An investigation into the role of waterproofing in a two-stage hypospadias repair

In our unit a two-stage procedure, using a full thickness preputial graft, has been adopted as the method of choice for the repair of hypospadias proximal to the coronal sulcus. In 1993 an audit was undertaken to establish our complication rate for this procedure. Twenty-two consecutive patients who completed a two-stage repair between January 1988 and December 1993 were studied. An unacceptably high fistula rate was identified (63%, 14/22 cases). Consequently our technique was modified by transposing a vascularised flap of preputial areolar tissue over the urethral suture line, at the time of urethroplasty. A second group of 22 consecutive patients, operated upon between January 1994 and July 1997, were subsequently investigated and a dramatic improvement in the fistula rate was demonstrated (4.5%, 1/22 cases). These cases represent a subgroup of almost 200 cases, which the senior author has managed over the last 10 years. The senior author undertook or supervised the surgery in all 44 cases, which were the focus of this study, and the introduction of a waterproofing layer represents the only change in technique.     

CTLA-4 blockade synergizes with tumor-derived granulocyte-macrophage colony-stimulating factor for treatment of an experimental mammary carcinoma

Generation of a T cell-mediated antitumor response depends on T cell receptor engagement by major histocompatibility complex/antigen as well as CD28 ligation by B7. CTLA-4 is a second B7 receptor expressed by T cells upon activation that, unlike CD28, appears to deliver an inhibitory signal to T cells. Recently, we and others demonstrated that administration of an anti-CTLA-4 antibody was sufficient to promote regression of several murine tumors. However, certain tumors, such as the SM1 mammary carcinoma, remain refractory to this type of immunotherapy. In the present study, we report that the combination of both CTLA-4 blockade and a vaccine consisting of granulocyte-macrophage colony-stimulating factor-expressing SM1 cells resulted in regression of parental SM1 tumors, despite the ineffectiveness of either treatment alone. This synergistic therapy resulted in long-lasting immunity to SM1 and depended on both CD4(+) and CD8(+) T cells. Interestingly, synergy was not observed between CTLA-4 and a B7-expressing SM1 vaccine. Given that granulocyte-macrophage colony-stimulating factor promotes differentiation and activation of dendritic cells as well as enhances cross-priming of T cells to tumor-derived antigens and that SM1 is major histocompatibility complex class II-negative, our findings suggest that CTLA-4 blockade acts at the level of a host-derived antigen-presenting cell. In addition, these results also support the idea that the most effective and synergistic vaccine strategy targets treatments that enhance T cell priming at the level of host-derived antigen-presenting cells.     

Metastatic vertebral disease in children

We retrospectively reviewed 19 children with osseous vertebral metastases. The average age was 10.9 years at diagnosis of the primary tumor and 11.2 years at diagnosis of metastasis. The location of the multiple metastases was cervical (three), thoracic (14), and lumbar (10). Treatment consisted of chemotherapy (19), radiation therapy (12), and operation (seven). Ten children died at an average of 13 months after diagnosis of the primary tumor; nine are alive at an average of 72 months after diagnosis. All four children treated with chemotherapy, spinal radiation, and laminectomy, and who survived > 2 months, developed deformity. In this particular situation, we encourage consideration of spinal stabilization when it is appropriately coordinated with radiation and chemotherapy.     

Radiosensitivity of atomic bomb survivors as determined with a micronucleus assay

We have developed a system in which a unique double-stranded break (DSB) can be introduced into a yeast chromosome during mitotic growth. The recognition site for the endonuclease I-SceI was inserted at different places in the yeast genome in haploid and diploid cells expressing this endonuclease. Induction of the break in haploids results in cell death if no intact copy of the cleaved region is present in the cell. If such a copy is provided on a plasmid, as an ectopic gene duplication, or on a homologous chromosome, the break can be repaired. Repair results in two identical copies in the genome of the locus which has been cut. We call this phenomenon homozygotization by reference to diploids heterozygous for the cut site in which repair leads to homozygosis at this site. We have compared the efficiencies of repair in the various topological situations examined, and conclude that some mechanism must search for regions of homology to both sides of the DSB and that repair is successful only if the homologies are provided by the same template molecule.     

Biochemical outcome after radical prostatectomy, external beam radiation therapy, or interstitial radiation therapy for clinically localized prostate cancer

CONTEXT: Interstitial radiation (implant) therapy is used to treat clinically localized adenocarcinoma of the prostate, but how it compares with other treatments is not known. OBJECTIVE: To estimate control of prostate-specific antigen (PSA) after radical prostatectomy (RP), external beam radiation (RT), or implant with or without neoadjuvant androgen deprivation therapy in patients with clinically localized prostate cancer. DESIGN: Retrospective cohort study of outcome data compared using Cox regression multivariable analyses. SETTING AND PATIENTS: A total of 1872 men treated between January 1989 and October 1997 with an RP (n = 888) or implant with or without neoadjuvant androgen deprivation therapy (n = 218) at the Hospital of the University of Pennsylvania, Philadelphia, or RT (n = 766) at the Joint Center for Radiation Therapy, Boston, Mass, were enrolled. MAIN OUTCOME MEASURE: Actuarial freedom from PSA failure (defined as PSA outcome). RESULTS: The relative risk (RR) of PSA failure in low-risk patients (stage T1c, T2a and PSA level < or =10 ng/mL and Gleason score < or =6) treated using RT, implant plus androgen deprivation therapy, or implant therapy was 1.1 (95% confidence interval [CI], 0.5-2.7), 0.5 (95% CI, 0.1-1.9), and 1.1 (95% CI, 0.3-3.6), respectively, compared with those patients treated with RP. The RRs of PSA failure in the intermediate-risk patients (stage T2b or Gleason score of 7 or PSA level >10 and < or =20 ng/mL) and high-risk patients (stage T2c or PSA level >20 ng/mL or Gleason score > or =8) treated with implant compared with RP were 3.1 (95% CI, 1.5-6.1) and 3.0 (95% CI, 1.8-5.0), respectively. The addition of androgen deprivation to implant therapy did not improve PSA outcome in high-risk patients but resulted in a PSA outcome that was not statistically different compared with the results obtained using RP or RT in intermediate-risk patients. These results were unchanged when patients were stratified using the traditional rankings of biopsy Gleason scores of 2 through 4 vs 5 through 6 vs 7 vs 8 through 10. CONCLUSIONS: Low-risk patients had estimates of 5-year PSA outcome after treatment with RP, RT, or implant with or without neoadjuvant androgen deprivation that were not statistically different, whereas intermediate- and high-risk patients treated with RP or RT did better then those treated by implant. Prospective randomized trials are needed to verify these findings.     

