine (2 mg/kg, i.p.) and 20 min later they were overdosed with sodium pentobarbital and their brains either perfused or frozen. Vibratome-cut sections were immunostained for the detection of c-fos, JunB, Krox 24, somatostatin, substance P, dynorphin, tyrosine hydroxylase, and enkephalin. Cryostat-cut sections from the caudate were immunostained for the detection of c-fos, JunB, and Krox 24, as well as in situ hybridization for proenkephalin mRNA. Sections from the globus pallidus were used for the autoradiographic localization of D2 dopamine and A2a adenosine receptors. Sections from the substantia nigra were used for the autoradiographic localization of D1 dopamine and cannabinoid receptors. A second group of rats were injected in opposing striata with biotin-labeled c-fos AS DNA and c-fos S DNA. Ten hours later they were challenged with apomorphine (2 mg/kg, i.p.) and 20 min later brains were either perfused or frozen. Sections from these brains were cut throughout the rostral-caudal extent of the forebrain and the biotin labeled AS DNA was localized. 3. Krox 24 was expressed at high levels on the sense side of the brain in the striatum and overlying neocortex. However, on the AS-injected side there was a reduction in Krox 24 expression in striatum and overlying cortex. The biotin-labeled AS studies confirmed that the striatal infusion spread throughout the dorsal striatum as well as the overlying neocortex. We did not detect any changes in neurotransmitter receptors, neuropeptides, or tyrosine hydroxylase in AS/S-injected rat brains. 4. These results demonstrate that c-fos AS reduces Krox 24 expression in striatal and neocortical neurons but does not change the expression of a number of other proteins involved in basal ganglia function. Whether this effect is due to nonspecific actions of c-fos AS or to its effects on a component of the transduction pathway responsible for basal Krox 24 expression (NMDA receptors?) is unknown.

Immediate-early gene protein expression in neurons undergoing delayed death, but not necrosis, following hypoxic-ischaemic injury to the young rat brain

A unilateral hypoxia-ischaemia (HI) 21-day-old rat preparation was used to assess the effects of HI on the expression of the immediate-early gene proteins (IEGPs) c-Fos/FRAs, Fos B, c-Jun, Jun B, Jun D, Krox 20, Krox 24, and on the mRNA for the neurotrophic factor, brain-derived neurotrophic factor (BDNF). Moderate HI (15 min hypoxia) produced delayed, selective neuronal death and was associated with a rapid induction of c-Fos, Fos B, Jun B, Jun D, and c-Jun proteins, but not Krox 20 protein or BDNF mRNA, in neurons on the side of HI and also a delayed expression of c-Jun (and to a lesser extent c-Fos/FRA's and Fos B) 24-48 h after HI in neurons that underwent delayed neuronal death. Krox 24 showed an initial induction followed by a long-lasting suppression of its expression in regions undergoing cell loss. Severe HI (60 min hypoxia) resulted in seizures and rapid neuronal loss and infarction (necrotic cell death) on the side of HI, and was associated with early induction of c-Fos, Fos B, c-Jun, Jun B, Jun D, Krox 20 and Krox 24 protein and BDNF mRNA in neurons on the non-ligated side of the brain. Fos, c-Jun, Jun B, Jun D and Krox 24, but not Krox 20, Fos B, or BDNF mRNA, were also induced in non-nerve cells on the damaged side of the brain after both moderate and severe HI, and many of these cells appeared to be dividing. Thus, moderate HI induces IEGP's in neurons and non-nerve cells in damaged regions, whereas severe HI induces IEGP's and BDNF in non-damaged regions. c-Jun (and to a lesser extent c-Fos/FRA's) showed a prolonged expression in neurons undergoing delayed, but not necrotic, cell death suggesting that they may be involved in the biochemical cascade that causes selective delayed neuronal death. BDNF was not induced by HI, and therefore, does not appear to play an endogenous neuroprotective role in the CNS.

Neuronal rescue with transforming growth factor-beta 1 after hypoxic-ischaemic brain injury

Transforming growth factor-beta 1 (TGF-beta 1) mRNA is induced from 5 h to 3 days following hypoxic-ischaemic brain injury. Cell death also develops during this time suggesting that extracellular accumulation of this peptide may be involved in the processes that regulate cell loss. We examined the effect of rhTGF-beta 1 (0,2.5, 10,50 ng) injected into the cerebral lateral ventricle of rats 2 h after severe hypoxic-ischaemic brain injury. Histological outcome and B4-isolectin histochemistry were assessed 5 and 2 days, respectively following hypoxia. Treatment with 10 ng TGF-beta 1 reduced the microglia reaction (p < 0.05), the magnitude of neuronal loss (p < 0.01) and the area of cortical infarction (p < 0.05). Exogenous TGF-beta 1 given soon after hypoxic-ischaemic brain injury may have therapeutic potential and act by inhibiting the microglial reaction.

c-fos antisense generates apomorphine and amphetamine-induced rotation

Sodium pentobarbital anaesthetized rats were injected ipsilaterally with an antisense oligonucleotide to c-fos and contralaterally with a sense of oligonucleotide to c-fos in the striatum. Ten hours later they were injected with amphetamine or apomorphine and their behaviour was observed for a further 2 h at which time they were overdosed with anaesthetic and their brains were removed, frozen and processed for Fos and Jun B immunohistochemistry. Rats showed amphetamine- and apomorphine-induced rotation towards the antisense injected striatum. The antisense oligonucleotide also strongly inhibited the amphetamine-induced expression of c-Fos and Jun B in striatal neurones. These results suggest that antisense to c-fos produces a biochemical change in the injected striatum that then, 10 h later, blocks amphetamine- and apomorphine-induced behavioural and biochemical effects.