SEARCH · PubMed Health

Results for “excision”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

PubMed1983

Mechanism of F factor-enhanced excision of transposon Tn5.

The reversion of lac:: Tn5 insertion mutations was used to examine the control of excision of the kanamycin-resistance transposon Tn5 in Escherichia coli. Earlier work which showed that the fertility factor F enhances Tn5 excision had led another group to suggest that this is due to the product of a putative transposable element-specific "recombination" gene in the F factor which can act on Tn5 located anywhere in the genome. We show, however, that Tn5 is excised from sites in the lac operon of F'lac plasmids several orders of magnitude more efficiently than from the same sites in the chromosomes of F-, F+ or homozygous lac:: Tn5[F'lac:: Tn5] strains. Thus F enhances Tn5 excision, but only if F and Tn5 are in cis in the same DNA molecule. Bacterial crosses showed that transfer of F'lac:: Tn5 plasmids by conjugation stimulates Tn5 excision, and that transfer is frequent even within F' populations. These results suggest that the ability of F to enhance excision is the consequence of DNA transfer in conjugation.

Conjugation, Genetic↗

PubMed1991

RecA-dependent increased precise excision of Tn10 in Salmonella typhimurium.

UV irradiation induced the precise excision of Tn10 inserted in met, trp or srl in a Salmonella typhimurium strain; mitomycin C was also found to induce the frequency of precise excision of Tn10 from srl or met. Precise excision of Tn10 was not increased by either UV or mitomycin C in a recA mutant. Similarly, a recA mutant derived from a uvrD strain showed a drastic reduction in the high spontaneous levels of precise excision of Tn10 of this strain. These results indicate that recA is involved in the increased precise excision of Tn10. In contrast to point mutations excision of Tn10 was found to be UV inducible in a top mutant.

Chromosome Deletion↗

PubMed1989

Local excision for selected colorectal carcinomas.

In summary, local excision is a useful tool in the management of selected colorectal carcinomas. The advent of the fibreoptic colonoscope has revised the concept of local excision when dealing with carcinoma-containing polyps of the colon. The clinician now has the means of locally excising certain carcinomas which would have required laparotomy in the not so distant past. In dealing with carcinoma of the rectum, local excision is not advocated for all rectal carcinomas. In fact, when the previously discussed tumour related factors are considered, local excision should be the ultimate procedure in less than 5% of operations performed for rectal carcinomas. However, when appropriately used, local excision provides a less morbid alternative to more radical procedures without compromising patient survival rates or local recurrence rates.

Colorectal Neoplasms↗

PubMed2006

Local excision of stratified T1 rectal cancer.

BACKGROUND: Local excision has been accepted therapy for T1 rectal cancers. A recent study demonstrated that primary tumors with deeper submucosal invasion were associated with a higher rate of lymph node metastases than those with shallow invasion. Our aim was to determine the effect of the depth of submucosal penetration on recurrence and mortality rates following transrectal excision of T1 tumors. METHODS: This was a 34-year retrospective review of patients who had transrectal excision with clear margins for T1 rectal cancer. Tumors were stratified into submucosal (SM) levels, and recurrence and mortality rates were determined. RESULTS: Of 101 patients with T1 rectal cancer undergoing local excision, 31 had a full-thickness transrectal excision. Eight (26%) of the 31 patients developed a local recurrence, 2 of whom had both a local and distant recurrence. Four patients (13%) died from metastatic rectal cancer. CONCLUSIONS: The recurrence rate for transrectal excision of T1 rectal cancer is high. It may be beneficial for patients with early rectal cancer to have postoperative chemoradiation therapy or a more radical surgical procedure.

Aged↗

PubMed2006

Does the insertion of more than one wire allow successful excision of large clusters of malignant calcification?

