Coupling of strain, stress, and oxygen non-stoichiometry in thin film Pr0.1Ce0.9O2-δ

Stress and strain in thin films of Pr0.1Ce0.9O2-δ, supported on yttria stabilized zirconia (YSZ) and sapphire substrates, induced by large deviations from oxygen stoichiometry (δ = 0) were investigated by in situ high temperature X-ray diffraction and wafer curvature studies. The measured stresses and strains were correlated with change in δ, measured in situ using optical transmission spectroscopy of defect centers in the films and compared with prior chemical capacitance studies. The coefficient of chemical expansion and elastic modulus values for the films were found to be 18% less than, and 16% greater than in the bulk, respectively. Irreproducible stress and strain during cycling on YSZ substrates was observed and related to microstructural changes as observed by TEM. The enthalpy of defect formation was found to be similar for films supported on sapphire and YSZ, and appeared to decrease with tensile stress, and increase with compressive stress. Larger stresses observed for YSZ supported films as compared to sapphire supported films were found and accounted for by the difference in film orientations.

Clinical Study to Assess the Stain Removal Effectiveness of a Tooth Whitening Regimen with Added Whitening Booster

OBJECTIVE

This randomized, controlled clinical trial was conducted to assess the extrinsic stain reduction achieved by brushing with a whitening dentifrice and powered toothbrush, and to determine whether the addition of a whitening booster paste to this regimen would enhance its stain reducing effectiveness.

METHODS

Sixty qualifying subjects were randomly assigned either to Regimen One, a whitening dentifrice (Arm & Hammer Truly Radiant [TR] toothpaste] and powered toothbrush (Arm & Hammer Truly Radiant [TR] Extra Whitening Spinbrush); Regimen Two, the dentifrice and powered toothbrush with the addition of a whitening booster; or Regimen Three, a negative control (Colgate Cavity Protection toothpaste and an ADA standard manual brush). They were instructed in the use of their assigned products and then brushed unsupervised at home for two minutes, twice daily, for 14 days. Extrinsic tooth stain was assessed at baseline and after two, five, and 14 days using a Modified Lobene Stain Index (MLSI) with Lobene inclusion criteria of ≥ 1.5.

RESULTS

All three treatment groups had statistically significant (p < 0.0001) mean total MLSI reductions from baseline at each time point, in a time-dependent manner. Day 14 reductions were 22.2% for Colgate Cavity Protection, 29.1% for Regimen One, and 34.4% for Regimen Two. Reductions for Regimen One and Regimen Two were significantly greater compared to Regimen Three, the negative control, at each time period (p < 0.01), and those for Regimen Two were significantly greater compared to Regimen One on days 2 and 14 (p < 0.05) and directionally more effective on day 5 (p = 0.0673).

CONCLUSION

The combination of Truly Radiant toothpaste and Truly Radiant Spinbrush provides safe and effective stain removal that can be further enhanced by the addition of the whitening booster.

Diabetic retinopathy and VEGF

Diabetic retinopathy remains the leading vascular-associated cause of blindness throughout the world. Its treatment requires a multidisciplinary interventional approach at both systemic and local levels. Current management includes laser photocoagulation, intravitreal steroids, and anti-vascular endothelial growth factor (VEGF) treatment along with systemic blood sugar control. Anti-VEGF therapies, which are less destructive and safer than laser treatments, are being explored as primary therapy for the management of vision-threatening complications of diabetic retinopathy such as diabetic macular edema (DME). This review provides comprehensive information related to VEGF and describes its role in the pathogenesis of diabetic retinopathy, and in addition, examines the mechanisms of action for different antiangiogenic agents in relation to the management of this disease. Medline (Pubmed) searches were carried out with keywords “VEGF”, “diabetic retinopathy”, and “diabetes” without any year limitation to review relevant manuscripts used for this article.

Predictive value of bronchoscopy after infant cardiac surgery: a prospective study

BACKGROUND AND AIMS

Airway evaluation following infant cardiac surgery often reveals evidence of tracheobronchial narrowing. We studied the association between airway narrowing and extubation failure (EF) in this population.

