Taping alone for persistent ventral curvature after urethral plate transection in hypospadias

INTRODUCTION

Ventral penile curvature is a key factor in determining the surgical approach to proximal hypospadias repair. However, there is limited evidence regarding the efficacy and long-term effects of the procedures used to address curvature. This study aimed to evaluate the effects of urethral plate transection alone with tissue traction therapy on penile curvature in two-stage repair of proximal hypospadias.

MATERIAL AND METHODS

This was a prospective study of primary hypospadias patients who underwent a two-stage repair with urethral plate transection as the sole straightening procedure. After stage 1, taping was applied as tissue traction therapy and continued until stage 2. Penile curvature was measured using a goniometer under artificial erection before and immediately after urethral plate transection and during the second stage of repair. The primary focus of this investigation is the angle of curvature after 6-month taping.

RESULTS

The study included 46 patients with a median age of 13 months at the start of treatment. The median angle of penile ventral curvature was 70° after degloving, 60° after urethral plate transection, and 0° during the second stage of repair. Full correction of ventral curvature was achieved in 42 patients (91 %).

DISCUSSION

This publication is the first of its kind to propose taping as a method for penile traction therapy in hypospadias. The study reveals that penile ventral lengthening can be achieved through tissue traction therapy following UP transection alone. These findings challenge the current consensus that complete straightening of the penis in the first stage is necessary to prevent recurrent curvature and that ventral lengthening is required to correct corporal disproportion. However, further validation and long-term data are needed to definitively confirm the effectiveness of tissue traction therapy after urethral plate transection.

CONCLUSIONS

This study demonstrated significant resolution rate of penile ventral curvature in proximal hypospadias following urethral plate transection alone with taping. Long-term follow-up studies are needed to confirm the sustainability of the results through puberty.

An alternative lower tract approach to ectopic duplex system ureteroceles feasible in young children

INTRODUCTION

The best surgical approach to ectopic ureters and ureteroceles is yet to be determined. The objective of this study is to provide an alternative lower tract surgical approach to ectopic ureters and duplex system ureteroceles that can be safely performed in young children.

METHODS

The "in-and-out" bladder approach was performed via an open intravesical incision. The upper and lower pole ureters were mobilized and brought into the bladder. The dilated ureter/ureterocele was cut open, and the distal part was deuroepithelialized. Subsequently, common sheath reimplantation was performed. The ureterocele wall was not involved during the whole procedure. We retrospectively reviewed all patients who underwent surgery for ureteroceles and ectopic ureters between January 1, 2004, and December 31, 2019. Patients with intravesical ureteroceles were excluded. Outcome parameters included the presence of hydronephrosis or reflux, split renal function on DMSA scan, incidence of urinary tract infection, and urinary incontinence.

RESULTS

A total of 32 patients with ectopic duplex system ureterocele who underwent the "in-and-out" bladder approach between 2004 and 2019 were included in the retrospective study. The median age at operation was 7.8 months (range: 1.5 months-3.0 years). The median length of follow-up was 6.1 years (range: 1.0 years-14.3 years). Sixteen patients (55%) had ipsilateral vesicoureteral reflux. Five patients postoperatively developed a urinary tract infection within 1-3 years. No patients required further endoscopic treatment or surgeries. During long-term follow-up, two patients (6.3%) had intermittent day wetting at the ages of 4 and 5 years and were managed conservatively. The symptoms of intermittent day wetting subsided during follow-up.

CONCLUSIONS

The "in-and-out bladder" approach can be performed in complex duplex system ureteroceles and enables early intervention; it is a single and simple operation with a satisfactory long-term continence rate.

Accelerating space radiation countermeasure development through drug repurposing

The discovery of safe and effective radiation countermeasures (MCM) for long-duration spaceflight is challenging due to the complexity of the space radiation biology and high safety requirements. There are few if any clinically-validated molecular targets for this use case, and preclinical models have several known limitations. These challenges make the evaluation of existing FDA-approved drugs for this indication, or drug repurposing, an attractive strategy to accelerate space radiation countermeasure development. Drug repurposing offers several advantages over de novo drug discovery including established manufacturing methods, human clinical safety data, and well-understood dosing and pharmacokinetic considerations. There are limitations working with a fixed set of possible candidate compounds, but some properties of repurposed drugs can be tailored for well-defined new indications through reformulation and development of drug combinations. Drug repurposing is thus an attractive strategy for mitigating the high risks and costs of drug development and delivering new countermeasures to protect human from space radiation in long-term missions.

Vesicocutaneous fistula: continent vesicostomy, an easier route for comfortable clean intermittent catheterization

INTRODUCTION

Clean intermittent catheterization (CIC) through the urethra is the treatment of choice for patients with neurogenic bladder (NGB) or other etiologies that lead to incomplete bladder emptying. However, urethral catheterization can be problematic. Vesicocutaneous fistula (VCF) is a continent catheterizable channel with a low rate of complications. The aim of the study was to evaluate the safety and effectiveness of VCF as a route for CIC.

MATERIAL AND METHODS

The authors retrospectively reviewed patients who underwent creation of the VCF for bladder drainage from November 2001 to December 2017. Demographics, indication for VCF, pre-operative and postoperative laboratory/radiologic studies, incidence of febrile urinary tract infection (UTI), and adherence to CIC through VCF were examined.

RESULTS

Vesicocutaneous fistula was created in a total of 20 patients (nine males and 11 females; median age, 13.2 years [range: 3.8 months-22.8 years]). The median follow-up time was 30.5 months (range: 5.9 months-16.9 years). The underlying etiologies that resulted in NGB included spina bifida (n = 10), cerebral palsy (n = 2), caudal regression syndrome (n = 2), and others (n = 6). Before creation of the VCF, 13 patients (65%) had either grade ≥3 unilateral or bilateral hydronephrosis as per the Society for Fetal Urology grading system. Thirteen patients (65%) had experienced at least one febrile UTI the year before the creation of the VCF. At the last follow-up, renal function was improved or stabilized in 14 patients (70%). Fifteen patients (75%) had experienced no febrile UTI in the last 1 year. Upper urinary tract dilatation resolved or improved in 10 patients (77%). The VCF continence rate was 88%. In this study, bladder augmentation or the Mitrofanoff procedure was not performed. During maturation, nine patients (45%) had granuloma; five of those cases subsided within 2 years without any intervention. Five patients had VCF stricture, and only one required revision surgery (5%).

DISCUSSION

The VCF continence rate was comparable with that of the Mitrofanoff procedure. Adherence to CIC through VCF lowered the rate of UTI and preserved the upper urinary tract. Bladder emptying by CIC through VCF provided the same benefits as those of the Mitrofanoff procedure: extra privacy, social independence, and reduction of parental burden. Although a long maturation stage of 6 months was required, the rate of major complications was low. Most complications were conservatively manageable and seldom required revision surgery.

CONCLUSIONS

Vesicocutaneous fistula is a continent catheterizable conduit, an alternative option for bladder management in patients with NGB who cannot undergo urethral CIC smoothly.

Fixation of lung apex in spontaneous pneumothorax is safe and efficient in decrease recurrences

BACKGROUND

Video-assisted thoracoscopic bullectomy with pleurodesis is widely used to treat spontaneous pneumothorax. However, 1%-3% of patients experience postoperative complications that may require reoperation, such as bleeding or prolonged air leaks, and 3%-7% of patients require a repeat thoracoscopic bullectomy due to recurrence. Therefore, a modified procedure with improved outcomes is required.

METHODS

Between January 1, 2011 and December 31, 2015, 196 patients with spontaneous pneumothorax underwent thoracoscopic bullectomy and pleurodesis with or without fixation of the lung apex to the chest wall. In patients in the fixation group, the lung apex was fixed to the chest wall with two non-absorbable sutures after bullectomy and pleurodesis. The treatment of each lung was considered an independent operation in patients with bilateral spontaneous pneumothorax.

