Immunohistochemistry for CDX2 expression in non-goblet-cell Barrett's oesophagus.

Interest has increased in CDX2 gene expression in oesophageal non-goblet-cell columnar metaplasia as recent investigations indicate such metaplasia possesses neoplastic potential. This study aims to assess expression of the transcription factor CDX2 specifically in non-goblet-cell cardia and fundic oesophageal metaplastic tissue, and to compare the location of CDX2 expression in non-goblet-cell specimens to that in goblet-cell specimens. A total of 43 patient specimens (20 fundic-type metaplasia, 42 cardia-type metaplasia and 18 intestinal metaplasia goblet cell-positive) were examined in this study. These were selected over six months from a patient database using the systematised nomenclature of human and veterinary medicine coding system (SNOMED). CDX2 was detected in patient specimens with an anti-CDX2 mouse monoclonal antibody. The types of mucosa in each specimen were confirmed by haematoxylin and eosin (H&E) staining. Fundic specimens were consistently CDX2-negative (0%). CDX2 expression was distinct in 55% of cardia and 100% of intestinal cases. Nearly all cardia-positive cases displayed focal expression (95.5%) and all intestinal cases displayed diffuse distribution of expression. Almost all cardia- and intestinal-positive specimens demonstrated epithelial expression (95.5% and 100%, respectively). The percentage of cardia-positive specimens with deep tissue expression was lower than in intestinal specimens (31.8% vs. 94.4%, respectively). This study confirms CDX2 as an early marker for Barrett's oesophagus in the absence of goblet cells as expression was noted in cardia metaplasia. CDX2 appears to induce the transformation of the normal oesophageal mucosa to cardia type, which then differentiates to an intestinal type under the influence of gastro-oesophageal reflux disease.

Changes in ventral respiratory column GABAaR ε- and δ-subunits during hibernation mediate resistance to depression by EtOH and pentobarbital.

During hibernation in the 13-lined ground squirrel, Ictidomys tridecemlineatus, the cerebral cortex is electrically silent, yet the brainstem continues to regulate cardiorespiratory function. Previous work showed that neurons in slices through the medullary ventral respiratory column (VRC) but not the cortex are insensitive to high doses of pentobarbital during hibernation, leading to the hypothesis that GABA(A) receptors (GABA(A)R) in the VRC undergo a seasonal modification in subunit composition. To test whether alteration of GABA(A)R subunits are responsible for hibernation-associated pentobarbital insensitivity, we examined an array of subunits using RT-PCR and Western blots and identified changes in ε- and δ-subunits in the medulla but not the cortex. Using immunohistochemistry, we confirmed that during hibernation, the expression of ε-subunit-containing GABA(A)Rs nearly doubles in the VRC. We also identified a population of δ-subunit-containing GABA(A)Rs adjacent to the VRC that were differentially expressed during hibernation. As δ-subunit-containing GABA(A)Rs are particularly sensitive to ethanol (EtOH), multichannel electrodes were inserted in slices of medulla and cortex from hibernating squirrels and EtOH was applied. EtOH, which normally inhibits neuronal activity, excited VRC but not cortical neurons during hibernation. This excitation was prevented by bicuculline pretreatment, indicating the involvement of GABA(A)Rs. We propose that neuronal activity in the VRC during hibernation is unaffected by pentobarbital due to upregulation of ε-subunit-containing GABA(A)Rs on VRC neurons. Synaptic input from adjacent inhibitory interneurons that express δ-subunit-containing GABA(A)Rs is responsible for the excitatory effects of EtOH on VRC neurons during hibernation.

Testosterone restores respiratory long term facilitation in old male rats by an aromatase-dependent mechanism.

Steroidal sex hormones play an important role in the neural control of breathing. Previous studies in our laboratory have shown that gonadectomy in young male rats (3 months) eliminates a form of respiratory plasticity induced by intermittent hypoxia, known as long term facilitation (LTF). Testosterone replenishment restores LTF in gonadectomized male rats, and this is dependent on the conversion of testosterone to oestradiol by aromatase. By middle age (12 months), male rats no longer exhibit LTF of hypoglossal motor output; phrenic LTF is significantly reduced, and this persists into old age. We tested the hypothesis that LTF can be restored in old male rats by administration of testosterone. Intact Fischer 344 rats (>20 months) were implanted with Silastic tubing containing testosterone (T), T plus an aromatase inhibitor (T+ADT), or 5α-dihydrotestosterone (DHT), a form of testosterone not converted to oestradiol. One week post-surgery, LTF of hypoglossal and phrenic motor output was measured. By comparison with control rats, hypoglossal LTF was increased in testosterone-treated rats, with levels approaching that of normal young rats. LTF was not restored in T+ADT or DHT-treated rats. Aromatase levels in hypoglossal and phrenic nuclei did not change with age. As serum testosterone levels did not decline with age, local bioavailability of testosterone in old rats may be a limiting factor in the expression of this form of respiratory plasticity. Our findings suggest that testosterone supplementation could potentially be used to enhance upper airway control in the elderly.

