Controversies in the management of paratesticular rhabdomyosarcoma: is staging retroperitoneal lymph node dissection necessary for adolescents with resected paratesticular rhabdomyosarcoma?

PURPOSE: Use of retroperitoneal lymph node dissection (RPLND) in paratesticular rhabdomyosarcoma (PTRMS) is controversial and has changed over the past 2 decades. The Intergroup Rhabdomyosarcoma Study Group (IRSG) required ipsilateral RPLND (IRPLND) for all patients with PTRMS treated on IRS-III (1984-91), but changed to clinical evaluation of RPLNs using computerized tomography (CT) in IRS-IV (1991 through 1997). In IRS-IV, only those patients with identified lymph node involvement on CT required surgical evaluation of the RPLNs. Nodal radiation therapy was administered only to patients with RPLNs recognized as positive; such patients received more intensive chemotherapy as well. Thus, they compared the incidence of recognized RPLN involvement using these 2 different approaches. They then analyzed patient outcome to determine whether this change in management affected outcome. METHODS: Eligible patients with group I or II PTRMS who were treated on IRS III (n = 100) or IRS IV (n = 134) were analyzed. Failure-free survival (FFS) and survival (S) rates were estimated using the Kaplan-Meier method and compared using the log-rank test. RESULTS: There was a significant change in the distribution of patients with group I versus II tumors from IRS-III to IRS-IV (group I, 68% in IRS-III versus 82% in IRS-IV). This was the result of decreased node recognition when CT was used to stage RPLNs in IRS-IV and was most notable for adolescents (>10 years of age). Overall, 3-year FFS was 92% for patients treated on IRS-III and 86% for those treated on IRS-IV (P =.10), whereas survival estimates were 96% and 92%, respectively (P =.30). Adolescents were at higher risk of RPLN relapse than were children (<10 years of age) and their FFS and survival were worse, regardless of IRS protocol. Furthermore, adolescents with recognized group II tumors experienced better 3-year FFS than those with group I tumors on IRS-IV (100% versus 68%, P =.06), most likely as a result of receiving radiotherapy and intensified chemotherapy. CONCLUSIONS: Use of only CT scan evaluation of RPLN in IRS-IV led to a decrease in identification of RPLN involvement in boys who present with localized PTRMS, and a higher rate of regional relapse as compared with IRS-III. Adolescents had much higher likelihood of RPLN disease, and they fared significantly worse than did younger children on both studies. Furthermore, adolescent boys with group I tumors experienced worse FFS than those with Group II tumors on IRS-IV, probably because some patients with group II tumors were not identified by CT imaging and thus received less effective therapy. These data suggest that adolescents should have ipsilateral RPLN dissection as part of their routine staging, and those with positive lymph nodes require intensified chemotherapy as well as nodal irradiation.     

Laparoscopic Nissen fundoplication with carbon dioxide pneumoperitoneum preserves cell-mediated immunity in an immature animal model

PURPOSE: The aim of this study is to elucidate the effects of laparoscopic Nissen fundoplication (LNF) with carbon dioxide (CO(2)) or helium (He) on the cell-mediated immune response in a pediatric animal model compared with open Nissen fundoplication (ONF). METHODS: Cell immune response was evaluated in 45 1-week-old Sprague Dawley rats using the delayed type hypersensitivity (DTH) skin test. Animals were sensitized against keyhole limpet hemocyanin (KLH) by subcutaneous injection (0.5 mg) in complete Freund's adjuvant. Animals were challenged 2 weeks later by an intradermal injection of KLH (0.3 mg) in sterile saline (challenge 1, baseline). Rats with positive DTH skin reaction at 24 and 48 hours after challenge 1 were put randomly into 4 groups (n = 10 each): I, only anesthesia (control); II, LNF with CO(2), III, LNF with He; IV, ONF. Animals were injected intradermally with KLH (0.3 mg) immediately before the procedures (challenge 2) and 3 and 6 days postoperatively (challenges 3 and 4). RESULTS: DTH skin reactions were measured 24 and 48 hours after each challenge. There were no significant changes in cell-mediated immunosuppression after LNF with CO(2). However, a transient cell-mediated immunosuppression was observed after LNF with He and ONF. All fundoplications were intact at the time of necropsy. CONCLUSIONS: These data suggest a transient suppression of cell-mediated immunity in open procedures when compared with laparoscopic interventions using CO(2) in a pediatric animal model. In addition, the type of gas used during laparoscopy also may modulate this transient immunosuppression.     

