Arterial tortuosity syndrome presented as nonvisualization of thoracic aorta in preoperative transthoracic echocardiogram: A case report

Arterial tortuosity syndrome is a rare genetic disorder characterized by dilation, elongation, and significant tortuosity of major arteries. Approximately 100 cases of this disorder have been reported worldwide, including 3 reports in Iran. We describe a case of arterial tortuosity syndrome suspected during the preoperative evaluation for hypertrophic pyloric stenosis, where the thoracic aorta was not visualized appropriately in transthoracic echocardiography. Our report focuses on identifying the disease through diagnostic imaging.

Comparison of QT dispersion before and after PDA device closure in pediatrics

Background

Numerous studies have shown that QT dispersion (QTd) can be a suitable criterion for risk assessment of arrhythmia in patients with congenital heart disease. Pulmonary arterial hypertension (PAH) increases the risk of cardiac arrhythmia by changing ventricular repolarization homogeneity. In this study, we assessed QTd changes after PDA device closure and the effect of PAH on these changes.

Methods

Between October 2018 and March 2021, 97 patients (48 males; 49 females; mean age 31.36 ± 4.26 months; range 3 months to 14 years) who satisfied the primary inclusion criteria and did not meet the exclusion criteria and underwent PDA device closure intervention were included in the study. Echocardiography was performed before the procedure. QT corrected (QTc), and QTd and PR intervals were measured according to the patients’ standard 12‐lead ECGs in two periods, preoperative (1 day) and after (3 months).

Results

In the general group, QTc and QTd decreased significantly after PDA closure. Based on our classification of the patients in two groups of high PAP and normal PAP, the three parameters QTc, QTd, and PR interval were assessed separately in the two groups. All three parameters decreased significantly in the normal PAP and high PAP groups.

Conclusions

However, a left‐to‐right shunt through the patent ductus arteriosus can affect ventricular repolarization; this effect seems to be particularly more significant when there is pulmonary hypertension.

Signal Processing of Heart Rate for Predicting Sepsis in Premature Neonates

The heart rate characteristic (HeRO score) is a figure derived from the analysis of premature neonate's electrocardiogram signals, and can be used to detect infection before the onset of clinical symptoms. The United States and Europe accept this diagnostic technique, but we require more tests to prove its efficacy. This method is not accepted in other developed countries so far. The present study aimed to investigate changes in the heart characteristics of two neonates in Akbar Abadi Hospital in Tehran. Experts chose one newborn as a sepsis case, and the other neonate was healthy. The results were analyzed and compared with previous studies. In this research, a group of five neonates was selected randomly from the neonatal intensive care unit, and cardiac leads were attached to them for recording heart rates. We selected two neonates from the five cases, as a case (proven sepsis) and control, to analyze heart rate variability (HRV). Then, we compared the differences in the heart rate of both neonates. Analysis of HRV of these two neonates showed that the pattern of HRV is compatible with reports from US studies. Considering the results of this study, heart rates and their analysis can provide useful indicators for mathematical modeling before the onset of clinical symptoms in newborns.

Fabrication of ZrO2-Bearing lithium-silicate glass-ceramics by pressureless sintering and spark plasma sintering

OBJECTIVE

the present study evaluated the effect of the Spark Plasma Sintering (SPS) and Pressureless Sintering (PLS) methods on the physical and mechanical properties of ZrO₂-bearing Lithium Silicate (ZLS) glass-ceramics.

METHOD

SPS and PLS methods were used for fabricating of the zirconia-bearing Lithium Silicate glass-ceramics. Several sintering temperatures were applied in order to achieving the best mechanical and physical properties in both methods. For this purpose, the particle size measurement of the glass powder was performed. Field Emission Scanning Electron Microscope (FESEM) was carried out for evaluation of the microstructure. X-ray diffraction (XRD) was used to investigate the amorphous or crystalline state of the samples. Fourier Transform Infrared Spectroscopy (FTIR) was used for the investigation of the chemical bonds. Flexural strength, Vickers microhardness, fracture toughness, and physical properties such as bulk density, water absorption, and the apparent porosity of the samples were measured.

RESULTS

It is possible to fabricate ZLS glass-ceramics by the SPS method at a sintering temperature approximately 350 °C lower than the sintering temperature of the PLS method. Results of the SPS showed SGC, 550 °C (SPS Glass Ceramic sintered at 550 °C) had the highest flexural strength (255.10 ± 15.44 MPa), fracture toughness (3.15 ± 0.62 MPam^1/2), Vickers microhardness (7.96 ± 0.13 GPa) and bulk density (2.63 ± 0.02 g/cm³); the lowest water absorption (0.11 ± 0.12) and, apparent porosity (0.25 ± 0.32). Results of the PLS showed PLGC, 900 °C (PLS Glass Ceramic sintered at 900 °C) had the flexural strength (160.27 ± 12.69 MPa), the highest Vickers microhardness (7.22 ± 0.67 GPa) and bulk density (2.53 ± 0.03 g/cm³); the lowest water absorption (0.15 ± 0.21) and, apparent porosity (0.39 ± 0.54). According to the XRD patterns and FESEM images, SGC, 550 °C has Li₂Si₂O₅ spherical nanocrystals (approximately 50-100 nm diameters).