Interferon-gamma and interleukin-4 responses in relation to serum IgE levels in persons infected with human T lymphotropic virus type I and Strongyloides stercoralis

Possible immunologic interaction between infection with human T lymphotropic virus type 1 (HTLV-1), a retrovirus, and the intestinal parasite Strongyloides stercoralis was investigated in persons infected with one or both agents. This was done by examining the cytokine responses of peripheral blood mononuclear cells (PBMC) to mitogens and Strongyloides antigen. PBMC of subjects infected with HTLV-1 spontaneously produced interferon (IFN)-gamma with levels that correlated inversely with serum IgE levels. HTLV-1-infected subjects also had poor interleukin (IL)-4 responses to mitogenic stimulation, unlike persons without HTLV-1 infection. It is postulated that the IFN-gamma produced by activated T cells in some HTLV-1-infected persons acts to down-regulate IL-4 with consequent reduction of serum IgE levels. The impaired IgE responses and other effects of IL-4 down-regulation may be contributing factors to more severe disease and impaired response to treatment of strongyloidiasis in some HTLV-1-infected persons.     

The anaerobic oxidation of ammonium

From recent research it has become clear that at least two different possibilities for anaerobic ammonium oxidation exist in nature. 'Aerobic' ammonium oxidizers like Nitrosomonas eutropha were observed to reduce nitrite or nitrogen dioxide with hydroxylamine or ammonium as electron donor under anoxic conditions. The maximum rate for anaerobic ammonium oxidation was about 2 nmol NH4+ min-1 (mg protein)-1 using nitrogen dioxide as electron acceptor. This reaction, which may involve NO as an intermediate, is thought to generate energy sufficient for survival under anoxic conditions, but not for growth. A novel obligately anaerobic ammonium oxidation (Anammox) process was recently discovered in a denitrifying pilot plant reactor. From this system, a highly enriched microbial community with one dominating peculiar autotrophic organism was obtained. With nitrite as electron acceptor a maximum specific oxidation rate of 55 nmol NH4+ min-1 (mg protein)-1 was determined. Although this reaction is 25-fold faster than in Nitrosomonas, it allowed growth at a rate of only 0.003 h-1 (doubling time 11 days). 15N labeling studies showed that hydroxylamine and hydrazine were important intermediates in this new process. A novel type of hydroxylamine oxidoreductase containing an unusual P468 cytochrome has been purified from the Anammox culture. Microsensor studies have shown that at the oxic/anoxic interface of many ecosystems nitrite and ammonia occur in the absence of oxygen. In addition, the number of reports on unaccounted high nitrogen losses in wastewater treatment is gradually increasing, indicating that anaerobic ammonium oxidation may be more widespread than previously assumed. The recently developed nitrification systems in which oxidation of nitrite to nitrate is prevented form an ideal partner for the Anammox process. The combination of these partial nitrification and Anammox processes remains a challenge for future application in the removal of ammonium from wastewater with high ammonium concentrations.     

CT findings in chondroradionecrosis of the larynx

PURPOSE: Our goal was to describe the CT findings before and after radiation therapy in a series of patients with laryngeal chondroradionecrosis. METHODS: The CT studies obtained before and after radiation therapy in nine patients with the diagnosis of laryngeal chondroradionecrosis were reviewed retrospectively. RESULTS: CT scans revealed abnormalities in all patients. A variable degree of laryngeal soft-tissue swelling was seen in eight of the patients. In four patients, cartilaginous abnormalities were visible initially, and appeared in three of four other patients who had further follow-up CT studies. Six patients had involvement of the thyroid cartilage; collapse of the thyroid cartilage was seen in two cases and gas bubbles were visible adjacent to the thyroid cartilage in three cases. Four patients with involvement of the thyroid cartilage eventually underwent total laryngectomy, and one died suddenly in severe respiratory distress. In all three patients with arytenoidal involvement, anterior dislocation of this cartilage was seen; in two of these patients, the adjacent part of the cricoid cartilage showed some sclerosis. Two patients with arytenoidal necrosis (both with cricoidal sclerosis) kept a functional larynx. In one case, cricoidal sclerosis was seen in association with lysis of the thyroid cartilage. CONCLUSION: The CT appearance of laryngeal chondroradionecrosis is nonspecific, but the diagnosis can be strongly suggested in cases of sloughing of the arytenoid cartilage, fragmentation and collapse of the thyroid cartilage, and/or in the presence of gas bubbles around the cartilage.