[Hepatitis B Virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) among Hospitalized Mentally Disabled Patients is not transmitted by their nurses or family members].

BACKGROUND: Prevalence of hepatitis B virus (HBV) infection has been reported to be higher in the institutionalized mentally disabled patients than that of the general population previously reported in Iran. This study aims to investigate HBV infection among nurses and families of the hospitalized mentally disabled patients. MATERIAL AND METHODS: This study was conducted on 110 nurses and family members of the mentally disabled patients who were hospitalized in five residential care centers of Tehran. The presence of hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (HBcAb) was examined using the enzyme-linked immunosorbent assay (ELISA). Afterwards, HBV DNA was extracted, and then propagated via a nested polymerase chain reaction (PCR) and specific primers. Finally, a phylogenetic tree was constructed using the neighbor-joining method to compare virus genomes in the nurses' serum with other isolated HBVs worldwide. RESULTS: Out of 102 studied nurses, three (3%) were positive for HBsAg (100% female). Also, no patient was positive for the HBV genome, while eight (7.3%) nurses were positive for HBcAb including two (25%) males and six (75%) females. Genome sequencing of one DNA positive sample showed that the isolated virus from this patient contained sub genotype D1 and subtype ayw2. The results of none of the family members were positive for HBsAg, HBcAb, or HBV DNA. CONCLUSION: This study showed a higher prevalence of HBsAg among nurses (3%) compared to the Iranian general population (1.7-2.1%). The virus isolated from the nurses belonged to subgenotype D1 and subtype ayw2 in accordance with previous Iranian reports. Also, there was no drug-resistant or vaccine-escape mutations in the obtained viral genome. Moreover, low immune pressure on the virus in the asymptomatic chronic HBV patients might be responsible for low nucleotide divergence among the derived HBV genome.

Partial esophageal transplantation is possible as part of a multivisceral graft.

We report a case of a 9-year-old female with inflammatory myofibroblastic tumor (IMT), which involved the upper retroperitoneum, visceral vessels, stomach and distal esophagus. Complete resection of the tumor required a multivisceral (MV) transplant. Due to tumor involvement, resection of the distal third of recipient esophagus was necessary. Gastrointestinal continuity was subsequently established via esophagoesophagostomy to donor esophagus en bloc with a standard MV graft. After 1.9 years of follow-up, the patient has no symptoms of dysphagia or reflux. This case illustrates the feasibility of including the distal donor esophagus as part of an MV graft.

Reno-portal anastomosis as an approach to pediatric kidney transplantation in the setting of inferior vena cava thrombosis.

In pediatric renal transplantation in the setting of IVC thrombosis, the retrohepatic IVC or gonadal veins are often used for outflow. However, if use of systemic venous outflow is unsuccessful, options become limited. We report the use of the portal vein for venous outflow in kidney retransplantation in the setting of IVC thrombosis. The patient is a 19-month-old male who developed end-stage renal failure at seven months of age secondary to hypotension after spontaneous rupture of an accessory renal vein. The IVC was occluded during emergent laparotomy, and the patient developed extensive IVC thrombosis. The first two transplant attempts used the retrohepatic IVC for venous outflow. Despite good initial flow, in both instances the renal vein thrombosed on post-operative day 1. In an unsuccessful salvage attempt of the second transplant, a reno-portal anastomosis was performed. With few options for vascular access, a third transplant was attempted. The reno-portal stump from the second transplant was used for outflow. The patient recovered well from his third transplant (creatinine 0.6 mg/dL 35 months post-surgery), demonstrating that the portal vein can be used for outflow in cases of extensive IVC thrombosis.

Aorto-mesenteric and renal allograft transplant: a novel treatment for midaortic syndrome.