METHODS

Prospective cohort study of infants (age ≤6 months) from March-September 2009. Flexible bronchoscopy (FB) evaluations were obtained using a standardised protocol after operative intervention. The primary endpoint was the development of extubation failure (EF; defined as the need for invasive mechanical ventilation ≤48 h after primary extubation) and several secondary endpoints.

RESULTS

Fifty-three patients were evaluated at a median age of 81 [interquartile range (IQR) 13-164] days and weight of 4.2 (IQR 3.2-6.0) kg; 13 (25 %) of the patients had single ventricle palliations and two subsequently underwent heart transplantation. Significant airway narrowing was noted in 15 of 30 [50 %, 95 % confidence interval (CI) 31-69 %] patients who underwent FB; ten of the 53 patients (19 %, 95 %CI 10-32 %) subsequently developed EF. Narrowed airway calibre on bronchoscopy had a sensitivity and specificity of 50 % (95 %CI 28-71 %) and 50 % (95 %CI 28-71 %), respectively, for EF. The single greatest predictor of EF by univariate analysis was the need for preoperative ventilation [odds ratio (OR) 6.5, 95 %CI 1.3-33.2, p = 0.03]. Patients with EF had a greater likelihood of intensive care readmission (OR 4.8, 95 %CI 1.1-21, p < 0.04) during the same hospital admission.

CONCLUSIONS

Airway narrowing on FB is noted frequently after infant cardiac surgery. Overall assessment and presence of narrowing on bronchoscopy had poor sensitivity and specificity for EF in our cohort. Expert assessment of tracheobronchial narrowing on FB has poor to moderate inter-rater reliability.

Diagnostic strategy for mucolipidosis II/III

Overlapping clinical phenotypes are a diagnostic challenge to the clinician, especially in the cases of mucolipidosis (ML) and mucopolysaccharide disorders (MPS), due to overlapping phenotypes. Present study was carried out in 147 children suspected to have ML or MPS and 100 controls. They were screened for ML II/III by colorimetric method using substrate pNCS. Six children were found screen positive for ML II/III and further confirmatory study showed significantly raised activity in plasma confirming high specificity of the ML screening test. Forty-two (28.5%) children out of remaining 141 children that were screen negative, were found to have various MPS disorders, while rest 99 had normal enzyme activity in plasma and leucocytes. Present study demonstrates prompt and specific chemical method that can be used as a tool for estimating ML II/III, with high specificity.

Staged abdominal closure after small bowel or multivisceral transplantation

Following paediatric SBMT, size discrepancy between the recipient's abdomen and the graft may lead to ACS, graft dysfunction, and death. We report our experience with SAC in these patients. Between 04/1993 and 03/2009, 57 children underwent 62 SBMTs. When abdominal wall tension seemed excessive for safe PAC, SAC was performed, using a Silastic® sheet and a vacuum occlusive dressing. Transplantations with SAC (23 combined liver and small bowel [CLB]) were compared with those with PAC [14 ISB and 25 CLB]. Indications for transplantation, preoperative status (after stratification for ISB/CLB transplants), age at transplantation, donor-to-recipient weight ratio, reduction in bowel and/or liver, and incidence of wound complications were not different in both groups. Post-operative intubation, stay in intensive care unit, and hospital stay were prolonged after SAC. Two deaths were related to ACS after PAC, none after SAC. Since 2000, one-yr patient survival is 73% after ISB transplantation and 57% vs. 75% after CLB transplantation with PAC vs. SAC, respectively (NS). SAC safely reduces severe ACS after paediatric SBMT and can be combined with graft reduction for transplantation of small recipients.

A Neocentric Isochromosome Yp Present as Additional Small Supernumerary Marker Chromosome – Evidence against U-Type Exchange Mechanism?

Here we report the first case of an inverted duplicated neocentric small supernumerary marker chromosome present in a karyotype 47,XX,+mar(Y). As expected a partial disomy of Ypter to Yp11.2 did not lead to any major malformations. However, the formation of an inverted duplicated chromosome from a Y chromosome is not possible by a U-type exchange, as has been suggested for such kind of neocentric marker chromosomes. Thus, some evidence is here provided that this concept might not always be true.

