Dynamic Sensitivity of Corneal TRPM8 Receptors to Menthol Instillation in Dry Eye Versus Normal Subjects.

PURPOSE: To assess the sensitivity of corneal cold receptors to a known transient receptor potential melastatin 8 (TRPM8) agonist, menthol, in dry eye and normals, and to determine whether factors such as disease duration or age affect responses. METHODS: Dry eye disease (DED) (N = 33) and normal (N = 15) subjects were randomly assigned to receive Rohto® Hydra (0.01% menthol) or Systane® Ultra treatments (OU) in a prospective, double-blind, crossover study. DED subjects had documented disease and symptom response scores >2 on a 0- to 5-point scale. Normals had no history of DED and scores <2 on the same scale. Endpoints included mean cooling score (0 = not cool and 10 = very cool) evaluated at 0, 0.5, 1, 2, 3, and 4 min post-instillation, sum cooling scores (5 time points, range 0-60), and ocular signs and symptoms. RESULTS: Mean (±SD) ages were similar, 62.2 ± 8.6-year (DED) versus 53.5 ± 7.6-year (normal). Corneal sensitivity scores were not different between groups. Mean cooling scores at 0.5-4 min post-menthol instillation were significantly higher in DED subjects (P ≤ 0.03). Sum cooling scores were significantly higher (P = 0.04) in DED subjects with a disease duration <10 years (N = 18, 28.3 ± 2.58) versus ≥10 years (N = 15, 20.2 ± 2.76). Age did not affect cooling response in either group. CONCLUSION: DED subjects had greater sensitivity to cold than normal subjects. DED duration, and not age, was critical to cooling sensitivity. The finding that cooling scores were higher in subjects with DED for less than 10 years compared to more than 10 years suggests that corneal cold receptor sensitivity decreases as the duration of DED increases.

Use of the Controlled Adverse Environment (CAE) in Clinical Research: A Review.

The many internal and external factors that contribute to the pathophysiology of dry eye disease (DED) create a difficult milieu for its study and complicate its clinical diagnosis and treatment. The controlled adverse environment (CAE®) model has been developed to minimize the variability that arises from exogenous factors and to exacerbate the signs and symptoms of DED by stressing the ocular surface in a safe, standardized, controlled, and reproducible manner. By integrating sensitive, specific, and clinically relevant endpoints, the CAE has proven to be a unique and adaptable model for both identifying study-specific patient populations with modifiable signs and symptoms, and for tailoring the evaluation of interventions in clinical research studies.

P63 expression in conjunctival proliferative diseases: pterygium and laryngo-onycho-cutaneous (LOC) syndrome.

PURPOSE: Compare expression of p63 in pterygium and laryngo-onycho-cutaneous (LOC) syndrome with normal conjunctiva. METHODS: P63 immunohistochemical detection was carried out in normal, pterygium, and LOC conjunctival tissue. In vitro, growth of normal conjunctival biopsy specimens, pterygium, and LOC in growth tissue was compared. RESULTS: In normal conjunctiva, p63 was poorly expressed in the infranasal quadrant, with 36% of cells stained vs. 55 to 59% in other quadrants (p < 0.05). In pterygium, p63 was overexpressed (59% cells stained) compared to normal supranasal (55%) and normal infranasal conjunctiva (36%, p < 0.05). In LOC, p63 was only expressed in 39% of cells vs. 58% in normal supratemporal conjunctiva (p < 0.05). Cytokeratin 19 was expressed by all cells cultured from normal conjunctival tissue. CONCLUSIONS: This study emphasizes the importance of using control tissue explanted from the correspondent conjunctival quadrant when studying proliferative disorders. Different pathogenesis may account for the differences in p63 expression between pterygium and LOC.

Exercise distributed across day and night does not alter circadian period in humans.

