PubMed HealthSearch

Biomedical subjects

T G Wilson

Publications and source records attributed to T G Wilson.

At least 19 recordsLinked to original sources

Laparoscopic surgery in women with a clinical diagnosis of acute appendicitis.

OBJECTIVES: To assess the routine use of diagnostic laparoscopy and laparoscopic appendicectomy in women with a clinical diagnosis of acute appendicitis. METHODS: Women who presented with a clinical diagnosis of acute appendicitis between 1 January 1992 and 31 August 1993 were prospectively assessed and 107 underwent diagnostic laparoscopy. RESULTS: Appendicitis was confirmed in 63 women (59%) and no diagnosis could be made in seven (6%). An alternative diagnosis, most commonly a gynaecological disorder, was made in 37 women (35%). Twenty-eight women with an alternative diagnosis (76%) did not require a laparotomy. Seventy-three patients had a laparoscopic appendicectomy, with an 8% conversion rate to an open operation. The morbidity rate for laparoscopic procedures was 3%, the median inpatient stay was two days and the median time to return to normal activities was eight days. CONCLUSIONS: Diagnostic laparoscopy should be performed in women who present with a clinical diagnosis of acute appendicitis to confirm the diagnosis, reduce the rate of unnecessary appendicectomy and avoid an unnecessary laparotomy. When acute appendicitis is confirmed, appendicectomy may be performed laparoscopically.

Activities of Daily Living

Molecular analysis of the Methoprene-tolerant gene region of Drosophila melanogaster.

Adult functions of juvenile hormone (JH) have been described for Drosophila melanogaster and other dipteran insects, but preadult function for this hormone remains largely unknown in this order of insects. We have identified a mutation of Drosophila, Methoprene-tolerant (Met), which appears to alter JH reception during late larval development. The molecular cloning of Met will be a step toward understanding this gene and possibly identifying a preadult role(s) for JH. Molecular cloning was initiated using the technique of transposon-tagging with a transposable P element. P-element insertional alleles of Met were generated, and genomic libraries were constructed from two of these alleles. From these libraries P-element-bearing clones were isolated that in situ hybridized to the cytogenetic region where Met had been previously localized by genetic methods. Two of the alleles were shown to have complete P-elements inserted in similar, but not identical, locations in the predicted cytogenetic region where Met is located. A late-larval cDNA library was screened to identify transcriptional units in this region, and clones were recovered with homology to a DNA fragment abutting the P-element insertion site. These clones may represent Met cDNA molecules.

Alleles

Peroperative endoscopic sphincterotomy during laparoscopic cholecystectomy for choledocholithiasis.

The development of laparoscopic cholecystectomy has created a dilemma in the management of choledocholithiasis. A number of options exist, including endoscopic sphincterotomy (ES) before laparoscopic cholecystectomy in patients with suspected common bile duct (CBD) calculi, laparoscopic bile duct exploration, open CBD exploration and postoperative ES. None of these options has emerged as ideal or universally acceptable. An alternative technique, peroperative ES, has been developed. A prospective assessment of the use of peroperative ES in 13 patients in whom choledocholithiasis was demonstrated with operative cholangiography is presented. Eleven patients had successful ES and clearance of stones. The CBD could not be cannulated in one patient, and an adequate ES for stone extraction could not be performed in the remaining patient. Both procedures were converted to open CBD exploration. Complications were mild postoperative pancreatitis (two patients) and pulmonary atelectasis (one). The median total operating time was 165 min and the median postoperative hospital stay was 3 days. Peroperative ES at the time of laparoscopic cholecystectomy provides a safe technique for clearance of the CBD.

Adult

Clinical effectiveness of fluoride-releasing elastomers. II. Enamel microhardness levels.

The purpose of this study was to examine the effect of fluoride-releasing elastomers on enamel microhardness levels. Sixteen teeth from four patients scheduled to have premolars extracted as part of their orthodontic treatment were examined in this study. Orthodontic brackets were bonded to the buccal surface of the test teeth with a nonfluoridated adhesive. Two of the patients had fluoride-releasing elastomers placed on the right upper and lower brackets and conventional elastomers placed on the left side. This sequence was reversed for the remaining two patients. After 1 calendar month, the experimental teeth were extracted, sectioned, and embedded in acrylic. Microhardness tests were performed 50 to 75 microns cervical to the bracket. Indentations were taken at the surface and continued in 20 microns increments to a depth of 200 microns. Results showed the enamel was significantly harder (p < 0.05) in the fluoride group at the 20 microns depth compared with the control group. No other microhardness readings showed a statistically significant difference.

