21184188
Temperature sensitivity and fluorescence detection.
Fluorescence detectors are about three orders of magnitude more sensitive and specific making them ideal for trace analysis and complex sample matrices. However, temperature dependence of the signal is a disadvantage to fluorescence detectors. We have previously reported degradation of malondialdehyde (MDA)-thiobarbituric acid (TBA) adduct at room temperature. The present experiments tested the notion that the detector response may be blunted due to increase in temperature over time. Repeated injections of the same standard curve over 4 h found a significant effect of time on the slopes of peak area-concentration curves. When the samples were iced and injected alternating with ambient temperature standard curve samples, no differences in slopes were seen between iced and ambient temperature samples. Cooling the housing of the fluorescence lamp significantly increased the fluorescence in the samples. Fluorescence increased 2.5% (95% confidence interval, 1.5-3.6%) for each 1 degrees C fall in temperature. MDA-TBA adduct remained stable at room temperature. Since the fluorescence signal is temperature sensitive, letting the detector warm up for 2 h to obtain a steady temperature is more likely to give reproducible results compared to a detector that has not warmed up. These results have implications for other applications utilizing fluorescence detectors.
11453581
Proinflammatory effects of oxidative stress in chronic kidney disease: role of additional angiotensin II blockade.
Oxidative stress plays an important role in causing progressive chronic kidney disease (CKD). We examined the influence of add-on ANG II receptor blockade administered as losartan (50 mg/day for 1 mo) on oxidative stress and proinflammatory state of the kidney in patients with CKD. All subjects were taking an angiotensin-converting enzyme inhibitor plus other antihypertensive agents. Oxidative stress to lipids and proteins was measured by an HPLC assay for malondialdehyde (MDA) and carbonyl concentration, respectively. Urinary inflammation was measured by monocyte chemotactic protein-1 (MCP-1) excretion rate. The etiology of CKD was type 2 diabetes mellitus in 12 and glomerulonephritis in 4 patients. There was no change in proteinuria or 24-h ambulatory blood pressure (BP) with add-on ANG II receptor blockade with losartan therapy. Before losartan therapy, urinary protein and albumin oxidation were 99 and 71% higher, respectively, compared with in plasma (P < 0.05). There was a 35% reduction in urinary oxidized albumin with add-on losartan therapy (P = 0.036). Urinary and plasma MDA were elevated compared with age-matched controls. Urinary MDA was significantly reduced from 4.75 +/- 3.23 to 3.39 +/- 2.17 micromol/g creatinine with add-on losartan therapy. However, plasma MDA or oxidized proteins did not change in response to additional ANG II blockade. A good correlation was seen between the change in urinary oxidized albumin and MCP-1 levels (r = 0.61, P = 0.012). These data demonstrate that oxidative damage to urinary protein and lipids can be reduced with additional ANG II receptor blockade, independently of reductions in proteinuria or BP. Urinary measurements of markers of oxidative damage to lipids and proteins appear to be more sensitive than plasma measurements in patients with CKD. The significant association of the change in urinary MCP-1 with a reduction in oxidative stress supports the role of the redox state in the kidney with renal fibrosis and progressive kidney damage.
36005104
Volume Overload in Dialysis: The Elephant in the Room, No One Can See
interests of the authors. However, considering the totality of the evidence, I am less convinced that this marker is superior to other volume markers. First, there are few head-to-head studies comparing BIA to other established markers of volume. Second, there is no range that defines ‘normal’. Unlike blood pressure (BP) or cholesterol, there is no target that has been established. The normal values are obtained from healthy subjects whose body composition differs substantially from those on dialysis. Extrapolating from healthy subjects to those with ESRD on hemodialysis does not appear scientifically valid. Third, there is no study to my knowledge that demonstrates convincingly that compared to probing dry weight without BIA, BIA-guided dry weight reduction results in improved outcomes. Most data provided to support the use of BIA are associative and observational. A large amount of observational data does not prove causation. We therefore have to be cautious in interpreting these data as ‘strongly indicative of fluid overload’. Nearly all markers of volemia suffer from the same shortcomings. These shortcomings include lack of normative data, and data being largely observational and associative in nature. As an example, several observational studies suggest that B-type natriuretic peptide (BNP), NT-proBNP or other natriuretic peptides are associated with volume state among people with ESRD on dialysis [2–10] . However, only one study has been reported to date that relates the change in BNP to an intervention of probing dry weight [11] . In this study, a direct relationship existed at baseline between BNP and interdialytic ambulatory BP. Since interdialytic ambulatory BP is reVolume overload is the invisible threat to the health of dialysis patients. Currently, Medicare incentivizes the measurement of the dose of dialysis (urea reduction ratio) but has no measure of volume. Perhaps this is because the few who can recognize the epidemic nature of volume excess cannot agree on how to define it. Whereas, some have proposed interdialytic weight gain (IDWG) as a marker of volume, the in-depth review of Hecking et al. [1] quite clearly and importantly makes the distinction that IDWG should not be confused with hypervolemia. One has to wonder how IDWG got confused with dry weight in the first place. It appears that epidemiologists decided to use IDWG as a proxy of dry weight because of its ready availability in large databases. IDWG is a marker that is convenient; it can be measured easily and it can be related to outcomes such as all-cause mortality. This analysis was performed and a relationship emerged between IDWG and all-cause mortality. But establishing a relationship between IDWG and mortality does not establish causality. It could be numerous other factors, measured and unmeasured, associated with IDWG which may be causally related to mortality. Factors such as missing or cutting short dialysis, not taking medications as prescribed, and consuming a diet rich in phosphorus and potassium are some confounding factors that may also be associated with IDWG but may be more plausibly related to mortality. The authors discuss several markers of volume excess. Although several exist, one marker, bioimpedance analysis (BIA), is discussed in great detail. This is understandable given both the academic and intellectual property Published online: July 6, 2013 Nephrology American Journal of
22176722
Alar web in cleft lip nose deformity: study in adult unilateral clefts.
BACKGROUND
The correction of alar webbing in unilateral cleft lip nose deformity is challenging because of progressive distortions in the alar web region during the period of growth. Alar webbing is a persistent universal deformity in both the primary and secondary cleft lip noses. The purpose of this article is to study the alar web deformity in adult patients with unilateral cleft lip noses.