In rodents, increased activity due to running-wheel access is associated with a change in observed circadian period. In humans, exposure to exercise has failed to demonstrate similar effects on period. Methodological issues with prior studies such as light exposure during exercise, length of study, and method of measuring period confounded those evaluations of the effect of exercise on period in humans. In the present experiment, the authors examined the effect of exercise on period in 8 subjects using a 44-day within-subjects inpatient study. They used a 20-h forced desynchrony protocol, in which subjects were exposed to exercise across circadian phases under dim light conditions. Exercise consisted of three 45-min sessions per wake period on an ergometer. Target exercise intensity was ~65% of maximal heart rate. Intrinsic circadian period was measured using both core body temperature and hourly plasma melatonin samples. Consistent with previous reports, the authors find no effect of exercise on endogenous circadian period as measured by either core body temperature or melatonin. Exercise distributed across biological day and night does not appear to affect circadian period.

Early repair of hemitruncus: excellent early and late outcomes.

OBJECTIVE: Anomalous origin of 1 of the branch pulmonary arteries from the aorta with 2 normal semilunar valves (hemitruncus) is a rare entity. There have been several small case series reported. We report here our single-institution surgical experience with hemitruncus from 1982 to 2006. METHODS: A retrospective case review of all cases of conotruncal anomalies at Children's Hospital Boston revealed 16 patients with hemitruncus. Ten patients had surgery in the neonatal period (<30 days), 4 at 1 to 6 months, 1 at 8 months, and 1 at 2 years. Diagnosis of hemitruncus was the indication for operation in all but 1. Fourteen of the 16 had anomalous right pulmonary artery from aorta, and 2 had left pulmonary artery from aorta. Common associated anomalies included patent foramen ovale in 14, patent ductus arteriosus in 11, and ventricular septal defect in 4. All patients had elevated right ventricular pressures with systemic pressures in 5 and suprasystemic pressures in 9. RESULTS: There was 1 operative death in this series in an infant who died from sepsis following ligation of a tracheoesophageal fistula. One patient required reoperation for supravalvular aortic stenosis and right pulmonary artery stenosis 1 year postoperatively. Three patients required 4 catheter-based interventions postoperatively. At 20 years, survival by Kaplan-Meier was 93%; freedom from reoperation, 93%; and freedom from catheter reintervention, 79%. CONCLUSIONS: Early repair of hemitruncus results in excellent hemodynamic and anatomic results. Survival is excellent, with a low incidence of reoperation or reintervention.

Regional low-flow perfusion versus circulatory arrest in neonates: one-year neurodevelopmental outcome.

BACKGROUND: Regional low-flow perfusion of the brain is a bypass technique commonly used during stage 1 reconstruction in neonates with hypoplastic left heart syndrome and related variants. The neurodevelopmental outcome of these children is unknown. METHODS: Twenty-nine infants (22 boys, 7 girls) with hypoplastic left heart syndrome or variant requiring single ventricle palliation and aortic arch reconstruction were studied between 1999 and 2004. Mental Developmental Index (MDI) and Psychomotor Developmental Index were assessed using Bayley Scales of Infant Development and correlated with intraoperative and perioperative variables. Results are reported as mean +/- standard deviation. RESULTS: Average age at stage 1 operation and at bidirectional Glenn was 7 +/- 8 days and 6.0 +/- 2 months, respectively. The MDI was in the low average range (87.7 +/- 13.2). The Psychomotor Developmental Index was in the mildly delayed range (75.2 +/- 14.5). Regional low-flow perfusion was used in 31% (9 of 29 patients), with an average circulatory arrest time of 23.5 +/- 13.4 minutes. Deep hypothermia and circulatory arrest was used as the primary operative strategy in 69% of patients (20 of 29 patients), with an average circulatory arrest time of 44.3 +/- 15.3 minutes (p = 0.003). No differences in MDI or Psychomotor Developmental Index scores were observed between the regional low-flow perfusion and non-regional low-flow perfusion groups (MDI, 88.0 +/- 12.1 versus 87.6 +/- 14.0; p = 0.93, respectively; Psychomotor Developmental Index, 75.5 +/- 15.1 versus 75.0 +/- 14.6; p = 0.93, respectively). Lowest operative temperature (<16 degrees C) and birth order (<2 versus >3) significantly related to MDI (89.6 versus 72.8; p = 0.047). CONCLUSIONS: At 1 year of age, neurodevelopmental outcomes of patients undergoing stage 1 using regional low-flow perfusion were similar to outcomes observed in children exposed to circulatory arrest. The association of birth order and MDI suggests that early intervention may benefit these patients.