AIM: To determine whether the insertion of more than one localization wire for larger areas of malignant microcalcification reduces the need for re-excision. METHOD: This is a retrospective study of 101 cases of malignant calcifications preoperatively marked by one or more wires. Surgical and histopathology data were obtained from hospital records. Mammograms and specimen radiographs were evaluated without knowledge of the eventual outcome, i.e., whether further surgery was required or not. All cases had a preoperative diagnosis of malignancy. RESULT: In this study the group of patients in which two or more wires were inserted had mammographically larger lesions (p<0.000001) but did not have a greater chance of needing re-excision (p=0.822). Mammograms that demonstrated flecks of microcalcification outlying the main cluster were also more likely to require further surgery (p<0.01). Calcifications associated with high-grade ductal carcinoma in situ (DCIS) had three times the risk of requiring further surgery (p<0.01). However, as reported in other studies re-excision was not related to breast size (p=0.63) [Kollias J, Gill PG, Beamond B, Rossi H, Langlois S, Vernon-Roberts E. Clinical and radiological predictors of complete excision in breast-conserving surgery for primary breast cancer. Aust N Z J Surg 1998;68:702-6]. CONCLUSION: It was previously suggested that the risk of re-excision for DCIS is related to the size of the initial lesion [Cheng L, Al-Kaisi NK, Gordon NH, Liu AY, Gebrail F, Shenk RR. Relationship between the size and margins of ductal carcinoma in situ of the breast and residual disease. J Nat Cancer Inst 1997;89:1356-60]. However, in the present study larger clusters of microcalcification that have been 'bracketed' by two or more wires do not appear to have a greater requirement for re-excision. Grading of the malignant microcalcifications preoperatively may encourage the surgeon to take a wider margin. Careful examination of the mammograms at localization to include outlying flecks could help to reduce the need for further surgery.

Breast Neoplasms↗

PubMed2006

Radial head fracture in the medial collateral ligament deficient elbow; biomechanical comparison of fixation, replacement and excision in human cadavers.

A widely used clinical recommendation is that in the presence of medial collateral ligament injuries, two-part radial head fractures should be fixed rather than excising or replacing the radial head. Direct biomechanical data comparing fracture fixation, radial head replacement and excision in a human cadaveric elbow model, have not been previously described. Such comparison is clinically important as with the increasing availability of radial head implants and promising follow up results, the role of radial head replacement in fracture management may have to be redefined. In this study, five fresh cadaveric elbows had radial head fracture creation and medial collateral ligament division, fracture fixation, radial head replacement and excision. Valgus and varus laxity were determined using an electromagnetic tracking system. Radial head replacement leads to a similar valgus (P=0.80) [corrected] laxity as compared to radial head fixation. Radial head excision resulted in a significantly greater valgus laxity as compared to radial head fixation (P=0.02) or replacement (P=0.03). Both radial head excision and replacement led to a greater varus laxity as compared to fixation. Our results suggest that in the elbow with medial collateral ligament injury and two-part radial head fracture, fixation is overall biomechanically superior as compared to replacement and excision.

Aged↗

PubMed2006

Is excision of a choledochal cyst in the neonatal period necessary?

PURPOSE: Although the incidence of choledochal cyst (CC) diagnosed in the prenatal or neonatal period is increasing, excision of CC in early infancy is not universally recommended. To validate the rationale of excision of CC in the neonatal period, operative complications and the histologic grade of liver fibrosis at the time of excision of CC were compared in three age groups. METHODS: 198 patients who underwent excision of CC, were divided into three age groups, i.e., within 30 days old (group 1, n = 11), 1 to 12 month-old (group 2, n = 40) and over 12 month-old (group 2, n = 147). Retrospective review of their medical records was performed. RESULTS: The overall operative complications were 12 (7 cholangitis, 4 bleeding, 1 ileus). No complication occurred in the group 1. The grade of liver fibrosis had statistically significant positive correlation among groups. CONCLUSION: Excision of CC in the neonatal period is a safe procedure. The grade of liver fibrosis increased with age. These results support the rationale of early excision of CC.

Age Factors↗

PubMed1992

Diathermy loop excision in the management of cervical intraepithelial neoplasia: diagnosis and treatment in one procedure.

