The relationship between human papillomavirus and p53 gene in conjunctival squamous cell carcinoma

PURPOSE: The p53 tumor-suppressor gene has been documented to exist in mutated forms in many types of squamous cell carcinoma in the body. Also in conjunctival squamous cell carcinoma, human papillomavirus (HPV) is accepted as an oncogenic factor. The objective of our study was to establish a correlation between p53 overexpression and the presence of HPV infection within tumor tissues from patients with conjunctival squamous cell carcinoma. METHODS: Tissue sections obtained from paraffin-embedded conjunctival squamous cell carcinoma specimens from 23 patients were examined with light microscopy, polymerase chain reaction (PCR), and immunohistochemistry. RESULTS: Seventy-eight percent of tumors were positive for p53, whereas 22% were positive for HPV. The proportion of patients positive for both p53 and HPV was 17%, whereas another 17% of the patients were negative for both p53 and HPV. Therefore no significant disproportion was found in the distribution of patients' HPV status and p53 status (p = 1.00). No significant correlation or linear association was found between the HPV status and p53 status (r = 0.022; p = 0.920). CONCLUSION: We could not show any statistical association between abnormal p53 gene-product expression by immunohistochemistry in conjunctival squamous cell carcinomas and HPV infection by PCR detection techniques.     

DNA methylation patterns at relapse in adult acute lymphocytic leukemia.

PURPOSE: Aberrant DNA methylation of promoter-associated CpG islands is an epigenetic DNA modification observed in acute leukemias that in certain cases has been associated with a poor prognosis and increased relapse rates. To study the role of DNA methylation in relapse mechanisms in acute lymphocytic leukemia (ALL), we have compared the methylation status of five genes at the time of initial presentation and at first relapse in 25 adult patients with ALL. EXPERIMENTAL DESIGN: Genes studied included the estrogen receptor (ER), multidrug resistance gene 1 (MDR1), p73, p15, and p16. DNA was extracted from paraffin-embedded bone marrow biopsies. DNA methylation was analyzed using PCR of bisulfite-modified DNA. RESULTS: Results indicate that methylation at the time of relapse was stable in 92% of patients for p73, 88% for ER, 80% for p16, 72% for MDR1, and 60% for p15. Only one case had p16 methylation at initial presentation, whereas 6 patients (P = 0.0001) had methylation at relapse. Three cases had concomitant methylation of p15 and p16 at relapse. The degree of MDR1 methylation inversely correlated with the presence of MDR1 expression as detected by immunohistochemistry. Eighteen patients (72%) had acquired no or one methylation change, whereas the rest (28%) had methylation changes in two or three genes. No clinical-biological correlations were found between methylation of any particular gene or pattern. CONCLUSIONS: In summary, DNA methylation patterns are stable in a majority of patients with relapsed ALL, but a subset of patients acquire new methylation changes, in particular affecting cell cycle regulatory genes.     

Strength of a 'no-bottle' adhesive system bonded to enamel and dentine

Existing bonding systems permit effective bonding to enamel or dentine. Bonding to dentine is mainly achieved through the hybridization of dentine with resin. However, despite their success, the 'three-bottle' systems do have drawbacks--the large number of steps involved may be confusing and prone to errors of application, as well as being time consuming. Recently developed systems have significantly reduced the number of steps and the total treatment time, but deliver a reliable outcome.     

A study of the thermal degradation of poly(mono-n-alkyl itaconates)

The thermal degradation of the first six members of poly(mono-n-alkyl itaconates) by thermogravimetry (TG), differential scanning calorimetry (DSC), Fourier Transform infrared (FTIR) and FTIR evolved gas analysis (FTIR-EGA) was studied. The degradation mechanism involves cyclic anhydride formation followed by crosslinking due to the linear anhydride formation. In both processes water and/or alcohol evolution was detected. Also, decarboxylation processes take place on all polymers at high temperatures ( > 180°C). A mechanism of the degradation process is proposed.     

Epididymal sparing bilateral simple orchiectomy with epididymoplasty: preservation of esthetics and body image

PURPOSE: We report the surgical technique and results of epididymal sparing bilateral simple orchiectomy as an esthetic alternative to standard bilateral simple orchiectomy and luteinizing hormone releasing hormone (LH-RH) agonist injection therapy in patients with prostate cancer. MATERIALS AND METHODS: The study included 91 consecutive epididymal sparing bilateral simple orchiectomy (BSO) procedures that were performed at the Atlanta Veterans Affairs Medical Center during a 25-month period. All patients had pathologically confirmed prostate cancer. A total of 52 patients (57.1%) were receiving LH-RH agonist therapy prior to the procedure and the remaining 39 (42.9%) were not. All procedures were performed in an outpatient clinic setting using spermatic cord anesthesia block as the only method of anesthesia. In the 52 patients who were on LH-RH agonist therapy prior to the procedure the overall impression/satisfaction with the procedure was evaluated using a questionnaire. RESULTS: All 91 procedures were performed at the urology outpatient clinic using local anesthesia. Mean patient age was 74.2 years (range 44 to 86). Mean serum prostate specific antigen was 58.9 ng/ml. The mean time required to perform the spermatic cord anesthesia block was 3.9 minutes (range 2 to 6) and the volume of anesthetic solution was 18.9 ml per case (range 10 to 32). Despite significant difference in testicular size between patients receiving and not receiving LH/RH agonists there were no differences in anesthesia time or anesthetic volume (3.9 and 3.9 minutes, p = 0.97, and 18.6 and 19.4 ml, respectively, p = 0.47). Mean operative time for BSO excluding anesthesia time was 36.9 minutes (range 18 to 70). Mean operative time was similar in patients receiving and not receiving LH-RH agonists (36.2 and 37.8 minutes, respectively, p = 0.39). The procedure was well tolerated, as judged by the mean intraoperative pain score during BSO of 0.2 (range 0 to 3). The majority of patients (76 or 83.5%) were pain-free during the procedure. Pain scores were similar in patients who were and were not receiving LH-RH agonists during BSO (p = 0.97). There were no adverse events. Followup data were available on 26 of the 52 patients who were receiving LH-RH agonist therapy prior to the procedure. Of them 96.2% were satisfied with the results and 84.6% preferred the procedure over medical castration therapy with LH-RH agonist therapy. CONCLUSIONS: Epididymal sparing bilateral simple orchiectomy is a simple and safe procedure that can be conveniently performed in an outpatient clinic setting using pure local anesthesia. Preservation of the epididymis and subsequent epididymoplasty is effective for maintaining the esthetic appearance of the scrotum and patient satisfaction. The procedure offers patients the convenience of 1-time surgical therapy over lifelong medical injection therapy at a significantly lower cost and without significantly compromising the esthetic appearance of the scrotum.