Delayed-Action Preparations

The economic value of contraception: a comparison of 15 methods.

OBJECTIVES: The purpose of the study was to determine the clinical and economic impact of alternative contraceptive methods. METHODS: Direct medical costs (method use, side effects, and unintended pregnancies) associated with 15 contraceptive methods were modeled from the perspectives of a private payer and a publicly funded program. Cost data were drawn from a national claims database and MediCal. The main outcome measures included 1-year and 5-year costs and number of pregnancies avoided compared with use of no contraceptive method. RESULTS: All 15 contraceptives were more effective and less costly than no method. Over 5 years, the copper-T IUD, vasectomy, the contraceptive implant, and the injectable contraceptive were the most cost-effective, saving $14,122, $13,899, $13,813, and $13,373, respectively, and preventing approximately the same number of pregnancies (4.2) per person. Because of their high failure rates, barrier methods, spermicides, withdrawal, and periodic abstinence were costly but still saved from $8933 to $12,239 over 5 years. Oral contraceptives fell between these groups, costing $1784 over 5 years, saving $12,879, and preventing 4.1 pregnancies. CONCLUSIONS: Contraceptives save health care resources by preventing unintended pregnancies. Up-front acquisition costs are inaccurate predictors of the total economic costs of competing contraceptive methods.

Contraception

Entero-pouch fistula: a rare complication of right colon continent urinary diversion.

PURPOSE: Entero-conduit fistulas have been reported in patients with ileal and jejunal conduit urinary diversions, and entero-pouch fistulas have been reported in those with Kock pouch and other ileal neobladders. We now report that entero-pouch fistula is a rare complication of continent urinary diversion using the right colon. MATERIALS AND METHODS: A review of the charts of 146 patients who had undergone right colon urinary diversion during the last 6 years revealed that entero-pouch fistula developed in 3. A total of 36 patients had had previous pelvic radiation, including the 3 with entero-pouch fistulas. Two patients presented with nausea, vomiting and abdominal pain, and 1 presented with diarrhea and food particles in the urine. Hyperchloremic metabolic acidosis was present in 2 of the patients and radiography of the pouch confirmed the diagnosis in all 3. RESULTS: Conservative therapy, which included a low residue diet and continuous drainage of the pouch, was successful in 2 of the 3 patients and surgical excision of the entero-pouch fistula was required in 1 since the fistula did not close after 12 weeks. CONCLUSIONS: Although rare, an entero-pouch fistula should be suspected in patients who present with gastrointestinal symptoms and hyperchloremic metabolic acidosis after right colon reservoir urinary diversion. Conservative therapy is recommended initially.

Aged

Clinical effectiveness of fluoride-releasing elastomers. I: Salivary Streptococcus mutans numbers.

The purpose of this study was to examine the effect of fluoride-releasing elastomers on salivary Streptococcus mutans numbers. Twenty-four patients with fixed orthodontic appliances were randomly divided into experimental and control groups consisting of 12 patients each. Conventional elastomers were in place while two baseline whole saliva samples were collected from each subject in both groups at their regular appointments. After the second baseline sample was taken, conventional elastomers were replaced with fluoride-releasing elastomers in the experimental group, whereas conventional elastomers were continued in the control group. Three saliva samples were then collected from all subjects at 1-week intervals. Conventional elastomers were placed in all subjects while two postexperimental saliva samples were collected at regular appointments. Results showed that the control group demonstrated no significant changes (p > 0.05) in the percentage of S. mutans over the 13-week study period. However, after the fluoride-releasing elastomers were placed, the percent of salivary S. mutans decreased significantly (p < 0.01) in the experimental group. There was no significant effect after the fluoride-releasing elastomers were in place for 2 or more weeks.

Adolescent

The ITI Dental Implant System.

The ITI Dental Implant System is a unique, single-stage implant with research of 20-years duration. The technique, developed by Schroeder and coworkers, was designed to simplify the surgical and restorative aspects of implant therapy for both the patient and the clinician. This article describes the system, its advantages over two-stage systems, and indications for its use.

Dental Implantation, Endosseous

Surgical resection in patients with nonseminomatous germ cell tumor who fail to normalize serum tumor markers after chemotherapy.