OBJECTIVE: Diathermy loop excision was performed as a new diagnostic-treatment in patients with cervical cytologic diagnoses consistent with an epithelial abnormality. STUDY DESIGN: A total of 424 patients with cervical cytologic diagnoses consistent with an epithelial abnormality, but macroscopically or colposcopically not consistent with invasive carcinoma, were subjected to diathermy loop excision to diagnose and treat cervical lesions in one procedure. RESULTS: The diagnostic accuracy rate was 99%. In patients with histologically confirmed grade 3 cervical intraepithelial neoplasia, pretreatment cytologic diagnosis and subsequent histopathologic diagnosis corresponded in 73% of cases. In 91% of all patients the diathermy loop excision was sufficient for complete treatment. Cervical morphologic findings after treatment allowed adequate cytologic follow-up. There was no evidence that diathermy loop excision influenced fertility or pregnancy outcome. CONCLUSION: Diathermy loop excision is a reliable, well-tolerated, inexpensive, and efficient technique for the management of cervical intraepithelial neoplasia. This outpatient procedure is especially recommended in younger patients, because diathermy loop excision preserves the function of the cervix.

Electrocoagulation↗

PubMed2003

Enhanced DNA excision repair in CCRF-CEM cells resistant to 1,3-bis(2-chloroethyl)-1-nitrosourea, quantitated using the single cell gel electrophoresis (Comet) assay.

Enhanced DNA repair activity is important for the development of cellular resistance to alkylating agents. Here, we quantitated the kinetics of DNA excision repairs initiated by 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) in human leukemia CCRF-CEM cells. CEM cells that had been established resistant to BCNU (CEM-R) were evaluated in comparison with parental CEM cells (CEM-S). The excision repair kinetics were quantitated as the amount of DNA single strand breaks, which were generated from the incision/excision of the damaged DNA and were diminished by the rejoining of renewed DNA, using the single cell gel electrophoresis (Comet) assay. CEM-R cells were 10-fold more resistant to BCNU than CEM-S cells, and also showed cross-resistance to melphalan and cisplatin. In response to the treatment with BCNU, both CEM-S and CEM-R cells initiated an incision/excision reaction at the end of the incubation period, and completed the rejoining process within 4 hr. While CEM-S cells could not repair the damage induced by the high concentration of BCNU, CEM-R cells completed the repair process regardless of BCNU concentrations, suggesting enhanced excision repairs in CEM-R cells. The excision repair activity of CEM-R cells was increased with regard to the incision reaction and to the rate of the repair. Similar results were obtained using ultraviolet C, suggesting enhanced nucleotide excision repair in CEM-R cells. Thus, the enhanced DNA excision repairs were successfully quantitated in the resistant leukemic cell line using the Comet assay. The evaluation of the repair activity may predict the sensitivity of cancer cells to chemotherapy and provide a clue to overcome the resistance.

Antineoplastic Agents, Alkylating↗

PubMed1998

Reproductive outcome after treatment of mild endometriosis with laparoscopic excision and electrocoagulation.

OBJECTIVE: To compare the pregnancy rates (PRs) of infertile women with mild endometriosis treated laparoscopically by surgical excision and by electrocoagulation. Laparoscopic treatment of minimal and mild endometriosis usually is done by laser or electrocoagulation. Whether surgical excision is associated with similar results is unknown. DESIGN: Retrospective study with a historical control. SETTING: University teaching hospitals. PATIENT(S): One hundred one infertile women undergoing laparoscopic treatment of mild endometriosis. INTERVENTION(S): Forty-eight women were treated with electrosurgery (historical control) and 53 women were treated with excision. MAIN OUTCOME MEASURE(S): The PRs of the two groups of women were evaluated using life-table calculations and the Mantel-Cox test. RESULT(S): Of the total 24 pregnancies (PR: 57.1%) in the electrosurgery group, there were 3 spontaneous abortions (12.5%) and 1 ectopic pregnancy (4.2%). The total PR in the excision group was 53.5%, the abortion rate was 17.4% (4 of 23), and the ectopic PR was 8.7% (2 of 23). The median interval between surgery and conception was 10.7 months in the electrosurgery group and 13.3 months in the excision group. There was no statistically significant difference in the probability of conception between the two groups of women (Mantel-Cox test: z = 0.24). Using the Cox proportional-hazards model, the effects of age and duration of infertility were evaluated and were found not to be associated with a decreased PR. CONCLUSION(S): There is no difference in the PRs of infertile women with mild endometriosis treated laparoscopically by surgical excision and by electrocoagulation. The difference between these two modalities in women with endometriosis-related pelvic pain remains to be determined.

