Technical note: valuation of an enteric methane emissions measurement system for cattle.

Through the process of enteric fermentation, cattle produce methane (CH), a potent greenhouse gas (GHG). Growing public concern about climate change has increased the need for accurate methods of measuring CH emissions from cattle directly to improve emission inventories and evaluate emissions mitigation techniques. The present study evaluated a ventilated head box system capable of measuring CH and carbon dioxide (CO) emissions, and oxygen (O) consumption from cattle. Six Holstein heifers were used to measure CH and CO emissions and O consumption from 2 ad libitum intake measurement periods (ADAPT and ADLIB) and 1 measurement period (RESTRICT) with intake restricted to 2% of BW on a DM basis. Methane emissions during RESTRICT were significantly lower ( < 0.0001) than both ad libitum periods. Daily CH4 emission rates per animal were 235.0 ± 6.19 L/d, 228.3 ± 6.18 L/d, and 193.2 ± 8.88 L/d for the periods ADAPT, ADLIB, and RESTRICT, respectively. Carbon dioxide emission rates were 3627 ± 90.72 L/d, 3632 ± 90.47, and 3184 ± 104.79 L/d for the ADAPT, ADLIB, and RESTRICT periods, respectively. Oxygen consumption rates were 3391 ± 99.77 L/d, 3454 ± 99.57 L/d, and 3002 ± 111.36 L/d for the periods ADAPT, ADLIB, and RESTRICT, respectively. The head box system evaluated provides an accurate method of measuring emissions from cattle and can provide information about daily variations and peaks in emissions.

Impacted morselized cancellous bone: mechanical effects of defatting and augmentation with fine hydroxyapatite particles.

Geotechnical engineering testing techniques were used to study the mechanical properties of morselized cancellous bone (MCB) and the effects of defatting and augmentation with fine hydroxyapatite (HA) particles. Bovine and human cancellous bone was morselized, rinsed, and manually squeezed to remove excess fluid, producing a standard surgical MCB sample that was also used as a control. Some of the MCB was defatted with heat and detergent and mixed with HA particles in ratios ranging from 0% to 100% HA. Compaction tests were used to determine the effects of moisture content and the amount of MCB that can be packed into a confined space. One-dimensional consolidation tests were used to determine the uniaxial strain behavior, confined modulus, and steady-state creep rate. The compaction tests demonstrated that defatting and adding HA particles significantly increased density. The one-dimensional consolidation tests showed that strain was decreased, modulus was increased and the creep rate was decreased by defatting and adding HA.

Systematic review of clinical effectiveness of pressurised metered dose inhalers versus other hand held inhaler devices for delivering beta (2 )agonists bronchodilators in asthma.

OBJECTIVES: To determine the clinical effectiveness of pressurised metered dose inhalers compared with other hand held inhaler devices for delivering short acting beta(2) agonists in stable asthma. DESIGN: Systematic review of randomised controlled trials. DATA SOURCES: Cochrane Airways Group specialised trials database (which includes hand searching of 20 relevant journals), Medline, Embase, Cochrane controlled clinical trials register, pharmaceutical companies, and bibliographies of included trials. TRIALS: All trials in children or adults with stable asthma that compared the pressurised metered dose inhaler (with or without a spacer device) against any other hand held inhaler device containing the same beta(2) agonist. RESULTS: 84 randomised controlled trials were included. No differences were found between the pressurised metered dose inhaler and any other hand held inhaler device for lung function, blood pressure, symptoms, bronchial hyperreactivity, systemic bioavailability, inhaled steroid requirement, serum potassium concentration, and use of additional relief bronchodilators. In adults, pulse rate was lower in those using the pressurised metered dose inhaler compared with those using Turbohaler (standardised mean difference 0.44, 95% confidence interval 0.05 to 0.84); patients preferred the pressurised metered dose inhaler to the Rotahaler (relative risk 0.53, 95% confidence interval 0.36 to 0.78); hydrofluoroalkane pressurised metered dose inhalers reduced the requirement for rescue short course oral steroids (relative risk 0.67, 0.49 to 0.91). CONCLUSIONS: No evidence was found to show that alternative inhaler devices are more effective than standard pressurised metered dose inhalers for delivering acting beta(2 )agonist bronchodilators in asthma. Pressurised metered dose inhalers remain the most cost effective delivery devices.