OBJECTIVE: Patients with high-stage nonseminomatous germ cell tumors treated with platinum-based chemotherapy who have residual radiographic evidence of disease and fail to normalize tumor markers present a difficult clinical dilemma. Some authors feel that these patients are not appropriate surgical candidates. Our practice has been to offer certain patients salvage surgery in an attempt for cure. This report is designed to review that experience and critically analyze the results. METHOD: We report a series of 16 such patients with advanced-stage nonseminomatous germ cell tumors who had persistently elevated alpha fetoprotein and/or human chorionic gonadotropin. All underwent resection of all radiographically evident sites of residual disease following induction or salvage chemotherapy. RESULTS: Ten patients had only retroperitoneal (RP) metastasis. Six patients had more than one site of residual disease--4 RP and lung, 2 RP and liver. There were no postoperative deaths. The mean postoperative stay was eleven days (range 7 to 36 days). Six patients (37%) are alive and free of disease at a mean of seventy-four months following surgery (range 20 to 145 months). Five had RP disease only. Ten patients died of disease at a mean of eight months postoperatively (range 5 to 21 months). CONCLUSIONS: Patients with advanced nonseminomatous germ cell tumor who fail to normalize their serum tumor markers after adequate platinum-based chemotherapy should be considered for surgical resection of all radiographically evident residual disease. In select cases this practice offers the only viable chance for cure.

Biomarkers, Tumor

Endoscopic retrograde cholangiopancreatography following laparoscopic cholecystectomy.

Laparoscopic cholecystectomy is the preferred method of treatment for symptomatic choledocholithiasis. Since its introduction there has been an increase in postoperative diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP). The aim of this study was to assess the indications and results of ERCP following laparoscopic cholecystectomy. Sixty-one patients had an ERCP following laparoscopic cholecystectomy. Two broad groups were identified: Group 1 (35 patients) had filling defects (consistent with stones) noted on operative cholangiography, which were not successfully flushed or extracted at the time of laparoscopic cholecystectomy; Group 2 consisted of patients who developed problems following laparoscopic cholecystectomy. Nine patients had post-laparoscopic cholecystectomy pain with abnormal liver function tests (LFT), four of whom had common bile duct (CBD) injuries and three had CBD stones. Eleven patients had post-laparoscopic cholecystectomy pain with a normal diameter common bile duct on ultrasound and normal LFT; only one had a CBD stone. Five patients with a persisting bile leak following laparoscopic cholecystectomy had an ERCP and endoscopic sphincterotomy. In three the leak ceased, while two required subsequent open surgery to drain bile collections and ligate the cystic duct. One patient presented with an episode of transient jaundice but had a normal ERCP. There were six post-ERCP complications; three patients had mild pancreatitis, two had a minor haemorrhage and one an asymptomatic duodenal perforation. Endoscopic retrograde cholangiopancreatography post-laparoscopic cholecystectomy was most valuable for the management of retained stones and the diagnosis and management of post-laparoscopic cholecystectomy pain in association with abnormal LFT. The diagnostic yield was low (9%) when the LFT were normal.

Adolescent

Urological evaluation and management of renal-proximity stab wounds.

The urological evaluation and management of renal-proximity stab wounds remain controversial. Questions regarding the "best" first radiographic study and the indications for nonoperative management are still unanswered. At the Los Angeles County-University of Southern California Medical Center we retrospectively reviewed the charts of 244 patients evaluated between January 1985 and December 1990 for renal-proximity stab wounds. There were 184 patients who presented without hematuria, 46 who presented with microscopic hematuria and 14 who presented with gross hematuria. When used as the first diagnostic study, an excretory urogram was 96% accurate in establishing the presence or absence of injury. In 34 patients additional evaluation was done with computerized tomography and/or angiography. A total of 43 injuries (17.6%) was found, of which 27 were successfully managed nonoperatively and 16 were managed surgically (1 nephrectomy). One patient had significant postoperative hemorrhage after partial nephrectomy, which was successfully managed with angiographic embolization. We conclude that although the degree of hematuria was a good indication of renal injury, the absence of hematuria did not preclude injury. In addition, excretory urography appears to be an acceptably reliable first study at our institution. We advocate a renal angiogram as the second radiographic study of choice because it reliably stages significant injuries and offers the possibility of therapeutic transcatheter embolization. Most renal injuries, when accurately staged, can safely be managed nonoperatively.

Adolescent

Laparoscopic cholecystectomy for acute inflammation of the gallbladder.

