A case of dumbbell-shaped accessory scrotum with concomitant lipoma.

BACKGROUND: Accessory scrotum is a congenital scrotal anomaly that is usually located anterior to the anus and frequently presents with a lipoma in a bead-like shape. Herein, we present an unusual case of an accessory scrotum with a lipoma connected by a narrow stalk and located posterior to the anus. CASE PRESENTATION: A 1-month-old boy was referred to our hospital for a perineal mass present at birth. He was born at 37 weeks and 2 days, with a birth weight of 2962 g. No abnormalities occurred during the perinatal period, and the birth was uneventful. The mass had an unusual shape, comprising two masses connected by a narrow stalk. The base of the mass was posterior to the anus and was connected to the rectal mucosa. The proximal mass was elastic and soft without skinfolds, whereas the distal mass was elastic and soft with a scrotum-like skinfolds. Magnetic resonance imaging showed no spina bifida. High-intensity adipose tissues in both masses and low-intensity vessels or fibrous stroma in cord-like structures between the two masses were found on T2-weighted images. At 3 months of age, the patient underwent resection in the prone jackknife position. No tumorous lesions were connected to the mass on the rectal and coccyx sides, and the mass was completely removed, preserving the anal sphincter. Histologically, the distal mass had characteristics of a scrotum, whereas the proximal mass was exclusively a lipoma. The connecting stalk had normal skin structures and a blood vessel with parallel-running nerve bundles. The postoperative course was uneventful, and the patient was discharged on postoperative day 6. CONCLUSIONS: This case of accessory scrotum was unusual in its location and the presence of a stalk connecting the accessory scrotum and lipoma. The mechanism underlying accessory scrotum development remains unclear, and our report may impact the discourse regarding the embryological development of the accessory scrotum.

Regeneration Process of an Autologous Tissue-Engineered Trachea (aTET) in a Rat Patch Tracheoplasty Model.

The treatment of long-tracheal lesion is difficult because there are currently no viable grafts for tracheal replacement. To solve this problem, we have developed an autologous Tissue-Engineered Trachea (aTET), which is made up of collagenous tissues and cartilage-like structures derived from rat chondrocytes. This graft induced successful long-term survival in a small-animal experiment in our previous study. In this study, we investigated the regeneration process of an aTET to attain reproducible success. We prepared an aTET by using a specially designed mold and performed patch tracheoplasty with an aTET. We assigned twenty-seven rats to three groups according to the three types of patch grafts used: aTET patches (the aTET group), fresh tracheal autograft patches (the Ag group), or polylactic acid and polycaprolactone copolymer sheets (the PPc group). In each group, gross and histological evaluations were performed at 1 month (n = 3), 3 months (n = 3), and 6 months (n = 3) after implantation. We obtained high survival rates in all groups, but only the PPc group attained thick tracheal walls with granular tissues and no tracheal regeneration. On the other hand, the aTET and Ag groups reproducibly achieved complete tracheal regeneration in 6 months. So, an aTET could be a promising candidate for tracheal regeneration grafts.

Efflorescence kinetics of sodium carbonate decahydrate: a universal description as a function of temperature, degree of reaction, and water vapor pressure.

The efflorescence of sodium carbonate decahydrate (SC-DH) required to form its monohydrate (SC-MH) was systematically studied under isothermal and linear nonisothermal conditions at different atmospheric water vapor pressures (p(H2O)) using a humidity-controlled thermogravimetry instrument equipped with a cooling circulator. The universal kinetic description at various temperatures (T) and p(H2O) values was evaluated using the extended kinetic equation with an accommodation function (AF) comprising p(H2O) and the equilibrium pressure of the reaction (Peq(T)). By optimizing two exponents in the AF, all kinetic data were universally described in terms of the isoconversional kinetic relationship examined at individual degrees of reaction (α). This enabled the examination of the isothermal kinetic relationship and the parameterization of the contribution of the self-generated water vapor, allowing the incorporation of kinetic data recorded in a stream of dry N2 into the universal kinetic description as a function of T, α, and p(H2O). The results indicated that the reaction is physico-geometrically controlled by the surface reaction at the hemispherical top surface of SC-DH particles and subsequent advancement of the reaction interface toward the center and bottom of these particles, where the interfacial process is regulated by an elementary step of the consumption of H2O vacancies to form the SC-MH building unit. The apparent activation energy (Ea) of ∼178 kJ mol-1 was determined using the extended kinetic approach considering the effect of p(H2O) correlated with the intrinsic Ea of the Arrhenius-type temperature dependence (∼63 kJ mol-1) by subtracting the contribution of the temperature dependence of Peq(T) in the AF.

Liver-Spleen Volume Ratio as a Predictor of Native Liver Survival in Patients with Biliary Atresia.

