Response of Canola productivity to integration between mineral nitrogen with yeast extract under poor fertility sandy soil condition

Canola is one of the important oil crops and is considered the most promising oil source and adapts to reclaimed soil conditions. The current study aimed to evaluate the influence of yeast extract (YE) integrated with nitrogen (N) rates and treatments were arranged as follows: Control (without F0), 95 kg N ha^-1 (F1), 120 kg N ha^-1 (F2), 142 kg N ha^-1 (F3), 95 kg N ha^-1 + YE (F4), 120 kg N ha^-1 + YE (F5) and 142 kg N ha^-1 + YE (F6) on physico-chemical properties, yield and its components for three Canola genotypes i.e. AD201 (G1), Topaz and SemuDNK 234/84 under the sandy soil. In this work, Results reveal that increasing rates of Nitrogen fertilization from 95 kg N ha^-1 to 142 kg N ha^-1 have a great effect on physicochemical properties yield and its components. The result proved that 142 kg N ha^-1 with yeast treatment was the best treatment for three Canola genotypes. Also, the result showed that seed yield was positively correlated with Chl. a/b ratio, plant height, number of branches/plant, number of pods/plant, and number of seeds/pod, and a strong negative correlation was detected between seed oil percentage when the amount of nitrogen fertilization applied without or with yeast extract is increased.

COVID-19 during pregnancy should we really worry from vertical transmission or rather from fetal hypoxia and placental insufficiency? A systematic review

Background

COVID-19 is the largest outbreak to strike humanity. The wide scale of fatalities and morbidities lead to a concurrent pandemic of uncertainty in scientific evidence. Conflicting evidences are released on daily basis about the neonatal outcomes of COVID-19-positive mothers. The aim of this study was to use the relevant case reports and series to determine the percentage of newborns who test positive for COVID-19 who are born to COVID-19-positive mothers. Secondary outcomes included examining laboratory abnormalities among COVID-19-positive neonates, and any depicted placental abnormalities in COVID-19-positive mothers. For this purpose, systematic review was performed on all studies reporting primary data on fetus-mother pairs with COVID-19. Data bases were searched for studies that met our inclusion and exclusion criteria.

Results

Final screening revealed 67 studies, from which the primary data of 1787 COVID-19 mothers were identified and had their pregnancy outcome analyzed. Only 2.8% of infants born to COVID-19-positive mothers tested positive, and this finding is identical to percentages reported in former Coronaviridae outbreaks, whereas 20% manifested with intrauterine hypoxia alongside placental abnormalities suggestive of heavy placental vaso-occlusive involvement.

Conclusions

These findings suggest that while vertical transmission is unlikely, there appears to be an underlying risk of placental insufficiency due to the prothrombotic tendency observed in COVID-19 infection. Guidelines for proper prophylactic anticoagulation in COVID-positive mothers need to be established.

A Hierarchical 3D TiO2 /Ni Nanostructure as an Efficient Hole-Extraction and Protection Layer for GaAs Photoanodes

Photoelectrochemical (PEC) water splitting is a promising clean route to hydrogen fuel. The best-performing materials (III/V semiconductors) require surface passivation, as they are liable to corrosion, and a surface co-catalyst to facilitate water splitting. At present, optimal design combining photoelectrodes with oxygen evolution catalysts remains a significant materials challenge. Here, we demonstrate that nickel-coated amorphous three-dimensional (3D) TiO₂ core-shell nanorods on a TiO₂ thin film function as an efficient hole-extraction layer and serve as a protection layer for the GaAs photoanode. Transient-absorption spectroscopy (TAS) demonstrated the role of nickel-coated (3D) TiO₂ core-shell nanorods in prolonging photogenerated charge lifetimes in GaAs, resulting in a higher catalytic activity. This strategy may open the potential of utilizing this low-cost (3D) nanostructured catalyst for decorating narrow-band-gap semiconductor photoanodes for PEC water splitting devices.

Gallium Phosphide photoanode coated with TiO2 and CoOx for stable photoelectrochemical water oxidation

Gallium Phosphide (GaP) has a band gap of 2.26 eV and a valance band edge that is more negative than the water oxidation level. Hence, it may be a promising material for photoelectrochemical water splitting. However, one thing GaP has in common with other III-V semiconductors is that it corrodes in photoelectrochemical reactions. Cobalt oxide (CoO_x) is a chemically stable and highly active oxygen evolution reaction co-catalyst. In this study, we protected a GaP photoanode by using a 20 nm TiO₂ as a protection layer and a 2 nm cobalt oxide co-catalyst layer, which were both deposited via atomic layer deposition (ALD). A GaP photoanode that was modified by CoO_x exhibited much higher photocurrent, potential, and photon-to-current efficiency than a bare GaP photoanode under AM1.5G illumination. A photoanode that was coated with both TiO₂ and CoO_x layers was stable for over 24 h during constant reaction in 1 M NaOH (pH 13.7) solution under one sun illumination.

