Characterization of the interaction of metal-protoporphyrins photosensitizers with ß- lactoglobulin.

We investigated the interaction of a series of metal-protoporphyrins (PPIXs) with bovine ß- lactoglobulin (BLG) using a combination of optical spectroscopy and computational simulations. Unlike other studies, the simulations were not merely used to rationalize the experimental data but were employed to refine the experimental data itself. The study was carried out at two pH values, 5 and 9, where BLG is known to have different conformation dictated by the so-called Tanford transition which occurs near pH 7.5. The transition is postulated to regulate access to the interior binding cavity of the protein, thus the pH variation was used as a parameter to investigate whether PPIXs access the central cavity of BLG. The results of our study show that indeed binding increases significantly at alkaline pH, however, the increased affinity is not due to the accessibility of the central cavity. Instead, binding appears to be determined by the tendency of PPIXs to form large inhomogeneous aggregates at acidic pH which hinders interactions with proteins. The binding site determined through a combination of experimental and computational methods is located at the interface between two BLG monomers where the long α-helix segment of the protein face each other. This region is rich in positively charged Lys residues that interact with the propionic acid chains of the protoporphyrins. Establishing the modality of binding between protoporphyrins and BLG would have important consequences for the use of BLG:PPIX complexes in applications such as artificial photoreceptors, artificial metallo-enzymes, delivery of photosensitizers for phototherapy and even solar energy conversion.

Effects of Combined Inorganic Nitrate and Nitrite Supplementation on Cardiorespiratory Fitness and Skeletal Muscle Oxidative Capacity in Type 2 Diabetes: A Pilot Randomized Controlled Trial.

Nitric oxide (NO) stimulates mitochondrial biogenesis in skeletal muscle. However, NO metabolism is disrupted in individuals with type 2 diabetes mellitus (T2DM) potentially contributing to their decreased cardiorespiratory fitness (i.e., VO2max) and skeletal muscle oxidative capacity. We used a randomized, double-blind, placebo-controlled, 8-week trial with beetroot juice containing nitrate (NO3−) and nitrite (NO2−) (250 mg and 20 mg/day) to test potential benefits on VO2max and skeletal muscle oxidative capacity in T2DM. T2DM (N = 36, Age = 59 ± 9 years; BMI = 31.9 ± 5.0 kg/m2) and age- and BMI-matched non-diabetic controls (N = 15, Age = 60 ± 9 years; BMI = 29.5 ± 4.6 kg/m2) were studied. Mitochondrial respiratory capacity was assessed in muscle biopsies from a subgroup of T2DM and controls (N = 19 and N = 10, respectively). At baseline, T2DM had higher plasma NO3− (100%; p < 0.001) and lower plasma NO2− levels (−46.8%; p < 0.0001) than controls. VO2max was lower in T2DM (−26.4%; p < 0.001), as was maximal carbohydrate- and fatty acid-supported oxygen consumption in permeabilized muscle fibers (−26.1% and −25.5%, respectively; p < 0.05). NO3−/NO2− supplementation increased VO2max (5.3%; p < 0.01). Further, circulating NO2−, but not NO3−, positively correlated with VO2max after supplementation (R2= 0.40; p < 0.05). Within the NO3−/NO2− group, 42% of subjects presented improvements in both carbohydrate- and fatty acid-supported oxygen consumption in skeletal muscle (vs. 0% in placebo; p < 0.05). VO2max improvements in these individuals tended to be larger than in the rest of the NO3−/NO2− group (1.21 ± 0.51 mL/(kg*min) vs. 0.31 ± 0.10 mL/(kg*min); p = 0.09). NO3−/NO2− supplementation increases VO2max in T2DM individuals and improvements in skeletal muscle oxidative capacity appear to occur in those with more pronounced increases in VO2max.