Midaortic syndrome (MAS) is a rare condition characterized by stenosis of the aorta and often involving renal and visceral arteries. Current therapies include medical management of associated hypertension, and interventional procedures such as angioplasty or surgical bypass. We report a 2-year-old female with severe MAS who was initially treated with angioplasty and stents in both her aorta and superior mesenteric artery (SMA). Due to the presence of long segment stenoses, her renal arteries were not amenable to surgical reconstruction and she rapidly progressed to Stage V chronic kidney disease. The patient underwent bilateral nephrectomy and renal transplantation using a donor thoracoabdominal aorta allograft to provide inflow for the kidney as well as to bypass the nearly occluded aorta. The donor SMA was used to bypass the native SMA stenosis. Postoperatively, the patient had normalization of four limb blood pressures. She weaned from five anti-hypertensive agents to monotherapy with excellent renal function. This is the first reported case of thoracoabdominal aortic bypass using allograft aorta to address MAS. This approach allowed for successful kidney transplantation with revascularization of the mesenteric, and distal aortic circulation using allograft conduit that will grow with the child, obviating the need for repeated interventional or surgical procedures.

Multivisceral transplantation using a 2.9 kg neonatal donor.

Prematurity and very low birthweight have often been considered relative contraindications to neonatal organ donation. Organ procurement from neonatal donors is further complicated by unclear guidelines regarding neonatal brain death. We report a successful case of multivisceral transplantation using a graft from a 10-day-old, 2.9 kg, neonatal donor born at 36 6/7 wk in a 3.2 kg, three month old with intestinal and liver failure secondary to midgut volvulus. There was immediate liver graft function with correction of recipient coagulopathy, but delayed normalization of laboratory values and delayed return of bowel function. At six-yr post-transplant follow-up, the patient has normal intestine and liver function. Her last histologically confirmed rejection episode was 30 months prior to last follow-up. This case suggests that multivisceral grafts from very young or small neonatal donors may be transplanted successfully in selected cases. We propose a re-examination of the brain death guidelines for premature and young infants to potentially increase the availability of organs for infant recipients.

Valley polarization and susceptibility of composite fermions around a filling factor nu=3/2.

We report magnetotransport measurements of fractional quantum Hall states in an AlAs quantum well around a Landau level filling factor nu=3/2, demonstrating that the quasiparticles are composite fermions (CFs) with a valley degree of freedom. By monitoring the valley level crossings for these states as a function of applied symmetry-breaking strain, we determine the CF valley susceptibility and polarization. The data can be explained well by a simple Landau level fan diagram for CFs, and are in nearly quantitative agreement with the results reported for CF spin polarization.

Valley susceptibility of an interacting two-dimensional electron system.

We report direct measurements of the valley susceptibility, the change of valley population in response to an applied symmetry-breaking strain, in an AlAs two-dimensional electron system. As the two-dimensional density is reduced, the valley susceptibility dramatically increases relative to its band value, reflecting the system's strong electron-electron interaction. The increase has a remarkable resemblance to the enhancement of the spin susceptibility and establishes the analogy between the spin and valley degrees of freedom.

Dependence of persistent gaps at landau level crossings on relative spin.

We report measurements of the quantum Hall state energy gap at avoided crossings between Landau levels originating from different conduction band valleys in AlAs quantum wells. These gaps exhibit an approximately linear dependence on the magnetic field over a wide range of fields and filling factors. More remarkably, we observe an unexpected dependence of the gap size on the relative spin orientation of the crossing levels, with parallel-spin crossings exhibiting larger gaps than antiparallel-spin crossings.

Spin-dependent resistivity at transitions between integer quantum hall states.

The longitudinal resistivity at transitions between integer quantum Hall states in two-dimensional electrons confined to AlAs quantum wells is found to depend on the spin orientation of the partially filled Landau level in which the Fermi energy resides. The resistivity can be enhanced by an order of magnitude as the spin orientation of this energy level is aligned with the majority spin. We discuss possible causes and suggest a new explanation for the spikelike features observed at the edges of quantum Hall minima near Landau level crossings.

Dependence of spin susceptibility of a two-dimensional electron system on the valley degree of freedom.

We report measurements of the spin susceptibility, chi proportional, variant g(v)g*m*, in an AlAs two-dimensional electron system where, via the application of in-plane stress, we transfer electrons from one ellipsoidal conduction-band valley to another (g(v) is the valley degeneracy, and m* and g* are the electron effective mass and g factor). At a given density, when the two valleys are equally populated (g(v)=2), the measured g*m* is smaller than when only one valley is occupied (g(v)=1). This observation counters the common assumption that a two-valley two-dimensional system is effectively more dilute than a single-valley system because of its smaller Fermi energy.