Improved solar hydrogen production by engineered doping of InGaN/GaN axial heterojunctions

InGaN-based nanowires (NWs) have been investigated as efficient photoelectrochemical (PEC) water splitting devices. In this work, the InGaN/GaN NWs were grown by molecular beam epitaxy (MBE) having InGaN segments on top of GaN seeds. Three axial heterojunction structures were constructed with different doping types and levels, namely n-InGaN/n-GaN NWs, undoped (u)-InGaN/p-GaN NWs, and p-InGaN/p-GaN NWs. With the carrier concentrations estimated by Mott-Schottky measurements, a PC1D simulation further confirmed the band structures of the three heterojunctions. The u-InGaN/p-GaN and p-InGaN/p-GaN NWs exhibited optimized stability in pH 0 electrolytes for over 10 h with a photocurrent density of about -4.0 and -9.4 mA/cm², respectively. However, the hydrogen and oxygen evolution rates of the Pt-treated u-InGaN/p-GaN NWs exhibited a less favorable stoichiometric ratio. On the other hand, the Pt-decorated p-InGaN/p-GaN NWs showed the best PEC performance, generating approximately 1000 µmol/cm² hydrogen and 550 µmol/cm² oxygen in 10 h. The band-engineered p-InGaN/p-GaN axial NWs-heterojunction demonstrated a great potential for highly efficient and durable photocathodes.

Quantified hole concentration in AlGaN nanowires for high-performance ultraviolet emitters

p-Type doping in wide bandgap and new classes of ultra-wide bandgap materials has long been a scientific and engineering problem. The challenges arise from the large activation energy of dopants and high densities of dislocations in materials. We report here, a significantly enhanced p-type conduction using high-quality AlGaN nanowires. For the first time, the hole concentration in Mg-doped AlGaN nanowires is quantified. The incorporation of Mg into AlGaN was verified by correlation with photoluminescence and Raman measurements. The open-circuit potential measurements further confirmed the p-type conductivity, while Mott-Schottky experiments measured a hole concentration of 1.3 × 1019 cm-3. These results from photoelectrochemical measurements allow us to design prototype ultraviolet (UV) light-emitting diodes (LEDs) incorporating the AlGaN quantum-disks-in-nanowire and an optimized p-type AlGaN contact layer for UV-transparency. The ∼335 nm LEDs exhibited a low turn-on voltage of 5 V with a series resistance of 32 Ω, due to the efficient p-type doping of the AlGaN nanowires. The bias-dependent Raman measurements further revealed the negligible self-heating of devices. This study provides an attractive solution to evaluate the electrical properties of AlGaN, which is applicable to other wide bandgap nanostructures. Our results are expected to open doors to new applications for wide and ultra-wide bandgap materials.

Flexible InGaN nanowire membranes for enhanced solar water splitting

III-Nitride nanowires (NWs) have recently emerged as potential photoelectrodes for efficient solar hydrogen generation. While InGaN NWs epitaxy over silicon is required for high crystalline quality and economic production, it leads to the formation of the notorious silicon nitride insulating interface as well as low electrical conductivity which both impede excess charge carrier dynamics and overall device performance. We tackle this issue by developing, for the first time, a substrate-free InGaN NWs membrane photoanodes, through liftoff and transfer techniques, where excess charge carriers are efficiently extracted from the InGaN NWs through a proper ohmic contact formed with a high electrical conductivity metal stack membrane. As a result, compared to conventional InGaN NWs on silicon, the fabricated free-standing flexible membranes showed a 10-fold increase in the generated photocurrent as well as a 0.8 V cathodic shift in the onset potential. Through electrochemical impedance spectroscopy, accompanied with TEM-based analysis, we further demonstrated the detailed enhancement within excess charge carrier dynamics of the photoanode membranes. This novel configuration in photoelectrodes demonstrates a novel pathway for enhancing the performance of III-nitrides photoelectrodes to accelerate their commercialization for solar water splitting.

Surface Passivation of GaN Nanowires for Enhanced Photoelectrochemical Water-Splitting

Hydrogen production via photoelectrochemical water-splitting is a key source of clean and sustainable energy. The use of one-dimensional nanostructures as photoelectrodes is desirable for photoelectrochemical water-splitting applications due to the ultralarge surface areas, lateral carrier extraction schemes, and superior light-harvesting capabilities. However, the unavoidable surface states of nanostructured materials create additional charge carrier trapping centers and energy barriers at the semiconductor-electrolyte interface, which severely reduce the solar-to-hydrogen conversion efficiency. In this work, we address the issue of surface states in GaN nanowire photoelectrodes by employing a simple and low-cost surface treatment method, which utilizes an organic thiol compound (i.e., 1,2-ethanedithiol). The surface-treated photocathode showed an enhanced photocurrent density of -31 mA/cm² at -0.2 V versus RHE with an incident photon-to-current conversion efficiency of 18.3%, whereas untreated nanowires yielded only 8.1% efficiency. Furthermore, the surface passivation provides enhanced photoelectrochemical stability as surface-treated nanowires retained ∼80% of their initial photocurrent value and produced 8000 μmol of gas molecules over 55 h at acidic conditions (pH ∼ 0), whereas the untreated nanowires demonstrated only <4 h of photoelectrochemical stability. These findings shed new light on the importance of surface passivation of nanostructured photoelectrodes for photoelectrochemical applications.

Vertically aligned InGaN nanowires with engineered axial In composition for highly efficient visible light emission

We report on the fabrication of novel InGaN nanowires (NWs) with improved crystalline quality and high radiative efficiency for applications as nanoscale visible light emitters. Pristine InGaN NWs grown under a uniform In/Ga molar flow ratio (UIF) exhibited multi-peak white-like emission and a high density of dislocation-like defects. A phase separation and broad emission with non-uniform luminescent clusters were also observed for a single UIF NW investigated by spatially resolved cathodoluminescence. Hence, we proposed a simple approach based on engineering the axial In content by increasing the In/Ga molar flow ratio at the end of NW growth. This new approach yielded samples with a high luminescence intensity, a narrow emission spectrum, and enhanced crystalline quality. Using time-resolved photoluminescence spectroscopy, the UIF NWs exhibited a long radiative recombination time (τ_r) and low internal quantum efficiency (IQE) due to strong exciton localization and carrier trapping in defect states. In contrast, NWs with engineered In content demonstrated three times higher IQE and a much shorter τ_r due to mitigated In fluctuation and improved crystal quality.