RESULTS

The patients in each group had comparable backgrounds. In the fixation group, 67 patients underwent 87 operations, four of which (in three patients) led to recurrences (recurrence rate, 4.60%). There were no readmissions or reoperations within 30 days in this group. In the non-fixation group, 128 patients underwent 161 operations, 14 of which (in nine patients) led to recurrences (recurrence rate, 8.7%). In addition, three patients in this group required reoperation and two were readmitted within 30 days.

CONCLUSIONS

Modified thoracoscopic bullectomy with fixation of the lung apex is a safe procedure that provides better outcomes with lower complication rates.

Prevalence and risk of fracture diagnoses in women across the adult life span: a national cross-sectional study

In a national sample of women veterans, the rate of lower limb fracture diagnosis was the highest across ages 18-74 years; rates of fracture diagnosis of other skeletal sites peaked in women aged 75+. Women with two or more primary care visits or mental healthcare visits had elevated odds of fracture diagnosis.

INTRODUCTION

We assessed the prevalence and healthcare utilization characteristics associated with a diagnosis of any fracture in women of all adult ages within the Veterans Health Administration.

METHODS

In 344,488 women during fiscal year 2012, logistic regression models for fracture diagnosis included age, race/ethnicity, residence, number of primary care visits, number of mental healthcare visits, and degree of service-connected disability.

RESULTS

Lower limb fracture diagnosis was most prevalent across ages 18-74 years and peaked in women aged 55-64 years. In women aged 75+, the prevalence rates of fracture diagnosis at the hip (102, 95 % CI = 88-115 per 10,000 women), upper limb (100, 95 % CI = 87-114 per 10,000 women), and lower limb (84, 95 % CI = 72-97 per 10,000 women) were the highest. Fractures at other skeletal sites peaked in those aged 75+ years. Black women had the lowest odds of a fracture diagnosis, followed by Asian/Pacific Islander and Hispanic women compared to non-Hispanic White (by 25-51 %, P < 0.05). Having two or more primary care visits or any mental health visit was each associated with an increased risk. Women with five or more primary care visits had a 3.36-fold (95 % CI = 3.02-3.75) greater odds than those with no such visit, and separately, women with five or more mental health visits had a 1.51-fold (95 % CI = 1.43-1.60) greater odds. Women with a fracture diagnosis had higher overall healthcare costs than those without (P < 0.001).

CONCLUSIONS

Prevalence of fracture diagnosis differed by age, race/ethnicity, and skeletal site of fracture. Fracture diagnosis may identify women veterans with greater overall healthcare needs.

Association of SNPs in the PPARγ gene and hypertension in a Mongolian population

The association of single nucleotide polymorphisms (SNPs) in PPARγ with hypertension is controversial. The aim of the present study was to clarify the contributions of PPARγ genetic variants to hypertension through an association study. A total of 414 unrelated Mongolian herdsmen and 524 Han farmers were included in this study. Fourteen intronic SNPs were analyzed and genotyped using a polymerase chain reaction/ligase detection reaction assay. Prior to correction for multiple testing, the SNPs rs6802898 and rs12633551 were significantly associated with the prevalence of hypertension in the Han and Mongolian populations, respectively. The genetic association of each SNP with hypertension was individually tested using logistic regression. The SNP rs6802898 was associated with hypertension in both dominant (P = 0.033) and additive models (P = 0.026) in the Han population, whereas the SNP rs12633551 was associated with hypertension in both dominant (P = 0.014) and additive models (P = 0.0073) in the Mongolian population. Moreover, SNP rs12633551 had a significant effect on systolic and diastolic blood pressure response. However, none of these associations were statistically significant after Bonferroni correction for multiple testing, although there was a significant difference among the haplotypes in the Han and Mongolian populations. Interestingly, there was an association of the PPARγ haplotypes with hypertension even after Bonferroni correction. Thus, determination of the PPARγ haplotypes in different populations may prove informative for assessment of the genetic risk for hypertension.

Association of NPRA and NPRC gene variants and hypertension in Mongolian population

NPRA and NPRC are candidate susceptibility genes for essential hypertension (EH) and play a key role in the regulation of plasma levels and biological effects of natriuretic peptides. The aims of the present study were to find new genetic markers in the NPRA and NPRC genes and to assess relationships between variants and EH. A total of 797 unrelated Mongolian herdsmen were enrolled, including 389 EH patients and 408 normotensive controls. Genotyping was performed using the polymerase chain reaction/ligase detection reaction assay. The distribution of the T-allele frequency of rs1847018 in NPRC differed significantly between hypertensive subjects and controls. There was an association between rs1847018 and EH in the additive model in NPRC (P < 0.05). There were no significant differences in the genotype and allele frequency distributions for any of the 3 single nucleotide polymorphisms in NPRA between EH and normotensive individuals. In NPRA, the frequency of haplotype TCA in the EH group was significantly lower than in controls, while the frequency of haplotype TCG was significantly higher in the EH group than in controls; Individuals who possessed the TCA haplotype had a significantly lower risk of EH, whereas the presence of haplotype TCG was significantly associated with a higher risk of EH. However, there was no significant difference between the EH group and controls in any of the 8 haplotypes in NPRC. Rs1847018 is a genetic marker of EH in NPRC, and the frequency of haplotype TCA and TCG in NPRA is associated with EH in the Mongolian population.

Association of regulator of G protein signaling (RGS5) gene variants and essential hypertension in Mongolian and Han populations

Genetic variants of the RGS5 gene are believed to be risk factors for hypertension and cardiovascular diseases. In this study, we investigated the association between RGS5 gene variants and hypertension in the Mongolian and Han populations. Peripheral blood was obtained from 429 unrelated Mongolian herdsmen and 416 Han farmers [including essential hypertension (EH) patients and controls]. Nine tagSNPs within the RGS5 genes were retrieved from HapMap, and the samples were individually genotyped using the polymerase chain reaction/ligase detection reaction assay. The distribution of the allele frequency of rs12035879 differed significantly between hypertensive subjects and controls in the Han population, while the distribution of the allele and genotype frequencies of rs16849802 differed significantly between hypertensive subjects and controls in the Mongolian population. We observed an association between rs16849802 and EH in the Mongolian population. The frequency of haplotype GAA was significantly higher in the EH group than in controls in the Mongolian population. However, the EH group and controls did not differ significantly in all 6 haplotypes in the Han population. The rs16849802 and haplotype GAA independently increased the risk of EH in Mongolian patients, and may be used as a risk factor for the prediction of high blood pressure.

Chest Wall Constriction after the Nuss Procedure Identified from Chest Radiograph and Multislice Computed Tomography Shortly after Removal of the Bar

BACKGROUND

This study radiographically examined the changes in the chest walls of patients with pectus excavatum (PE) after Nuss bar removal, to define the deformation caused by the bar and stabilizer. In the first part of the study, we compared the changes in chest radiographs of patients with PE to a preoperation PE control group. In the second part, we used multislice computed tomography (CT) scans to provide three-dimensional reconstructions with which to evaluate the changes to the thoracic wall.

METHODS

Part 1 From June 2006 to August 2011, 1,125 patients with PE who had posteroanterior chest radiographs taken before undergoing the Nuss procedure at four hospitals were enrolled as a preoperative control group. At the same time, 203 patients who had the bar removed were enrolled as the study group. The maximum dimensions of the outer boundary of the first to ninth rib pairs (R1-R9, rib pair width), chest height, and chest width were measured. Part 2 Thirty-one consecutive patients with PE (20 males and 11 females) who underwent Nuss bar removal were evaluated 7 to 30 days after operation. During this period, a further 34 patients with PE who had undergone CT imaging before bar insertion were evaluated and compared with the postoperative group.

RESULTS

Part 1 The width of the lower ribs (R4-R9) after bar removal was significantly less than in the age-matched controls. The ribs adjacent to the bar (R5-R7) showed the greatest restriction. The width of the upper ribs (R1-R3) 2 to 3 years after bar placement did not differ significantly from the controls. Patients who were operated on after 10 years of age had less of a restrictive effect. Three years of bar placement resulted in more restriction than a 2-year period, particularly in patients younger than 10 years old. Part 2: A significant constriction of the chest wall was observed in 13 patients after removal of the Nuss bar. Constriction at ribs 5 to 8 was found to be present adjacent to the site of bar insertion. However, constriction of the chest wall was found in only 3 of the 34 patients in the preoperative group. The severity of constriction (as graded by the spline model) also increased in the postoperative group.