METHODS
Twenty-five patients aged 13 years and older presenting with unilateral cleft nasal deformity were included. Preoperative and postoperative measurements of the nose, along with detailed intraoperative recording of the deformed anatomy, were done. Preoperative magnetic resonance imaging was also done in selected cases. Transcolumellar open rhinoplasty was performed in all the cases, and nasal septal straightening with centralization was done. Cleft alar base augmentation was done using bone graft to restore symmetry of the nasal tripod. Both the cleft and noncleft alar cartilages were extensively mobilized from the skin and mucosal sides. The overgrown and caudally slumped cleft-side alar cartilage was resected caudally and was then resuspended in a symmetrical position with the noncleft alar cartilage. A midline-strut septal cartilage extension graft was used to restore the tip aesthetics. The skin overlying the alar web was in-rolled after semilunar cartilage resection, and skin excision was also done to restore symmetry with the opposite vestibule. The remaining secondary cleft nasal and lip deformities were corrected depending upon the specific presenting pathologic abnormality.


RESULTS
The cleft alar cartilage was found to be caudally displaced in all the cases. The caudal border of the lateral crus was prolapsing in the cavity of the vestibule on the superomedial aspect and was tenting the skin in the area of the weak triangle, producing the characteristic alar web deformity. In the study group, the maximum width of the cleft alar cartilage at the level of the lateral crus was increased by approximately 4 mm when compared with the noncleft alar cartilage. The before- and after-rhinoplasty surgery results were objectively assessed using a patient, surgeon, and independent observer survey. The cosmetic result of the nasal tip complex was found to be very good and good (90%), satisfactory (5%), and poor (5%) in patients.


CONCLUSIONS
The alar web in unilateral cleft lip nose deformity is the result of caudal overgrowth and migration of the alar cartilage. The caudal edge of the prolapsed lateral crus overhangs the cleft-side nasal aperture on its superomedial aspect, producing this deformity. Satisfactory correction of this deformity should envisage caudal resection and repositioning of the dislocated alar cartilage along with caudal resection of the lateral crus with in-rolling of the skin after resection to achieve symmetric results in unilateral cleft lip rhinoplasty.
191311
Assessment of iothalamate plasma clearance: duration of study affects quality of GFR.
BACKGROUND AND OBJECTIVES
Measurement of GFR is important for the management of chronic kidney disease (CKD). Although bolus administration of radiocontrast agents is commonly used to measure GFR, the optimal duration of sampling to assess their plasma clearance is unknown. The purpose of this study was to evaluate whether the duration of plasma sampling influences precision and estimation of GFR.


DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS
GFR was measured by sampling plasma 12 times over 5 h in 56 patients with CKD (mean age 64 yr, 98% men, 79% Caucasian, 34% diabetics, estimated GFR 31.8 +/- 14.2 ml/min/1.73 m(2)). In a subset of 12 patients we measured GFR by sampling plasma 17 times over 10 h.


