Mitochondrial Dynamics and Heart Failure

Mitochondrial dynamics, fission and fusion, were first identified in yeast with investigation in heart cells beginning only in the last 5 to 7 years. In the ensuing time, it has become evident that these processes are not only required for healthy mitochondria, but also, that derangement of these processes contributes to disease. The fission and fusion proteins have a number of functions beyond the mitochondrial dynamics. Many of these functions are related to their membrane activities, such as apoptosis. However, other functions involve other areas of the mitochondria, such as OPA1's role in maintaining cristae structure and preventing cytochrome c leak, and its essential (at least a 10 kDa fragment of OPA1) role in mtDNA replication. In heart disease, changes in expression of these important proteins can have detrimental effects on mitochondrial and cellular function.

Systematic review of noninvasive prenatal diagnosis for abnormal chromosome genetic diseases using free fetal DNA in maternal plasma

We evaluated the system accuracy of noninvasive prenatal diagnosis for abnormal chromosome genetic diseases using cell-free fetal DNA in maternal plasma. Previous studies were searched in the MEDLINE database using the following keywords: "prenatal" and "aneuploidy" and "noninvasive or non-invasive" and "maternal". Identified studies were filtered using a QUADAS instrument. Four studies were identified and analyzed using QUADAS. The studies included 4167 cases of Down syndrome patients determined by noninvasive prenatal diagnosis with a sensitivity of 100% and specificity of 99.3%; There were 3455 cases of Edwards syndrome patients determined by noninvasive prenatal diagnosis with a sensitivity of 97.4% and specificity of 99.95%. Therefore, noninvasive prenatal diagnosis can be used to identify abnormal chromosomes with high accuracy using free fetal DNA in the maternal plasma.

Expression of high-mobility group box protein 1 in diabetic foot atherogenesis

The role of high mobility group box 1 (HMGB1) has been demonstrated in stroke and coronary artery disease but not in peripheral arterial occlusive disease (PAOD). The pathogenesis of HMGB1 in acute and chronic vascular injury is also not well understood. We hypothesized that HMGB1 induces inflammatory markers in diabetic PAOD patients. We studied 36 diabetic patients, including 29 patients with PAOD, who had undergone amputation for diabetic foot and 7 nondiabetic patients who had undergone amputation after traumatic injury. Expression of HMGB1 and inflammatory markers were quantified using immunohistochemical staining. Mitochondrial DNA copy number was quantified using real-time polymerase chain reaction. Compared with that in the traumatic amputation group, HMGB1 expression in vessels was significantly higher in the diabetes and diabetic PAOD groups. In all subjects, arterial stenosis grade was positively correlated with the expression levels of HMGB1, 8-hydroxyguanosine, malondialdehyde, vascular cell adhesion molecule 1, and inflammatory markers CD3, and CD68 in both the intima and the media of vessels. Furthermore, HMGB1 expression level was positively correlated with 8-hydroxyguanosine, vascular cell adhesion molecule 1, nuclear factor-kB, CD3, and CD68 expression. Within the PAOD subgroup, subjects with HMGB1 expression had higher expression of the autophagy marker LC3A/B and higher mitochondrial DNA copy number. HMGB1 may be an inflammatory mediator with roles in oxidative damage and proinflammatory and inflammatory processes in diabetic atherogenesis. Moreover, it may have dual effects by compensating for increased mitochondrial DNA copy number and increased autophagy marker expression.

Influence of repeated infusion of capsaicin-contained red pepper sauce on esophageal secondary peristalsis in humans

BACKGROUND

The transient receptor potential vanilloid 1 has been implicated as a target mediator for heartburn perception and modulation of esophageal secondary peristalsis. Our aim was to determine the effect of repeated esophageal infusion of capsaicin-contained red pepper sauce on heartburn perception and secondary peristalsis in healthy adults.

METHODS

Secondary peristalsis was performed with mid-esophageal injections of air in 15 healthy adults. Two separate protocols including esophageal infusion with saline and capsaicin-contained red pepper sauce and 2 consecutive sessions of capsaicin-contained red pepper sauce were randomly performed.