Adult↗

PubMed2002

Safety and outcome of endoscopic snare excision of the major duodenal papilla.

BACKGROUND: The optimal management of adenoma of the major duodenal papilla is not established. Options include surgical excision, endoscopic ablative techniques, snare excision, and observation with periodic biopsies. The aims of this retrospective study were to determine the safety and outcome of snare excision of the papilla. METHODS: Twenty-eight snare excisions of the papilla were performed in 26 patients. Sixteen had familial adenomatous polyposis. In 22 procedures, a minisnare was used, and in 6 cases a prototype snare was designed for excision of the papilla. Pancreatic stents were placed as a prophylactic measure at the discretion of the endoscopist (n = 10). RESULTS: Histopathologically, resected tissue included 25 adenomas, 1 inflammatory polyp, 1 invasive malignancy, and 1 normal papilla. Immediate complications were minor bleeding (n = 2), mild pancreatitis (n = 4) and a duodenal perforation (n = 1). The presence (n = 10) or absence (n = 18) of a pancreatic stent did not correlate with subsequent pancreatitis (2 in each group, p = NS). Follow-up was available for 21 patients (median, 9 months; range, 2-32 months). Pancreatic duct stenosis at the papillectomy site resulted in pancreatitis in 2 patients (17%) at, respectively, 4 months and 24 months. Follow-up endoscopy revealed recurrent/residual adenomatous tissue in 2 (10%). CONCLUSIONS: Snare excision of the major duodenal papilla was well tolerated. Most complications were mild except for a small duodenal perforation. Stenosis of the pancreatic duct orifice with pancreatitis may be a late complication.

Adenomatous Polyposis Coli↗

PubMed1988

An approach to excision of congenital giant pigmented nevi in infancy and early childhood.

Complete prophylactic excision of "large" and "giant" congenital nevocellular nevi (CNCN) often involves multiple surgical procedures begun in early infancy and not completed until late adolescence. Timely use of combined modalities of excision and reconstruction, beginning in infancy, and recognizing the benefits and limitations of each technique in each body region may allow completion of the excision of even the most extensive lesions in early childhood. In addition to minimizing the risk of malignant transformation, early complete excision may minimize the late psychologic stress caused by the appearance of the lesion and the late decision to attempt total excision. Tissue expansion and extensive excision and grafting in infancy and early childhood may significantly improve the final cosmetic result following treatment of these extensive lesions.

Child↗

PubMed1997

Early and late results of excision of choledochal cysts.

BACKGROUND/PURPOSE: Reports on the late results of choledochal cyst excision with hepaticojejunostomy in children are relatively few. METHODS: Of the 84 patients who had choledochal cyst who came under our care, 79 have had definitive surgery, three are awaiting surgery, one is being observed with Caroli's disease, and the parents of one child have refused surgery. Thirty-eight patients treated decades ago had internal drainage procedures. Since 1972, 41 patients have had cyst excision with hepaticojejunostomy using a 40-cm Roux loop without an antireflux procedure. Early complications in those who underwent cyst excision with hepaticojejunostomy included anastomotic leak in three patients who required reoperation, cholangitis in two, and fluid collection in the gall-bladder bed that required no intervention in one. RESULTS: During a follow-up period ranging from 4 months to 17 years (mean, 8.5 years), anastomotic stricture, cholangitis, and intrahepatic stone formation developed in two children after being well for 8 years and over 11 years. These children required additional surgical procedures to overcome their problems. Asymptomatic intrahepatic stones 2 years after cyst excision with hepaticojejunostomy developed in a third child. There was no mortality in the entire group that underwent cyst excision and they are all enjoying a good quality of life. CONCLUSIONS: Careful, long-term follow-up is important in children who have choledochal cyst excision with hepaticojejunostomy.