Dietary Inorganic Nitrate/Nitrite Supplementation Reduces Central and Peripheral Blood Pressure in Patients With Type 2 Diabetes Mellitus.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) have increased cardiovascular risk due to elevated blood pressure (BP). As low levels of nitric oxide (NO) may contribute to increased BP, we determined if increasing NO bioavailability via eight weeks of supplementation with beetroot juice containing inorganic nitrate/nitrite (4.03 mmol nitrate, 0.29 mmol nitrite) improves peripheral and central BP relative to nitrate/nitrite-depleted beetroot juice. METHODS: Peripheral and central BP were assessed at heart-level in supine subjects using a brachial artery catheter and applanation tonometry, respectively. RESULTS: Nitrate/nitrite supplementation reduced peripheral systolic BP (148 ± 16 to 142 ± 18 mm Hg, P < 0.05) but not placebo (150 ± 19 to 149 ± 17 mm Hg, P = 0.93); however, diastolic BP was unaffected (supplement-by-time P = 0.08). Central systolic BP (131 ± 16 to 127 ± 17 mm Hg) and augmented pressure (13.3 ± 6.6 to 11.6 ± 6.9 mm Hg, both P < 0.05) were reduced after nitrate/nitrite, but not placebo (134 ± 17 to 135 ± 16 mm Hg, P = 0.62; 14.1 ± 6.6 to 15.2 ± 7.4 mm Hg, P = 0.20); central diastolic BP was unchanged by the interventions (supplement-by-time P = 0.16). Inorganic nitrate/nitrite also reduced AIx (24.3 ± 9.9% to 21.0 ± 9.6%) whereas no changes were observed following placebo (24.6 ± 9.3% to 25.6 ± 9.9%, P = 0.46). CONCLUSIONS: Inorganic nitrate/nitrite supplementation improves peripheral and central BP as well as AIx in T2DM. CLINICAL TRIALS REGISTRATION: Trial Number NCT02804932.

Sodium nitrate supplementation improves blood pressure reactivity in patients with peripheral artery disease.

BACKGROUND & AIMS: Peripheral artery disease (PAD) is characterized by elevated blood pressure (BP), low nitric oxide availability (NO), and exaggerated pressor responses to sympatho-excitatory stressors. Inorganic nitrate reduces peripheral BP in healthy and chronically diseased populations. The objective of this study was to investigate the effects of eight-weeks of sodium nitrate (NaNO3) supplementation on indices of BP in PAD patients. METHODS: 21 patients with PAD were recruited to participate in this study, undergoing 8-weeks of NaNO3 (n = 13; 73 ± 9 years) or placebo (n = 8; 69 ± 10 years) supplementation. BP responsiveness to a cold pressor test (CPT) were examined prior to and following the supplementation period. The systolic BP response (change from rest) during the first (26 ± 10 vs. 19 ± 11 mmHg) and second minutes (32 ± 10 vs. 26 ± 12 mmHg) of CPT were reduced following NaNO3 (P < 0.05 for both) but not after placebo (first minute: 22 ± 10 vs. 24 ± 10 mmHg, P = 0.30; second minute 26 ± 10 vs 27 ± 10 mmHg, P = 0.72) supplementation. CONCLUSION: Our data suggest that eight-weeks of NaNO3 supplementation reduces BP responsiveness to sympatho-excitatory stimuli. CLINICAL TRIALS REGISTRATION NUMBER: NCT01983826.

Effects of Whey Protein Supplementation on Aortic Stiffness, Cerebral Blood Flow, and Cognitive Function in Community-Dwelling Older Adults: Findings from the ANCHORS A-WHEY Clinical Trial.