CONCLUSION

The growth of the chest wall was restricted after placement of the Nuss bar for PE correction. Long-term follow-up of chest wall growth is needed to clarify whether such constriction resolves with time.

Postnatal donor lymphocytes enhance prenatally-created chimerism at the risk of graft-versus-host disease

The major barrier to clinical application of in utero hematopoietic stem cell transplantation is insufficient chimerism for phenotypic correction of target diseases or induction of graft tolerance. Postnatal donor lymphocyte infusion (DLI) may enhance donor cell levels so as to further facilitate tolerance induction. We created murine mixed chimeras in utero. Chimeras with <10% donor cells were subjected to postnatal DLI to evaluate the effects of DLI on chimerism augmentation and skin tolerance induction. Within one day after DLI, recipients experienced a transient peaking of donor chimerism, which could be as high as 20~40%. However, the transient chimerism peaking didn't benefit donor skin survivals despite immediate skin placement after DLI. In case of fruitful DLI, chimerism augmentation was usually observed after a latent period of 2~4 weeks. Otherwise, chimerism would return to around pre-DLI levels by days 7~14. Peripheral chimerism of >3% could be consistently boosted up to >10%, whereas chimerism of <0.2% hardly showed any significant enhancement. As for chimerism levels of 0.2~3%, chimerism augmentation up to >10% succeeded in 3(15%) of 20 recipients. Notably, chimerism augmentation by postnatal DLI was often associated with unexpected death or graft-versus-host disease (GVHD). In conclusion, transient chimerism augmentation by DLI played no role in facilitating graft tolerance. Substantial augmentation by DLI demanded a threshold chimerism level and posed a serious risk of GVHD to the recipients. It raised the concern about using postnatal DLI to broaden therapeutic horizons of in utero hematopoietic stem cell transplantation.

Rapid increase in the height and width of the upper chest in adolescents with primary spontaneous pneumothorax

BACKGROUND

We determined the chest height in a cohort of patients with primary spontaneous pneumothorax (PSP) who had received chest radiographic examinations prior to the attack. The aim of this study was to determine when their chest height began to change and how this was related to the PSP.

METHODS

From June 2009 to February 2012, the chest posteroanterior radiographs of 156 patients with PSP (Group 1) were reviewed. Among another 3134 patients with PSP, we identified 52 patients who had a chest posteroanterior radiograph prior to the attack (Group 2). We also recruited 196 controls for comparison (Group 3). The chest height and chest width at different levels were measured and analyzed.

RESULTS

Before 14 years of age, the chest height of patients in Group 2 was no different from that of patients in Group 3. By the age of 14 years, however, the chest height and upper chest width of patients with PSP was significantly higher than that of the normal controls. The difference from normal chest height did not increase at adulthood.

CONCLUSION

The rapid increase in chest height and upper chest width is a unique finding in patients with PSP. It might be attributable to the occurrence of PSP. This finding may also help to identify patients who are at risk of PSP.

Outcomes after surgery in patients with previous stroke

BACKGROUND

Limited information is available on the association between a medical history of stroke and postoperative outcomes. This study investigated the outcomes following non-neurological surgery in patients with previous stroke.

METHODS

Using Taiwan's National Health Insurance Research Database, a nationwide cohort study was conducted of patients who underwent non-neurological surgery between 2008 and 2010 with a medical history of stroke in the 24-month period before operation. Patients who had non-neurological surgeries without previous stroke were selected as controls by the propensity score-matched pair method. Thirty-day postoperative complications and in-hospital mortality were compared between the two groups.

RESULTS

Some 1 426 795 adults underwent major inpatient non-neurological surgery, of whom 45 420 had a medical history of previous stroke. Patients with previous stroke who underwent surgery had an increased risk of postoperative pneumonia, septicaemia, acute renal failure, acute myocardial infarction, pulmonary embolism and 30-day in-hospital mortality (adjusted rate ratio (RR) 1·79, 95 per cent c.i. 1·61 to 1·99). Compared with controls, patients with previous stroke due to intracerebral haemorrhage (RR 3·41, 2·97 to 3·91), and those who were treated in intensive care (RR 2·55, 2·24 to 2·90) or underwent neurosurgery (RR 2·49, 2·12 to 2·92), had an increased 30-day in-hospital mortality rate. Postoperative mortality also increased with stroke-related co-morbidities, and with stroke 1-6 months before surgery (RR 3·31, 2·91 to 3·75).

CONCLUSION

Patients with previous stroke had a higher risk of adverse postoperative outcomes; their 30-day in-hospital mortality rate was nearly twice that of patients without previous stroke.

Allogeneic lymphocytes exerted graft-versus-host rather than tolerogenic effects on preimmune fetuses

BACKGROUND

Among cell suspensions from different origins, lymphocytes were reported to have the superiority of tolerance-conferring capacity in preimmune hosts. However, this belief was derived directly from murine combinations with fewer major histocompatibility complex (MHC) barriers that are exceptional in the clinical arena. Because of the potential for prenatal tolerance induction to facilitate postnatal therapies, it is important to examine the relative merits and hazards of fully MHC-mismatched naïve lymphocytes as the prenatal tolerogenic agent in the preimmune fetus to cross MHC barriers.

MATERIALS AND METHODS

In utero injection of C57BL/6 splenic lymphocytes was conducted in gestational day 14 FVB/N fetuses. Then, FVB/N recipients were subjected to the evaluation of hematopoietic chimerism, donor-specific tolerance, and graft-versus-host disease (GVHD).

RESULTS

With a dose of ≥ 5 × 10(5) C57BL/6 lymphocytes, the recipients born alive either died unexpectedly by maternal cannibalization or succumbed to GVHD within postnatal 1 mo. GVHD mice showed significant hematopoietic chimerism that was dominated by donor CD3 T cells. It was found that allogeneic lymphocytes could rapidly damage the fetal liver within 5 d after injection. Fetal recipients could survive a dose of ≤ 2 × 10(5) allogeneic lymphocytes beyond 1 mo of age, but at best showed microchimerism that was insufficient to confer donor-specific skin tolerance.

CONCLUSIONS

Fully MHC-mismatched lymphocytes injected in utero had lethal graft-versus-host effects, which might rapidly develop within 1 wk after injection in preimmune fetuses. They were incapable of conferring significant hematopoietic chimerism and graft tolerance even at bearable doses.

Fusion yield enhancement in magnetized laser-driven implosions

Enhancement of the ion temperature and fusion yield has been observed in magnetized laser-driven inertial confinement fusion implosions on the OMEGA Laser Facility. A spherical CH target with a 10 atm D2 gas fill was imploded in a polar-drive configuration. A magnetic field of 80 kG was embedded in the target and was subsequently trapped and compressed by the imploding conductive plasma. As a result of the hot-spot magnetization, the electron radial heat losses were suppressed and the observed ion temperature and neutron yield were enhanced by 15% and 30%, respectively.

Lack of association of variants of the renal salt reabsorption-related genes SLC12A3 and ClC-Kb and hypertension in Mongolian and Han populations in Inner Mongolia

Abnormalities in renal sodium chloride and water reabsorption play important roles in the development of hypertension. Mutations in the genes involved in renal sodium chloride reabsorption can affect blood pressure. Recently, the R904Q variant of the sodium/chloride transporters, member 3 (SLC12A3) gene and the T481S variant of the chloride channel Kb (ClC-Kb) gene were found to be implicated in essential hypertension. We investigated a possible role of the SLC12A3 and ClC-Kb genes in the prevalence of essential hypertension in the Mongolian and Han ethnic groups. The study population comprised 308 unrelated Mongolians with essential hypertension, 271 Mongolian normotensives, 285 unrelated Han with essential hypertension, and 194 Han normotensives living in Inner Mongolia. The presence of the SLC12A3 R904Q and ClC-Kb-T481S polymorphisms was determined using TaqMan PCR. The risk factors for hypertension were age, body mass index, alcohol consumption, total plasma cholesterol, and low-density lipoprotein cholesterol. The genotype and allele frequencies of SLC12A3 R904Q and ClC-Kb-T481S were not significantly different between hypertensive patients and controls in the Mongolian (SLC12A3 R904Q, P = 0.471 and P = 0.494, ClC-Kb-T481S, P = 0.960 and P = 0.960, respectively) and Han (SLC12A3 R904Q, P = 0.765 and P = 0.777, ClC-Kb-T481S, P = 0.100 and P = 0.103, respectively) populations. There was no significant association between the SLC12A3 R904Q variant and the ClC-Kb-T481S variant and essential hypertension in either ethnic group.