Anomalies of binocular function in patients with longstanding asymmetric keratoconus.

AIMS: To study binocular function in patients with longstanding asymmetric keratoconus. METHODS: In 20 adult patients with longstanding asymmetric keratoconus managed with a scleral contact lens a full clinical and orthoptic assessment was performed with and without the scleral contact lens in the poorer eye. RESULTS: All 20 patients had a corrected acuity of at least 6/9 in their better eye. With the scleral lens in situ the acuity of the poorer eye ranged from 6/6 to 6/60 and without the lens from 6/18 to hand movements. Patients were aged from 18 to 68 years and had worn a scleral contact lens for between 3 and 106 months. Without the contact lens in their poorer eye all patients had a small exotropia and all showed suppression, with the exception of one patient who had a right hypertropia with diplopia. With the scleral lens in situ 12 patients had an exophoria or esophoria, six a microexotropia, and two a manifest exotropia with suppression. CONCLUSIONS: Binocular function breaks down in some adult patients with longstanding asymmetric keratoconus. This is probably caused by longstanding unilateral visual deprivation. There are similarities to the breakdown of binocular function seen in some patients with a longstanding dense unilateral adult onset cataract who can develop intractable diplopia following cataract surgery.

Evaluation of motor vehicle driving performance in patients with chronic diplopia.

BACKGROUND: Uncorrected diplopia is a condition that may make it unsafe for a person to operate a motor vehicle. In some jurisdictions, physicians are required by law to report the person with diplopia to the appropriate authority. METHODS: In this masked study, 10 patients of varying ages with stable diplopia of greater than 6 months' duration and 10 age-matched control subjects were placed in a driving simulator and evaluated on their performance. Various cues and threats, including near-accident situations, were presented; stimulus recognition and reaction times were recorded. RESULTS: No significant difference was found between the groups for either cue or threat recognition responses or reaction times. Increasing age was the factor most associated with poor response performance on all test measures (P < .001). Slowed response time in patients with poor binocular single vision was the only other significant association. CONCLUSION: Although response times were slower in subjects with poor binocular single vision scores, stimulus recognition responses were not significantly different; in our opinion, stimulus recognition is more relevant to driving performance and therefore chronic diplopia does not appear to be a contraindication for driving a motor vehicle.

Induction of TNF-alpha and MnSOD by endotoxin: role of membrane CD14 and Toll-like receptor-4.

Endotoxin (LPS) is a potent inducer of tumor necrosis factor-alpha (TNF-alpha) and manganese superoxide dismutase (MnSOD). Recent evidence suggests that LPS induction of TNF-alpha and MnSOD mRNAs is mediated through distinct intracellular signal transduction pathways. Membrane CD14 (mCD14) and Toll-like receptor-4 (TLR4) mediate LPS induction of TNF-alpha in macrophages. In the current study, we evaluated the role of mCD14 and TLR4 in LPS induction of MnSOD using peritoneal macrophages from CD14 knockout (CD14-KO) mice and mice with the Tlr4 gene point mutation (C3H/HeJ) or deletion (C57BL/10ScCr). We studied mCD14-dependent (1 and 10 ng/ml) and mCD14-independent (1,000 ng/ml) concentrations of LPS. Compared with control (BALB/c) macrophages, LPS at 1 and 10 ng/ml failed to induce TNF-alpha or MnSOD mRNA in CD14-KO macrophages. However, LPS at 1,000 ng/ml induced TNF-alpha and MnSOD mRNAs equally in macrophages from CD14-KO and control mice. LPS (1, 10, or 1,000 ng/ml) failed to induce TNF-alpha or MnSOD mRNA and failed to activate nuclear factor-kappaB in C3H/HeJ or C57BL/10ScCr macrophages. Measurements of TNF-alpha and MnSOD enzyme activity paralleled TNF-alpha and MnSOD mRNA levels. These data demonstrate that, like TNF-alpha, induction of MnSOD by LPS is mediated by mCD14 and TLR4 in murine macrophages.