Adolescent↗

PubMed1998

Transvaginal repair of vesicovaginal fistulas after hysterectomy by vaginal cuff excision.

PURPOSE: When repairing vesicovaginal fistulas after hysterectomy there is often reluctance to excise totally the fistula tract for fear of enlarging the tissue defect. It has been suggested that consequent tension on suture lines may cause recurrence of an even larger fistula. On the other hand, a basic surgical principle is that scar tissue margins will not heal as quickly or at all compared to fresh viable margins. We reviewed whether our technique of total excision of the fistula tract and vaginal cuff scar provides an efficient cure rate. MATERIALS AND METHODS: We retrospectively analyzed the outcomes of 20 women who underwent vaginal cuff excision repairs of a vesicovaginal fistula after total hysterectomy. Women who had complex fistulas and/or prior radiation therapy were excluded from study. RESULTS: Of the 20 patients 3 (15%) sustained a bladder lesion that was repaired intraoperatively and 7 (35%) underwent 1 or more attempts at secondary repair. All fistulas were at the vaginal cuff. Mean fistula size was 0.7 cm. (11 women). All repairs were performed as soon as possible after presentation except 2 (10%) that were delayed because of the fistula appearance. The fistula tract was excised totally in all patients. All patients were cured. There were no postoperative complications and no significant or symptomatic vaginal shortening. CONCLUSIONS: Transvaginal vaginal cuff excision repair is an effective first attempt cure of vesicovaginal fistulas after hysterectomy. Excision of the fistula tract and vaginal cuff scar enables the surgeon to suture viable tissues in every layer, thereby providing conditions optimal for wound healing. This procedure obviates the need to wait for tissue readiness and to interpose a flap in the majority of patients.

Adult↗

PubMed1993

Influence of wide excision of the neurovascular bundle(s) on prognosis in men with clinically localized prostate cancer with established capsular penetration.

We analyzed 107 men with clinically localized prostate cancer who had pathologically established capsular penetration in the region of the neurovascular bundles to determine the effect of wide excision of the neurovascular bundle(s) on disease-free survival. In 38 patients established capsular penetration was not suspected clinically and the neurovascular bundle(s) were preserved. In 69 patients established capsular penetration was suspected, and 1 or both neurovascular bundles were excised widely with the prostate. Disease-free survival was defined by an undetectable serum prostate specific antigen (PSA) level postoperatively. Wide excision of the neurovascular bundle(s) resulted in negative surgical margins in 40 of 69 patients (58%) compared to only 17 of 38 (45%) in whom the neurovascular bundle(s) was left intact (p = 0.03). Median interval to disease recurrence, as defined by a measurable serum PSA level, was 22 months in the group in whom the neurovascular bundles were preserved versus 33 months in the group undergoing wide excision (p = 0.03). At 39 months, however, 70% of the patients in both groups had detectable PSA levels. Similarly, patients with positive surgical margins had a mean interval to recurrence of 17 months compared to 38 months for the group with negative surgical margins (p = 0.0004). By 43 months, however, 75% of the patients in both groups had a detectable PSA level and the Kaplan-Meier curves had converged. Although wide excision of the neurovascular bundle(s) resulted in negative surgical margins more often with resultant delayed disease progression, most patients with established capsular penetration ultimately failed radical prostatectomy despite wide excision of periprostatic soft tissue. It seems likely, therefore, that many of these patients have occult metastatic disease at operation. Thus, recent enthusiasm for radical prostatectomy in men with locally advanced prostate cancer may not be justified.

Adenocarcinoma↗

PubMed2006

Purification and characterization of Escherichia coli and human nucleotide excision repair enzyme systems.