Optically pumped GaN vertical cavity surface emitting laser with high index-contrast nanoporous distributed Bragg reflector

Laser operation of a GaN vertical cavity surface emitting laser (VCSEL) is demonstrated under optical pumping with a nanoporous distributed Bragg reflector (DBR). High reflectivity, approaching 100%, is obtained due to the high index-contrast of the nanoporous DBR. The VCSEL system exhibits low threshold power density due to the formation of high Q-factor cavity, which shows the potential of nanoporous medium for optical devices.

Towards highly efficient photoanodes: the role of carrier dynamics on the photoelectrochemical performance of InGaN/GaN multiple quantum well coaxial nanowires

The carrier dynamics in highly active InGaN/GaN coaxial nanowire photoanodes were studied for photoelectrochemical water splitting applications that can provide deeper insight to enhance the photon-to-electron conversion efficiency.

Fabrication of vertical light emitting diode based on thermal deformation of nanoporous GaN and removable mechanical supporter

A GaN vertical light emitting diode (LED) based on the novel lift-off method was demonstrated by high temperature regrowth over nanoporous (NP) GaN template formed by electrochemical (EC) etching. A two-step EC etching process was employed on a SiO2 patterned GaN surface to fabricate a nanoporous template with a controlled porosity profile, which enabled better structural stability than a single NP GaN. During the regrowth of LED structures, the high porosity GaN layer produced large coalesced voids due to the thermal deformation of nanopores. LED layers were then separated from the sapphire substrate and transferred to a Mo substrate by the removal of the SiO2 mechanical supporters that held the LED structure to suppress cracks and damage during the process. The vertical LEDs fabricated using this technique showed improved optical power emission as well as low series resistance.

Effects of low doses of inhaled nitric oxide combined with oxygen for the evaluation of pulmonary vascular reactivity in patients with pulmonary hypertension

The purpose of this study was to evaluate the hemodynamic effects of inhaled nitric oxide in oxygen (NO + O2) in patients with pulmonary hypertension. Eighteen patients (median age 31.5 months) with pulmonary hypertension inhaled through a mask 100% O2 and 20 parts per million NO + inspired O2 fraction (FiO2) at 0.4. Hemodynamic measurements were made at baseline and after O2 and NO + O2 administration. The pulmonary vascular resistance index decreased after inhalation of O2 and NO + O2 (p = 0.0018 and p = 0.0003, respectively), the decrease being significantly greater after NO + O2 (p = 0.0311). Concerning the transpulmonary pressure gradient, a reduction occurred in values after O2 and NO + O2 inhalation when compared with baseline values (p = 0.0014 and p = 0.0008). In patients with congenital heart disease, an increase occurred in pulmonary blood flow after O2 (p = 0.0089) and NO + O2 (p = 0.0019) compared with baseline values, and an increase also occurred in the pulmonary/systemic blood flow ratio after NO + O2 (p = 0.0017). The main side effect related to NO + O2 was pulmonary congestion in 3 patients. Low doses of NO combined with O2 demonstrated a selective pulmonary vasodilator response in patients with pulmonary hypertension. Despite its use for testing pulmonary reactivity, inhalation of NO + O2 should be carefully administered because of the potential risk of pulmonary congestion.

Uhl's anomaly. Differential diagnosis and indication for cardiac transplantation in an infant

We report the case of an 8-month-old female infant with Uhl's anomaly, who underwent successful cardiac transplantation. The clinical findings, complementary laboratory tests, anatomic findings, and differential diagnosis of the anomaly are discussed.

Double-outlet right ventricle with nonrelated ventricular septal defect: surgical results using the multiple patches technique

OBJECTIVE

Introduce a new surgical technique for biventricular correction of double-outlet right ventricle with noncommitted ventricular septal defect.

METHODS

From April 1987 to February 1996, 15 patients with double-outlet right ventricle with noncommitted ventricular septal defect were operated on using a new technique for biventricular repair with multiple bovine pericardial patches to create a tunnel between the left ventricle and the aorta. Ages ranged from two months to 13 years (mean age 4.8 years). Thirteen patients had situs solitus and levocardia, one patient had situs inversus and dextrocardia, and one patient had situs solitus and dextrocardia. Construction of the tunnel began at the right atrium. The ventricular septal defect (VSD) was enlarged anteriorly, if restrictive or small, and the first patch was sutured in the infero-posterior edge of the VSD. The second, third and sometimes the fourth patches were sutured in sequence, through the right ventriculotomy, directing the tunnel to the aortic annulus.

RESULTS

Overall mortality was 20%, with two early and one late death. The surviving patients were followed-up for a period ranging from ten months to nine years (mean 33 months), and all were in functional class I (NYHA). Minimal residual ventricular septal defect was observed in one patient, stenosis in two patients and moderate pulmonary insufficiency in one. There was no obstruction of the intraventricular tunnel between the LV and the aorta.