Association of TSC gene variants and hypertension in Mongolian and Han populations

We investigated a possible association between genetic variations in the thiazide-sensitive Na-Cl cotransporter (TSC) gene and essential hypertension (EH) in the Mongolian and Han ethnic groups in Inner Mongolia. Our study included 385 unrelated Mongolian herdsmen and 523 Han farmers. Nine tagSNPs of TSC were identified from the Chinese HapMap database based on pairwise r(2) ≥ 0.5 and minor allele frequency ≥0.05. Genotyping was performed using the PCR/ligase detection reaction assay. Association between tagSNPs and hypertension was investigated under the additive model. There were significant differences between the genotype and allele frequencies of rs13306673 between the EH group and the control group in the Han population. Significant associations were found between the rs7204044 variant and EH in both the Mongolian and Han ethnic groups. The frequency of haplotype GCA in the EH group was significantly higher than in the control group in the Mongolian population. In the Han population, the frequency of haplotype TGG was significantly higher in the EH group than in controls, whereas haplotype TGA occurred significantly less often in EH than in controls. We suggest that rs7204044 of TSC is a genetic factor for EH in these two ethnicities and that rs13306673 is a genetic factor for EH in the Han population.

Mycophenolate mofetil monotherapy in the management of paediatric uveitis

PURPOSE

To evaluate effectiveness and safety of mycophenolate mofetil (MMF) monotherapy in paediatric autoimmune uveitis.

METHODS

We reviewed medical records of patients, 18 years of age or younger, with autoimmune uveitis treated with MMF at our practice from 2005 to 2009. The dose and duration of MMF therapy, inflammation status, visual acuity, previous immunomodulatory therapies, and adverse effects were recorded. In addition, the following subgroups were defined: (1) Durable Disease Control: patients whose uveitis remained quiescent for at least 2 years on MMF monotherapy, with no more than two flare-ups successfully treated with an increase in MMF dosage and/or a short course (<1 month) of corticosteroids; (2) Short-term Inflammation Control: patients whose uveitis remained quiescent for less than 2 years, with no more than one flare-up successfully treated with an increase in MMF dosage and/or a short course of corticosteroids, or who initially achieved inflammation control but discontinued MMF because of significant adverse effects.

RESULTS

A total of 38 out of 52 patients (73.1%) obtained inflammation control following 2 months of MMF monotherapy, achieving ≤ 0.5+ grading in anterior chamber cell/flare and vitreous haze. In the cross-sectional analysis, 25 patients (48.1%) met the criteria for Durable Disease Control, and 13 others (25.0%) qualified for Short-term Inflammation Control. Visual acuity remained stable or improved in 94.2% of the study population. Six patients (11.5%) discontinued MMF because of significant adverse effects, the most common of which was gastrointestinal disturbances.

CONCLUSION

MMF monotherapy appears to be an effective and safe treatment in paediatric autoimmune uveitis.

A cross-sectional study of lung volume development in pectus excavatum patients: estimating the total lung volume from chest computed tomograph using 3-dimensional volumetric reconstruction

BACKGROUND/PURPOSE

This study quantified the lung volume development of pectus excavatum (PE) patients using chest computed tomography (CT) 3-dimensional volumetric reconstructions. The technique permits current and retrospective analyses of data from different institutions.

PATIENTS AND METHODS

We analyzed the records of PE patients who underwent chest CT preoperatively between 2005 and 2009 at 3 institutions. All patients were Chinese. A window of -992 to -198 Hounsfield units was chosen for calculating the CT total lung volume (TLV). The data were compared with the data for 73 microtia and other chest-wall tumor patients studied during the same period as a control group.

RESULTS

In total, 377 PE patients with Haller pectus index (PI) of at least 3.2 were identified for this study. Compared with the reported TLV data for 1050 healthy children and our control group, we found little evidence of a decreased TLV in PE patients at any age for either sex. The mean PI did not change significantly between the ages of 3 and 27 years. The PI was inversely correlated with the TLV (P < .001).

CONCLUSION

Our cross-sectional study provides evidence that the TLV of PE patients is within the reference range in children and adolescents.

Characterization of tolerance induction through prenatal marrow transplantation: the requirement for a threshold level of chimerism to establish rather than maintain postnatal skin tolerance

Hematopoietic chimerism resulting from prenatal marrow transplantation does not consistently result in allotolerance for unidentified causes. In a C57BL/6-into-FVB/N murine model, we transplanted T-cell-depleted adult marrow on gestational day 14 to elucidate the immunological significance of chimerism towards postnatal tolerance. Postnatally, chimerism was examined by flow cytometry, and tolerance by skin transplantation and mixed lymphocyte reaction. Regulatory T cells were quantified by FoxP3 expression. Peripheral chimerism linearly related to thymic chimerism, and predicted the degree of graft acceptance with levels >3% at skin placement, yielding consistent skin tolerance. Low- and high-level chimeras had lower intrathymic CD3(high) expression than microchimeras or untransplanted mice. Regardless of the skin tolerance status in mixed chimeras, donor-specific alloreactivity by lymphocytes was suppressed but could be partially restored by exogenous interleukin-2. Recipients that lost peripheral chimerism did not accept donor skin unless prior donor skin had engrafted at sufficient chimerism levels, suggesting that complete tolerance can develop as a consequence of chimerism-related immunosuppression of host lymphocytes and the tolerogenic effects of donor skin. Thus, hematopoietic chimerism exerted immunomodulatory effects on the induction phase of allograft tolerance. Once established, skin tolerance did not fade away along with spontaneous regression of peripheral and tissue chimerism, as well as removal of engrafted donor skin. Neither did it break following in vivo depletion of increased regulatory T cells, and subcutaneous interleukin-2 injection beneath the engrafted donor skin. Those observations indicate that the maintenance of skin tolerance is multifaceted, neither solely dependent upon hematopoietic chimerism and engrafted donor skin nor on the effects of regulatory T cells or clonal anergy. We conclude that hematopoietic chimerism generated by in utero hematopoietic stem cell transplantation is critical to establish rather than maintain postnatal skin tolerance. Therefore, the diminution of hematopoietic chimerism below a threshold level does not nullify an existing tolerance state, but lessens the chance of enabling complete tolerance.