BACKGROUND: The appropriate timing of liver transplantation (LT) in patients with biliary atresia (BA) who survived with their native livers until adolescence remains controversial. The liver-spleen volume ratio (LSR) has been reported to be efficacious in predicting the prognosis of chronic liver disease. We investigated whether LSR could predict long-term native liver prognosis and serve as an indication for LT in patients with BA. METHODS: Patients with BA who survived with their native liver until the age of 15 years were included. These patients were classified into 2 groups. The unfavorable prognosis group included patients who underwent or were awaiting LT or developed complications such as refractory cholangitis or gastrointestinal bleeding due to esophagogastric or intestinal varices. The favorable prognosis group included patients who survived with their native liver without complications. We compared the 2 groups regarding LSR, hematological, and histologic data. RESULTS: Of 19 patients, 8 were in the unfavorable prognosis group, and 11 were in the favorable prognosis group. LSR was significantly lower in the unfavorable prognosis group (P = .009). Analysis of the receiver operating characteristic curve showed that the area under the curve of the LSR was 0.891, which was higher than the area under the curve of liver fibrosis markers. The optimal LSR cut-off value for predicting poor native liver prognosis was 1.97, with a sensitivity of 75.0% and a specificity of 87.5%. CONCLUSIONS: The LSR reflects splenomegaly and liver atrophy. The LSR might be a reliable predictor of native liver prognosis and could guide decisions about LT in patients with BA.

Effect of atmospheric water vapor on independent-parallel thermal dehydration of a compacted composite of an inorganic hydrate: sodium carbonate monohydrate grains comprising crystalline particles and a matrix.

The effect of atmospheric water vapor on the thermal dehydration of sodium carbonate monohydrate (SC-MH), which was characterized as cubic grains of a compacted composite comprising columnar SC-MH crystals and a matrix, was systematically assessed using a humidity-controlled thermogravimetry system at various atmospheric water vapor pressures (p(H2O)). The thermal dehydration of the SC-MH compacted composite occurred via an induction period (IP) and partially overlapping two-step mass loss steps due to the thermal dehydration of the SC-MH matrix and columnar crystals. All component reaction steps were retarded with an increase in the p(H2O) value. The kinetics of individual reaction steps were universally described over different temperatures and p(H2O) values based on a kinetic equation that considered p(H2O) and the equilibrium pressure of the thermal dehydration. Additionally, the physico-geometrical consecutive surface reaction (SR) and subsequent phase boundary-controlled reaction (PBR) model was employed to describe the first mass loss step. The difference between the effects of atmospheric p(H2O) on SR and PBR processes was parameterized via an advanced kinetic analysis. The kinetic behavior of the second mass loss step was discussed based on a three-dimensional contracting geometry model with accelerating reaction interface advancement, where the changes in the rate behavior with atmospheric p(H2O) were explained by the total effect of atmospheric and self-generated p(H2O) on the kinetics. The present results provide additional insights into the independent-parallel thermal decomposition kinetics of composite materials by considering the effects of atmospheric and self-generated gases.

Physico-geometrical kinetics of the thermal dehydration of sodium carbonate monohydrate as a compacted composite of inorganic hydrate comprising crystalline particles and matrix.

The kinetics of the thermal dehydration of compacted composite grains of Na2CO3·H2O (SC-MH) comprising columnar SC-MH crystalline particles and an SC-MH matrix were investigated as a model system for composites of the same compound with a porphyritic texture. The presence of an induction period was confirmed as a novel finding for the thermal dehydration of SC-MH. The subsequent mass loss process was characterized as a partially overlapping two-step process attributed to the consecutive reactions of SC-MH matrix and columnar SC-MH crystalline particles. The overlapping nature of two reaction steps was revealed by determining the contributions and kinetic parameters of the individual reaction steps via a kinetic deconvolution analysis. Furthermore, the initial mass loss process caused by the thermal dehydration of the SC-MH matrix was characterized as a physico-geometrical consecutive process comprising a surface reaction and a subsequent three-dimensional (3D)-phase boundary-controlled reaction. The subsequent thermal dehydration of the columnar SC-MH crystalline particles compacted in the grains was characterized as being geometrically constrained by 3D-interface shrinkage, forming two reaction interfaces during the overlapping stage of the two reaction steps. It was expected from the kinetic results that the linear advancement rate of the second reaction interface was influenced by the water vapor produced at the reaction interface of the first reaction step. This caused the linear advancement rate of the second reaction interface to accelerate as the reaction proceeded due to contraction of the first reaction interface and completion of the first reaction step.

An advanced kinetic approach to the multistep thermal dehydration of calcium sulfate dihydrate under different heating and water vapor conditions: kinetic deconvolution and universal isoconversional analyses.