ANCHORS A-WHEY was a 12-week randomized controlled trial (RCT) designed to examine the effect of whey protein on large artery stiffness, cerebrovascular responses to cognitive activity and cognitive function in older adults. METHODS: 99 older adults (mean ± SD; age 67 ± 6 years, BMI 27.2 ± 4.7kg/m2, 45% female) were randomly assigned to 50g/daily of whey protein isolate (WPI) or an iso-caloric carbohydrate (CHO) control for 12 weeks (NCT01956994). Aortic stiffness was determined as carotid-femoral pulse wave velocity (cfPWV). Aortic hemodynamic load was assessed as the product of aortic systolic blood pressure and heart rate (Ao SBP × HR). Cerebrovascular response to cognitive activity was assessed as change in middle-cerebral artery (MCA) blood velocity pulsatility index (PI) during a cognitive perturbation (Stroop task). Cognitive function was assessed using a computerized neurocognitive battery. RESULTS: cfPWV increased slightly in CHO and significantly decreased in WPI (p < 0.05). Ao SBP × HR was unaltered in CHO but decreased significantly in WPI (p < 0.05). Although emotion recognition selectively improved with WPI (p < 0.05), WPI had no effect on other domains of cognitive function or MCA PI response to cognitive activity (p > 0.05 for all). CONCLUSIONS: Compared to CHO, WPI supplementation results in favorable reductions in aortic stiffness and aortic hemodynamic load with limited effects on cognitive function and cerebrovascular function in community-dwelling older adults.

Surgical Treatment for Refractory Gastroparesis: Stimulator, Pyloric Surgery, or Both?

BACKGROUND: Several surgical options exist for refractory gastroparesis (Gp) including gastric electric stimulation (GES) and pyloric surgery (PS) such as pyloromyotomy or pyloroplasty. Few studies exist comparing the outcomes of these surgeries. AIM: Compare the clinical outcomes of GES, PS, and simultaneous GES+PS for refractory Gp. METHODS: Patients undergoing surgical intervention at our medical center from January 2016 to April 2019 were given pre- and post-surgery questionnaires to assess their response to intervention: Patient Assessment of Upper Gastrointestinal Symptoms (PAGI-SYM) grading symptoms and Clinical Patient Grading Assessment Scale (CPGAS) grading response to treatment. Results are expressed as mean ± SE. RESULTS: One hundred thirty-two patients underwent surgical intervention; 12 were excluded. Mean CPGAS improvement overall was 2.8 ± 0.2 (p < 0.01): GES+PS had CPGAS score at 3.6 ± 0.5, pyloric interventions 3.1 ± 0.5, and GES 2.5 ± 0.4 (p > 0.05). Mean improvement in Gastroparesis Cardinal Symptom Index (GCSI) total score was 1.0 ± 0.1 (p < 0.01), with improvement of 1.1 ± 0.2 for GES + PS, 0.9 ± 0.2 for GES, and 0.9 ± 0.2 for PS (p > 0.05). GES and GES + PS, but not PS only, significantly improved symptoms of nausea and vomiting (p < 0.01). Among gastroparesis subtypes, patients with diabetic gastroparesis had more improvement on nausea/vomiting subscale compared with idiopathic gastroparesis (p = 0.028). CONCLUSIONS: Patients with refractory symptoms of Gp undergoing GES, PS, or combined GES+PS each had significant improvement of their GCSI total score. GES and combined GES+PS significantly improved nausea/vomiting. These results suggest GES or combined GES+PS appears better for nausea/vomiting predominant refractory Gp.

Inorganic nitrate supplementation enhances functional capacity and lower-limb microvascular reactivity in patients with peripheral artery disease.