Biological impact of low dose-rate simulated solar particle event radiation in vivo

C57Bl6-lacZ animals were exposed to a range of low dose-rate simulated solar particle event (sSPE) radiation at the NASA-sponsored Research Laboratory (NSRL) at Brookhaven National Laboratory (BNL). Peripheral blood was harvested from animals from 1 to 12 days after total body irradiation (TBI) to quantify the level of circulating reticulocytes (RET) and micronucleated reticulocytes (MN-RET) as an early indicator of radiation-induced genotoxicity. Bone marrow lymphocytes and hippocampal tissues from each animal were collected at 12 days and up to two months, to evaluate dose-dependent late effects after sSPE exposure. Early hematopoietic changes show that the % RET was reduced up to 3 days in response to radiation exposure but recovered at 12 days postirradiation. The % MN-RET in peripheral blood was temporally regulated and dependant on the total accumulated dose. Total chromosome aberrations in lymphocytes increased linearly with dose within a week after radiation and remained significantly higher than the control values at 4 weeks after exposure. The level of aberrations in the irradiated animals returned to control levels by 8 weeks postirradiation. Measurements of chromosome 2 and 8 specific aberrations indicate that, consistent with conventional giemsa-staining methods, the level of aberrations is also not significantly higher than in control animals at 8 weeks postirradiation. The hippocampus was surveyed for differential transcriptional regulation of genes known to be associated with neurogenesis. Our results showed differential expression of neurotrophin and their associated receptor genes within 1 week after sSPE exposure. Progressive changes in the profile of expressed genes known to be involved in neurogenic signaling pathways were dependent on the sSPE dose. Our results to date suggest that radiation-induced changes in the hematopoietic system, i.e., chromosome aberrations in lymphocytes, are transient and do not persist past 4 weeks after radiation. On the other hand, alteration in the profile of genes known to be involved in neurotrophic functions in the hippocampal tissue appears to persist for up to 8 weeks after radiation exposure. Such temporal changes confirm that, although cytogenetic changes after a single dose of low-dose and low-dose-rate protons appear to be transient, the impact of this exposure is sufficient to lead to persistent dynamic changes in neuronal tissues long after the initial radiation exposure.

Generalized measurable ignition criterion for inertial confinement fusion

A multidimensional measurable criterion for central ignition of inertial-confinement-fusion capsules is derived. The criterion accounts for the effects of implosion nonuniformities and depends on three measurable parameters: the neutron-averaged total areal density (rhoR(n)(tot)), the ion temperature (T(n)), and the yield over clean (YOC=ratio of the measured neutron yield to the predicted one-dimensional yield). The YOC measures the implosion uniformity. The criterion can be approximated by chi=(rhoR(n)(tot))(0.8) x (T(n)/4.7)(1.7)YOC(mu)>1 (where rhoR is in g cm(-2), T in keV, and mu approximately 0.4-0.5) and can be used to assess the performance of cryogenic implosions on the NIF and OMEGA. Cryogenic implosions on OMEGA have achieved chi approximately 0.02-0.03.

Pars plana vitrectomy in the management of paediatric uveitis: the Massachusetts Eye Research and Surgery Institution experience

PURPOSE

To assess the effectiveness and safety of pars plana vitrectomy (PPV) in the management of chronic paediatric uveitis.

METHODS

We reviewed records of patients 16 years old or younger who underwent PPV due to persistent uveitis. Data including inflammatory status, ocular findings, visual acuity, dosage and duration of various medical therapies, surgical techniques and complications were collected.

RESULTS

Twenty-eight eyes of 20 patients were included in the study. The diagnoses of uveitis included pars planitis in 15 eyes (54%), idiopathic panuveitis in 8 eyes (29%), and juvenile idiopathic arthritis-associated iridocyclitis in five eyes (18%). Six eyes presented with associated retinal vasculitis. The mean age at the time of PPV was 11.2 years. The mean follow-up after surgery was 13.5 months. All 28 eyes had active uveitis with or without medical therapy at the time of PPV. At last follow-up, uveitis control was achieved with or without adjuvant medical therapy in 27 eyes (96%). These included five of the six eyes with persistent retinal vasculitis. Two eyes that had 20-G PPV developed intra-operative retinal tears. Four eyes with pre-operative clear lenses developed cataract within the first 6 months after PPV.

CONCLUSIONS

PPV is effective and safe in the management of chronic paediatric uveitis and its complications. It was able to reduce the amount of systemic medications required to control inflammation in this study. Patients with uveitis complicated by retinal vasculitis, however, are more likely to require long-term medical therapy to achieve inflammatory control.

Analysis of changes to the anterior chest wall after the Nuss procedure-an objective measurement of pectus excavatum

INTRODUCTION

We report a noninvasive method for recording the deviation of the anterior chest wall (ACW) in patients with pectus excavatum before and after the insertion and removal of a Nuss bar.

PATIENTS AND METHOD

All patients undergoing the Nuss procedure at our institutions between June 2008 and February 2009 were enrolled in this study. A thermal plastic strip was used to cast the ACW at the skin level along the area corresponding to the tract of the inserted bar. The height of the ACW was defined as the perpendicular length from the xiphoid process to the transverse line drawn between the 2 midaxillary points.

RESULTS

Bar insertion caused a significant increase in ACW height and width. Bar removal reduced the corrective effects in terms of a significant decrease in ACW height; at the same time, an increase in ACW width was noted.

CONCLUSION

Feature extraction and analyses of permanent contour casts of the ACW help to understand immediate changes in the ACW after the Nuss procedure and may assist in the design of the bar at insertion. The Nuss bar in situ helped to maintain cosmetic benefits to the ACW.

Laser-driven magnetic-flux compression in high-energy-density plasmas

The demonstration of magnetic field compression to many tens of megagauss in cylindrical implosions of inertial confinement fusion targets is reported for the first time. The OMEGA laser [T. R. Boehly, Opt. Commun. 133, 495 (1997)10.1016/S0030-4018(96)00325-2] was used to implode cylindrical CH targets filled with deuterium gas and seeded with a strong external field (>50 kG) from a specially developed magnetic pulse generator. This seed field was trapped (frozen) in the shock-heated gas fill and compressed by the imploding shell at a high implosion velocity, minimizing the effect of resistive flux diffusion. The magnetic fields in the compressed core were probed via proton deflectrometry using the fusion products from an imploding D3He target. Line-averaged magnetic fields between 30 and 40 MG were observed.

Seeding magnetic fields for laser-driven flux compression in high-energy-density plasmas

A compact, self-contained magnetic-seed-field generator (5 to 16 T) is the enabling technology for a novel laser-driven flux-compression scheme in laser-driven targets. A magnetized target is directly irradiated by a kilojoule or megajoule laser to compress the preseeded magnetic field to thousands of teslas. A fast (300 ns), 80 kA current pulse delivered by a portable pulsed-power system is discharged into a low-mass coil that surrounds the laser target. A >15 T target field has been demonstrated using a <100 J capacitor bank, a laser-triggered switch, and a low-impedance (<1 Omega) strip line. The device has been integrated into a series of magnetic-flux-compression experiments on the 60 beam, 30 kJ OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The initial application is a novel magneto-inertial fusion approach [O. V. Gotchev et al., J. Fusion Energy 27, 25 (2008)] to inertial confinement fusion (ICF), where the amplified magnetic field can inhibit thermal conduction losses from the hot spot of a compressed target. This can lead to the ignition of massive shells imploded with low velocity-a way of reaching higher gains than is possible with conventional ICF.

Prenatal tolerance induction: relationship between cell dose, marrow T-cells, chimerism, and tolerance

It was reported that the dose of self-antigens can determine the consequence of deletional tolerance and donor T cells are critical for tolerance induction in mixed chimeras. This study aimed at assessing the effect of cell doses and marrow T cells on engraftment and tolerance induction after prenatal bone marrow transplantation. Intraperitoneal cell transplantation was performed in FVB/N (H-2K(q)) mice at gestational day 14 with escalating doses of adult C57BL/6 (H-2K(b)) marrows. Peripheral chimerism was examined postnatally by flow cytometry and tolerance was tested by skin transplantation. Transplantation of light-density marrow cells showed a dose response. High-level chimerism emerged with a threshold dose of 5.0 x 10(6) and host leukocytes could be nearly replaced at a dose of 7.5-10.0 x 10(6). High-dose transplants conferred a steady long-lasting donor-specific tolerance but were accompanied by >50% incidence of graft-versus-host disease. Depletion of marrow T cells lessened graft-versus-host disease to the detriment of engraftment. With low-level chimerism, tolerance was a graded phenomenon dependent upon the level of chimerism. Durable chimerism within 6 months required a threshold of > or = 2% chimerism at 1 month of age and predicted a 50% chance of long-term tolerance, whereas transient chimerism (<2%) only caused hyporesponsiveness to the donor. Tolerance induction did not succeed without peripheral chimerism even if a large amount of injected donor cells persisted in the peritoneum. Neither did an increase in cell doses or donor T-cell contents benefit skin graft survivals unless it had substantially improved peripheral chimerism. Thus, peripheral chimerism level can be a simple and straightforward test to predict the degree of prenatal immune tolerance.