Spin susceptibility of two-dimensional electrons in narrow AlAs quantum wells.

We report measurements of the spin susceptibility in dilute two-dimensional electrons confined to a 45 A wide AlAs quantum well. The electrons in this well occupy an out-of-plane conduction-band valley, rendering a system similar to two-dimensional electrons in Si-MOSFETs but with only one valley occupied. We observe an enhancement of the spin susceptibility over the band value that increases as the density is decreased, following closely the prediction of quantum Monte Carlo calculations and continuing at finite values through the metal-insulator transition.

Realization of an interacting two-valley AlAs bilayer system.

By using different widths for two AlAs quantum wells comprising a bilayer system, we force the X-point conduction-band electrons in the two layers to occupy valleys with different Fermi contours, electron effective masses, and g factors. Since the occupied valleys are at different X points of the Brillouin zone, the interlayer tunneling is negligibly small despite the close electron layer spacing. We demonstrate the realization of this system via magnetotransport measurements and the observation of a phase-coherent, bilayer nu=1 quantum Hall state flanked by a reentrant insulating phase.

Increased orbitofrontal cortex levels of choline in depressed adolescents as detected by in vivo proton magnetic resonance spectroscopy.

BACKGROUND: The frontal lobe has been implicated in the pathology of depression in adults. Through the use of magnetic resonance spectroscopy, altered brain choline levels have also been linked to the pathophysiology of affective disorders. METHODS: To identify possible alterations in orbitofrontal cortex levels of cytosolic choline in adolescents with and without depression, 22 depressed and 43 control adolescents were recruited. Of those recruited, usable proton magnetic resonance spectra were acquired from a voxel in the left anterior medial frontal lobe of 17 depressed (mean age 15.8+/-1.6) and 28 healthy adolescents (mean age 14.5+/-1.7). RESULTS: Orbitofrontal cytosolic choline/creatine (Cho/Cr) ratios (p =.032) and cytosolic choline/N-acetyl aspartate (Cho/NAA) ratios (p =.043) were significantly higher in the depressed subjects than in the control subjects. There were no significant differences between depressed and control subjects in gray or white matter content within the voxel. CONCLUSIONS: These findings suggest that brain cytosolic choline may be increased in depressed adolescents in comparison with control subjects and independent of a corresponding structural change. These results are consistent with similar, previously reported findings in adults and suggest that depression in adolescents is associated with alterations in orbitofrontal metabolism.

Hippocampal volume in primary unipolar major depression: a magnetic resonance imaging study.

BACKGROUND: Previous studies have shown that major depression is frequently accompanied by hypercortisolemia. There is some evidence suggesting that an increase in the glucocorticoid levels may make hippocampal cells more vulnerable to insults caused by hypoxia, hypoglycemia, or excitatory neurotransmitters. Using magnetic resonance imaging (MRI), the hippocampi of patients with major depression were measured and compared with values observed in control subjects. METHODS: Thirty-eight patients with primary unipolar major depression were recruited. Twenty control subjects were matched for age, gender, and years of education. The hippocampal volume was measured from coronal MRI scans in all of the subjects. Patients were also grouped and compared as responders and nonresponders to treatment with fluoxetine of 20 mg/day, for 8 weeks. Hamilton Depression Rating Scale (HDRS) was used to determine the severity of depression. RESULTS: No significant differences were observed between the hippocampal volumes of patients with major depression and control subjects; however, a significant correlation was observed between the left hippocampal volume of men and their HDRS baseline values. In addition, female responders had a statistically significant higher mean right hippocampal volume than nonresponders. CONCLUSIONS: The results of our study indicate no reduction in the volume of the hippocampus in patients with major depression. Nonetheless, the results do suggest that the effects of disease severity, gender, and treatment response may influence hippocampal volume.

[A propos a case of strangulated properitoneal hernia]. / A propos d'un cas de hernie propéritonéale étranglée.

The properitoneal hernias are very rare and their diagnosis is very difficult. The authors report one case and discuss the classification.