CONCLUSION

Based on these data, we conclude that this technical modification for the biventricular repair of the double-outlet right ventricle with noncommitted VSD allows for the construction of a tunnel with adequate internal diameter, respecting the spatial changes between the VSD and aorta. In addition, the intraventricular bovine pericardial tunnel takes up less space, thus reducing the incidence of right ventricle outlet obstruction.

Heart transplantation in neonates and children. Intermediate-term results

OBJECTIVE

To assess intermediate-term outcome in children who have undergone orthotopic heart transplantation.

METHODS

We carried out a longitudinal and prospective study between October '92 and June '99 comprising 20 patients with ages ranging from 12 days to 7 years (mean of 2.8 years). We employed a double immunosuppression protocol with cyclosporine and azathioprine and induction therapy with polyclonal antithymocyte serum. Survival and complications resulting from the immunosuppression protocol were analyzed.

RESULTS

The double immunosuppression protocol and the induction therapy with polyclonal antithymocyte serum resulted in an actuarial survival curve of 90% and 78.2% at 1 and 6 years, respectively, with a mean follow-up period of 3.6 years. One patient died due to acute rejection 40 days after transplantation; another patient died 2 years after transplantation due to lymphoproliferative disorder; a third patient died because of primary failure of the graft; and a fourth patient died due to bronchopneumonia. The major complications were as follows: acute rejection, infection, nephrotoxicity, and systemic hypertension. The means of rejection and infection episodes per patient were 2.9 and 3.4, respectively. After one year of transplantation, a slight reduction in the creatinine clearance and systemic hypertension were observed in 7 (38.9%) patients.

CONCLUSION

Heart transplantation made life possible for those patients with complex congenital heart diseases and cardiomyopathies in refractory congestive heart failure constituting a therapeutical option for this group of patients in the terminal phase.

Intraventricular repair of double-outlet right ventricle with noncommitted ventricular septal defect: advantages of multiple patches

OBJECTIVE

The objective of this paper is to report our experience with biventricular repair of double-outlet right ventricle with noncommitted ventricular septal defect by means of multiple patches that simplify and render feasible the intraventricular correction of this complex anomaly.

METHODS

From April 1987 to April 1999, in 18 patients with double-outlet right ventricle and noncommitted ventricular septal defect, a technical modification that used multiple patches of bovine pericardium was used to construct an intraventricular tunnel connecting the left ventricle to the aorta. Ages ranged from 2 months to 13 years (mean age 4.73 +/- 3.41 years).

RESULTS

The early mortality was of 11.1% (2 patients). Surviving patients were followed up for a mean of 2.65 years. Three late deaths (16.6%) occurred: 5 months, 7 months, and 7 months after the operation. All but 1 patient are in New York Heart Association class I.

CONCLUSION

The use of multiple patches for biventricular correction of this anomaly simplifies and renders feasible the intraventricular repair in cases in which the 1-patch technique was deemed impossible.

Critical aortic stenosis in the neonate. Clinical assessment and surgical outcome in 18 patients

OBJECTIVE

To assess neonates with aortic stenosis with early decompensation operated upon. (LCO) (CHF).

METHODS

A and retrospective study analyzing 6 neonates with LCO, group I (GI), and 12 neonates with CHF, group II (GII). Clinical radiographic, electrocardiographic and echocardiographic findings also provided comparative bases for the study, as did surgical and evolutional findings.

RESULTS

The mean ages at hospitalization and surgery (p = 0.0031) were 14.3 and 14.8 days in GI and 35.4 and 42.8 days in GII, respectively. Cardiac murmurs were more intense in GII (p = 0.0220). The aortic ring was smaller in GI (8.0 +/- 2.5mm) as compared to GII (11.4 +/ 1.4mm) (p = 0.2882). Ventricular function was reduced to 18 +/- 5.5% and 33.3 +/- 7.6% in GI and GII, respectively (p = 0.0162). Aortic atresia, however, was present only in 2 neonates in GI. Five of 6 patients in GI died but all patients in GII survived (p=0.0007). In the latter group, 84.6% of the patients were in functional class I (FC-I) in the long-term follow-up, with moderate residual lesions in 6 neonates, discrete residual lesions in 4, and reoperation in 2.

CONCLUSION

Aortic stenosis is a severe anomaly of the neonate, whose immediate evolution depends on the pre-operative anatomic and functional findings, and the late evolution essentially depends on the anatomic features of the valve.

Anomalous origin of the left coronary artery from the right pulmonary artery with intramural aortic trajectory. Clinicosurgical diagnostic implications

OBJECTIVE

Anomalous origin of the left coronary artery from the right pulmonary artery (AOLCARPA), is a rare entity that is usually associated with other defects. Of the 20 cases of AOLCARPA reported in the literature, 14 (70%) had associations. We describe four patients with AOLCARPA without associated defects, but with a peculiar intramural aortic trajectory.

METHODS

Fifty-five patients with anomalous origin of the left coronary artery were operated upon at INCORFMUSP. Four of the patients had the anomalous origin from the right pulmonary artery (RPA) without associated defects but with intramural aortic trajectory. Clinical and laboratory examinations were analyzed, as well as surgical findings.

RESULTS

All patients had congestive heart failure (CHF) and 3 also had angina pectoris. Two patients had a murmur of mitral regurgitation, signs of myocardial infarction on the ECG and cardiomegaly. The shortening fraction varied from 9% to 23%. The hemodynamic study confirmed the diagnosis of anomalous origin of the coronary artery, but the intramural trajectory and the origin from the RPA were established only at surgery. In 3 patients, the technique of side-to-side anastomosis was performed with a good outcome. One patient, who underwent end-to-side anastomosis, died 6 months after the surgery.