Atypical protein kinase C expression in phrenic motor neurons of the rat.

Atypical protein kinase C (PKC) isoforms play important roles in many neural processes, including synaptic plasticity and neurodegenerative diseases. Although atypical PKCs are expressed throughout the brain, there are no reports concerning their expression in central neural regions associated with respiratory motor control. Therefore, we explored the neuroanatomical distribution of atypical PKCs in identified phrenic motor neurons, a motor pool that plays a key role in breathing. Diaphragm injections of cholera toxin B were used to retrogradely label and identify phrenic motor neurons; immunohistochemistry was used to localize atypical PKCs in and near labeled motor neurons (i.e. the phrenic motor nucleus). Atypical PKC expression in the phrenic motor nucleus appears specific to neurons; aPKC expression could not be detected in adjacent astrocytes or microglia. Strong atypical PKC labeling was observed within cholera toxin B labeled phrenic motor neurons. Documenting the expression of atypical PKCs in phrenic motor neurons provides a framework within which to assess their role in respiratory motor control, including novel forms of respiratory plasticity known to occur in this region.

Differential expression of respiratory long-term facilitation among inbred rat strains.

We tested the hypotheses that: (1) long-term facilitation (LTF) following acute intermittent hypoxia (AIH) varies among three inbred rat strains: Fischer 344 (F344), Brown Norway (BN) and Lewis rats and (2) ventral cervical spinal levels of genes important for phrenic LTF (pLTF) vary in association with pLTF magnitude. Lewis and F344, but not BN rats exhibited significant increases in phrenic and hypoglossal burst amplitude 60min post-AIH that were significantly greater than control experiments without AIH, indicating strain differences in phrenic (98%, 56% and 20%, respectively) and hypoglossal LTF (66%, 77% and 5%, respectively). Ventral spinal 5-HT(2A) receptor mRNA and protein levels were higher in F344 and Lewis versus BN, suggesting that higher 5-HT(2A) receptor levels are associated with greater pLTF. More complex relationships were found for 5-HT(7), BDNF and TrkB mRNA. BN had higher 5-HT(7) and TrkB mRNA versus F344; BN and Lewis had higher BDNF mRNA levels versus F344. Genetic variations in serotonergic function may underlie strain differences in AIH-induced pLTF.

Hypoxic and hypercapnic ventilatory responses in aging male vs. aging female rats.

It is clear that sex hormones impact ventilation. While the effects of the menstrual cycle, pregnancy, testosterone, and progesterone on resting ventilation have been well documented, effects of sex hormones on the hypoxic (HVR) and hypercapnic ventilatory responses (HCVR) are inconclusive. In addition, in no study have systemic sex steroid hormone levels been measured. Age and sex differences in long-term facilitation in response to episodic hypoxia were found in anesthetized rats. The purpose of the present study was to assess the effects of sex and age [young, 3-4 mo; middle age, 12-13 mo; and old, >20 mo] on the HVR and the HCVR of awake rats relative to systemic hormone levels. Based on findings from long-term facilitation studies, we hypothesized that the HVR would be influenced by both sex and age. We found no age-related changes in the HVR or HCVR. However, female rats have a greater HVR than male rats at old age, and at middle age female rats have a greater HCVR than male rats. Additionally, we found no correlation between the minute ventilation/oxygen consumption and the progesterone-to-estrogen ratio during hypoxia or hypercapnia. However, changes in ventilatory responses with age were not similar between the sexes. Thus it is critical to take sex, age, estrous cycle stage, and systemic hormone levels into consideration when conducting and reporting studies on respiratory control.

Radial artery anomaly and its influence on transradial coronary procedural outcome.