Differential induction of TNF-alpha and MnSOD by endotoxin: role of reactive oxygen species and NADPH oxidase.

Endotoxin (lipopolysaccharide [LPS]) is known to induce the production of tumor necrosis factor (TNF)-alpha and the induction of manganese superoxide dismutase (MnSOD). We have recently demonstrated that induction of TNF-alpha and MnSOD by LPS is mediated through different signal transduction pathways. In the current study, we investigated the role of reactive oxygen species (ROS) in the induction of TNF-alpha and MnSOD messenger RNAs (mRNAs) in human monocytes. Hypoxia (1% O2) inhibited the production of superoxide (O2-) and the induction of MnSOD, but not TNF-alpha, mRNA. Diphenylene iodonium (DPI), a potent inhibitor of the reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, had no effect on LPS induction of MnSOD mRNA, whereas it markedly inhibited LPS-induced O2- production. Neither hypoxia nor DPI had any effect on LPS activation of nuclear factor (NF)-kappaB. These results suggest that (1) ROS is important in the induction of MnSOD, but not TNF-alpha, mRNA by LPS, (2) ROS from sources other than NADPH oxidase is involved in LPS induction of MnSOD mRNA, and (3) ROS-mediated LPS induction of MnSOD mRNA is independent of NF-kappaB activation.

Qualitative and quantitative analysis of a thermoset polymer, poly(benzoxazine), by pyrolysis-gas chromatography.

The chemical composition of a poly(benzoxazine) thermoset polymer (a copolymer of bisphenol-A benzoxazine and tert.-butylphenol benzoxazine) has been studied by pyrolysis-gas chromatography (Py-GC). Major pyrolysates have been identified and the possible degradation pathways have been investigated. A specific pyrolysate was identified for quantitative analysis after carefully proving the linear relationship between the pyrolysate signal intensity and monomer concentration over a wide range of compositions. A method to determine the concentration of the monomer that potentially acts as a cross-linking unit has been developed. In this study, Py-GC was shown to be an excellent analytical technique for the qualitative and quantitative analysis of thermoset polymers.

Resveratrol induces Fas signalling-independent apoptosis in THP-1 human monocytic leukaemia cells.

Resveratrol, a natural product present in wine, has recently been shown to inhibit the growth of a number of cancer cell lines in vitro. In the current study, we have demonstrated that resveratrol inhibits the growth of THP-1 human monocytic leukaemia cells in a dose-dependent manner with a median effective dose of 12 microM. It did not induce differentiation of THP-1 cells and had no toxic effect on THP-1 cells that had been induced to differentiate into monocytes/macrophages by phorbol myristate acetate. A significant fraction of resveratrol-treated cells underwent apoptosis as judged by flow cytometric analysis of DNA content, DNA fragmentation and caspase-specific cleavage of poly(ADP-ribosyl) polymerase. Resveratrol treatment had no effect on the expression of Fas receptor or Fas ligand (FasL) in THP-1 cells, nor did it induce clustering of Fas receptors. In addition, THP-1 cells were resistant to activating anti-Fas antibody, and neutralizing anti-Fas and/or anti-FasL antibodies had no protective effect against resveratrol-induced inhibition of THP-1 cell growth. The effect of resveratrol on THP-1 cells was reversible after its removal from the culture medium. These results suggest that (1) resveratrol inhibits the growth of THP-1 cells, at least in part, by inducing apoptosis, (2) resveratrol-induced apoptosis of THP-1 cells is independent of the Fas/FasL signalling pathway and (3) resveratrol does not induce differentation of THP-1 cells and has no toxic effect on differentiated THP-1 cells. Thus, resveratrol may be a potential chemotherapeutic agent for the control of acute monocytic leukaemia.

Differential induction of tumor necrosis factor alpha and manganese superoxide dismutase by endotoxin in human monocytes: role of protein tyrosine kinase, mitogen-activated protein kinase, and nuclear factor kappaB.