Intramedullary cervical neurenteric cyst mimicking an abscess

We describe a cervical intramedullary neurenteric cyst in a 12-year-old male patient who presented with gradual onset and progressively worsening neck pain, spastic quadriparesis and impaired sensation in the C(2) dermatome. MR imaging revealed a well-defined peripherally enhancing cystic intramedullary lesion with a posteroinferior enhancing nodule at the C(2)-C(3) level mimicking an abscess. There was no evidence of spinal dysraphism. The lesion was completely resected through a posterior approach and the patient showed radical improvement in his symptomatology. At follow-up after 3 years, he was asymptomatic and the MR imaging showed no evidence of any residual or recurrent cyst. The case presented here is unique, since a spinal neurenteric cyst showing intense peripheral contrast enhancement mimicking an abscess is unusual. The radiological features, pathogenesis and surgical considerations in cervical intramedullary neurenteric cysts are discussed and the relevant literature is briefly reviewed.

An imaging study of body composition including lipodeposition pattern in a patient of familial partial lipodystrophy (Dunnigan type)

Familial Partial Lipodystrophy, Dunnigan type (FPLD), is characterised by loss of subcutaneous fat from the limbs and an excessive accumulation of fat on the neck, shoulder girdle and face. Affected individuals have insulin resistance, dyslipidaemia and early cardiovascular events. Body composition (BC) with details of adipose tissue distribution were studied by Dual-Energy X-ray Absorptiometry (DEXA) and Magnetic Resonance Imaging (MRI) ina heterozygote for the FPLD mutation LMNA R482W, and in an age, sex and body mass index (BMI) matched normal control. DEXA revealed a marked decrease in total as well as regional fat percentage in the patient compared to a normal control. Marked reductions in subcutaneous fat in the extremities with substantial lipodeposition in the nape of the neck were confirmed with. MRI. The importance of increased perinephric, retroperitoneal and intermuscular fat in the thighs found in this patient, needs to be explored vis-à-vis the pathogenesis of insulin resistance found in FPLD.

Clinical, endocrine and metabolic studies in the kindred of familial partial lipodystrophy--a syndrome of insulin resistance

OBJECTIVE

To study clinical, endocrine and metabolic profiles in the kindred of subjects with familial partial lipodystrophy (FPLD, Dunnigan type).

MATERIAL AND METHODS

Twenty two relatives (10 males, 12 females), from an extended family with FPLD, were assessed for the phenotypic features, impaired glucose tolerance (IGT)/diabetes mellitus (DM), dyslipidemia and the presence of insulin resistance. Plasma glucose and serum lipids were measured using glucose oxidase and standard colorimetric methods. Serum insulin was estimated by radioimmunoassay.

RESULTS

The age was 12 to 67 years, two being adolescents. Two of the 20 adults were overweight and eight were underweight; BMI (adults) was 15.5 to 28.5. Features of FPLD were evident among eight out of 12 women. This typical phenotype was not obvious in all 10 male members. Varying degree of Hirsuitism was observed in four of 12 women, acanthosis nigricans in 11 out of 22 members and skin tags were present in only eight of 22; hypertension in six members and diabetes in four. Eleven members had either impaired glucose tolerance (IGT) (n=7), or DM (n=4). Ten of 20 members showed hyperinsulinemic response on oral glucose tolerance test (OGTT). Dyslipidemia was present in 13 family members.

CONCLUSION

The majority (2/3rd) of female members showed typical phenotypic features of FPLD, with a clustering of cardiovascular risk factors and insulin resistance syndrome. More than half the men without phenotypic features of FPLD had either IGT/DM, dyslipidemia, hypertension or cardiovascular disease.

Efficacy of two dentifrices on removal of natural extrinsic stain

PURPOSE

To evaluate the 6-week effect on natural extrinsic dental stain from the use of a dentifrice containing 10% aluminum oxide, 1500 ppm sodium monofluorophosphate in a precipitated calcium carbonate (PCC) base or a second dentifrice containing 0.5% calcium peroxide (CP), 1500 ppm sodium monofluorophosphate in a PCC base compared to a fluoride placebo dentifrice without stain removal ingredients.