KEY RESULTS

After repeated infusion of capsaicin-contained red pepper sauce, the threshold volume to activate secondary peristalsis was significantly increased during slow (p < 0.001) and rapid air injections (p = 0.004). Acute infusion of capsaicin-contained red pepper sauce enhanced heartburn perception (p < 0.001), but the intensity of heartburn perception was significantly reduced after repeated capsaicin-contained red pepper sauce infusion (p = 0.007). Acute infusion of capsaicin-contained red pepper sauce significantly increased pressure wave amplitudes of distal esophagus during slow (p = 0.003) and rapid air injections (p = 0.01), but repeated infusion of capsaicin-contained red pepper sauce significantly decreased pressure wave amplitude of distal esophagus during slow (p = 0.0005) and rapid air injections (p = 0.003).

CONCLUSIONS & INFERENCES

Repeated esophageal infusion of capsaicin appears to attenuate heartburn perception and inhibit distension-induced secondary peristalsis in healthy adults. These results suggest capsaicin-sensitive afferents in modulating sensorimotor function of secondary peristalsis in human esophagus.

MRI surrogates for molecular subgroups of medulloblastoma

BACKGROUND AND PURPOSE

Recently identified molecular subgroups of medulloblastoma have shown potential for improved risk stratification. We hypothesized that distinct MR imaging features can predict these subgroups.

MATERIALS AND METHODS

All patients with a diagnosis of medulloblastoma at one institution, with both pretherapy MR imaging and surgical tissue, served as the discovery cohort (n = 47). MR imaging features were assessed by 3 blinded neuroradiologists. NanoString-based assay of tumor tissues was conducted to classify the tumors into the 4 established molecular subgroups (wingless, sonic hedgehog, group 3, and group 4). A second pediatric medulloblastoma cohort (n = 52) from an independent institution was used for validation of the MR imaging features predictive of the molecular subtypes.

RESULTS

Logistic regression analysis within the discovery cohort revealed tumor location (P < .001) and enhancement pattern (P = .001) to be significant predictors of medulloblastoma subgroups. Stereospecific computational analyses confirmed that group 3 and 4 tumors predominated within the midline fourth ventricle (100%, P = .007), wingless tumors were localized to the cerebellar peduncle/cerebellopontine angle cistern with a positive predictive value of 100% (95% CI, 30%-100%), and sonic hedgehog tumors arose in the cerebellar hemispheres with a positive predictive value of 100% (95% CI, 59%-100%). Midline group 4 tumors presented with minimal/no enhancement with a positive predictive value of 91% (95% CI, 59%-98%). When we used the MR imaging feature-based regression model, 66% of medulloblastomas were correctly predicted in the discovery cohort, and 65%, in the validation cohort.

CONCLUSIONS

Tumor location and enhancement pattern were predictive of molecular subgroups of pediatric medulloblastoma and may potentially serve as a surrogate for genomic testing.

Brainstem auditory electrophysiology is supressed in term neonates with hyperbilirubinemia

BACKGROUND

Whether hyperbilirubinemia suppresses electrophysiological activity of the neonatal auditory brainstem remains to be investigated.

AIM

To determine whether hyperbilirubinemia suppresses the brainstem auditory electrophysiology in term neonates.

METHODS

Maximum length sequence brainstem auditory evoked response (MLS BAER) was recorded shortly after confirming hyperbilirubinemia in 58 term neonates. Wave amplitudes of the response were analyzed in detail.

RESULTS

Compared with age-matched term controls, the neonates with hyperbilirubinemia showed a significant reduction in the amplitudes of MLS BAER waves III and particularly V at all click rates 91-910/s. The reduction tended to be more significant at higher than lower rates. Wave I amplitude was reduced at 910/s. V/I amplitude ratio was decreased at all click rates. Therefore, the amplitudes of MLS BAER, particularly later, waves were all reduced. The amplitudes of all MLS BAER waves tended to be reduced with the increase in total serum bilirubin level. All wave amplitudes were correlated with the level of total serum bilirubin at some or most click rates.

CONCLUSIONS

Brainstem auditory electrophysiology is suppressed in neonates with hyperbilirubinemia, which related to the severity of hyperbilirubinemia. Wave amplitudes are valuable BAER variables to detect functional impairment of the brainstem and auditory pathway in neonatal hyperbilirubinemia, and are recommended to be used in assessing bilirubin neurotoxicity to the neonatal brain.