Nucleotide excision repair is a multicomponent, multistep enzymatic system that removes a wide spectrum of DNA damage by dual incisions in the damaged strand on both sides of the lesion. The basic steps are damage recognition, dual incisions, resynthesis to replace the excised DNA, and ligation. Each step has been studied in vitro using cell extracts or highly purified repair factors and radiolabeled DNA of known sequence with DNA damage at a defined site. This chapter describes procedures for preparation of DNA substrates designed for analysis of damage recognition, either the 5' or the 3' incision event, excision (resulting from concerted dual incisions), and repair synthesis. Excision in Escherichia coli is accomplished by the three-subunit Uvr(A)BC excision nuclease and in humans by six repair factors: XPA, RPA, XPChR23B, TFIIH, XPFERCC1, and XPG. This chapter outlines methods for expression and purification of these essential repair factors and provides protocols for performing each of the in vitro repair assays with either the E. coli or the human excision nuclease.

Animals↗

PubMed1982

The double scalpel and double punch excision of skin tumors.

A new technic is described for more accurately checking the surgical margins of skin tumors removed by standard surgical excision. Vertical sections of surgical specimens represent check points of the margin only 7 microns thick. This means most of the surgical margin is not checked microscopically, allowing small tumor islands at the margin to remain undetected. The technic is applicable wherever surgical excision is used to excise skin tumors. It is especially suitable for basal cell carcinoma. A variable-width knife holding two scalpel blades parallel to each other is set at 2 to 3 mm separation. When the excision is done as usual, the blades will cut a 2- to 3-mm strip of tissue representing the entire lateral borders of the excision. This specimen is easily mounted as a flat section for frozen or paraffin processing. These sections will be cut to show the entire lateral excision margin to be checked for tumor. A new punch with concentric cutting edges separated by 2 mm has been made to obtain a similar flat section. The circular defect is converted to a standard ellipse and closed primarily. This technic has the advantage of using primary closure for excellent cosmetic results. It requires little additional skill on the part of the surgeon and is easily handled by the pathology laboratory. It has been used in thirteen cases with no recurrence of tumors to date.

Basal Cell Carcinoma↗

PubMed1997

Surgical margins for excision of primary cutaneous melanoma.

BACKGROUND: A major controversy in the treatment of melanoma is the width of the surgical margin necessary for complete excision. Although surgical margins have decreased in recent years, the current recommendations are mainly based on arbitrary choices, only two of which have been tested in clinical trials. OBJECTIVE: Our purpose was to use prospective data, measuring the extent of subclinical melanoma extensions, to develop guidelines for predetermined surgical margins for the excision of cutaneous melanoma. METHODS: A prospectively collected series of 535 patients with 553 primary cutaneous melanomas was studied. All melanomas were excised by means of the fresh tissue technique of Mohs micrographic surgery with frozen section examination of the margin. The surgical margin needed for excision of melanoma was determined by measuring the invisible extensions of tumor around the melanoma. The minimum surgical margin was 6 mm and the total margin was calculated by adding an additional 3 mm for any melanoma requiring a subsequent stage to remove the tumor completely. RESULTS: Eighty-three percent of melanomas were successfully excised with a 6 mm margin; 9 mm removed 95% of the melanomas; and a 1.2 cm margin was necessary to remove 97% of all melanomas. Margins to remove melanomas on the head, neck, hands, and feet were wider than those on the trunk and extremities. Margins to remove melanomas that were more than 2 to 3 cm in diameter were wider than for smaller melanomas. CONCLUSION: Predetermined surgical margins for excision of melanoma or melanoma in situ by standard surgical techniques should include 1 cm of normal-appearing skin for melanomas on the trunk and proximal extremities that are smaller than 2 cm in diameter, or a 1.5 cm margin for tumors larger than 2 cm in diameter. For melanomas on the head, neck, hands, and feet, a minimum surgical margin of 1.5 cm is recommended or a margin of 2.5 cm for melanomas larger than 3 cm in diameter. Mohs micrographic surgery is a useful alternative to standard surgery when more narrow margins are desired, particularly for melanomas on the head, neck, hands, and feet, or melanomas larger than 2.5 cm in diameter, or for melanomas without distinct clinical margins.

Humans↗