Aortic atresia or severe left ventricular outflow tract obstruction with ventricular septal defect: results of primary biventricular repair in neonates.

BACKGROUND: Aortic atresia or severe aortic stenosis and left ventricular outflow tract obstruction is a frequent component of complex congenital heart disease. Aortic atresia or severe aortic stenosis and left ventricular outflow tract obstruction with two adequate ventricles is sometimes treated by Norwood palliation followed by late biventricular repair. We reviewed our experience with primary biventricular repair in this group of neonates. METHODS: Retrospective review identified 17 neonates (10 males) with aortic atresia or severe left ventricular outflow tract obstruction with ventricular septal defect and an adequate left ventricle undergoing primary biventricular repair between 1986 and 2002. Mean age was 7.7 +/- 2.9 days, weight 3.3 +/- 0.7 kg, and body surface area 0.21 +/- 0.04 kg/m2. Associated anomalies included arch hypoplasia, 7 (41%); aortic atresia, 7 (41%); and coarctation, 5 (29%). Results are reported as mean +/- standard deviation. RESULTS: Median follow-up was 6 years (range, 1 to 17.7 years). Three of the 17 (18%) died within 30 days. There were no deaths in this series since 1992. Nine patients (38.9%) required one reoperation, 7 of which were for conduit stenosis, 1 for left ventricular outflow tract obstruction, and 1 for residual ventricular septal defect with left ventricle-to-right atrium shunt. Freedom from death at 10 years was 82% by Kaplan-Meier estimate. CONCLUSIONS: Excellent long-term survival can be achieved by primary biventricular repair as corroborated by our survival rate of 82%. Primary biventricular repair is an effective operation for aortic atresia and severe left ventricular outflow tract obstruction with adequate sized left ventricle that avoids interstage attrition associated with Norwood palliation and is our procedure of choice.

Identifying contemporary and historic sources of soil polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in an industrial urban setting.

A study of soil polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) concentrations was undertaken in the vicinity of a municipal solid waste incinerator (MSWI) in Newcastle upon Tyne as a result of concerns raised by local residents about potential contamination from fugitive and stack emissions. The study area was divided into four sectors (north-east (NE), south-east (SE), north-west (NW) and south-west (SW)) around the MSWI, and sampling sites were located up to a distance of 2.25 km. Based on air dispersion modelling, the sampling density was four times greater in the NE (downwind) sector compared to the SW (upwind) direction, and twice as great in the NW and SE sectors. PCDD/F concentrations found in soil samples ranged from 6 to 1911 ng I-TEQ/kg DW with a median of 32 ng I-TEQ/kg DW. There was no evidence of elevated concentrations downwind of the MSWI compared to other directions, nor of any trend in concentration at increasing distance from the MSWI. We concluded, therefore, that the MSWI fugitive and stack emissions were not a major source of PCDD/F contamination. Analysis of PCDD/F homologue profiles showed that samples exhibiting furan-dominated and OCDD-dominated profiles and a profile characteristic of the MSWI ash occurred in distinct clusters. Those samples showing the furan-dominated profile had the largest PCDD/F concentrations measured as I-TEQ, followed by samples with the incinerator profile, the deposition profile, and the OCDD-dominated profile. We identified some contamination hotspots located in the SW and SE sampling sectors (upwind of the MSWI), and potential sources for these hotspots were sought by using historic land use data from maps of the locality dating back to 1856. We concluded that the cluster of very high concentrations of PCDD/F in soils showing the furan homologue profile were most likely to have resulted from the disposal of graphite electrode sludges from brine electrolysis carried out at a chemical works between the 1890s and the 1930s.