Chronic pain after caesarean delivery: an Australian cohort

We investigated the incidence of and risk factors for persistent pain after caesarean delivery. Over a 12-month period, women having caesarean delivery were recruited prospectively at an Australian tertiary referral centre. Demographic, anaesthetic and surgical data were collected and at 24 hour follow-up, women were assessed for immediate postoperative pain and preoperative expectations of pain. Long-term telephone follow-up was conducted at two and 12 months postoperatively. Complete data were obtained from 426 of 469 women initially recruited (90.6%). The incidence of persistent pain at the abdominal wound at two months was 14.6% (n=62) but subsequently reduced to 4.2% (n=18) at 12 months. At two months, 33 patients (7.8%) experienced constant or daily pain. At 12 months, five patients (1.1%) continued to have constant or daily pain which was mild. There was no apparent increase in incidence of persistent pain associated with general versus regional anaesthesia (relative risk [RR] 0.89, 95% confidence interval [CI] 0.49 to 1.6); emergency vs elective procedure (RR 0.65, 95% CI 0.39 to 1.07); higher acute pain scores (RR 1.1, 95% CI 0.69 to 1.75); or history of previous caesarean delivery (RR 0.81, 95% CI 0.50 to 1.33). Persistent pain, usually of a mild nature, is reported by some women two months after their caesarean delivery, but by 12 months less than 1% of women had pain requiring analgesia or affecting mood or sleep. All declined a pain clinic review. Clinicians and patients can be reassured that caesarean delivery is unlikely to lead to severe persistent pain in the long-term.

Esophageal solid bolus transit: studies using combined multichannel intraluminal impedance and manometry in healthy volunteers

The purpose of this study is to apply combined multichannel intraluminal impedance and esophageal manometry (MII-EM) to test esophageal function during solid swallowing in a normal healthy population. We determined whether combined MII-EM with solid bolus is more sensitive than that with viscous bolus in the detection of motility abnormality. Eighteen healthy volunteers (11 men and 7 women; mean age 22 years, range 20-26 years) underwent combined MII-EM with a catheter containing four impedance-measuring segments and five solid-state pressure transducers. Each subject received 10 viscous and 10 solid materials. Tracings were analyzed manually for bolus presence time, total bolus transit time, contraction amplitude, duration, and onset velocity. Three hundred and sixty swallows including viscous and solid materials were analyzed. Contraction amplitude for the viscous swallows was higher at 20 cm above the lower esophageal sphincter (LES) (P= 0.049) but lower at 15 cm above the LES (P < 0.001). Duration of contractions for the solid swallows was longer at 15 cm (P= 0.002) and 10 cm above the LES (P= 0.011) compared with viscous swallows. The total bolus transit time for solid was significantly shorter than that for viscous boluses (6.8 vs. 7.7 seconds, P < 0.001). Bolus presence time appeared to be similar between viscous and solid boluses (except in the proximal esophagus). The percentage of swallows with ineffective peristalsis by manometry, as well as those with incomplete bolus transit by impedance, did not differ between viscous and solid swallows. The proportion of manometrically ineffective solid swallows with incomplete bolus transit was greater than that of viscous swallows (62.1% vs. 34.8%, P= 0.05). Application of solid boluses may potentially enhance diagnostic capability of esophageal function testing. Solid boluses can be regarded as a valuable complement to viscous boluses in the detection of esophageal motility abnormalities when applied with combined MII-EM.

Effects of probiotic, Clostridium butyricum, on growth performance, immune function, and cecal microflora in broiler chickens