A mutant Escherichia coli lipopolysaccharide (LPS) lacking myristoyl fatty acid markedly stimulates the activity of manganese superoxide dismutase (MnSOD) without inducing tumor necrosis factor alpha (TNFalpha) production by human monocytes (Tian et al., 1998, Am J Physiol 275:C740.), suggesting that induction of MnSOD and TNFalpha by LPS are regulated through different signal transduction pathways. The protein tyrosine kinase (PTK)/mitogen-activated protein kinase (MAPK) pathway plays an important role in the LPS-induced TNFalpha production. In the current study, we determined the effects of PTK inhibitors, genistein and herbimycin A, on the induction of MnSOD and TNFalpha in human monocytes. Genistein (10 microg/ml) and herbimycin A (1 microg/ml) markedly inhibited LPS-induced protein tyrosine phosphorylation, phosphorylation and nuclear translocation of MAPK (p42 ERK, extracellular signal-regulated kinase), and increases in the steady state level of TNFalpha mRNA as well as TNFalpha production. In contrast, at similar concentrations, genistein and herbimycin A had no effect on the LPS-induced activation of nuclear factor kappaB (NFkappaB) and induction of MnSOD (mRNA and enzyme activity) in human monocytes. In addition, inhibition of NFkappaB activation by gliotoxin and pyrrodiline dithiocarbamate, inhibited LPS induction of TNFalpha and MnSOD mRNAs. These results suggest that (1) while PTK and MAPK are essential for the production of TNFalpha, they are not necessary for the induction of MnSOD by LPS, and (2) while activation of NFkappaB alone is insufficient for the induction of TNFalpha mRNA by LPS, it is necessary for the induction of TNFalpha as well as MnSOD mRNAs.

Induction of TNF-alpha and MnSOD by endotoxin: effect of E5531, a synthetic non-toxic lipid A analog.

E5531, a synthetic lipid A analog, has been shown to inhibit endotoxin (lipopolysaccharide, LPS)-induced tumor necrosis factor-alpha (TNF-alpha) production by human monocytes and murine macrophages. Whether it also inhibits LPS induction of manganese superoxide dismutase (MnSOD) is not clear. In the current study, we demonstrated that E5531, while having no effect on TNF-alpha and MnSOD mRNAs by itself, markedly inhibited LPS- and lipid A-, but not TNF-alpha-, induced increases in TNF-alpha and MnSOD mRNAs in human monocytes. In contrast, E5531 at concentrations and conditions that markedly inhibit LPS-induced increases in TNF-alpha and MnSOD mRNAs, and TNF-alpha production by human monocytes, had no effect on murine peritoneal macrophages. These results demonstrate that E5531 is a potent LPS antagonist in human monocytes. However, it does not show antagonist action against LPS in murine macrophages in the range of concentrations tested, suggesting that E5531 is a more potent antagonist in humans than in mice.

Objective benefit of laser palatoplasty for non-apnoeic snoring.

Laser palatoplasty (LPP) is widely used for the treatment of non-apnoeic snoring, despite the lack of objective data supporting its use. We report measurements of snoring in a prospective study of LPP, and we compare the results with a previous study of uvulopalatopharyngoplasty (UPPP). Twenty patients with an apnoea/hypopnoea index < 20 h-1 underwent LPP for habitual snoring. Overnight sound recordings were compared before and 6 months after operation using three objective indices; L, (the level exceeded by the loudest 1% of sound), L5 (the level exceeded by the loudest 5% of sound) and P50 (% total sleep time above 50 dBA). The subjective impression of snoring severity (Wilcoxon test, P < 0.001), and objective indices L1 and P50 (t-test, P < 0.001) showed significant reductions after LPP. The mean change in L1 was 4.2 dBA, comparable to that we previously reported for UPPP, while P50 was reduced to less than one-third its preoperative value. No other sleep variables changed significantly following LPP. We conclude that LPP results in reduced snoring volume comparable to that following UPPP.

Psychometric performance before and after laser palatoplasty for non-apnoeic snoring.