Peripheral artery disease (PAD) is characterized by functional and vascular impairments as well as elevated levels of inflammation which are associated with reduced nitric oxide (NO) bioavailability. Inorganic nitrate supplementation boosts NO bioavailability potentially improving functional and vasodilatory capacities and may reduce inflammation. Twenty-one patients with PAD were randomly assigned to sodium nitrate (NaNO3) or placebo supplementation groups for eight-weeks. Outcome measures included a 6-min walk test (6 MWT), blood flow and vasodilator function in the forearm and calf, as well as plasma inflammatory and adhesion biomarker concentrations. NaNO3 elevated plasma nitrate (32.3 ±â€¯20.0 to 379.8 ±â€¯204.6 µM) and nitrite (192.2 ±â€¯51.8 to 353.1 ±â€¯134.2 nM), improved 6 MWT performance (387 ±â€¯90 to 425 ±â€¯82 m), peak calf blood flow (BFPeak; 11.6 ±â€¯4.9 to 14.1 ±â€¯5.1 mL/dL tissue/min), and peak calf vascular conductance (VCPeak; 11.1 ±â€¯4.3 to 14.2 ±â€¯4.9 mL/dL tissue/min/mmHg) (p < 0.05 for all). Improvements in calf BFPeak (r = 0.70, p < 0.05) and VCPeak (r = 0.61, p < 0.05) correlated with changes in 6 MWT distance. Placebo supplementation did not change plasma nitrate or nitrite, 6 MWT, calf BFPeak, or calf VCPeak. Forearm vascular function nor inflammatory and adhesion biomarker concentrations changed in either group. Eight-weeks of NaNO3 supplementation improves vasodilatory capacity in the lower-limbs of patients with PAD, which correlated with improvement in functional capacity.

Reduced blood pressure responsiveness to skeletal muscle metaboreflex activation in older adults following inorganic nitrate supplementation.

The vasoactive molecule nitric oxide (NO) contributes to regulation of blood pressure (BP) at rest and during exercise. Age-related exaggerated increased BP responses during exercise have been proposed to be due in part to a decreased NO bioavailability and possibly an enhanced skeletal muscle metaboreflex. In the present study we sought to determine if age-related differences in BP responses to skeletal muscle metaboreflex activation exist. Additionally, since NO bioavailability can be improved with exogenous nitrate (NO3-) via the nitrate-nitrite-NO pathway, we tested the hypothesis that inorganic NO3- supplementation would reduce BP responses to muscle metaboreflex activation in healthy older adults. 13 older adults (67 ±â€¯1 years) participated in a randomized, double-blind, placebo controlled crossover study consisting of four weeks of NO3- supplementation [beetroot powder; 250 mg (∼4.03 mmol) of NO3- and 20 mg (∼0.29 mmol) of NO2-] and four weeks of placebo (beetroot powder devoid of NO3-/NO2-). Skeletal muscle metaboreflex testing consisted of isometric handgrip exercise (IHG) at 30% of maximal voluntary contraction immediately followed by post exercise forearm ischemia (PEI), which was achieved by inflation of a rapid pressure cuff (240 mmHg) around the upper arm. BP responses were analyzed as the change (Δ) from baseline to the end of IHG and PEI. An additional 10 young adults (25 ±â€¯1 years) were recruited to serve as a reference cohort and address if BP responses to skeletal muscle metaboreflex activation were greater with aging. BP responses to IHG were similar between the young and older adults. However, older adults demonstrated a greater increase in systolic BP during PEI (P < 0.05). Plasma NO3- and NO2-were increased following NO3- supplementation in older adults (P < 0.01). ΔSystolic BP (19 ±â€¯2 vs. 13±3 mmHg, P < 0.05), ΔDiastolic BP (7 ±â€¯1 vs. 5±1 mmHg, P < 0.05) and ΔMean arterial pressure (11 ±â€¯1 vs. 8±2 mmHg, P < 0.05) were reduced during PEI following four weeks of NO3-supplementation, whereas placebo had no effect on ΔSystolic BP (16 ±â€¯2 vs. 17±2 mmHg), ΔDiastolic BP (5 ±â€¯1 vs. 7±1 mmHg), and ΔMean arterial pressure (8 ±â€¯1 vs. 10±1 mmHg) during PEI (all P > 0.05). These data suggest that inorganic NO3- supplementation attenuates skeletal muscle metaboreflex mediated increases in BP during exercise in older adults.

Inorganic nitrate supplementation attenuates peripheral chemoreflex sensitivity but does not improve cardiovagal baroreflex sensitivity in older adults.