Four hundred and fifty 1-d-old male Lingnan Yellow broiler chickens were used to investigate the effects of Clostridium butyricum on growth performance, immune function, and cecal microflora. The birds were randomly assigned to 5 treatments and offered the same antibiotic-free basal diets for 42 d. The treatments were as follows: no addition (control), 1 × 10(7) cfu C. butyricum/kg of diet (CB1), 2 × 10(7) cfu C. butyricum/kg of diet (CB2), 3 × 10(7) cfu C. butyricum/kg of diet (CB3), and 10 mg of colistine sulfate/kg of diet (antibiotic). Birds fed either CB2 or antibiotic had greater overall BW than those in the control group. During d 1 to 7, d 21 to 42, and d 1 to 42, birds fed either CB2 or CB3 or the antibiotic diet had greater ADG compared with those in the control group. No significant differences were observed in BW or ADG among the CB2, CB3, and antibiotic groups. Birds fed the CB2 or CB3 diet had greater concentrations of IgA and IgG in the serum from d 14 to 42 and greater IgM in the serum from d 21 to 42 than those in the control group. Birds fed the CB3 diet had a greater concentration of complement component 3 in the serum than those in the control group from d 7 to 42. Dietary C. butyricum decreased (P < 0.05) Escherichia coli in cecal contents on d 14 and 42, and both CB2 and CB3 decreased (P < 0.05) cecal Salmonella and Clostridium perfringen from d 14 to 42 compared with the control. Broilers fed either CB2 or CB3 had greater cecal Lactobacillus and Bifidobacterium counts from d 21 to 42, and birds fed C. butyricum had greater cecal C. butyricum counts during the whole period compared with those in the control group. The results indicate that C. butyricum promotes growth performance and immune function and benefits the balance of the intestinal microflora in broiler chickens.

Effects of mosapride on esophageal secondary peristalsis in humans

BACKGROUND

Secondary peristalsis is important for the clearance of refluxate or retained food bolus from the esophagus. Mosapride is a prokinetic agent that enhances GI motility by stimulating 5-hydroxytrypatamine(4) (5-HT(4) ) receptors, but its effects on secondary peristalsis are yet unclear in humans. We aimed to investigate the effect of a 5-HT(4) agonist mosapride on esophageal distension-induced secondary peristalsis in normal subjects.

METHODS

After a baseline recording esophageal motility, secondary peristalsis was generated by slow and rapid mid-esophageal injections of air in 15 healthy subjects. Two separate sessions with 40mg oral mosapride or placebo were randomly performed to test their effects on esophageal secondary peristalsis.

KEY RESULTS

Mosapride decreased the threshold volume for triggering secondary peristalsis during rapid air distension (4.5±0.3 vs 5.3±0.4mL; P=0.04) but not slow air distension (14.3±1.2 vs 13.3±1.3mL; P=0.41). Secondary peristalsis was triggered more frequently in response to rapid air distension after application of mosapride [100% (90-100%) vs 90% (80-100%); P=0.02]. Mosapride significantly increased pressure wave amplitudes of secondary peristalsis during slow (135.4±13.8 vs 105.0±12.9mmHg; P=0.001) and rapid air distensions (124.0±11.6 vs 95.9±14.0mmHg; P=0.002).

CONCLUSIONS & INFERENCES

Mosapride enhances sensitivity to distension-induced secondary peristalsis and facilitates secondary peristaltic contractility. These data provide an evidence for modulation of esophageal secondary peristalsis by the 5-HT(4) agonist mosapride, as well support for its clinical utility.

Control of esophageal distension-induced secondary peristalsis by the GABA(B) agonist baclofen in humans

BACKGROUND

Secondary peristalsis is important for the clearance of retained food bolus or refluxate from the esophagus. The effects of the gamma aminobutyric acid receptor type B (GABA(B) ) agonist on secondary peristalsis remain unclear in humans. We aimed to investigate the effect of a GABA(B) agonist baclofen on esophageal secondary peristalsis.

METHODS

After a baseline recording of esophageal motility, secondary peristalsis was generated by slow and rapid mid-esophageal injections of air in 15 healthy subjects. Two separate sessions with 40mg oral baclofen or placebo were randomly performed to test their effects on secondary peristalsis.

KEY RESULTS

Baclofen increased the threshold volume for triggering secondary peristalsis during slow air distension (P=0.003) and rapid air distension (P=0.002). Baclofen reduced the rate of secondary peristalsis by rapid air distension from 90% to 30% (P=0.0002). Baclofen increased basal lower esophageal sphincter pressure (P=0.03). Baclofen did not affect any of peristaltic parameters during primary or secondary peristalsis.