This study aims to identify the kinetic features of individual reaction steps of the multistep thermal dehydration of calcium sulfate dihydrate (CS-DH) to anhydride via a hemihydrate (CS-HH) intermediate by achieving the universal kinetic description of each reaction step under different heating and water vapor pressure (p(H2O)) conditions. The mass loss processes of the thermal dehydration of CS-DH were systematically traced via humidity-controlled thermogravimetry under isothermal and linear nonisothermal conditions at various atmospheric p(H2O) values. After reconfirming the variation in the thermal dehydration pathway from a single-step dehydration to anhydride to a multistep process via the CS-HH intermediate with an increase in the p(H2O) value, the kinetic curves for each component reaction step were obtained by separating each component process from the partially overlapping mass-loss curves by kinetic deconvolution analysis as required. The induction period (IP) and the mass-loss processes of the thermal dehydrations of CS-DH to anhydride and CS-HH intermediate were compared, wherein more significant retardation effects of water vapor were observed for the IP process followed by direct dehydration to anhydride and for the mass-loss process from CS-DH to the CS-HH intermediate. The universal kinetic behavior of the thermal dehydration of the CS-HH intermediate to anhydride was compared with that of the CS-HH reagent; thus, comparable universal kinetic behaviors were observed except the reaction geometry. Based on the universal kinetic results, the key kinetic phenomenon for regulating the variation of the thermal dehydration pathway of CS-DH was discussed.

A Retransplant Case for Hepatopulmonary Syndrome Without Liver Cirrhosis or Portosystemic Shunt After Living-Donor Liver Transplantation: A Case Report.

Hepatopulmonary syndrome (HPS) is a disease of gas exchange caused by intrapulmonary shunting secondary to liver disease-associated intrapulmonary vascular dilation. HPS is characterized by the triad of cirrhosis, chronic liver disease, or portosystemic shunting (PSS); arterial hypoxemia; and intrapulmonary arteriovenous shunting in the absence of a primary cardiopulmonary anomaly. We encountered a rare case of HPS without liver disease or PSS. The patient was an 8-year-old girl who underwent living donor liver transplantation (LDLT) shortly after developing fulminant hepatitis at 11 months of her age. Eight years after LDLT, hypoxemia and shortness of breath developed. The shunt ratio on 99mTc-macroaggregated albumin (MAA) lung perfusion scintigraphy (99mTc-MAA lung scan) was 32%. The patient had no cardiopulmonary disease, so we diagnosed her illness as HPS. We did not find cirrhosis, chronic liver disease, or PSS as a cause of HPS. We thought the graft was the cause of HPS. A second transplantation was planned. One year after the diagnosis of HPS, the shunt ratio on 99mTc-MAA lung scan worsened to 42%, digital clubbing appeared, and hypoxemia was worsening. Thus, we performed a second LDLT. After LDLT the shunt ratio on 99mTc-MAA lung scan normalized (6%) and cyanosis resolved. We determined that the graft was the cause of HPS; the typical causes of HPS were not clearly revealed in the histologic examination of the second liver explant. Acute rejection occurred twice after LDLT, so we speculated that HPS occurred because the graft became stressed over the long term.

Successful Surgical Resection and Chemotherapy for Unresectable Hepatoblastoma With Pulmonary Metastases and for Lung Recurrence After Liver Transplantation: A Case Report.

BACKGROUND: Liver transplantation (LTx) is indicated for unresectable hepatoblastoma (HB) without distal metastasis. However, to our knowledge, there is no consensus on the management of unresectable HB with pulmonary metastases, or on the treatment of recurrent HB. We report a successful case of metastatic HB treated with repeated lung resection, chemotherapy, and LTx. This study strictly complied with the Helsinki Congress and the Istanbul Declaration regarding donor source. CASE REPORT: Our case was a 1-year-old boy who developed pre-treatment extent of disease (PRETEXT) Ⅲ HB with multiple pulmonary metastases. The liver tumor was unresectable because it involved all hepatic veins. After 3 cycles of chemotherapy (cisplatin/carboplatin plus doxorubicin), the remaining 2 pulmonary metastases were resected and living donor liver transplantation (LDLT) was performed. Five months after LDLT, a tumor recurrence was detected in the right lung. Repeat lung resection was performed followed by 1 cycle of chemotherapy (carboplatin plus doxorubicin). There has been no recurrence for 18 months since the last lung resection. DISCUSSION: Previous reports revealed that 14 patients, including the present case, underwent LTx after resection of metastatic HB pulmonary lesions. Of these patients, the 2-year survival rate after LTx was 91%. Recurrence was reported in 5 patients, 2 of whom were successfully treated with repeated resection of the metastatic lesions. LTx after resection of lung recurrence may be a potential treatment for unresectable HB with pulmonary metastases.

Geometrical constraints of thermal dehydration of ß-calcium sulfate hemihydrate induced by self-generated water vapor.