Metal contamination of urban soils in the vicinity of a municipal waste incinerator: one source among many.

Concern from local residents about possible contamination with metals and PCDD/F (dioxins and furans) from fugitive and stack emissions from the Byker municipal solid waste incinerator in Newcastle upon Tyne led the City Council to initiate a study of the concentration of these pollutants in soils. We report here the results for the metals and arsenic. Soils were sampled at distances up to 2.25 km from the incinerator stack. The intensity of sampling in concentric zones was four times greater in the northeast (down-wind) direction, and twice as great in the northwest and southeast directions, compared to the southwest (up-wind) direction. In total 163 samples were collected and analyzed for total As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. Concentrations were generally elevated above background levels, but were typical of those found in other urban areas. For As, Cd, Cu, Hg, Pb, and Zn, contamination hotspots were identified. These were spread throughout the sampling area, and there was no evidence of greater concentrations down-wind of the incinerator compared to other directions, nor of any trend in concentration at increasing distance from the incinerator. We concluded that metal contamination resulting from the incinerator could not be detected in an environment with generally elevated concentrations. Potential sources for many of the hotspots of contamination were identified in a survey of historic land use based on maps of the locality dating back to 1856. Detailed investigations of particular areas with serious contamination will now be undertaken by the local authorities using the CLEA (Contaminated Land Exposure Assessment) model.

A novel hemoglobin-based blood substitute protects against myocardial reperfusion injury.

HBOC-201 (Biopure; Cambridge, MA) is a glutaraldehyde-polymerized bovine hemoglobin (Hb) solution that is stroma free, has lower viscosity than blood, and promotes O(2) unloading. We investigated the effects of HBOC-201 in a canine model of myocardial ischemia-reperfusion injury. Dogs were anesthetized and subjected to 90 min of regional myocardial ischemia and 270 min of reperfusion. HBOC-201 or 0.9% saline vehicle equivalent to 10% total blood volume was infused 30 min before myocardial ischemia. Hemodynamic data and peripheral blood samples were taken at baseline, 1 h of myocardial ischemia, and 1, 2, and 4 h of reperfusion. At 270 min of reperfusion, the area at risk (AAR) per left ventricle and the area of infarction (Inf) per AAR were determined. The myocardial AARs in the two study groups were similar. In addition, myocardial blood flow (as measured by radioactive microspheres) in the ischemic zone was similar between the vehicle and HBOC-201 groups. HBOC-201-infused dogs demonstrated a significant (P < 0.01) 56% reduction in Inf/AAR. Analysis of blood samples taken at 4 h of reperfusion showed a significant (P < 0.05) reduction in creatine kinase MB isoform for the HBOC-201 group. Histological analysis of the myocardium demonstrated significant (P < 0.01) reductions in neutrophil infiltration in the HBOC-201 group. These data indicate that treatment with HBOC-201 before myocardial ischemia-reperfusion reduces the extent of myocardial inflammation and ischemia-reperfusion injury in the canine myocardium.

Floppy aortic graft reconstruction for germ cell tumor invasion of the infrarenal aorta.

Significant aortic invasion by metastatic nonseminomatous germ cell tumors can present difficult problems intraoperatively in attempted curative retroperitoneal lymph node dissection. Aortic replacement with Dacron graft has been a successful method of dealing with this predicament. We describe a new approach of intraoperative floppy aortic graft reconstruction in a young patient with testicular germ cell cancer in whom a 14 cm pseudoaneurysm involving the infrarenal aorta developed after four courses of preoperative chemotherapy. This technique prevents significant lower extremity and pelvic ischemia during resection of the aorta and retroperitoneal tumor while providing the urologic surgeon with excellent exposure and minimal interference from the aortic graft.