Costochondral changes in the chest wall after the Nuss procedure: ultrasonographic findings

PURPOSE

The Nuss procedure is one of the most popular surgeries for correcting pectus excavatum. However, little is known regarding stress and strain on the deformed ribs after inserting the pectus bar. We used ultrasonography to investigate costochondral changes before and after the Nuss procedure.

METHODS

Ninety-five patients underwent the Nuss procedure between July 2007 and February 2008 at 2 institutions. Chest ultrasonography, specifically of the bones and cartilage, was performed 1 day before and 1 week after the operation.

RESULTS

Postoperatively, all patients showed various degrees of deformation from the second to sixth cartilages bilaterally. The cartilages were not fractured. Of these patients, 28 (29.5%) had significant changes, including acute angulation of the costochondral junction and rib fractures near the pectus bar. These changes were associated with increased age (P < .01) and the degree of postoperative sternum elevation (P < .01). The pectus index and sex were not significant predictors of rib damage.

CONCLUSIONS

The Nuss procedure created significant stress and strain over the deformed cartilages. Approximately 29% of the patients showed localized, self-limited costochondral changes via chest ultrasonography.

Psychiatric manifestations in young females with congenital adrenal hyperplasia in Taiwan

BACKGROUND

Congenital adrenal hyperplasia (CAH) is a syndrome of prenatal and/or postnatal androgen excess secondary to genetic deficits in the cytochrome p450 enzymes of the cortisol synthesis pathway. Women with CAH may suffer from different degrees of androgenization. This study documented psychiatric manifestations in young women born with CAH in Taiwan.

METHODS

From July 1, 2005 to February 31, 2006 the psychiatric morbidity, gender identity and sex-typed behavior during childhood of 11 young women with CAH were assessed either using questionnaire-based semi-structured interviews or self-reported questionnaires.

RESULTS

Of the 11 young women (mean age 15.3 +/- 5.6 years), 3 (27.3%) had salt-wasting CAH and 8 (72.7%) had simple-virilizing CAH. Two patients without prior gender assignment (delayed diagnosis) were evaluated for primary amenorrhea at age 19 and 24 years, respectively. Four of the eleven participants (36.4%) had had an axis I psychiatric diagnosis within the past year. The subjects with more atypical sex-typed behavior in childhood tended to have a higher risk of minor psychiatric illness (r = -0.706, p < 0.05).

CONCLUSIONS

This study examined the impact of CAH on the patients' psychological wellbeing. Psychiatric needs were found to be unmet. Earlier psychiatric evaluation and intervention for these patients is suggested.

Inflammatory myofibroblastic tumor presenting as acute abdomen: report of one case

Inflammatory myofibroblastic tumor (IMT) is a very rare benign tumor composed of myofibroblastic spindle cells of uncertain etiology, which can occur at any age and affect any organ system. More and more cases of IMT in children have been described in pediatric literature in recent years. However, this tumor occurring intraabdominally in children has rarely been reported in Taiwan. Here we present a 1-year-9-month-old boy who had fever and abdominal pain only for 2 days, symptoms mimicking acute abdomen. After imaging study, a huge tumor nearly 10 cm in diameter was incidentally found over the right abdomen with unknown origin and nature. After surgical removal of the tumor, IMT was confirmed by the pathological findings. It is very difficult to make an accurate preoperative diagnosis on this tumor according to past experience, so the role of pathological diagnosis with immunohistochemical study becomes important. This case illustrates that IMT should be considered as a possible cause of intra-abdominal mass in children who have fever of unknown origin.

Analysis of senior medical students' preferences in specialty choice a survey in a medical school in northern Taiwan

BACKGROUND

Medical centers in Taiwan have found it difficult to recruit sufficient residents in the fields of surgery and gynecology & obstetrics over the last few years. It is important to realize why this phenomenon occurs. The purposes of this study are to investigate the important (critical) factors that Taiwan medical students currently consider when choosing their specialties, and to derive the relative weight of each factor.

METHODS

We constructed a three-tier analytic hierarchy process (AHP) model in the questionnaire sent out to 200 senior students at a medical school in northern Taiwan. The relative weight of each factor in the model was calculated, and the Kruskal-Wallis test as well as the t-test was applied to test for any significant differences in opinion among the students.

RESULTS

On the first tier of the AHP model, the aspect of "personal preferences and work achievement" had the highest weight of 0.455, followed by "specialty characteristics" with 0.281 and the "specialty training process" with 0.263 for all respondents. Of the 14 criteria on the second tier, "personal intelligence/ability preference" had the highest weight of 0.191, followed by "career opportunities" with 0.105 and "lifestyle after completion of training" with 0.093 for all respondents. As students got older, their perception of specialties changed. Students might modify their decision as their views of the various specialties evolve.

CONCLUSIONS

"Personal intelligence and/or ability preference" is the most important factor, while the economic factors, such as future income, is ranked lower (7th place). Knowledge of the attitudes of a new generation of medical students could form the basis for the development of strategies to enhance the attractiveness of specialties that currently lack sufficient applicants.

Particle radiation alters expression of matrix metalloproteases resulting in ECM remodeling in human lens cells

Relatively low doses of space radiation have been correlated with an increased incidence and earlier appearance of cataracts in space travelers. The lens is a radiosensitive organ of the body with a very obvious late end point of radiation damage--cataract. However, many molecular changes occur in the lens soon after radiation exposure and long before the appearance of an opacification. The goal of our research is to elucidate early mechanisms associated with particle radiation-induced cataractogenesis, with the ultimate goal of developing countermeasures. Normal, cultured non-immortalized human lens cells were grown on matrix-coated plastic tissue culture vessels and irradiated with particle beams at Lawrence Berkeley National Lab (LBNL) or at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Lab. Samples were harvested at different times after radiation exposure. Using a focused genetic approach, total RNA and protein extracts from control and irradiated samples were processed and probed for the expression of genes associated with extracellular matrix (ECM) proteases. Matrix metalloproteinases (MMPs) have previously been studied in adult postmortem human lenses, in post-cataract intraocular lens (IOL) surgery capsular bags and with immortalized human lens cell cultures. Significant differences exist in the expression pattern with these various model systems. We have evidence for the cell stage-specific expression of MMP family of genes during lens fiber differentiation, and for radiation-induced alterations in the misregulation of MMP expression. Our data indicate that radiation exposure may lead to differences in the expression of radiation stress responses, which may impact selective ECM remodeling and cell differentiation.

Evaluation of the impact of shielding materials in radiation protection in transgenic animals

We are using a plasmid-based transgenic mouse mutation model system to evaluate the effectiveness of aluminum or low-density polyethylene (LDPE) shielding after 250 MeV/u protons or 1 GeV/u iron ion irradiation. Transgenic mice, with multiple copies of the plasmid pUR288 lacZ transgene integrated into the genome of every cell of the animal, were either irradiated or sham-treated. Multiple endpoints, including early cytogenetic damage in erythrocytes at 48 h after exposure, chromosome aberrations in bone marrow lymphocytes, and lacZ mutant frequencies (MF) in brain and spleen tissues were measured in the same animals. The frequency of total circulating reticulocytes (fRET) dropped precipitously at 48 h after 2 Gy of proton irradiation. The average level of micronucleated reticulocytes (fMN-RET) was fivefold higher in the irradiated samples relative to the controls at the same time point. There was an increase in total chromosome aberrations in bone marrow lymphocytes at 8 weeks after proton irradiation but this increase was not statistically significant relative to the controls. Evaluation of the lacZ MF in the brain and spleen tissues showed that proton irradiation induced a twofold increase in MF in each tissue. Similar samples were collected from animals that were shielded from the proton beam by aluminum. Compared to the unshielded treatment group, we noted no difference in fRET, fMN-RET, chromosome aberrations in lymphocytes and lacZ MF in brain and spleen tissues obtained from these animals. In a separate study, animals were exposed to high-energy iron ions with or without 10 or 15 cm LDPE. Using the same approach, we noted a precipitous drop in fRET, and an elevation in fMN-RET within 48 h after 1 Gy of iron ions. Total chromosome aberrations in bone marrow lymphocytes were slightly elevated but not significant at 8 weeks after iron ion exposure. Shielding animals with 10 or 15 cm of polyethylene appeared to have no effect on the level of RET, MN-RET or chromosome aberrations in these animals. LacZ MF in brain and spleen tissues increased 1.5-2-fold above control levels after 1 Gy iron ions at 8 weeks after treatment. On the other hand, MF in tissues harvested from shielded animals appeared to be lower than their unshielded litermates, suggesting the polyethylene shielding was effective in reducing the iron-induced genomic damage in tissues. Although shielding may be effective, in some cases, in reducing the physical dose of particle radiation, our cytogenetic results showed that the biological impact of the particle beam remain unchanged. On the other hand, reduction in transgene MF in tissues from LDPE-shielded animals but not in the aluminum-shielded animals strongly suggests that careful consideration of the biological endpoints used is necessary in the evaluation of the efficacy of the selected shielding material.