CONCLUSIONS & INFERENCES

This study provides an evidence for inhibitory modulation of esophageal secondary peristalsis by the GABA(B) agonist baclofen. Activation of secondary peristalsis is probably modulated by GABA(B) receptors; however, baclofen does not lead to any motility change in secondary peristalsis.

17β-Estradiol, aging, inflammation, and the stress response in the female heart

Heat shock proteins (HSPs) are a cardioprotective class of proteins induced by stress and regulated by the transcription factor, heat shock factor (HSF)-1. 17β-estradiol (E(2)) indirectly regulates HSP expression through rapid activation of nuclear factor-κB (NF-κB) and HSF-1 and protects against hypoxia. As males experience a loss of protective cellular responses in aging, we hypothesized that aged menopausal (old ovariectomized) rats would have an impaired HSP response, which could be prevented by immediate in vivo E(2) replacement. After measuring cardiac function in vivo, cardiac myocytes were isolated from ovariectomized adult and old rats with and without 9 weeks of E(2) replacement. Myocytes were treated with E(2) in vitro and analyzed for activation of NF-κB, HSF-1, and HSP expression. In addition, we measured inflammatory cytokine expression and susceptibility to hypoxia/reoxygenation injury. Cardiac contractility was reduced in old ovariectomized rats and could prevented by immediate E(2) replacement in vivo. Subsequent investigations in isolated cardiac myocytes found that in vitro E(2) activated NF-κB, HSF-1, and increased HSP 72 expression in adult but not old rats. In response to hypoxia/reoxygenation, myocytes from adult, but not old, rats had increased HSP 72 expression. In addition, expression of the inflammatory cytokines TNF-α and IL-1β, as well as oxidative stress, were increased in myocytes from old ovariectomized rats; only the change in cytokine expression could be attenuated by in vivo E(2) replacement. This study demonstrates that while aging in female rats led to a loss of the cardioprotective HSP response, E(2) retains its protective cellular properties.

A cured patient who came back for consultation: neuropathic scrotal pruritus relieved after ipsilateral inguinal hernia repair

When no demonstrable cause is uncovered after excluding inflammatory dermatosis, infectious disease or a manifestation of anorectal disease, anogenital pruritus is often described as 'idiopathic'. Lumbosacral radiculopathy was described by Cohen et al. as one of the possible causes of 'idiopathic' anogenital pruritus. We report a case of a patient with chronic pruritus of the right scrotum that was relieved immediately post-ipsilateral inguinal hernia repair. This is, to the best of our knowledge, the first case of neuropathic scrotal pruritus secondary to direct nerve compression by an inguinal hernia. We propose that a proper examination for the presence of inguinal hernia be performed in the work-up for scrotal pruritus.

Effects of capsaicin-containing red pepper sauce suspension on esophageal secondary peristalsis in humans

BACKGROUND

Capsaicin-sensitive afferents have been implicated in the modulation of gastrointestinal sensorimotor functions. Secondary peristalsis is important for the clearance of retained refluxate or material from the esophagus. The aim of this study was to evaluate the effects of capsaicin-containing red pepper sauce suspension on esophageal secondary peristalsis in healthy adults.

METHODS

After a baseline recording of esophageal motility, secondary peristalsis was generated by slow and rapid mid-esophageal injections of air in 10 healthy subjects. Two separate sessions with saline and capsaicin-containing red pepper sauce were randomly performed to test their effects on esophageal secondary peristalsis.

KEY RESULTS

Infusion of capsaicin significantly increased pressure wave amplitude during rapid (P = 0.002) and slow air infusions (P = 0.01). After capsaicin, the threshold volume to generate secondary peristalsis was significantly decreased during rapid (P < 0.05) and slow air infusions (P = 0.02). Infusion of saline did not affect any parameters of secondary peristalsis during rapid or slow air infusion. The administration of capsaicin was accompanied by the occurrence of heartburn in all subjects.

CONCLUSIONS & INFERENCES

The acute administration of capsaicin-containing red pepper sauce suspension enhances sensitivity to distension-induced secondary peristalsis and facilitates secondary peristaltic contractility. These data suggest the involvement of capsaicin-sensitive afferents in the modulation of esophageal distension-induced secondary peristalsis in humans.