Psychometric tests are an objective way of examining cognitive functioning, and have shown impairment in patients with obstructive sleep apnoea. Non-apnoeic snoring may cause reduced concentration, but psychometric tests have been used rarely in this population. We investigate whether their use can demonstrate an improvement in cognitive performance in 20 non-apnoeic snorers following Laser Palatoplasty (LPP). The subjects completed psychometric tests, Beck Anxiety and Depression Inventories and an Epworth Sleepiness Scale on two occasions before LPP and once postoperatively. The only index to show any significant change with LPP was the Beck Depression Inventory (P < 0.005), which was reduced by a mean of 1.6 units following surgery. There was also a highly significant improvement in information processing between the preoperative tests, for which no explanation could be found. Our results suggest that commonly applied psychometric tests are unable to demonstrate significant improvements following surgery for non-apnoeic snoring. However, we have demonstrated for the first time a significant reduction in depression following surgery, which is evidence that snoring is more than a social nuisance.

Mediastinal evaluation utilizing the reverse Trendelenburg radiograph.

When thoracic aortic rupture is suspected, a 45-degree reverse Trendelenburg (RT) anteroposterior (AP) chest radiograph should place the mediastinal structures in a more appropriate position and allow a more accurate evaluation than a supine AP radiograph. One hundred ninety-one consecutive hemodynamically stable adult patients with major blunt thoracic trauma were initially evaluated for mediastinal abnormalities associated with aortic disruption by both supine AP chest radiograph and an AP chest radiograph with the patient in 45-degree RT position. One hundred four patients underwent contrast aortography based on mediastinal abnormalities detected on the supine AP chest radiograph. Twenty of these patients had abnormal aortograms demonstrating traumatic aortic disruption confirmed at surgery. Supine and RT chest radiographs were retrospectively compared in a blinded fashion to evaluate their specificity and positive predictive value for detection of traumatic thoracic aortic rupture. If RT chest radiographic findings had been used to determine the need for further assessment, 29 angiograms (26%) would have been eliminated, specificity would have increased from 52 per cent to 69 per cent, and positive predictive value would have increased from 19 per cent to 27 per cent. Both supine and RT chest radiographs demonstrated mediastinal widening in all 20 patients with abnormal aortograms, with no missed thoracic aortic disruptions (100% sensitivity). This study indicated that the RT chest radiograph may be used instead of the standard supine radiograph as the initial screen for mediastinal evaluation, maintaining a high sensitivity and eliminating the cost and morbidity of many unnecessary aortograms.

Pertussis toxin-induced lung edema. Role of manganese superoxide dismutase and protein kinase C.

The mechanism by which pertussis toxin (Ptx) causes lung edema is not clear. We investigated the role of pulmonary manganese superoxide dismutase (MnSOD) and protein kinase C (PKC) in Ptx-induced lung edema. We demonstrated that intraperitoneal injection of Ptx at a concentration of 5 microg/100 g body weight caused a similar degree of lung edema in 2 d, as measured by lung wet weight/dry weight ratio, in heterozygous MnSOD gene (Sod2)-knockout mice (Sod2(+/-)) and in their wild-type littermates (Sod2(+/+)). The level of lung MnSOD activity in Sod2(+/-) mice was approximately half that of Sod2(+/-) mice. Ptx had no effect on levels of lung MnSOD messenger RNA, immunoreactive protein, or enzyme activity in either Sod2(+/+) or Sod2(+/-) mice. Ptx also had no effect on lung copper-zinc SOD, catalase, and glutathione peroxidase activities in these mice. On the other hand, Ptx caused the activation of lung PKC, for example, by translocation of a 72-kD PKC isoform from the cytosolic fraction to the membrane fraction. Pretreatment of mice with bisindolylmaleimide, a PKC inhibitor, prevented both the Ptx-induced activation of PKC and lung edema. These data suggest that Ptx-induced lung edema in mice is, at least in part, due to the activation of lung PKC.

The use of (a)symmetry of the rest position of the eyes under general anesthesia or sedation-hypnosis in the design of strabismus surgery: A favorable pilot study in 51 exotropia cases.