BACKGROUND: The transradial approach for percutaneous coronary procedures has the advantage of reduced access site complications but is associated with specific technical challenges in comparison with the transfemoral approach. Transradial procedure failures can sometimes be due to variation in radial artery anatomy. However, data describing such variations are limited. OBJECTIVE: To evaluate the incidence and impact of radial artery anomalies in patients undergoing transradial coronary procedures. METHODS: Retrograde radial arteriography was performed in all patients presenting for a first-time radial procedure. Patient characteristics, radial artery anatomy and procedural outcome were assessed. RESULTS: 1540 consecutive patients were studied, 70.6% male, mean (SD) age 63.6 (11.1) years. The overall incidence of radial artery anomaly was 13.8% (n = 212). 108 (7.0%) patients had a high-bifurcating radial origin, 35 (2.3%) had a full radial loop, 30 (2.0%) had extreme radial artery tortuosity and 39 (2.5%) had miscellaneous anomalies such as radial atherosclerosis and accessory branches. Overall transradial procedural success was 96.8%. Procedural failure was more common in patients with anomalous anatomy than in patients with normal anatomy (14.2% vs 0.9%, p<0.001). Procedural failure in patients with high radial bifurcation, radial loop, severe radial tortuosity and other anomalies was 4.6%, 37.1%, 23.3% and 12.9%, respectively. 15 (1%) vascular complications occurred, all of which were treated conservatively without ischaemic sequelae. CONCLUSION: Anomalous radial artery anatomy is relatively common and is a significant cause of procedural failure. Within each specific anomalous pattern there is a differential procedural failure rate. This has implications for clinical practice and suggests a need for imaging of the radial artery after sheath insertion.

Randomised clinical trial of a laxative alone versus a laxative and a bulking agent after primary repair of obstetric anal sphincter injury.

OBJECTIVE: To compare two postpartum laxative regimens in women who have undergone primary repair of obstetric anal sphincter injury. DESIGN: Randomised controlled trial. SETTING: National Maternity Hospital, Dublin. POPULATION: A total of 147 postpartum women who had sustained anal sphincter injury at vaginal birth. METHODS: Women were randomised to receive either lactulose alone thrice daily for the first three postpartum days followed by sufficient lactulose to maintain a soft stool over the following 10 days (lactulose group, n = 77) or the lactulose regimen combined with a sachet of ispaghula husk daily for the first 10 postpartum days (Fybogel group, n = 70). All patients kept a diary of bowel habit for the first 10 postpartum days and were invited to return for review at 3 months postpartum. MAIN OUTCOME MEASURES: Patient discomfort with first postpartum bowel motion, incidence of postnatal constipation and incontinence and incontinence score in postnatal period. RESULTS: Pain scores were similar in the two treatment groups; but incontinence in the immediate postnatal period was more frequent with the two preparations compared with lactulose alone (32.86% versus 18.18%, P = 0.03). CONCLUSIONS: This study does not support routine prescribing of a stool-bulking agent in addition to a laxative in the immediate postnatal period for women who have sustained anal sphincter injury at vaginal delivery.

Percutaneous closure of an aortic paravalvular leak via the transradial approach.

Percutaneous closure of aortic and mitral paraprosthetic leaks using the Amplatzer occluders (muscular ventricular septal defect occluder) is now a well recognized procedure although as "off label" use. Aortic paravalvular leak closure is usually carried out via transfemoral puncture, but problems with this approach include the need to stop warfarin and the inadequate length of standard delivery sheaths. We report the first case of percutaneous aortic paravalvular leak closure through the radial artery route.

A randomised controlled trial comparing the routine use of an Angio-Seal STS device strategy with conventional femoral haemostasis methods in a district general hospital.

Femoral artery closure devices reduce the time to haemostasis and ambulation. Most district general hospitals (DGHs) now perform day case angiography on site. The purpose of this study was to assess the Angio-Seal self-tightening suture (STS) device in comparison with manual compression in this environment. A prospective randomised controlled trial was undertaken comparing the Angio-Seal STS device with manual pressure recording complications, time from end of procedure and patient satisfaction in a DGH setting. Angiography lists of 206 patients undergoing day case diagnostic cardiac catheterisation with a five French sheath at a DGH were randomised by intention to treat to receive either manual compression or a six French Angio-Seal STS device. Time from sheath removal to mobilisation, complication rate and patient satisfaction were compared. There were no significant differences between the two groups in terms of demographics (manual compression: Angio-Seal; male (%) 58 vs. 57, age (years) 65.4 vs. 66.3, body mass index (kg/m(2)) 27.7 vs. 27.5). Despite randomisation, only 74 of 107 patients in the Angio-Seal group actually had a device deployed. Angio-Seal use was associated with significantly shorter times to mobilisation (87.6 vs. 144.1 min; p < 0.001), significantly less bruising (bruise size at 1 week (28.5 vs. 82.5 cm(3); p < 0.01) and no increase in vascular complications. In addition, patients were more satisfied with Angio-Seal devices in terms of length of immobility. The routine use of Angio-Seal closure devices result in earlier mobilisation, less bruising, increased patient satisfaction with no increase in other complications in comparison to manual pressure.