Aging is associated with increased peripheral chemoreceptor activity, reduced nitric oxide (NO) bioavailability, and attenuation of cardiovagal baroreflex sensitivity (BRS), collectively increasing the risk of cardiovascular disease. Evidence suggests that NO may attenuate peripheral chemoreflex sensitivity and increase BRS. Exogenous inorganic nitrate ([Formula: see text]) increases NO bioavailability via the [Formula: see text]-[Formula: see text]-NO pathway. Our hypothesis was that inorganic [Formula: see text] supplementation would attenuate peripheral chemoreflex sensitivity and enhance spontaneous cardiovagal BRS in older adults. We used a randomized, placebo-controlled crossover design in which 13 older (67 ± 3 yr old) adults ingested beetroot powder containing (BRA) or devoid of (BRP) [Formula: see text] and [Formula: see text] daily over 4 wk. Spontaneous cardiovagal BRS was assessed over 15 min of rest and was quantified using the sequence method. Chemoreflex sensitivity was assessed via ~5 min of hypoxia (10% fraction of inspired O2) and reported as the slope of the relationship between O2 saturation (%[Formula: see text]) and minute ventilation (in l/min) or heart rate (in beats/min). Ventilatory responsiveness to hypoxia was reduced after BRA (from -0.14 ± 0.04 to -0.05 ± 0.02 l·min-1·%[Formula: see text]-1, P = 0.01) versus BRP (from -0.10 ± 0.05 to -0.11 ± 0.05 l·min-1·%[Formula: see text]-1, P = 0.80), with no differences in heart rate responsiveness (BRA: from -0.47 ± 0.06 to -0.33 ± 0.04 beats·min-1·%[Formula: see text]-1, BRP: from -0.48 ± 0.07 to -0.42 ± 0.06 beats·min-1·%[Formula: see text]-1) between conditions (interaction effect, P = 0.41). Spontaneous cardiovagal BRS was unchanged after BRA and BRP (interaction effects, P = 0.69, 0.94, and 0.39 for all, up, and down sequences, respectively), despite a reduction in resting systolic and mean arterial blood pressure in the experimental (BRA) group ( P < 0.01 for both). These findings illustrate that inorganic [Formula: see text] supplementation attenuates peripheral chemoreflex sensitivity without concomitant change in spontaneous cardiovagal BRS in older adults. NEW & NOTEWORTHY Exogenous inorganic nitrate supplementation attenuates ventilatory, but not heart rate, responsiveness to abbreviated hypoxic exposure in older adults. Additionally, inorganic nitrate reduces systolic and mean arterial blood pressure without affecting spontaneous cardiovagal baroreflex sensitivity. These findings suggest that inorganic nitrate may attenuate sympathetically oriented pathologies associated with aging.

Effects of acute dietary nitrate supplementation on aortic blood pressure and aortic augmentation index in young and older adults.

PURPOSE: Aging is associated with elevated blood pressure (peripheral and aortic; BP) and aortic augmentation index (AIx) which may contribute to aortic BP. Although inorganic nitrate consumption reduces peripheral BP in both young and older adults, the effects of nitrate consumption on aortic BP and wave reflection in young and older adults is unknown. Therefore, we sought to characterize the effects of nitrate consumption on aortic BP and AIx in young and older adults. METHODS: Noninvasive aortic pressure waveforms were synthesized from high-fidelity radial pressure waveforms via applanation tonometry before and following (60, 90, 120, 150, and 180 min) consumption of a nitrate-rich beetroot juice in 26 healthy adults (young: 25 ± 4 years, n = 14; older: 64 ± 5 years, n = 12). Aortic BP and indices of aortic wave reflection (AIx and AIx normalized for heart rate; AIx@75bpm) were calculated from the generated aortic pressure waveform. RESULTS: Nitrate consumption increased plasma nitrite in both groups 60-180 min following beetroot consumption (P < 0.001). Nitrate consumption reduced peripheral and aortic BP in both young and older adults (P < 0.05), with the change being similar between age groups. Conversely, indices of aortic wave reflection were reduced only in young adults following nitrate consumption (range of change from baseline over time: AIx@75bpm, -4.3 to -8.8%, P < 0.05), whereas aortic AIx remained unchanged in the older adults. CONCLUSIONS: Taken together, our results suggest that acute dietary nitrate supplementation reduces peripheral and aortic BP similarly in young and older adults despite differential effects on aortic AIx between age groups.