BACKGROUND AND PURPOSE: Studies support techniques of intraoperative adjustment under general anesthesia, of eye muscle surgery, based upon the rest position (deviation) to improve surgical results. None, however, have examined the (a)symmetry, per se, of the rest position and its influence on surgical outcomes. METHODS: Retrospective/prospective patient chart data and photographs taken of patients under anesthesia were judged for (a)symmetry of deviation and correlated with (a)symmetry of surgery performed on 51 exotropic patients. Two groups were compared: "matched" (symmetrical surgery for symmetrical deviations and asymmetrical surgery for asymmetrical deviations) and "opposite" in which the reverse was performed. RESULTS: Sensory results were "statistically significantly" better (p=0.027), the need for postoperative adjustment of adjustable sutures was "statistically significantly" less (p=0.031) and the motor results tended to be improved (p=0.237) ("clinically/medically significant") when surgery was "matched" to the deviation under anesthesia. CONCLUSION: Use of the (a)symmetry of deviations under anesthesia can improve surgical results. Therefore, the final decision as to which muscles to operate on might best be delayed until the time of surgery when that (a)symmetry can be observed. This pilot study should be confirmed by a proper completely prospective randomized study.

Erythropoietic protoporphyria improving during pregnancy.

Erythropoietic protoporphyria is an uncommon disorder which causes a photosensitive cutaneous reaction, and occasionally hepatic dysfunction in affected individuals. We report a patient with erythropoietic protoporphyria who improved symptomatically during her two pregnancies. In the latter pregnancy, quantitative levels of plasma and erythrocyte protoporphyrins were reduced by more than half during the pregnancy compared with the levels before pregnancy and during lactation.

Induction of Mn SOD in human monocytes without inflammatory cytokine production by a mutant endotoxin.

Endotoxin selectively induces monocyte Mn superoxide dismutase (SOD) without affecting levels of Cu,Zn SOD, catalase, or glutathione peroxidase. However, little is known about the structure-activity relationship and the mechanism by which endotoxin induces Mn SOD. In this study we demonstrated that a mutant Escherichia coli endotoxin lacking myristoyl fatty acid at the 3' R-3-hydroxymyristate position of the lipid A moiety retained its full capacity to coagulate Limulus amoebocyte lysate compared with the wild-type E. coli endotoxin and markedly stimulated the activation of human monocyte nuclear factor-kappaB and the induction of Mn SOD mRNA and enzyme activity. However, in contrast to the wild-type endotoxin, it failed to induce significant production of tumor necrosis factor-alpha and macrophage inflammatory protein-1alpha by monocytes and did not induce the phosphorylation and nuclear translocation of mitogen-activated protein kinase. These results suggest that 1) lipid A myristoyl fatty acid, although it is important for the induction of inflammatory cytokine production by human monocytes, is not necessary for the induction of Mn SOD, 2) endotoxin-mediated induction of Mn SOD and inflammatory cytokines are regulated, at least in part, through different signal transduction pathways, and 3) failure of the mutant endotoxin to induce tumor necrosis factor-alpha production is, at least in part, due to its inability to activate mitogen-activated protein kinase.

Susceptibility of heterozygous MnSOD gene-knockout mice to oxygen toxicity.

Recent studies have shown that homozygous Mn superoxide dismutase (Sod2) gene-knockout mice (Sod2(-/-)) die shortly after birth with extensive myocardial injury, whereas heterozygous mutants (Sod2(+/-)) are phenotypically normal in room air. In the current study, we showed that Sod2(+/-) mice with approximately 50% of normal pulmonary MnSOD activity and normal levels of lung CuZnSOD, catalase, and glutathione peroxidase activities were not substantially more susceptible to 100% O2 toxicity than their normal Sod2(+/+) littermates. The mean (+/- SD) survival of Sod2(+/-) mice in 100% O2 was 101.4 +/- 14.8 h (n = 20) versus 103.2 +/- 11.3 h (n = 20) for Sod2(+/+) littermates (P > 0.60). In addition, Sod2(+/-) mice with approximately 50% of normal heart MnSOD activity and Sod2(+/+) mice did not develop any ultrastructural abnormalities in the myocardium at 75 h or 90 h after 100% O2 exposure. These results suggest that in mice, only 50% of MnSOD activity may be sufficient for normal resistance to 100% O2 toxicity.