Retinal projections to the subcortical visual system in congenic albino and pigmented rats.

The primary visual pathway in albino mammals is characterized by an increased decussation of retinal ganglion cell axons at the optic chiasm and an enhanced contralateral projection to the dorsal lateral geniculate nucleus. In contrast to the primary visual pathway, little is known about the organization of retinal input to most nuclei of the subcortical visual system in albino mammals. The subcortical visual system is a large group of retinorecipient nuclei in the diencephalon and mesencephalon. These areas mediate a range of behaviors that include both circadian and acute responses to light. We used a congenic strain of albino and pigmented rats with a mutation at the c locus for albinism (Fischer 344-c/+; LaVail MM, Lawson NR (1986) Development of a congenic strain of pigmented and albino rats for light damage studies. Exp Eye Res 43:867-869) to quantitatively assess the effects of albinism on retinal projections to a number of subcortical visual nuclei including the ventral lateral hypothalamus (VLH), ventral lateral preoptic area (VLPO), olivary pretectal nucleus (OPN), posterior limitans (PLi), commissural pretectal area (CPA), intergeniculate leaflet (IGL), ventral lateral geniculate nucleus (vLGN) and superior colliculus (SC). Following eye injections of the neuroanatomical tracer cholera toxin-beta, the distribution of anterogradely transported label was measured. The retinal projection to the contralateral VLH, PLi, CPA and IGL was enhanced in albino rats. No significant differences were found between albino and pigmented rats in retinal input to the VLPO, OPN and vLGN. These findings raise the possibility that enhanced retinofugal projections to subcortical visual nuclei in albinos may underlie some light-mediated behaviors that differ between albino and pigmented mammals.

Conversion from testosterone to oestradiol is required to modulate respiratory long-term facilitation in male rats.

Sex hormones modulate plasticity in the central nervous system, including respiratory long-term facilitation (LTF), a form of serotonin-dependent respiratory plasticity induced by intermittent hypoxia. Since gonadectomy (GDX) attenuates LTF in male rats, we tested the hypotheses that: (1) testosterone replenishment restores LTF in gonadectomized male rats, and (2) that the conversion of testosterone to oestradiol (under the influence of aromatase) is required for these effects. Intact and sham operated male F344 rats were compared to gonadectomized rats implanted with Silastic tubing containing testosterone (T), T plus an aromatase inhibitor (ADT), or 5alpha-dihydrotestosterone (DHT), a form of testosterone not converted to oestradiol. Seven days postsurgery, LTF was studied in anaesthetized, neuromuscularly blocked and ventilated rats while monitoring integrated phrenic and hypoglossal (XII) motor output. LTF was elicited by three 5 min hypoxic episodes (P(a,O(2)) = 35 - 45 mmHg). Although significant phrenic and XII LTF were observed in all rat groups, GDX reduced both phrenic and XII LTF, an effect reversed by T. In contrast, LTF was not restored in T + ADT or DHT-treated gonadectomized rats. We conclude that the conversion of testosterone to oestradiol modulates phrenic and XII LTF in male F344 rats.

Cardiac resynchronisation therapy for heart failure.

Cardiac resynchronisation therapy (CRT) reduces symptoms and improves left ventricular function in chronic heart failure (CHF) patients with left ventricular systolic dysfunction and prolonged QRS duration. Recent studies have demonstrated a reduction in mortality associated with CRT. When combined with an implantable cardioverter defibrillator (ICD) reduction in mortality is likely to reduce further. Cardiac resynchronisation therapy is well tolerated and free from compliance issues and therefore should be considered for all suitable patients. Identifying patients who will derive maximum benefit requires further study and has health economic implications. We review here the CRT trial evidence as well as the implantation technique and complications. We also describe a case report where an intra-aortic balloon pump was used successfully as a bridge to CRT to treat a patient with end-stage heart failure.

Cardiac arrests at the Cenotaph.