MATERIALS AND METHODS

A total of 94 subjects were entered in the study, and stratified into three balanced groups according to their baseline mean Lobene Stain Index scores. The three groups were randomly assigned to use one of the two test dentifrices or the placebo dentifrice. The three groups were well balanced with regard to their mean baseline stain index scores, gender and tobacco habits. Subjects were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice and a commercially available soft bristled toothbrush. Extrinsic dental stain examinations, which included mean stain area and mean stain intensity, were conducted at baseline and 6 weeks. Examinations were conducted by the same dental examiner (F.A.) on the subjects at each examination.

RESULTS

After 6 weeks' use of their assigned products, those subjects in the aluminum oxide/PCC dentifrice group and those subjects in the CP/PCC dentifrice group demonstrated statistically significant improvements, as compared to the fluoride placebo dentifrice group without stain removal ingredients.

Serum leptin concentrations in hyperinsulinemia in the sets of obese, lipodystrophic and/or non-obese patients

OBJECTIVE

To study the relationship between serum leptin and circulating insulin under basal and in response to oral glucose administration in hyperinsulinemic patients with or without obesity.

MATERIAL AND METHOD

Fifteen female patients of known hyperinsulinemia provided material for the study. Leptin and insulin in sera were estimated by radioimmunoassay methods.

RESULTS

Eight of the 15 hyperinsulinemic patients with high body mass index (BMI) (31 +/- 0.94 kg/m2) had significantly (p < 0.01) elevated serum leptin concentrations (26.1 +/- 2 ng/ml) as compared to the levels in the remaining seven non-obese hyperinsulinemic patients with BMI of 20 +/- 1.0 kg/m2; their mean levels of serum leptin were low 5.7 +/- 1.1 ng/ml. Four of the latter group had face-sparing partial lipodystrophy. The mean circulating leptin concentrations in the control group of seven healthy normoinsulinemic and regularly menstruating women with normal BMI (19 +/- 0.95 kg/m2) were 13.7 +/- 1.8 ng/ml.

DISCUSSION

The results of the present study in 15 hyperinsulinemic patients show that circulating levels of leptin are not related to serum insulin. However, there was a positive correlation with BMI. An interesting observation of the study is that, notwithstanding the normal BMI, the group of hyperinsulinemic patients with face-sparing partial lipodystrophy had the lowest levels of circulating leptin concentrations. They were closer to the values found in prepubertal girls.

The activated clotting time loading dose response ratio (ACTLORR) as an indicator of heparin demand during cardiopulmonary bypass

Data relating to the activated clotting time response to a 4 mg/kg heparin loading dose were collected prospectively in 358 patients having cardiopulmonary bypass. After excluding patients with factors known to cause relative heparin resistance or sensitivity, the activated clotting time (ACT) loading dose response ratio (ACTLORR) was calculated retrospectively in 263 patients and found to correlate significantly (p = 0.0001) with the need for extra heparin administration during bypass. Where the ACTLORR was above 5.5, 92% of patients required no additional heparin during the first 90 minutes of bypass (n = 98). Where the ACTLORR was between 4.0 and 5.0, it was far less predictive, with approximately 35% of patients requiring additional heparin. This study indicates that a large ACT response to the initial heparin loading dose (a high ACTLORR) is predictive of stable, adequate anticoagulation during the first 90 minutes of bypass, but that a low initial response is not necessarily associated with declining ACTs and the need for additional heparin administration.

Re-inventing the wheel; the use of autologous and fresh donor blood in cardiac surgery

From the opening of a new cardiac surgical programme in November 1992, autologous and fresh donor blood (FDB) were used rather than cold stored blood (CSB) wherever possible in patients undergoing operations involving the use of cardiopulmonary bypass (CPB). In the first 250 consecutive patients, autologous blood was used in 168 (67.2%), fresh blood was used in 188 (75.2%). A total of 740 units of fresh blood were obtained on the day of operation (mean 3.9 +/- 1.6 units per patient able to supply donors; 4.9 +/- 1.7 units in the 147 who received fresh blood) and 728 units of stored blood were used (mean 3.08 +/- 1.84 units per patient where fresh blood was used; 6.2 +/- 2.5 units in the 114 where no fresh blood was used). The use of autologous blood significantly reduced FDB and CSB requirements (p < 0.001), was associated with a shorter intensive care and total postoperative stay (p = 0.006 and p = 0.033 respectively), even though there were more urgent and emergency cases in this group (p = 0.009) and no significant difference in chest drainage. Coagulopathy developed in 41 patients (16.4%) and was significantly associated with bypass time (p = 0.0001) and preoperative renal dysfunction (p = 0.005), although not with advanced age, sex, redo operation, diabetes or glucose-6-phosphate dehydrogenase deficiency. Patients with coagulopathy had significantly more transfused blood and blood products (p = 0.0001) and longer intensive care and total postoperative stays (p = 0.0001). In terms of blood conservation, the use of autologous blood was of primary importance.(ABSTRACT TRUNCATED AT 250 WORDS)