A comparison of engineered urinary bladder and intestinal smooth muscle for urinary bladder wall replacement in a rabbit model

BACKGROUND/PURPOSE

The small intestine is the most common resource for bladder augmentation. Little is known whether intestinal smooth muscle cells (SMCs) may be engineered into bladder tissue. We investigated the phenotypic and functional characteristics of engineered bladder and intestinal SMCs as bladder wall replacement in a rabbit model.

METHODS

One month after an initial 70% partial cystectomy, 3 autoaugmentation surgeries were performed, including traditional autoaugmentation (TA, n = 6), TA using engineered bladder SMCs (TA + B, n = 6), and TA using intestinal SMCs (TA + I, n = 6). All were followed up by bladder volume measurement and retrieved on the first, third, and sixth month. The grafts and the native bladder wall were evaluated with immunocytochemistry and electrical field stimulation (EFS). Statistical analysis was performed using analysis of variance.

RESULTS

Both the TA + I and TA + B groups showed significant and similar bladder capacity increment in all time points. The engineered muscle cells demonstrated the typical "contraction-relaxation" response to supramaximal EFS. There were no statistical differences in both the TA + I and TA + B groups in contractility force.

CONCLUSION

Engineered SMCs derived from urinary bladder and small intestine could retain their phenotype after implantation in vivo. Both exhibited a similar degree of contractility to EFS. These results suggest that there are no phenotypic or functional differences between muscle cells obtained from the 2 different organs. Both have the potential to be engineered into normal bladder tissues.

Long-term changes in bone and cartilage after Ravitch's thoracoplasty: findings from multislice computed tomography with 3-dimensional reconstruction

BACKGROUND/PURPOSE

The aim of the study was to evaluate the long-term changes in the bones, cartilage, and chest wall contour after a Ravitch's thoracoplasty (RTP) using multislice computed tomography with 3-dimensional reconstruction (3D-MSCT).

METHODS

Between 1985 and 2000, 114 patients with pectus excavatum (PE) underwent RTP in our hospital; 3D-MSCT was performed in 36 patients 4 to 18 years after the initial operation. Twenty-four patients with PE with no surgical intervention were enrolled as a control group.

RESULTS

Partial or complete calcification of the regenerated cartilage was found in 23 (64%) of the patients. Threadlike regenerated cartilage or the complete absence of some segment was seen in 14 cases (39%). Clubbing of the bony end was found in 23 cases (64%). Shortening of the gap between the rib end and the sternum (n = 17, 47%) and "constrict-in" of the ribs (n = 13, 36%) were common after RTP. In the control group, no significant bone or cartilage change occurred compared to the RTP group.

CONCLUSIONS

Modern 3D-MSCT technology can clearly depict the cartilage and bone in patients with PE. More than 60% of the patients with PE showed significant long-term changes in the bone and cartilage after RTP. Further studies are warranted to evaluate the impact of these abnormal findings.

Recurrent ileocolic intussusception after different surgical procedures in children

Intussusception in children may recur after surgical correction. Ileopexy has popularly been used as a procedure to prevent recurrent intussusception, but its effect has not been well evaluated. The present study compared the incidence of recurrent intussusception after several different surgical procedures for intussusception in children. The charts of 278 children undergoing surgical reduction of ileocolic intussusception over 17 years were retrospectively reviewed. The incidence of recurrent intussusception was compared among the three surgical procedures: simple manual reduction, manual reduction plus ileopexy, and segmental resection. Simple manual reduction was performed in 67 (24.1%) of the 278 patients, manual reduction plus ileopexy in 186 (66.9%), and resection of the involved segment in 25 (9.0%). There were four episodes of recurrence in three (4%) patients who had had manual reduction, nine episodes in eight (4%) patients who had undergone ileopexy, and none after segmental resection. There was no statistical difference in recurrent rate among the three groups (reduction vs. ileopexy, P = 0.95; reduction vs. resection, P = 0.28; ileopexy vs. resection, P = 0.29). Ileopexy is not better than simple manual reduction in preventing recurrence of ileocolic intussusception in children.

Factors influencing medical students' choice of specialty

BACKGROUND/PURPOSE

Medical school graduates are the source of a country's physicians. Determining how the graduates of these schools select their areas of specialization is the key to achieving a balanced distribution of doctors among all specialties. The purposes of this study were to determine the factors that influence medical students' choice of medical specialty, and to derive the relative weight of each factor.

METHODS

We constructed a two-tiered analytic hierarchy process (AHP) model which was represented in a questionnaire sent to 500 senior medical students to survey their opinions. The relative weight of each factor in the model was calculated. Analysis of variance and t test were applied to test for any significant differences in opinion among the students.

RESULTS

On the first tier of the AHP model, the aspect of "personal preferences and work achievement" had the highest weight of 0.460, followed by "specialty characteristics" with 0.291, and then the "specialty training process" with 0.249. Of the 14 criteria on the second tier, "personal intelligence/ability preference" had the highest weight of 0.197, followed by "career opportunities" with 0.107 and "lifestyle after completion of training" with 0.094.

CONCLUSION

This study found that personal intelligence/ability preference and career opportunities were more important factors to the current generation of students in choosing a specialty. Knowledge of these students' attitudes could form the basis for the development of strategies to enhance the attractiveness of specialties facing the problem of a shortage of manpower.

Intermittent hydronephrosis secondary to ureteropelvic junction obstruction: clinical and imaging features

OBJECTIVE

We sought to assess the clinical and imaging findings in intermittent hydronephrosis secondary to ureteropelvic junction obstruction, with particular emphasis on the characteristic ultrasonographic findings.

METHODS

This prospective, longitudinal, observational study included all children who had intermittent ureteropelvic junction obstruction and presented with abdominal pain over 6 years. Renal ultrasound was used as an initial screening tool to detect intermittent hydronephrosis. Renal ultrasonography was repeated every 1 to 2 days to record serial changes from the symptomatic to the asymptomatic stage. Their clinical manifestations and imaging findings were studied.

RESULTS

Eighteen patients (14 boys, 4 girls) were studied. Most had sharp pain that began acutely and typically lasted for <2 days. Most of the children (16 of 18) had nausea and vomiting that accompanied the pain. The acute episode generally resolved spontaneously and was followed by a pain-free interval that ranged from days to months. Factors that predisposed to an attack included increased water intake, vigorous exercise, or bladder distention. All patients had clearly demonstrable obstruction of the renal pelvis during an acute attack, a finding that diminished or resolved during the symptom-free intervals. During convalescence, all patients had renal pelvic wall thickening on ultrasonography. This finding appeared on the second or third day after a painful episode subsided, persisted for 6 to 9 days, and then disappeared in the symptom-free stage. Pyeloplasty was performed in 17 patients, none of whom had recurrent pain on follow-up. Extrinsic obstructions were found in 9 patients.