Effect of acute nitrate supplementation on neurovascular coupling and cognitive performance in hypoxia.

The matching of oxygen supply to neural demand (i.e., neurovascular coupling (NVC)) is an important determinant of cognitive performance. The impact of hypoxia on NVC remains poorly characterized. NVC is partially modulated by nitric oxide (NO), which may initially decrease in hypoxia. This study investigated the effect of acute NO-donor (nitrate) supplementation on NVC and cognitive function in hypoxia. Twenty healthy men participated in this randomized, double-blind, crossover design study. Following normoxic cognitive/NVC testing, participants consumed either nitrate (NIT) or a NIT-depleted placebo (PLA). Participants then underwent 120 min of hypoxia (11.6% ± 0.1% O2) and all cognitive/NVC testing was repeated. NVC was assessed as change in middle cerebral artery (MCA) blood flow during a cognitive task (incongruent Stroop) using transcranial Doppler. Additional computerized cognitive testing was conducted separately to assess memory, executive function, attention, sensorimotor, and social cognition domains. Salivary nitrite significantly increased following supplementation in hypoxia for NIT (+2.6 ± 1.0 arbitrary units (AU)) compared with PLA (+0.2 ± 0.3 AU; p < 0.05). Memory performance (-6 ± 13 correct) significantly decreased (p < 0.05) in hypoxia while all other cognitive domains were unchanged in hypoxia for both PLA and NIT conditions (p > 0.05). MCA flow increased during Stroop similarly in normoxia (PLA +5 ± 6 cm·s(-1), NIT +7 ± 7 cm·s(-1)) and hypoxia (PLA +5 ± 9 cm·s(-1), NIT +6 ± 7 cm·s(-1)) (p < 0.05) and this increase was not altered by PLA or NIT (p > 0.05). In conclusion, acute hypoxia resulted in significant reductions in memory concomitant with preservation of executive function, attention, and sensorimotor function. Hypoxia had no effect on NVC. Acute NIT supplementation had no effect on NVC or cognitive performance in hypoxia.

Gastric Electric Stimulation for Refractory Gastroparesis: A Prospective Analysis of 151 Patients at a Single Center.

BACKGROUND: Gastric electric stimulation (GES) is used to treat patients with refractory gastroparesis symptoms. However, the effectiveness of GES in clinical practice and the effect of GES on specific symptoms of gastroparesis are not well delineated. AIMS: To determine the effectiveness of GES for treatment for refractory symptoms of gastroparesis, the improvement in specific symptoms of gastroparesis, and clinical factors impacting on outcome. METHODS: Enterra GES was used to treat refractory gastroparesis symptoms. Patients filled out a symptom severity questionnaire (PAGI-SYM) prior to insertion. At each follow-up visit, the patient filled out PAGI-SYM and assessed their therapeutic response using the Clinical Patient Grading Assessment Scale (CPGAS). RESULTS: One hundred and fifty-one patients (120 females) with refractory gastroparesis (72 diabetic, 73 idiopathic, 6 other) underwent GES. Of the 138 with follow-up (1.4 ± 1.0 years), the average CPGAS was 2.4 ± 0.3 (SEM): 104 patients (75 %) improved (CPGAS > 0) and 34 (25 %) did not (CPGAS ≤ 0). Sixty patients (43 %) were at least moderately improved (CPGAS score ≥4). Clinical improvement was seen in both diabetic and idiopathic patients with the CPGAS in diabetic patients (3.5 ± 0.3) higher in idiopathic patients (1.5 ± 0.5; p < 0.05). Symptoms significantly improving the most included nausea, loss of appetite, and early satiety. Vomiting improved in both diabetic and idiopathic patients although the diabetic subgroup experienced a significantly greater reduction in vomiting than the idiopathic subgroup. CONCLUSIONS: In this cohort of patients with refractory gastroparesis, GES improved symptoms in 75 % of patients with 43 % being at least moderately improved. Response in diabetics was better than in nondiabetic patients. Nausea, loss of appetite, and early satiety responded the best.