Preliminary clinical experience with the Jyros bileaflet mechanical prosthesis

The Jyros bileaflet mechanical prosthesis is unique among bileaflet valve designs in that there is no fixed hinge mechanism and after implantation, the leaflets are free to rotate as determined by blood flow through the orifice. Between November 1992 and April 1994, 56 Jyros valves were implanted in 44 patients at 45 operations. There were 31 males and 13 females (ratio 2.3:1), with a mean age of 3714 and a range owelve patientsplacement (AVR) (26.7%), 19 had mitral valve replacement (MVR) (42.2%), and 14 had AVR plus MVR (DVR) (31.1%). In three DVR patients the Jyros valve was implanted only in the mitral position. There was one hospital death following DVR (2.3% mortality). Total follow-up of 341 patient-months (28.4 patient-years) is 100% complete. There were no late deaths. There was one reoperation for acute mitral prosthetic thrombosis (3.5%/patient-year). Another Jyros valve was inserted; leaving 53 valves at risk in 42 patients at the close of follow-up. There were no episodes of thromboembolism, transient ischemic attacks, endocarditis, hemolysis, or valve dysfunction, but three patients had four episodes of anticoagulant-related hemorrhage. Echocardiographic follow-up data was available in 29 patients and indicated satisfactory hemodynamic performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of microalbuminuria in diabetic subjects

Total 193 diabetic patients were investigated to assess the prevalence of microalbuminuria. Urinary albumin excretion rate (UAER) was measured by radioimmunoassay (RIA) on 3 hours urine samples. The prevalence of microalbuminuria (UAER) > 15 micrograms/min was 41%. Microalbuminuria was commonly observed in patients having diabetes for more than 5 years. A significant correlation was found between duration of diabetes and microalbuminuria (p < 0.01). Glycemic control (fasting and postprandial blood sugar) did not show any correlation with UAER, whereas blood urea (r.39, p < 0.01), creatinine (r.26, p < 0.05) and chloride (r.24, p < 0.05) were positively correlated. A significant correlation was found between raised blood pressure and UAER (p < 0.01).

A newer avenue for evaluation of thyroid dysfunction

Attempt has been made to rationalise the biochemical assessment of patients suspected to have thyroid dysfunction by introduction of a new rapid and supersensitive immunoradiometric assay (IRMA) for TSH. 294 patients were subjected to thyroid investigation viz; tT3, tT4 and TSH (IRMA). Of these, 51 (17.34%) were hypothyroid, 22 (7.48%) were hyperthyroid and 221 (75.1%) were euthyroid. The ratio of thyroid disorder in male to female was 1:3.38. In all patients with hyperthyroidism TSH (IRMA) was 0.05 to undetectable and it was more than 4.5 ulu/ml in hypothyroid patients. TSH (IRMA) was low in one euthyroid patient a 0.34% incidence of false negativity. In 2 patients with subclinical hyperthyroidism TSH (IRMA) was low while tT3 and tT4 were normal. TSH (IRMA) therefore may obviate the need for more time consuming and expensive TRH test and simplify the approach to thyroid function tests in patients suspected to have masked or overt hyperthyroidism.

Synthesis of putative oxidized metabolites of 8-methylbenzo[a]pyrene

Synthesis is described of trans-7,8-dihydroxy-7,8-dihydro-8-methylbenzo[a]pyrene and trans-7,8-dihydroxy-anti-9,10-epoxy-8-methyl-7,8,9,10-tetrahydrobenzo[a] pyrene, potential proximate and ultimate carcinogenic metabolites, respectively, of 8-methylbenzo[a]pyrene.