Disease progression in non-erosive reflux disease (NERD): impact of initial esophageal acid exposure

We investigated the 5-year clinical course in a cohort of patients with typical reflux symptoms and negative endoscopy. Prospective follow-up was conducted in patients with non-erosive reflux disease (NERD) for at least 5 years after initial evaluation with esophageal pH monitoring and upper gastrointestinal endoscopy. Within the last year of follow-up, reflux symptoms occurred in 27 of the 30 patients (90%). Twenty-five of twenty-seven symptomatic patients (93%) were on acid suppression therapy. The majority of our patients (70%) remained unchanged regarding their endoscopic status over 5 years. Progression to erosive esophagitis occurred in four patients with Los Angeles (LA) A (13%), three patients with LA B (10%), and two patients with LA C (7%). The presence of pathological acid exposure did not alter the presence of reflux symptoms over 5 years. Disease progression to erosive esophagitis occurred more frequently in patients with pathological acid exposure than those without pathological acid exposure (P= 0.025). Most NERD patients have symptoms and require acid suppression therapy 5 years after their initial diagnosis. Initial pathological acid exposure does not influence the use of acid suppression; however, it does influence the progression of NERD within 5 years of follow-up.

Organization and neurochemical properties of intersegmental interneurons in the lumbar enlargement of the adult rat

Intersegmental interneurons with relatively short axons perform an important role in the coordination of limb movement but surprisingly little is known about their organization and how they contribute to neuronal networks in the adult rat. We undertook a series of anatomical tract-tracing studies to label cell bodies and axons of intersegmental neurons in the lumbar cord and characterized their neurochemical properties by using immunocytochemistry. The b-subunit of cholera toxin was injected into L1 or L3 segments of seven rats in the vicinity of lateral or medial motor nuclei. In L5 lumbar segments, cells were found to be concentrated in contralateral lamina VIII, and in ipsilateral lamina VII and laminae V-VI following injections into the lateral and medial motor nuclei respectively. About 25% of labelled cells contained calbindin or calretinin or a combination of both. Calbindin positive cells were mainly distributed within the ipsilateral side of the L5 segment, especially within the ipsilateral dorsal horn whereas there was a concentration of calretinin cells in contralateral lamina VIII. A small population of cells around the central canal were cholinergic. We also examined axon terminals that projected from L1/3 to the L5 contralateral lateral motor nucleus. The majority of these axons were excitatory (75%) and made direct contacts with motoneurons. However, most inhibitory axons in L5 contained a mixture of GABA and glycine (20%) and about 22% of the total population of axons contained calbindin. In contrast, 19% of all intra-segmental axons in the L3 contralateral lateral motor nucleus were found to be purely glycinergic and 17% contained a mixture of GABA and glycine. This study shows that short range interneurons form extensive ipsi- and contralateral projections within the lumbar enlargement and that many of them contain calcium binding proteins. Those projecting contralaterally to motor nuclei are predominantly excitatory.

Evidence for neurotrophic factors associating with TRPV1 gene expression in the inflamed human esophagus

BACKGROUND

Transient receptor potential vanilloid-1 (TRPV1) receptor has been implicated in the mechanism of acid induced inflammation in gastro-esophageal reflux disease (GERD). It has been demonstrated that the increase in nerve growth factor (NGF) and glial derived neurotrophic factor (GDNF) was associated with the increased expression of TRPV1. We aimed to determine whether expression of TRPV1 was increased in severe inflamed human esophagus, and to test the hypothesis whether the expression of TRPV1 was mediated by neurotrophic factors such as NGF and GDNF.

METHODS

We compared biopsies taken from the distal esophagus of 15 patients with erosive GERD, 16 asymptomatic patients (AP), and 10 healthy controls. We assessed the biopsies with reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative polymerase chain reaction (qPCR) for TRPV1, NGF, and GDNF. Immunohistochemical analysis of TRPV1 protein expression was also determined.

KEY RESULTS

Transient receptor potential vanilloid-1 mRNA level and its protein expression were significantly greater in patients with erosive esophagitis than AP (P < 0.001) and healthy controls (P < 0.001). Nerve growth factor and GDNF gene levels in the esophageal mucosa were also significantly increased in patients with erosive esophagitis compared with AP and healthy controls (all P < 0.001). Transient receptor potential vanilloid-1 mRNA correlated well with NGF (r = 0.61, P < 0.001) and GDNF (r = 0.58, P < 0.001).