CONCLUSION

Association with other defects usually occurs in the AOLCARPA, and the intramural aortic trajectory is difficult to clinically diagnose but easy to surgically correct.

Ebstein's anomaly with coarctation of the aorta. An unusual association

Ebstein's anomaly with coarctation of the aorta is an extremely unusual condition. In this report, the clinical and surgical features of 3 male patients, aged 7 months, 4 years and 14 years, are discussed. All patients were in situs solitus. The first 2 patients had atrioventricular and ventriculoarterial discordance and progressed to heart failure in the neonatal period. The third had atrioventricular and ventriculoarterial concordance, as well as Wolf-Parkinson-White syndrome, with frequent episodes of paroxysmal tachycardia. The 3 patients underwent surgery for correction of the coarctation of the aorta. The patient with atrioventricular and ventriculoarterial concordance underwent tricuspid valvuloplasty using a DeVega-like technique. In addition, ablation of 2 anomalous pathways (Kent bundle), which were detected by the electrophysiologic study, was also subsequently performed. The 3 patients showed a good postoperative outcome for 2 years, although, in those with discordance, the surgical procedure did not influence the dysplasia of the tricuspid valve, because this valve showed light to moderate dysfunction.

Aortopulmonary window. Clinical and surgical assessment of 18 cases

OBJECTIVE

Aortopulmonary window (APW) is an uncommon congenital malformation. Its clinical presentation is dependent on the size of the defect and on the associated lesions. We evaluated our experience with this anomaly and compared it with 296 cases reported in the literature.

METHODS

Retrospective study of 18 patients diagnosed as having APW (age range from 13 days to 31 years, 13 (72.2%) females), divided into two groups: Group A (GA): 10 patients with isolated APW, and Group B (GB): 8 patients with associated lesions.

RESULTS

Heart failure occurred in 14 patients, and cyanosis in 3:2 from GB (tetralogy of Fallot--TF, and double outlet right ventricle--DORV), and one from GA with pulmonary hypertension. In 5 patients from GA the diagnosis of mitral regurgitation was made based on a systolic murmur and LV hypertrophy on the EKG. In GB, clinical findings were determined by the associated defect. Diagnosis was established by echocardiography in 11 (61.2%) of the patients. In 3 patients, a wrong diagnosis of mitral regurgitation was made, in 1 a patent ductus arteriosus was diagnosed and in 3 others, the diagnosis of APW was masked by other important associated defects (2 cases of DORV and 1 case of TF). The diagnosis was made by catheterization in 3 (16.6%) patients, by surgery in 3 (16.6%) and by necropsy in 1 (5.5%). Corrective surgery was performed in 14 (77.7%) patients, with one immediate death and good long-term follow-up in the remaining patients.

CONCLUSION

APW can be confused with other defects. Clinical findings, associated with an adequate echocardiogram can provide the information for the correct diagnosis.

Multiple rhabdomyomas in monozygotic twins

Rhabdomyoma is the most frequent primary cardiac tumor seen during infancy. We report multiple rhabdomyomas diagnosed in twins in the neo natal period. To the best of our knowledge, this is the first instance of this happening.

[Absence of right atrioventricular connection. Morphological and clinical presentation when the dominant ventricle is morphologically right]

Absent right atrioventricular connection, with the left atrium connected to a dominant left-sided morphologically right ventricle is a rare situation. We report five cases with these anatomical features, with emphasis on the morphological and clinical aspects. Although this combination of lesions is very uncommon, the sequential segmental analysis can easily provide an accurate description of the anomaly.

Double outlet right ventricle with intact atrial septum and restrictive ventricular septal defect: an analysis of two cases

Two cases of double outlet right ventricle with restrictive ventricular septal defect are described. This is an uncommon presentation that causes left ventricular dysfunction because of left ventricular outflow tract obstruction. The presence of an intact atrial septum leads to severe pulmonary hypertension, which tends to aggravate the right ventricular output. In the presence of a normal left ventricle, the authors suggest the possibility of enlargement of the ventricular septal defect in order to perform a biventricular repair. The association of a supramitral valve ring in both cases, and the isolation of the left subclavian artery and an aortopulmonary fenestration in one of these cases, are also discussed. In addition we explore factors that cause restrictive ventricular septal defects as well as the mechanisms that may lead to spontaneous closure of ventricular septal defect in a double outlet right ventricle.

[Hemodynamic evaluation and clinical outcome of children with severe dilated cardiomyopathy eligible for heart transplantation]

PURPOSE

To evaluate hemodynamic parameters and clinical outcome of children with severe cardiomyopathy who are candidates for heart transplantation.

METHODS

Twenty four children aged from 4 months to 10 years and 8 months (mean 3.7 +/- 2.5 years) from February 1992 to May 1996, were submitted to hemodynamic study and the following parameters were measured: cardiac output, mean pulmonary artery pressure (MPAP) and capillary wedge pressure. The pulmonary vascular resistance index (PVRI) and transpulmonary pressure gradient (TGP) were calculated.

RESULTS

Ten (41.6%) children were transplanted (group A), 5 (20.8%) are still waiting heart transplantation (group B) and 9 (37.6%) died (group C). The mean age of the B and C group were significantly different. The PVRI, MPAP and TPG were significant lower in group A than group C (p = 0.01; p = 0.044 and p = 0.023 respectively).