RESULTS
Short sampling intervals considerably overestimated GFR measured using total plasma iothalamate clearance, especially in larger patients. In the higher estimated GFR group (>30 ml/min/1.73 m(2)), the 5-h GFR was 17% higher and 2-h GFR 54% higher compared with the 10-h GFR, which averaged 40.3 ml/min/1.73 m(2). In the lower estimated GFR group (<30 ml/min/1.73 m(2)), the 5-h GFR was 36% higher and 2-h GFR 126% higher compared with the 10-h GFR, which averaged 22.2 ml/min/1.73 m(2). Short sampling duration also reduced the precision of the estimated GFR from 1.67% for 10-h GFR, to 3.48% for 5-h GFR, and to 7.07% for 2-h GFR.


CONCLUSIONS
GFR measured over a longer duration with multiple plasma samples spanning the distribution and elimination phases may improve precision and provide a better measure of renal function.
24249726
Regulation of circadian blood pressure: from mice to astronauts.
PURPOSE OF REVIEW
Circadian variation is commonly seen in healthy people; aberration in these biological rhythms is an early sign of disease. Impaired circadian variation of blood pressure (BP) has been shown to be associated with greater target organ damage and with an elevated risk of cardiovascular events independent of the BP load. The purpose of this review is to examine the physiology of circadian BP variation and propose a tripartite model that explains the regulation of circadian BP.


RECENT FINDINGS
The time-keeper in mammals resides centrally in the suprachiasmatic nucleus. Apart from this central clock, molecular clocks exist in most peripheral tissues including vascular tissue and the kidney. These molecular clocks regulate sodium balance, sympathetic function and vascular tone. A physiological model is proposed that integrates our understanding of molecular clocks in mice with the circadian BP variation among humans. The master regulator in this proposed model is the sleep-activity cycle. The equivalents of peripheral clocks are endothelial and adrenergic functions. Thus, in the proposed model, the variation in circadian BP is dependent upon three major factors: physical activity, autonomic function, and sodium sensitivity.