Simulation and its role in medical education

Medical education is increasingly laying emphasis on a curriculum based on cognitive, psychomotor, and affective domains of learning which were originally proposed nearly 50 years ago. These reforms are framed around best standards of care, error management and patient safety, patient autonomy, and resource allocation. There is a worldwide shift in the method of medical education towards experiential (‘hands-on’) medical learning; however, applying this concept to real patients is less acceptable to society and is subject to legal and ethical issues.     

Mild idiopathic lateral cerebral ventricular dilatation in utero: sonographic evaluation

The authors prospectively studied 20 fetuses with mild dilatation of the lateral cerebral ventricles but no other detectable central nervous system abnormality. One case (5%) occurred in a diabetic pregnancy, and three (15%) involved twin pregnancies. Fifteen (75%) fetuses were male, and one (5%) had trisomy 21. Postnatal follow-up at 15-31 months showed a normal outcome in eight cases (40%), an uncertain prognosis in four cases (20%), and death in eight cases (40%). Serial antenatal sonograms were obtained in 17 cases. Among the eight cases with a normal outcome, seven demonstrated no additional sonographic abnormalities and six showed resolution of the ventricular dilatation antenatally. Conversely, all 12 fetuses with demise or an uncertain prognosis demonstrated additional sonographic abnormalities, and six showed stable or progressive ventricular dilatation on follow-up sonograms. Since mild idiopathic lateral ventricular dilatation has a widely variable prognosis, antenatal detection of this finding warrants search for additional findings and follow-up sonography.     

Subthreshold Oscillations Induced By Spinal Nerve Injury In Dissociated Muscle And Cutaneous Afferents Of Mouse DRG

Whole cell patch-clamp recordings were obtained from dissociated mouse lumbar dorsal root ganglion (DRG) neurons. Recordings were made from control neurons and neurons axotomized by transection of the corresponding spinal nerve 1-2 days prior to dissociation. Medium to large muscle and cutaneous afferent neurons were identified by retrograde transport of True Blue or Fluoro-Gold injected into the corresponding peripheral tissue. Action potentials were classified as non-inflected spikes (A(0)) and inflected spikes (A(inf)). High-frequency, low-amplitude subthreshold membrane potential oscillations were observed in 8% of control A(0) neurons, but their incidence increased to 31% in the nerve injury group. Fifty percent of axotomized muscle afferent A(0) cells displayed oscillations, while 26% of axotomized cutaneous afferents exhibited oscillations. Lower-frequency oscillations were also observed in a small fraction (4%) of A(inf) neurons on strong depolarization. Their numbers were increased after the nerve injury, but the difference was not statistically significant. The oscillations often triggered burst firing in distinct patterns of action potential activity. These results indicate that injury-induced membrane oscillations of DRG neurons, previously observed in whole DRG of rats, are present in dissociated DRG neurons of the adult mouse. Moreover, these observations indicate that both muscle and cutaneous afferents in the A(beta) size range give rise to injury-induced membrane oscillations, with muscle afferents being more prone to develop oscillations.     

Antibody to Hepatitis B Surface Antigen in Vaccinated Health Care Workers

Background

Health care workers (HCWs) in Armed Forces are immunised against Hepatitis B virus (HBV), however they are not subjected to anti-HBs (antibody to Hepatitis B surface antigen) assessment after primary vaccination. The present study was undertaken to determine the protection offered by HBV vaccine in HCW.

Methods

Cross-sectional study was carried out at tertiary care hospital. A total 146 HBV vaccine compliant HCW were evaluated for quantitative anti-HBs by enzyme immune assay.

Result

129 (88.4%) subjects had protective levels of anti-HBs. Higher age at vaccination was an important risk factor in low vaccine response. Decline in anti-HBs with time was evident. Anti-HBs levels were more than 10mIU/ml in subjects even after 11 years of primary vaccination. There was no difference in protection in booster and non booster groups.

Conclusion

Age is the most important factor in HBV vaccine response. Booster dose of HBV vaccine is not necessary in healthy HCW for atleast ten years after primary vaccination. The study recommends early primary vaccination of HCW and ‘initial’ anti-HBs assay for confirmation of vaccine response.Key Words: Anti-Hepatitis B surface antigen, Health care workers, Hepatitis B virus vaccine