CONCLUSION

The profile of the hemodynamic parameters of children with severe dilated cardiomyopathy was compatible with the clinical findings. The age was the only difference comparing groups B and C. PVRI, MPAP and TPG were significant factors between group A and C. The older the patient, the worse was the prognosis.

Choreoathetosis after cardiac surgery with hypothermia and extracorporeal circulation

Eleven children, 4-48 months old, with congenital cyanotic heart defects developed choreoathetoid movements 2-12 days after cardiac surgery with hypothermia and extracorporeal circulation (ECC). The abnormal movements mainly involved the limbs, facial musculature, and tongue, leading to a severe dysphagia. The symptoms had an acute onset, after a period of apparent neurologic normality, and had a variable outcome. Of the nine children that survive, three had abnormal movements when last seen (41 days to 12 months of follow-up). The other six children had a complete regression of the choreoathetoid movements 1-4 weeks after onset. No specific finding was observed in the CT scans, cerebrospinal fluid examination, or EEG that could be related to the abnormal movements. Symptomatic therapy with haloperidol with or without benzodiazepines led to symptomatic improvement in six children, although there was no evidence that this treatment modified the evolution of the disease. The authors conclude that the choreoathetoid syndrome after cardiac surgery with deep hypothermia and ECC is an ill-defined entity requiring additional study to better understand its pathogenesis so that preventive measures can be taken to avoid a condition that can lead to permanent and incapacitating neurologic sequelae.

[Complete atrioventricular septal defect. Anatomo-functional correlation between patients with and without Down's syndrome]

PURPOSE

To compare clinical course, causes and symptoms beginning enset time in children with complete atrioventricular canal with and without Down's syndrome.

METHODS

Records of 80 patients < 2 years of age, were reviewed. There were 55 (69%) with Down's syndrome-group I (GI) and 25 (31%) without-group II (GII). Age at synpton enset intensity, functional class, clinical repercussion and anatomic variations in patients undergoing corrective surgery were evaluated.

RESULTS

Mean age at symptoms onset was similar for the two groups (50 +/- 75 days). Class II (NYHA) was more frequent in GI (31 patients-56.5%) and class III-IV (NYHA) in GII (19 patients-76%) p < 0.005. Clinical repercussion evaluation showed that congestive heart failure was present in 34 (62%) patients of GI and 21 (84%) of GII; and, pulmonary hypertension was in 21 (38%) patients of GI and 4 (16%) patients of GII p < 0.04. Mean pulmonary arterial pressure of 50 mmHg or more was present in 68% of children with Down's syndrome and in 35% of GII. Clinical course until surgical correction was down hill in 33 (60%) from GI and 21 (84%) from GII p < 0.03. Seventy seven patients underwent surgical correction. CAVC type A of the Rastelli classification was predominant in both groups, GI 37 (67%)-GII 25 (100%). There or more severe valvar morphologic lesions in group II (38%) than in group I (8%).

CONCLUSION

There seems to be a pulmonary vascular hyperreactivity predominance in Down's children and cardiac insufficiency signs in the normal genetic group.

[Pulmonary artery sling]

The authors present a case of a two-year-old boy with stridor since birth, and also recurrent episodes of pulmonary infections, due to mechanical compression of distal trachea by a left pulmonary artery sling. They discussed diagnostic approach, surgical management and review of the literature. To our knowledge, it is the first case of sling of the pulmonary artery reported in Brazil and the fifth in a latin language country.

[Systematic quantification of the arteries in lung biopsies of patients with congenital heart defects and its contribution to the therapeutic management]

PURPOSE

To determine the value of the quantitative analysis of lung biopsies from patients with congenital cardiac defects.

METHODS

Fourty nine biopsies were examined, from patients: 43 patients increased pulmonary blood flow, 3 with pulmonary atresia and large systemic-to-pulmonary collateral vessels, and 3 with decreased pulmonary flow. The degree of lesion was determined as in Heath-Edwards and of Rabinovitch and col.

RESULTS

The Heath and Edwards grade was determined in 41 cases; I in nine; II in 23; III in eight; IV in one; 3 biopsies showed evidence of reduced pulmonary flow and 5 had no signs of vascular disease. The Down patients (7) presented a greater proportion of severe lesions. Quantitative evaluation was obtained in 35 biopsies: 11 had grade B and 24 had grade C. Wall atrophy and dilatation of intraacinar arteries were detected in 7 cases, what suggested the existence of obstructive lesions in proximal vessels, even if not sampled. Medical thickness greater than 2 times the normal were observed in pre-acinar arteries from 14 biopsies.

CONCLUSION

The morphometric approach allowed us to detect severe lesions which the qualitative analysis alone would not indicate adequately. In the patients presenting decreased pulmonary flow, morphometry made possible to assess if the degree of arterial wall hypertrophy was compatible with a surgery of atrio-pulmonary anastomosis.

[Tetralogy of Fallot associated with left atrial isomerism]

The association of tetralogy of Fallot with atrial isomerism has been rarely reported. Eight cases (five with left isomerism and three with right isomerism) are known. This paper reports two other cases of tetralogy of Fallot with left atrial isomerism. The syndrome's defects were disguised and without clinical expression because of the presence of the right ventricular outlet obstruction of tetralogy of Fallot. These diagnostic elements, not recognized in one of the patients previous to surgical correction of tetralogy of Fallot, were present: junctional rhythm, bronchial isomerism, partial anomalous pulmonary vein connection, agenesy of inferior vena cava and abdominal heterotaxy; their identification previous to surgical correction of tetralogy of Fallot, is necessary for an adequate surgical management.