The thermal dehydration of calcium sulfate dihydrate exhibits a complex reaction behavior, in which the reaction pathway and kinetics vary depending on water vapor pressure (p(H2O)) applied as the atmospheric condition and generated in the course of the reaction. Under high p(H2O) conditions, a crystalline hemihydrate is produced as an intermediate, which subsequently dehydrates to form anhydride. In this study, the thermal dehydration of calcium sulfate hemihydrate under different self-generated p(H2O) conditions was investigated to gain further insight into the reactions in the calcium sulfate-water vapor system. The thermal dehydration of the hemihydrate under two sets of sampling conditions, namely, in open and lidded (semi-closed) pans, was systematically investigated via thermogravimetry (TG) in different heating program modes. The experimentally resolved TG curves were analyzed using the formal kinetic calculation methods based on isoconversional and isothermal kinetic relationships. Under both the sampling conditions, the thermal dehydration reaction was significantly influenced by self-generated p(H2O), which regulated the reaction proceeding from the top surface of the sample bed to the bottom. Under higher self-generated p(H2O) conditions in a lidded pan, the thermal dehydration under different heating program modes exhibited an invariant kinetic behavior characterized by a single set of kinetic parameters, whereas in an open pan the kinetic behavior varied between the reactions under isothermal and other heating modes. Based on the results of the formal kinetic analysis, an advanced kinetic modeling based on a physico-geometrical consecutive reaction model was examined to describe in detail the specific kinetic features of the reaction under self-generated p(H2O) conditions.

Thermal dehydration of calcium sulfate dihydrate: physico-geometrical kinetic modeling and the influence of self-generated water vapor.

Complex kinetic behaviors in the thermal dehydration of CaSO4·2H2O under varying water vapor pressure (p(H2O)) conditions impel researchers in the field of solid-state kinetics to gain a more comprehensive understanding. Both self-generated and atmospheric p(H2O) are responsible for determining the reaction pathways and the overall kinetic behaviors. This study focuses on the influence of the self-generated water vapor to obtain further insights into the complexity of the kinetic behaviors. The single-step mass-loss process under conditions generating a low p(H2O) was characterized kinetically by a physico-geometrical consecutive induction period, surface reaction, and phase boundary-controlled reaction, along with the evaluation of the kinetic parameters for the individual physico-geometrical reaction steps. Under the conditions in which more p(H2O) was generated, the overall reaction to form the anhydride was interpreted as a three-step process, comprising the initial reaction (direct dehydration to the anhydride) and a subsequent two-step reaction via the intermediate hemihydrate, which was caused by the variations in the self-generated p(H2O) conditions as the reaction advanced. The variations in the reaction pathways and kinetics behaviors under the self-generated p(H2O) conditions are discussed through a systematic kinetic analysis conducted using advanced kinetic approaches for the multistep process.

Revealing the effect of water vapor pressure on the kinetics of thermal decomposition of magnesium hydroxide.

This study aims to establish an advanced kinetic theory for reactions in solid state and solid-gas systems, achieving a universal kinetic description over a range of temperature and partial pressure of reactant or product gases. The thermal decomposition of Mg(OH)2 to MgO was selected as a model reaction system, and the effect of water vapor pressure p(H2O) on the kinetics was investigated via humidity controlled thermogravimetry. The reaction rate of the thermal decomposition process at a constant temperature was systematically decreased by increasing the p(H2O) value, accompanied by an increase in the sigmoidal feature of mass-loss curves. Under nonisothermal conditions at a given heating rate, mass-loss curves shifted systematically to higher temperatures depending on the p(H2O) value. The kinetic behavior under different temperature and p(H2O) conditions was universally analyzed by introducing an accommodation function (AF) of the form (P°/p(H2O))a[1 - (p(H2O)/Peq(T))b], where P° and Peq(T) are the standard and equilibrium pressures, respectively, into the fundamental kinetic equation. Two kinetic approaches were examined based on the isoconversional kinetic relationship and a physico-geometrical consecutive reaction model. In both the kinetic approaches, universal kinetic descriptions are achieved using the modified kinetic equation with the AF. The kinetic features of thermal decomposition are revealed by correlating the results from the two universal kinetic approaches. Furthermore, advanced features for the kinetic understanding of thermal decomposition of solids revealed by the universal kinetic descriptions are discussed by comparing the present kinetic results with those reported previously for the thermal decomposition of Ca(OH)2 and Cu(OH)2.

Perpendicular magnetic recording--its development and realization.

The principle of conventional magnetic recording is that magnetic fields are applied parallel to the plane of the magnetic medium. As described in this paper, the invention and development of a new method of placing the magnetized information perpendicular to the plane of the magnetic recording medium is presented. The yield in the mass production of high-density hard disk drives (HDDs) for perpendicular recording is much higher than that of HDDs for conventional recording. Consequently, it is estimated that as many as 75% of the 500 million HDDs to be shipped this year will use this technology.