CONCLUSIONS & INFERENCES

These results support the association of NGF and GDNF in the up-regulation of TRPV1 receptors in patients with erosive esophagitis.

Effects of lidocaine on esophageal secondary peristalsis in humans

BACKGROUND

Secondary peristalsis is important for the clearance of retained food bolus or refluxate from the esophagus. Lidocaine has been used to evaluate the role of mucosa-mediating pathways of esophageal reflexes in animal model, but its effects on esophageal secondary peristalsis are yet unclear in humans. We aimed to investigate whether esophageal secondary peristalsis can be affected by intraluminal infusion of lidocaine into the esophagus.

METHODS

After a baseline recording esophageal motility, secondary peristalsis was generated by slow and rapid mid-esophageal injections of air in 13 healthy subjects. Two separate sessions with saline and lidocaine were randomly performed to test their effects on esophageal secondary peristalsis by mid-esophageal air distension.

KEY RESULTS

Secondary peristalsis can be induced by slow or rapid air infusion. Secondary peristalsis was triggered less frequently in response to rapid air distension after lidocaine infusion (P = 0.001). After lidocaine infusion, the threshold volume to generate secondary peristalsis was significantly increased during rapid (P = 0.001), but not slow air infusions (P = NS). Infusion of lidocaine or saline did not affect pressure wave amplitude or duration during rapid and slow air infusions (P = NS).

CONCLUSIONS & INFERENCES

We have demonstrated selectively inhibitory effect of lidocaine on the triggering of esophageal secondary peristalsis during acute gaseous esophageal distension. The data suggest that part of the activation of secondary peristalsis is probably mediated by lidocaine-sensitive mechanoreceptors; however, the infusion of lidocaine does not lead to any motility change in secondary peristalsis induced by either slow or rapid air infusions.

Multiple epidermal cysts occurring in a tattoo

In decorative tattooing, pigment is introduced into the skin with needles or a tattoo gun to create a picture, motif or symbol. Various skin reactions have been reported in association with tattoos. These include acute inflammatory reactions, eczematous hypersensitivity reactions, pseudolymphomatous reactions and skin infections. We present a 24-year-old Malay man who developed multiple epidermal cysts a month after tattooing. To the best of our knowledge, this is the first case in the literature of epidermal cysts occurring after skin tattooing.

Cholinergic terminals in the ventral horn of adult rat and cat: evidence that glutamate is a cotransmitter at putative interneuron synapses but not at central synapses of motoneurons

Until recently it was generally accepted that the only neurotransmitter to be released at central synapses of somatic motoneurons was acetylcholine. However, studies on young mice (P0-10) have provided pharmacological evidence indicating that glutamate may act as a cotransmitter with acetylcholine at synapses between motoneurons and Renshaw cells. We performed a series of anatomical experiments on axon collaterals obtained from intracellularly labeled motoneurons from an adult cat and labeled by retrograde transport in adult rats to determine if glutamate is co-localized with acetylcholine by these terminals. We could find no evidence for the presence of vesicular glutamate transporters in motoneuron axon terminals of either species. In addition, we were unable to establish any obvious relationship between motoneuron terminals and the R2 subunit of the AMPA receptor (GluR2). However we did observe a population of cholinergic terminals in lamina VII which did not originate from motoneurons but were immunoreactive for the vesicular glutamate transporter 2 and formed appositions to GluR2 subunits. These were smaller than motoneuron terminals and, unlike them, formed no relationship with Renshaw cells. The evidence suggests that glutamate does not act as a cotransmitter with acetylcholine at central synapses of motoneurons in the adult cat and rat. However, glutamate is present in a population of cholinergic terminals which probably originate from interneurons where its action is via an AMPA receptor.

Stevens-Johnson syndrome and toxic epidermal necrolysis: efficacy of intravenous immunoglobulin and a review of treatment options

Toxic epidermal necrolysis (TEN) is a rare, severe adverse drug reaction. Steven-Johnson syndrome (SJS) represents the milder end of the spectrum. The exact pathogenesis of TEN and SJS is still unknown and many drugs, including prednisolone, cyclosporin and intravenous immunoglobulin (IVIG), have been used in an attempt to halt the disease process. The use of IVIG in particular is controversial. We share our experience with the use of IVIG in six patients with TEN. We will also review the various proposed mechanisms underlying TEN, the mechanism of action of IVIG in TEN and summarise useful treatment options.