[Neonate and infant heart transplantation]

PURPOSE

Heart transplantation has offered children with complex congenital heart diseases and severe cardiomyopathies a chance for survival. The present article was written to show the three year experience of this procedure at the Instituto do Coração-HCFMUSP.

METHODS

The methodology used was based on heart transplant indication criteria, inclusion criteria for donors, postoperative management, immunosuppression and prophylaxis as well as treatment of potential complications.

RESULTS

From November 1992 to November 1995, 11 children, aged 12 days old to six years (mean 2.5 years) underwent transplantation. Sixty percent of recipients were male; weight ranged from 3.5 to 17.8 kg (mean 10.3 kg). The mean age of donors was 4.4 years (a range of three weeks to ten years), 80% male, weight ranging from 3.8 to 20 kg (median 14.3 kg). The survival rate was 91% and the remaining 10 children are doing well. The most important complications were systemic hypertension, acute rejection and infection. The number of rejections and infections per patient were 3.5 and 4.7 episodes, respectively. The follow-up was between one month to three years (average 16 months).

CONCLUSION

In this experience, heart transplantation has given an additional opportunity for children with complex congenital heart diseases and cardiomyopathies, with a survival rate of 91% in three years.

[Total anomalous pulmonary venous connection. Experience with 70 cases]

PURPOSE

To evaluate the clinical and surgical experience with consecutive patients with isolated total anomalous pulmonary venous connection admitted to the Heart Institute, São Paulo, Brasil.

METHODS

Hospital records of 70 consecutive patients (January 1985 to December 1993) were retrospectively reviewed. There were 28 girls and 42 boys whose ages ranged from two days to four years (mean 20.4 +/- 29 weeks). The following variables were selected for analysis: anatomic type, age at admission, clinical status, the presence of infection, restrictive atrial septal defect, and the presence of pulmonary venous obstruction. Univariate and multivariate analysis were used to identify possible risk factors for death.

RESULTS

The abnormal anatomical connection was supracardiac in 63%, cardiac in 17%, infracardiac in 8.5% and mixed in 11.5% of the cases. Eighteen (25.7%) patients were admitted in poor clinical condition. Infection, mainly pulmonar, was present in 31 (44%) patients. Pulmonary venous obstruction was present in 21% of the patients. Atrial septostomy was performed in 38 patients, 13 of them admitted in a poor clinical status. The preoperative mortality was 15.7% and the operative, 17%. Statistical analysis demonstrated that infection, poor clinical status and age were risk factors for death.

CONCLUSION

Surgical correction of total anomalous pulmonary venous drainage in infancy can be performed at low risk with good results. However early referral to a cardiac care center, agressive preoperative stabilization and postoperative care are important.

[Anomalous origin of the left coronary artery. Concomitant correction with valvar replacement for mitral insufficiency]

A four year-old boy with an anomalous origin of the left coronary artery (LCA) directly from the right pulmonary artery was reported. He had been underwent to mitral valve replacement by a St Judes no. 29, due to severe mitral insufficiency, secondary to an extensive myocardial infarction including the anterior and posterior papilary muscles, beside the implantation of the LCA in the aorta. Instead of this favorable outcome, it's emphasized the need for earlier recognition to avoid risk sequelae.

Epidemiologic investigation of an outbreak of coagulase-negative Staphylococcus primary bacteremia in a newborn intensive care unit

Infections due to coagulase-negative Staphylococcus (CNS) are an ever-increasing nosocomial problem, particularly in the pediatric population. The authors describe a cluster of three primary bloodstream infections due to CNS in a newborn intensive care unit that occurred between November 23 and December 2, 1992. Two children died as a direct consequence of the bacteremia; at autopsy, one had a large bacteria-containing thrombus extending from the insertion site of a central catheter to the superior vena cava. The children were placed in isolation, and the nursing and medical staff were given topical nasal mupirocin. Plasmid analysis performed later disclosed three different blood isolates that also were different from any of the staff's nasal isolates. The authors concluded that molecular methods such as plasmid analysis are important tools in identifying true outbreaks and can prevent needless interventions, such as those during this cluster.

[Pulmonary valve agenesis. Clinico-surgical evaluation of 32 patients]

PURPOSE

To study the surgical and clinical evolution of 32 cases with absent pulmonary valve to propose the ideal period of time for surgical correction.

METHODS

Clinical and laboratorial analysis were performed in 32 infants, under 12 months of age, between 1980 an 1993, in an evolutive character. From the clinical viewpoint, hypoxic and/or congestive features were considered in previous and late periods related to surgical repair. Laboratorial studies as ECG (cavities overload), chest X-ray (cardiac size and pulmonary vascular markings) and echocardiogram (associated defects, pressure gradients and anatomical aspects of pulmonary arteries) were also analyzed. Cardiac catheterization was performed in 15 patients.

RESULTS

Early cyanosis in 84% of cases and "to and for "murmur in 90% of them facilitate clinical diagnosis in whom tetralogy of Fallot was associated in 30 patients. Refractory respiratory and cardiac insufficiency were responsible for operative indication in 12 patients, half of them, operated on under 12 months of age, died. Survival patients were repaired between two to 11 years old. Four deaths occurred early in life, before any surgical consideration and the 16 remaining patients will electively be considered for an opportune repair.