Nutritional limitation and resistance to opportunistic Aspergillus parasites in honey bee larvae.

Honey bees are threatened by land use changes which reduce the availability and diversity of pollen and nectar resources. There is concern that poor nutrition may be involved in recent population declines, either directly or due to indirect effects on immunocompetence. The larval stage is likely to be the most vulnerable to a poor diet, but the effects of larval nutrition on the disease susceptibility of bees are not well known. In this study we used laboratory-reared honey bee larvae to investigate the effects of diet quality on disease susceptibility to the opportunistic fungal parasites Aspergillus flavus, Aspergillus phoenicis and A. fumigatus. Larvae fed on a nutritionally poor diet were found to be significantly more susceptible to A. fumigatus. Larval resistance to A. fumigatus was enhanced by feeding with a diet supplemented with either dandelion or polyfloral pollens. This indicates that dandelion and polyfloral pollens contain elements that enhance resistance to this fungal disease, illustrating an interaction between nutrition and parasitism and emphasising the benefit of diverse floral resources in the environment to maintain honey bee health.

Cervical necrotizing fasciitis originating with a periapical infection.

BACKGROUND: Necrotizing fasciitis is a rapidly spreading, soft-tissue infection involving the subcutaneous tissues. Necrotizing fasciitis originating from a dental-related source is rare. Practitioners should be aware that this infection could occur in patients who are immunocompromised and in patients who are healthy. Practitioners must treat this disease aggressively with surgical debridement and intensive medical support. CASE DESCRIPTION: The authors present a case report of a man with poorly controlled diabetes mellitus in whom a periapical infection progressed into a maxillofacial space abscess and finally cervical necrotizing fasciitis (CNF). A delay in his initial visit to a dentist was evident. The authors observed a successful outcome in the patient after he underwent several wide surgical debridement procedures, hyperbaric oxygen therapy and a protracted, intensive hospital stay lasting 34 days. CONCLUSIONS: Dentists should suspect that a patient has CNF when maxillofacial cellulitis or an abscess does not respond to conventional therapy. Findings of spreading skin erythema, induration, purple discoloration and anesthesia suggest necrotizing fasciitis. Early computed tomography scans may reveal gas within the deep tissues of the neck, fascial plane involvement or both. CLINICAL IMPLICATIONS: CNF has high morbidity and mortality rates if rapid aggressive therapy is not pursued. Spread of this polymicrobial infection can lead to mediastinitis or cranial base involvement. Mortality is directly proportional to the time to intervention.

Cardioprotective role of sodium thiosulfate on chronic heart failure by modulating endogenous H2S generation.

BACKGROUND/AIMS: Sodium thiosulfate (STS) has been shown to be an antioxidant and calcium solubilizer, but the possible role of STS in dysfunctional ventricles remains unknown. Here, we assessed the effects of STS in the failing heart. METHODS: Heart failure was created by an arteriovenous fistula (AVF). Mice were divided into 4 groups: sham, AVF, sham + STS, and AVF + STS. STS (3 mg/ml) was supplemented with drinking water for 6 weeks in the appropriate surgery groups after surgery. RESULTS: M-mode echocardiograms showed ventricular contractile dysfunction with reduced aortic blood flow in AVF mice, whereas STS treatment prevented the decline in cardiac function. Ventricular collagen, MMP-2 and -9, and TIMP-1 were robustly increased with a decreasing trend in adenylate cyclase VI expression; however, STS supplementation reversed these effects in AVF mice. Among 2 enzymes that produce endogenous hydrogen sulfide (H(2)S), cystathionine-gamma-lyase (CSE) expression was attenuated in AVF mice with no changes in cystathionine-beta-synthase (CBS) expression. In addition, reduced production of H(2)S in AVF ventricular tissue was normalized with STS supplementation. Moreover, cardiac tissues were more responsive to H(2)S when AVF mice were supplemented with STS compared to AVF alone. CONCLUSIONS: These results suggested that STS modulated cardiac dysfunction and the extracellular matrix, in part, by increasing ventricular H(2)S generation.