SUMMARY
The integrated consideration of physical activity, autonomic function, and sodium sensitivity appears to explain the physiology of circadian BP variation and the pathophysiology of disrupted BP rhythms in various conditions and disease states. Our understanding of molecular clocks in mice may help to explain the provenance of blunted circadian BP variation even among astronauts.
21032742
Evaluation of carcinogenic effect of jute batching oil (JBO-P) fractions following topical application to mouse skin
Jute batching oil (JBO-P), a mineral oil fraction used in the processing of jute fibers, was, as reported in our earlier studies, found to be tumorigenic following repeated topical application to mouse skin. In the present investigation an attempt has been made to identify the carcinogenic constituents of this oil. The JBO was fractionated into (1) PAH free fraction, (2) fraction containing twoand three-ring PAHs and (3) more than three-ring PAH fractions by an enrichment procedure. These three JBO fractions along with unfractionated and reconstituted oil were then subjected to the in vivo assay of complete carcinogenic activity of JBO-P and its fractions following its topical application to mouse skin. The results showed that only unfractionated and reconstituted JBO-P samples per se were able to produce benign skin tumours, while all the other three fractions, i.e. PAH-free fraction, two- and three-ring PAH-containing fraction and more than threering PAH-containing fraction failed to produce tumours up to 40 weeks after application. In an extended study, mice belonging to the groups exposed to various fractions of JBO were promoted with 12-O-tetradecanoyl phorbol-13-acetate (TPA), a potent skin tumour promoter, for the two stage initiation-promotion protocol for skin carcinogenesis. After 14 weeks of promotion with TPA, all the surviving animals exposed to the fraction having more than three-ring PAHs developed benign tumours on their backs, while the other two fractions failed to do so. In view of these findings it can be concluded that none of the three JBO-P fractions possess complete carcinogenic activity, whereas only the fraction containing more than three-ring PAHs may act as a skin tumour initiator.
771397
Structural analysis of botulinum neurotoxin type E catalytic domain and its mutant Glu212-->Gln reveals the pivotal role of the Glu212 carboxylate in the catalytic pathway.
The seven serotypes of botulinum neurotoxins (A-G) produced by Clostridium botulinum share significant sequence homology and structural similarity. The functions of their individual domains and the modes of action are also similar. However, the substrate specificity and the peptide bond cleavage selectivity of their catalytic domains are different. The reason for this unique specificity of botulinum neurotoxins is still baffling. If an inhibitor leading to a therapeutic drug common to all serotypes is to be developed, it is essential to understand the differences in their three-dimensional structures that empower them with this unique characteristic. Accordingly, high-resolution structures of all serotypes are required, and toward achieving this goal the crystal structure of the catalytic domain of C. botulinum neurotoxin type E has been determined to 2.1 A resolution. The crystal structure of the inactive mutant Glu212-->Gln of this protein has also been determined. While the overall conformation is unaltered in the active site, the position of the nucleophilic water changes in the mutant, thereby causing it to lose its ability to activate the catalytic reaction. The structure explains the importance of the nucleophilic water and the charge on Glu212. The structural differences responsible for the loss of activity of the mutant provide a common model for the catalytic pathway of Clostridium neurotoxins since Glu212 is conserved and has a similar role in all serotypes. This or a more nonconservative mutant (e.g., Glu212-->Ala) could provide a novel, genetically modified protein vaccine for botulinum.
19667728
Protection against malignant conversion in SENCAR mouse skin by all trans retinoic acid: inhibition of the ras p21-processing enzyme farnesyltransferase and Ha-ras p21 membrane localization.
Many studies have shown that all trans retinoic acid (RA) exhibits significant protective effects against mouse skin tumor promotion and spontaneous as well as enhanced malignant conversion. In a recently completed study, we showed that under treatments in which papillomas on SENCAR mouse skin are induced at low and high probabilities to convert to malignant carcinomas, RA affords significant protection against both tumor promotion and subsequent malignant conversion. More than 95% of these mouse skin papillomas and carcinomas have been shown to contain point mutation at the 61 codon of Ha-ras oncogene. The ras oncogene encodes a p21 protein that, in its mutated form, transforms mammalian cells only when p21 is at the inner surface of the plasma membrane, by a series of enzymatic reactions in which the initial step is catalyzed by farnesyltransferase (FTase). In this study, we assessed whether the protective effect of RA against malignant conversion involves the inhibition of ras p21 processing in those tumors that contain the activated ras oncogene. The FTase activity and the levels of cytosolic and membrane-bound Ha-ras p21 were determined in all papillomas and carcinomas obtained from acetone- or RA-treated animals. No matter how the data were analyzed and what comparisons were considered, in all the protocols used, compared with controls, papillomas and carcinomas obtained from RA-treated groups showed significantly decreased (P < 0.01-0.001) FTase activity. Furthermore, the tissue samples from RA-treated groups in different protocols also showed significantly diminished membrane localization of Ha-ras p21, with a concomitant increase in cytosolic Ha-ras p21 levels. The analysis of these data also showed that in all the protocols used, the increased FTase activity and membrane localization of Ha-ras p21 were associated with the induction of papillomas and their subsequent malignant conversion to squamous cell carcinomas. Taken together, these results indicate a strong correlation between the inhibition of ras p21 farnesylation because of a decrease in FTase activity by RA and its protective effect against malignant conversion of papillomas to carcinomas. Based on the results of this study, it is tempting to suggest that clinical trials evaluating the preventive or therapeutic potential of retinoids may be directed more toward those clinical malignancies that are known to contain the activated ras oncogene.
37940035
Disseminated tuberculosis after anti-TNFalpha treatment.
20354418
Clinical significance of hyperattenuating mucoid impaction in allergic bronchopulmonary aspergillosis: an analysis of 155 patients.
BACKGROUND
Allergic bronchopulmonary aspergillosis (ABPA) is a disease that presents with diverse clinicoradiologic manifestations. High-attenuation mucus (HAM) is a characteristic radiologic finding seen in patients with ABPA; however, the clinical significance of the entity remains unknown.


AIMS AND OBJECTIVES
To describe the outcome of patients with ABPA who were demonstrated to have HAM, and compare with the outcome of patients without HAM.


METHODS
All consecutive patients with asthma presenting to the Chest Clinic of this institute over a 4-year period were screened with an Aspergillus skin test. Patients with positive findings were further investigated, and the diagnosis of ABPA was confirmed based on predefined criteria. The patients were further classified into two groups based on the presence of HAM on HRCT scan.


RESULTS
During the study period, 755 patients were screened for ABPA using the Aspergillus skin test; 291 patients (38.5%) had positive findings, and ABPA was diagnosed in 155 patients (mean age, 33.98 years; 76 women). Twenty-nine patients (18.7%) with ABPA were identified to have HAM on HRCT scans at presentation. The baseline characteristics were similar between the two groups, but patients with HAM had higher mean eosinophil counts, higher mean serum total IgE, and higher Aspergillus fumigatus-specific IgE levels. On multivariate analysis, both the severity of bronchiectasis and HAM predicted relapse of ABPA (odds ratio [OR], 1.23; 95% confidence interval [CI], 1.13 to 1.42; and OR, 3.61; 95% CI, 1.23 to 10.61, respectively). Failure to achieve complete remission was influenced by the severity of bronchiectasis but not by HAM (OR, 1.55; 95% CI, 1.29 to 1.85; and OR, 3.41; 95% CI, 0.89 to 13.1, respectively).


CONCLUSIONS
HAM impaction in ABPA is associated with initial serologic severity and frequent relapses but does not seem to influence complete remission.