Excitatory and inhibitory intermediate zone interneurons in pathways from feline group I and II afferents: differences in axonal projections and input

The aim of the present study was to compare properties of excitatory and inhibitory spinal intermediate zone interneurons in pathways from group I and II muscle afferents in the cat. Interneurons were labelled intracellularly and their transmitter phenotypes were defined by using immunocytochemistry. In total 14 glutamatergic, 22 glycinergic and 2 GABAergic/glycinergic interneurons were retrieved. All interneurons were located in laminae V-VII of the L3-L7 segments. No consistent differences were found in the location, the soma sizes or the extent of the dendritic trees of excitatory and inhibitory interneurons. However, major differences were found in their axonal projections; excitatory interneurons projected either ipsilaterally, bilaterally or contralaterally, while inhibitory interneurons projected exclusively ipsilaterally. Terminal projections of glycinergic and glutamatergic cells were found within motor nuclei as well as other regions of the grey matter which include the intermediate region, laminae VII and VIII. Cells containing GABA/glycine had more restricted projections, principally within the intermediate zone where they formed appositions with glutamatergic axon terminals and unidentified cells and therefore are likely to be involved in presynaptic as well as postsynaptic inhibition. The majority of excitatory and inhibitory interneurons were found to be coexcited by group I and II afferents (monosynaptically) and by reticulospinal neurons (mono- or disynaptically) and to integrate information from several muscles. Taken together the morphological and electrophysiological data show that individual excitatory and inhibitory intermediate zone interneurons may operate in a highly differentiated way and thereby contribute to a variety of motor synergies.

Fluorescence evolution of leachates during treatment processes from two contrasting landfills

Landfill leachates are composed of a complex mixture of organic matter, including a wide range of potentially fluorescent organic compounds. The fluorescence excitation-emission matrix (FEEM) of leachates during treatment processes is investigated. Particular attention is paid to the fluorescence evolution of leachates during treatment processes. Two typical types of landfill, landfill A (a direct municipal solid waste (MSW) landfill) and landfill B (disposal of bottom ashes from MSW incinerators), in a city in Southern China were selected. The results show that two characteristic and intense excitation-emission peaks located at Ex/Em = 310-330 nm/395-410 nm (peak alpha) and Ex/Em = 250-260 nm/450-460 nm (peak alpha') are observed. As the aromatic chemicals, capable of emitting fluorescence, are more recalcitrant to biodegradation than aliphatic chemicals, enhancement of the dissolved organic carbon normalized fluorescence intensities is demonstrated during treatment processes of leachate A and leachate B. This is confirmed by the variation of ultraviolet absorptivity of leachates at 254 nm. Peak alpha' and peak alpha are attributed to a mixture of xenobiotic organic compounds with low molecular weight and relatively stable aromatic fulvic-like matters with high molecular weight, respectively. Humic substances are more resistant to biodegradation than xenobiotic organic compounds, so a significant reduction in the Ialpha'/Ialpha values (fluorescence intensity ratios of peak alpha' and peak a) of leachate A was observed during treatment processes. However, no evident variation for the Ialpha/Ialpha values of leachate B was found during treatment processes owing to the low concentrations of xenobiotic organic compounds in leachate B after incineration.

Phrynoderma: a forgotten entity in a developed country

Phrynoderma is a type of follicular hyperkeratosis attributed to various nutritional deficiencies, most notably vitamin A. We report a case of a 31-year-old mentally-deficient man who was a resident of a voluntary welfare nursing home. He presented with characteristic hyperkeratotic follicular papules on his trunk in a setting of low serum level of vitamin A and malnutrition. Although commonly seen in South and East Asia, it is rarely reported in Singapore. However, there is still a population at risk here--patients with malabsorption and eating disorders, and institutionalised persons. Phrynoderma should, therefore, be considered in the differential diagnosis in patients with hyperkeratotic folliculitis, especially when malnutrition is also present.