CONCLUSION

Conservative clinical treatment is indicated, waiting for a more rigid bronchial wall can support the pressure of the dilated pulmonary arteries. This way, surgical repair is postponed for at least two years of age.

Favorable effects of immunosuppressive therapy in children with dilated cardiomyopathy and active myocarditis

Among 68 children with severe dilated cardiomyopathy, 43 (aged 10 months to 15 years) presented with active myocarditis, diagnosed by endomyocardial biopsy. They were divided into four treatment groups: I, controls: 9 patients submitted to conventional treatment (digitalis, diuretics, and vasodilators) for 8.1 +/- 0.7 (SD) months; II, prednisone: 12 patients received conventional therapy plus prednisone; III, azathioprine: 16 patients submitted to conventional therapy plus prednisone and azathioprine; IV, cyclosporine: 13 patients treated with conventional therapy plus prednisone and cyclosporine. Immunosuppressive therapy was maintained for a mean of 8.4 +/- 1.2 months. They were submitted to noninvasive (electrocardiogram, chest radiograph, Doppler echocardiogram, and radioisotopic scintigraphy) and invasive (hemodynamic) studies. In the control group only 2 of 9 patients showed clinical and hemodynamic improvement and 1 of 4, histologic regression of the myocarditis. Among patients submitted to conventional therapy plus prednisone, 3 of 12 presented clinical and hemodynamic improvement; 2 of 5 also showed histologic regression of inflammatory process. By contrast, patients treated with azathioprine or cyclosporine associated with prednisone had significantly better results: 13 of 16 and 10 of 13 patients, respectively, had clinical and hemodynamic improvement; all 6 patients in the azathioprine group and all 4 patients in the cyclosporine group had histologic regression of the myocarditis. Two patients in the prednisone group, one in the azathioprine group, and one in the cyclosporine group died during treatment, in cardiogenic shock. In our experience immunosuppressive therapy with azathioprine or cyclosporine associated with prednisone improves the prognosis of children with active myocarditis and severe ventricular dysfunction.

[Agenesis of the right pulmonary artery with severe pulmonary hypertension, attenuated by surgical correction]

A 22 months old infant with agenesis of right pulmonary artery, without other associated congenital heart defects, is reported. Reconstruction of pulmonary arteries by connecting them through a 7mm Goretex tube was performed, with clear clinical improvement in view of disappearance of signs of cardiac insufficiency and of hypoxemia. Contralateral pulmonary hypertension, at systemic level, decreased to 77% in the immediate postoperative period. So, this technique becomes the first option, before considering these cases for cardiopulmonary transplantation.

[Pulmonary atresia with intact ventricular septum. Natural development of the right ventricle]

A case of pulmonary atresia with intact ventricular septum and a hypoplastic right ventricle, with three wall formed portions, that became naturally well developed until 2 years of age, is related. A Blalock-Taussig shunt had been performed early in life. Z value of tricuspid valve of 0.3 and left ventricular in ECG has been changed to a well developed tricuspid annulus of 22 mm diameter and to a right ventricle overload after 2 years of follow-up, being possible surgical correction at that time. This observation, until today unknown, the natural increase of a congenitally hypoplastic cardiac chamber, favors the possibility to postpone the corrective operation to a better stage in this anomaly, when the risk becomes lower.

[Clinical manifestation of aortopulmonary window as mitral regurgitation caused by secondary dilatation of the valvar anulus]

Two patients with huge aortopulmonary window, both ten months-old, that showed curiously up at a clinical viewpoint, including echocardiography, as a mitral valve regurgitation with a dilated mitral ring secondary to the accentuated blood volume through it, were reported. Early signs of heart failure, accentuated systolic murmur at mitral area and overload of left heart cavities, characterized clinical impression of a congenital mitral insufficiency, in both cases. The correct diagnosis was established at operation and at necropsy study, bringing it to us the need to a more accurate analysis of the different diagnostic elements, especially in anomalies which clinical manifestations show great similarities.

Abnormal multimeric and oligomeric composition is associated with enhanced endothelial expression of von Willebrand factor in pulmonary hypertension

Abnormalities in endothelial von Willebrand factor (vWF) structure have been reported in pulmonary hypertension. These include loss of high molecular weight plasma multimers, resulting in decreased biologic activity. If endothelial processing of vWF is altered in this disorder, abnormalities in oligomeric composition may also be expected. We examined this possibility in ten adult patients with primary pulmonary hypertension. Enhanced endothelial vWF expression in these patients was indicated by increased plasma levels of vWF antigen (vWF:Ag) (214 +/- 91 vs 99 +/- 51 percent activity in controls, p < 0.001) and intense immunoperoxidase stain of pulmonary arterial endothelium for vWF (autopsy, 1 patient). Plasma from these patients also had a decreased capacity of inducing platelet aggregation in the presence of ristocetin, relative to vWF:Ag levels (57 +/- 20 percent activity). In addition to mild loss of the largest multimers, changes in oligomeric composition of plasma vWF were observed in most patients using both agarose and polyacrylamide gel electrophoresis. These included decreased concentration of dimeric (470 kDa) vWF in most patients, variable concentration of the 860-kDa fraction, and a relative decrease in subunit (223 kDa) density in subjects with elevated vWF:Ag. These findings provide additional information on the mechanisms responsible for endothelial production of dysfunctional vWF in patients with pulmonary hypertension.