CONCLUSIONS

The keys to diagnosis are awareness of the syndrome, a detailed history, and immediate and serial imaging studies during painful crises. A thickened renal pelvic wall during convalescence is an important ultrasonic sign of intermittent hydronephrosis.

Bladder autoaugmentation using various biodegradable scaffolds seeded with autologous smooth muscle cells in a rabbit model

BACKGROUND/PURPOSE

The prolapsed mucosa after bladder autoaugmentation usually collapses, and the volume increment is limited. This study is aimed at evaluating the efficacy of autoaugmentation assisted with 2 different scaffolds, polyglycolic acid (PGA) mesh and small intestinal submucosa (SIS), seeded with autologous bladder smooth muscle cells in a rabbit model.

METHODS

One month after an initial 70% partial cystectomy, various autoaugmentation surgeries were performed. These procedures included traditional autoaugmentation (n = 6) and traditional autoaugmentation covered with PGA or SIS without cell seeding (N) (PGA-N, n = 6; SIS-N, n = 6) or covered with scaffolds seeded with autologous bladder smooth muscle cells (C) (PGA-C, n = 6; SIS-C, n = 6). All were followed up by bladder volume measurement and retrieved on 1, 2, 3, and 6 months. Statistical analysis was by analysis of variance.

RESULTS

A normal urothelial layer was maintained in all groups. Only PGA-C group showed a significant bladder capacity increment as compared with the other groups in all time-points (P = .001, .000, .000, and .001 at first, second, third, and sixth months, respectively). The PGA-C group showed grossly normal bladder wall with scattered smooth muscle bundles. The other groups had marked graft shrinkage with only unorganized muscle fibers.

CONCLUSION

Cell-seeded PGA polymer facilitates smooth muscle regeneration, offers sufficient bladder wall backup, and achieves satisfactory volume increment after the autoaugmentation with time. The collagen matrix, although seeded with cells, did not offer adequate mechanical support after the surgery.

Effects of iron ions, protons and X rays on human lens cell differentiation

We have investigated molecular changes in cultured differentiating human lens epithelial cells exposed to high-energy accelerated iron-ion beams as well as to protons and X rays. In this paper, we present results on the effects of radiation on gene families that include or are related to DNA damage, cell cycle regulators, cell adhesion molecules, and cell cytoskeletal function. A limited microarray survey with a panel of cell cycle-regulated genes illustrates that irradiation with protons altered the gene expression pattern of human lens epithelial cells. A focus of our work is CDKN1A (p21(CIP1/WAF1)), a protein that we demonstrate here has a role in several pathways functionally related to LET-responsive radiation damage. We quantitatively assessed RNA and protein expression in a time course before and after single 4-Gy radiation doses and demonstrated that transcription and translation of CDKN1A are both temporally regulated after exposure. Furthermore, we show qualitative differences in the distribution of CDKN1A immunofluorescence signals after exposure to X rays, protons or iron ions, suggesting that LET effects likely play a role in the misregulation of gene function in these cells. A model of molecular and cellular events is proposed to account for precataractous changes in the human lens after exposure to low- or high-LET radiations.

Inflammatory myofibroblastic tumor of renal pelvis presenting with prolonged fever and abdominal pain in children: report of 1 case and review of literature

Inflammatory myofibroblastic tumor is a reactive proliferative lesion that occurs extremely rarely in the renal pelvis, especially during childhood. We report 1 such case that occurred in a child who presented with prolonged fever and abdominal pain. Ultrasonography and abdominal computed tomography revealed a left renal pelvic mass. She received conservative surgical treatment. The diagnosis was confirmed by pathological and immunohistochemical studies. Distinguishing inflammatory myofibroblastic tumor from other malignant renal pelvic tumors in children is essential to preventing unnecessary nephrectomy.

Lipoblastoma/lipoblastomatosis: a clinicopathologic study of 16 cases in Taiwan

Lipoblastoma/lipoblastomatosis is an uncommon benign lipomatous tumor affecting mainly infants and children. It presents as a painless mass located frequently in upper and lower extremities. The present study was conducted to characterize the clinicopathologic features of lipoblastoma/lipoblastomatosis in a Chinese population. A retrospective survey of 16 cases of pathologically confirmed lipoblastoma/lipoblastomatosis from 1988 to 2002 was performed. The available clinical information and histological sections were reviewed. The study involved 10 males and 6 females ranging in age from 5 to 49 months (median, 11.5 months). The patients presented with mass involving neck (n = 5), inguina (n = 3), feet (n = 2), arm (n = 1), leg (n = 1), thorax (n = 1), mesentery (n = 1), buttock (n = 1), and presacral region (n = 1). The lesions were removed surgically. Histologically, the majority (11/16) of primary tumors were of diffuse type. Follow-up ranging from 5 to 125 months was available in 13 patients. Four patients experienced a recurrence of tumors in the neck (n = 2) and lower extremities (n = 2) 11-84 months after operation. The most common site of involvement of lipoblastoma/lipoblastomatosis in our series was the neck. A follow-up period of more than 3 years is recommended for patients with this condition.

Comparison of murine cirrhosis models induced by hepatotoxin administration and common bile duct ligation

AIM: To build up the research models of hepatic fibrosis in mice.

METHODS: Inbred wild-type FVB/N mice were either treated with alpha-naphthyl-isothiocyanate (ANIT), allyl alcohol (AA), carbon tetrachloride (CCl₄), 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), and silica, or subjected to common bile duct ligation (CBDL) to induce hepatic injury. Liver biopsies were performed every 4 wk to evaluate hepatic fibrosis over a period of 6 mo. Cumulative cirrhosis and survival curves were constructed by life table method and compared with Wilcoxon test.

RESULTS: Under the dosages used, there was neither mortality nor cirrhosis in AA and silica-treated groups. DDC and ANIT caused cirrhosis within 4-12 and 12-24 wk, respectively. Both showed significantly faster cirrhosis induction at high dosages without significant alteration of survival. The duration for cirrhosis induction by CCl₄ ranged from 4 to 20 wk, mainly dependent upon the dosage. However, the increase in CCl₄ dosage significantly worsened survival. Intraperitoneal CCl₄ administration resulted in better survival in comparison with gavage administration at high dosage, but not at medium and low dosages. After CBDL, all the mice developed liver cirrhosis within 4-8 wk and then died by the end of 16 wk.

CONCLUSION: CBDL and administrations of ANIT, CCl₄, and DDC ensured liver cirrhosis. CBDL required the least amount of time in cirrhosis induction, but caused shortened lives of mice. It was followed by DDC and ANIT administration with favorable survival. As for CCl₄, the speed of cirrhosis induction and the mouse survival depended upon the dosages and the administration route.

Unexpected mortality in pediatric patients with postoperative Hirschsprung's disease

Hirschsprung's disease is characterized by lower intestinal obstruction. In this retrospective study, we investigated the postoperative complications and the causes of death in pediatric patients with Hirschsprung's disease. Between January 1981 and June 1998, 147 patients with Hirschsprung's disease underwent surgical intervention (129 with both colostomy and Soave's pull-through procedures) at Mackay Hospital. Of 147 total patients, 83.67% had aganglionosis in the rectosigmoid, 5.44% had colon involvement, and 4.08% had total colon aganglionosis, documented pathologically after a Soave's pull-through procedure. Any post-pull-through patient who showed symptoms of fever, leukocytosis, diarrhea, and clinical sepsis was diagnosed with Hirschsprung's enterocolitis. Four patients died within 4.5 months of surgery, and one patient died more than 4 years after surgery; these five patients were positive for Thomsen (T-) antigen. One patient died soon after rectal irrigation was performed in preparation for the surgery. All five of these patients had sepsis clinically, and anaerobic sepsis was attributed as the main cause of their deaths. Of interest in these cases is the presence of T-antigen, a potentially useful marker for anaerobic bacterial infection that may not be well known to most pediatricians. We recommend (1) determining the presence of T-antigen in patients with recurrent Hirschsprung's enterocolitis, (2) administering empirical antibiotics with anti-anaerobic activity as soon as possible, and (3) irrigating the colon in those patients who develop sepsis after a pull-through procedure.