SIGNIFICANCE

Different sintering temperatures in the SPS and PLS methods have an obvious effect on the microstructure, mechanical, and physical properties of ZrO₂-bearing Lithium Silicate (ZLS) glass-ceramics. Sintering temperature was decreased in SPS compared to the PLS method and nanocrystals of Li₂Si₂O₅ formed.

Hyperglycemia in VLBW infants; incidence, risk factors and outcome

BACKGROUND

Neonatal hyperglycemia, which is relatively common in very low birth weight (VLBW) infants, is associated with increased risk of morbidity and mortality.

OBJECTIVE

To study the incidence of neonatal hyperglycemia, associated risk factors and the outcome of it in VLBW infants hospitalized in a level III NICU in Tehran.

METHODS

All VLBW newborns admitted to the NICU of Mahdieh Hospital from April 2009 to March 2011 were considered eligible for this retrospective study. All relevant prenatal and perinatal data, as well as details of the hospital stay until discharge or death, were extracted from the case notes and analyzed.

RESULTS

Hyperglycemia (blood suger above 150 mg/dL) was observed in 179 (31.7%) of the 564 VLBW infants included in the study; 48 infants (26.8%), had received insulin. Risk factors included: low gestational age, (OR = 4.07, 95% CI = 2.09-7.93, P < 0.001), extremely low birth weight (ELBW) , (OR = 5.97, 95% CI = 3.77-9.44, P < 0.001), dopamine administration (OR = 2.19, 95% CI = 1.32-3.65, P = 0.003), intralipid (OR = 1.52, 95% CI = 1.04-2.22, P = 0.03), Low APGAR score at 5 minutes (OR = 4.44, 95% CI = 2.48-7.94, P < 0.001), RDS and its complications (OR = 4.20, 95% CI = 2.55-6.93, P < 0.001), were independently associated with hyperglycemia. Other findings with hyperglycemia were: high incidence of IVH >grade II (OR = 2.88, 95% CI = 1.28-6.49, P = 0.01), hospital stay more than 28 days in survivors,(OR = 3.56, 95% CI = 2.02-6.25, P < 0.001), mortality (OR = 4.42, 95% CI = 3.00-6.52, P < 0.001) and more retinopathy of prematurity (ROP ≥ stage II) in survivors (OR = 2.05, 95% CI = 1.11-3.78, P = 0.02).

CONCLUSION

Neonatal hyperglycemia developed in approximately one-third of our VLBW neonates. Relative prevalence and associated findings underscore the need for preventive measures and prompt management.

Orofacial clefts and risk factors in tehran, iran: a case control study

BACKGROUND

Non-syndromic cleft lip with or without cleft palate (CL/P) or cleft palate only (CPO) are orofacial clefts with multifactorial etiology. These include environmental factors and heterogeneous genetic background. Therefore, studies on different and homogenous populations can be useful in detecting related factors. The aim of the present study was to evaluate the risk factors in patients with non-syndromic cleft in Tehran, Iran.

METHODS

Data from 300 patients and 300 controls were collected between 2005 and 2010. Binary logistic regression analyses were used to calculate relative risk by odds ratio (OR) and %95 confidence interval.

RESULTS

Low maternal age (OR=1.06, 95% CI, 1.011-1.113), low socioeconomic status (OR=0.23, 95% CI, 0.007-0.074), maternal systemic disease (OR=0.364; 95% CI, 0.152-0.873) and passive smoking (OR=0.613, 95% CI, 0.430-0.874) increased the risk for CL/P and CPO. There was a significant difference in iron and folic acid use during pregnancy when the case and control groups were compared.

CONCLUSION

In assessing for orofacial cleft risk, we should consider lack of folic acid supplementation use, maternal age and systemic diseases and passive smoking as risk factors.

Purification and biochemical characterization of the ATH1 gene product, vacuolar acid trehalase, from Saccharomyces cerevisiae

The disaccharide trehalose plays a critical role in yeast cell survival during conditions of environmental stress. The vacuole of the yeast Saccharomyces cerevisiae contains an enzyme, acid trehalase (ATH), that is capable of degrading trehalose. Recently, a gene required for ATH activity, ATH1, was cloned and sequenced [Destruelle et al., (1995) Yeast 11, 1015-1025]. The relationship between ATH1 and ATH, however, was not determined. We have purified ATH and shown that it is the ATH1 gene product; peptide sequences from the purified protein correspond to the deduced amino acid sequence of Ath1p. In addition, antiserum to Ath1p specifically recognizes purified ATH.

Disruption of the yeast ATH1 gene confers better survival after dehydration, freezing, and ethanol shock: potential commercial applications

The accumulation of trehalose is a critical determinant of stress resistance in the yeast Saccharomyces cerevisiae. We have constructed a yeast strain in which the activity of the trehalose-hydrolyzing enzyme, acid trehalase (ATH), has been abolished. Loss of ATH activity was accomplished by disrupting the ATH1 gene, which is essential for ATH activity. The delta ath1 strain accumulated greater levels of cellular trehalose and grew to a higher cell density than the isogenic wild-type strain. In addition, the elevated levels of trehalose in the delta ath1 strain correlated with increased tolerance to dehydration, freezing, and toxic levels of ethanol. The improved resistance to stress conditions exhibited by the delta ath1 strain may make this strain useful in commercial applications, including baking and brewing.