This report describes the case histories of three veterans who suffered cardiac arrests at the 2005 Cenotaph Remembrance Parade. All three were successfully resuscitated and admitted to the St Thomas' Hospital Coronary Care Unit. They had internal cardioverter defibrillators (ICDs) inserted and remain well. All three plan to attend Remembrance ceremonies this year. We review the evidence between emotional stress and arrhythmias and the updated National Institute for Health and Clinical Excellence (NICE) guidelines for ICDs.

Sex hormone receptors are expressed in identified respiratory motoneurons in male and female rats.

Sex hormones including estrogen, progesterone and testosterone can influence breathing. However, it is not clear whether such hormones exert their effects directly on respiratory motoneurons. We used immunocytochemistry to demonstrate that estrogen receptor alpha, estrogen receptor beta and androgen receptor are localized in respiratory motor neurons. Motoneurons in the hypoglossal (XII) and the phrenic nuclei were retrogradely labeled from the tongue and the diaphragm respectively. Double-label fluorescence immunocytochemistry was used to show that sex hormone receptors are present in respiratory motoneurons of both male and female rats. These data suggest that in male and female rats, sex hormones can modulate the output of respiratory motoneurons directly.

Ageing and gonadectomy have similar effects on hypoglossal long-term facilitation in male Fischer rats.

Long-term facilitation (LTF), a form of serotonin-dependent respiratory plasticity induced by intermittent hypoxia, decreases with increasing age or following gonadectomy in male Sprague-Dawley (SD) rats. Ageing is accompanied by decreasing levels of testosterone, which in turn influences serotonergic function. In addition, LTF in young male rats differs among strains. Thus, we tested the hypothesis that LTF is similar in middle-aged and gonadectomized young male rats of an inbred rat strain commonly used in studies on ageing (F344) by comparison with SD rats. We further tested whether the magnitude of LTF correlates with circulating serum levels of testosterone and/or progesterone. Young and middle-aged intact and young gonadectomized (GDX) male Fischer 344 rats were anaesthetized, neuromuscularly blocked and ventilated. Integrated phrenic and hypoglossal (XII) nerve activities were measured before, during and 60 min following three 5-min episodes of isocapnic hypoxia. LTF was observed in phrenic motor output in young and middle-aged intact and young GDX rats. In contrast, XII LTF was observed only in young intact rats. In middle-aged and young GDX rats, XII LTF was significantly lower than in young intact rats (P < 0.05). Furthermore, XII LTF was positively correlated with the testosterone/progesterone ratio. These data show that serotonin-dependent plasticity in upper airway respiratory output is similar in F344 and SD rat strains. Furthermore, LTF is similarly impaired in middle-aged and gonadectomized male rats, suggesting that gonadal hormones play an important role in modulating the capacity for neuroplasticity in upper airway motor control.

Transrectal ultrasound-guided biopsy of the prostate gland: value of 12 versus 6 cores.

We investigated the effect on prostate carcinoma detection of 12 versus 6 core biopsies at transrectal ultrasound (TRUS), when all biopsies are taken from the lateral peripheral zone. This was a prospective study of 202 consecutive men, ages 51 to 81 years, referred for TRUS-guided biopsy of the prostate gland. All patients had prostate serum antigen levels higher than 4.0 ng/mL and/or abnormal digital rectal examination. In each case three biopsies were taken from the peripheral zones of the right and left lobes of the prostate. Biopsies were taken at the apex, midway between the apex and the base, and at the base. A second set of biopsies was taken from the same regions and analyzed separately. In total, twelve biopsies were taken. Note was subsequently made of additional carcinoma diagnosis increase in Gleason grade, and new diagnoses of carcinoma in the opposite side of the gland diagnosed on the second set of biopsies alone. Seventy-eight of the 202 men (38.6%) had prostatic carcinoma diagnosed on TRUS-guided biopsy. Of these 78 patients, six were diagnosed with malignancy based on the second set of biopsies alone, a 2.9% increase in the 202 patients, representing an increased yield of 8.3% (95% confidence interval, 5.3-28.6%). In nine cases (12.5%; 95% confidence interval, 6.2-22.9%), the Gleason tumor grade was increased on the second set of sextant biopsies; in an additional nine cases, carcinoma was detected in the opposite side of the gland. There were two complications (1%). A 12- versus six-core biopsy strategy for TRUS-guided biopsy of the prostate gland improves detection and histologic grading of prostate carcinoma. The added benefit of additional biopsies was lower in this series than in some prior studies using extensive biopsy protocols.