Role of copper and homocysteine in pressure overload heart failure.

Elevated levels of homocysteine (Hcy) (known as hyperhomocysteinemia HHcy) are involved in dilated cardiomyopathy. Hcy chelates copper and impairs copper-dependent enzymes. Copper deficiency has been linked to cardiovascular disease. We tested the hypothesis that copper supplement regresses left ventricular hypertrophy (LVH), fibrosis and endothelial dysfunction in pressure overload DCM mice hearts. The mice were grouped as sham, sham + Cu, aortic constriction (AC), and AC + Cu. Aortic constriction was performed by transverse aortic constriction. The mice were treated with or without 20 mg/kg copper supplement in the diet for 12 weeks. The cardiac function was assessed by echocardiography and electrocardiography. The matrix remodeling was assessed by measuring matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinases (TIMPs), and lysyl oxidase (LOX) by Western blot analyses. The results suggest that in AC mice, cardiac function was improved with copper supplement. TIMP-1 levels decreased in AC and were normalized in AC + Cu. Although MMP-9, TIMP-3, and LOX activity increased in AC and returned to baseline value in AC + Cu, copper supplement showed no significant effect on TIMP-4 activity after pressure overload. In conclusion, our data suggest that copper supplement helps improve cardiac function in a pressure overload dilated cardiomyopathic heart.

Cytochrome P450 (CYP) 2J2 gene transfection attenuates MMP-9 via inhibition of NF-kappabeta in hyperhomocysteinemia.

Hyperhomocysteinemia (HHcy) is associated with atherosclerotic events involving the modulation of arachidonic acid (AA) metabolism and the activation of matrix metalloproteinase-9 (MMP-9). Cytochrome P450 (CYP) epoxygenase-2J2 (CYP2J2) is abundant in the heart endothelium, and its AA metabolites epoxyeicosatrienoic acids (EETs) mitigates inflammation through NF-kappabeta. However, the underlying molecular mechanisms for MMP-9 regulation by CYP2J2 in HHcy remain obscure. We sought to determine the molecular mechanisms by which P450 epoxygenase gene transfection or EETs supplementation attenuate homocysteine (Hcy)-induced MMP-9 activation. CYP2J2 was over-expressed in mouse aortic endothelial cells (MAECs) by transfection with the pcDNA3.1/CYP2J2 vector. The effects of P450 epoxygenase transfection or exogenous supplementation of EETs on NF-kappabeta-mediated MMP-9 regulation were evaluated using Western blot, in-gel gelatin zymography, electromobility shift assay, immunocytochemistry. The result suggested that Hcy downregulated CYP2J2 protein expression and dephosphorylated PI3K-dependent AKT signal. Hcy induced the nuclear translocation of NF-kappabeta via downregulation of IKbetaalpha (endogenous cytoplasmic inhibitor of NF-kappabeta). Hcy induced MMP-9 activation by increasing NF-kappabeta-DNA binding. Moreover, P450 epoxygenase transfection or exogenous addition of 8,9-EET phosphorylated the AKT and attenuated Hcy-induced MMP-9 activation. This occurred, in part, by the inhibition of NF-kappabeta nuclear translocation, NF-kappabeta-DNA binding and activation of IKbetaalpha. The study unequivocally suggested the pivotal role of EETs in the modulation of Hcy/MMP-9 signal.