Direct vascular and cardioprotective effects of rosuvastatin, a new HMG-CoA reductase inhibitor.

OBJECTIVE: We examined the possible effects of a novel 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, rosuvastatin, on endothelial nitric oxide (NO) production and myocardial ischemia-reperfusion injury. BACKGROUND: Recent studies suggest that HMG-CoA reductase inhibitors promote vascular endothelial function through enhanced endothelial NO production. However, it is unclear whether all statins share this beneficial side effect or whether this effect is limited to the "natural" statins. METHODS: Wild-type mice (n = 158) were subjected to 30 min of regional myocardial ischemia and 24 h of reperfusion. Mice were treated with various doses of rosuvastatin (0.1, 0.5, 1.0, 2.0, and 5.0 mg/kg) 18 h before myocardial ischemia and reperfusion. RESULTS: Rosuvastatin significantly increased NO production from the vascular endothelium following acute administration to mice. In addition, rosuvastatin increased myocardial endothelial nitric oxide synthase (eNOS) messenger ribonucleic acid levels. Myocardial necrosis was reduced by approximately 40% with rosuvastatin therapy. Rosuvastatin attenuated myocardial injury when it was administered 6 h, but not 0 h or 3 h, before myocardial ischemia. In additional studies, rosuvastatin did not affect myocardial infarct size in eNOS-deficient mice compared to vehicle-treated eNOS mice. CONCLUSION: These data demonstrate that rosuvastatin increases vascular endothelial NO production and attenuates myocardial necrosis following ischemia and reperfusion in mice.

Differential response to myocardial reperfusion injury in eNOS-deficient mice.

Two strains of endothelial nitric oxide synthase (eNOS)-deficient (-/-) mice have been developed that respond differently to myocardial ischemia-reperfusion (MI/R). We evaluated both strains of eNOS(-/-) mice in an in vivo model of MI/R. Harvard (Har) eNOS(-/-) mice (n = 12) experienced an 84% increase in myocardial necrosis compared with wild-type controls (P < 0.05). University of North Carolina (UNC) eNOS(-/-) (n = 10) exhibited a 52% reduction in myocardial injury versus wild-type controls (P < 0.05). PCR analysis of myocardial inducible NO synthase (iNOS) mRNA levels revealed a significant (P < 0.05) increase in the UNC eNOS(-/-) mice compared with wild-type mice, and there was no significant difference between the Har eNOS(-/-) and wild-type mice. UNC eNOS(-/-) mice treated with an iNOS inhibitor (1400W) exacerbated the extent of myocardial necrosis. When treated with 1400W, Har eNOS(-/-) did not exhibit a significant increase in myocardial necrosis. These data demonstrate that two distinct strains of eNOS(-/-) mice display opposite responses to MI/R. Although the protection seen in the UNC eNOS(-/-) mouse may result from compensatory increases in iNOS, other genes may be involved.

Peak of circadian melatonin rhythm occurs later within the sleep of older subjects.

We investigated the relationship between sleep timing and the timing of the circadian rhythm of plasma melatonin secretion in a group of healthy young and older subjects without sleep complaints. The timing of sleep and the phase of the circadian melatonin rhythm were earlier in the older subjects. The relationship between the plasma melatonin rhythm and the timing of sleep was such that the older subjects were sleeping and waking earlier relative to their nightly melatonin secretory episode. Consequently, the older subjects were waking at a time when they had higher relative melatonin levels, in contrast with younger subjects, whose melatonin levels were relatively lower by wake time. Our findings indicate that aging is associated not only with an advance of sleep timing and the timing of circadian rhythms but also with a change in the internal phase relationship between the sleep-wake cycle and the output of the circadian pacemaker. In healthy older subjects, the relative timing of the melatonin rhythm with respect to sleep may not play a causal role in sleep disruption.