OBJECTIVE: The aim of this study was to prospectively assess the results of laparoscopic cholecystectomy in patients with acute inflammation of the gallbladder. SUMMARY BACKGROUND DATA: Laparoscopic cholecystectomy has become the standard treatment for symptomatic gallbladder disease. Its role in the surgical treatment of acute cholecystitis has not been defined, although a number of recent reports suggest that there should be few contraindications to an initial laparoscopic approach. METHODS: All patients presenting with symptomatic cholelithiasis from October 1990 until June 1992 were evaluated at laparoscopy with intention of proceeding to a laparoscopic cholecystectomy. The gross appearance of the gallbladder was categorized as acute inflammation, chronic inflammation, or no inflammation. Ninety-eight (23.4%) of 418 patients had acute inflammation of the gallbladder: 55 were edematous, 10 were gangrenous, 15 had a mucocele, and 18 had an empyema. RESULTS: The authors assessed outcome in these patients. The frequency of conversion to an open operation was 33.7% for acute inflammation, 21.7% for chronic inflammation (p < 0.05), and 4% for no inflammation (p < 0.001). The conversion rate was highest for empyema (83.3%) and gangrenous cholecystitis (50%), while the conversion rate for edematous cholecystitis was 21.8% and for acute inflammation with a mucocele it was 7%. The median operation time for successful laparoscopic cholecystectomy for acute inflammation was 105 minutes, which was longer than that with no inflammation (90 minutes). However, the incidence of complications was not different from that for chronic or no inflammation. The median postoperative stay for patients with acute gallbladder inflammation was 2 days for successful laparoscopic cholecystectomy and 7 days for patients converted to an open operation. CONCLUSIONS: Laparoscopic cholecystectomy for acute inflammation of the gallbladder is safe and is associated with a significantly shorter postoperative stay compared to open surgery. A greater number of patients required conversion to open operation compared to those with no obvious inflammation. Conversion to open operation was most frequent for empyema and gangrenous cholecystitis, suggesting that once this diagnosis is made, excessive time should not be spent in laparoscopic trial dissection before converting to an open operation.

Acute Disease

Laparoscopic appendicectomy: a prospective analysis.

The potential advantages of laparoscopic surgery for a number of abdominal operations including appendicectomy have been heralded. In this study the aims were to assess prospectively the role of routine diagnostic laparoscopy in the diagnosis of acute appendicitis and determine the efficacy of laparoscopic appendicectomy. Patients with suspected acute appendicitis had diagnostic laparoscopy. When the diagnosis was confirmed laparoscopic appendicectomy was performed. Where an alternative diagnosis was made the appropriate treatment was instituted. If no diagnosis could be made the macroscopically normal appendix was removed by laparoscopic appendicectomy. Eighty-one patients (50 female, 31 male) had an initial diagnostic laparoscopy; 53 had appendicitis and proceeded to laparoscopic appendicectomy. A diagnosis could not be established at diagnostic laparoscopy in six patients and they also proceeded to laparoscopic appendicectomy. An alternative diagnosis was made in the remaining 22 patients (19 female and 3 male), with five proceeding to laparotomy and one patient with mesenteric adenitis having laparoscopic appendicectomy. Seven patients having laparoscopic appendicectomy required conversion to an open operation due to a retrocaecal or perforated appendix. The median operating time for successful laparoscopic appendicectomy was 55 min (range 30-95). Morbidity occurred in five of 53 patients having a successful laparoscopic appendicectomy. The median postoperative hospital stay was 2 days. The median time before return to normal activities was 8 days. Diagnostic laparoscopy is a useful diagnostic technique in women with suspected acute appendicitis, as it improves diagnostic accuracy, reduces the negative appendicectomy rate and avoids unnecessary laparotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease

Radiographic evaluation of adult patients with blunt renal trauma.

Recent reports in the literature suggest that radiographic evaluation of the normotensive blunt trauma patient with microscopic hematuria is no longer necessary. Several facilities, however, including ours, continue to perform excretory urography (IVP) routinely in this setting. To evaluate further whether this practice is indicated, we retrospectively reviewed the records of 317 adults who presented to our facility between May 1986 and December 1989 after blunt trauma with resultant microscopic hematuria but no shock. All patients were radiographically assessed with an IVP. Of the 317 studies 29 (9%) had an abnormal result, including 28 with renal contusion and 1 with a nonfunctioning kidney (in which case further evaluation revealed a congenitally absent kidney). No significant urological injury was identified. Thus, no injury would have been missed if a policy of observation had been followed in these patients. Our data support other reports in the literature that radiographic staging is not necessary in the adult blunt trauma patient with microscopic hematuria but no shock.

Adult

Angiographic embolization of renal stab wounds.

Nonoperative management of renal stab wounds following complete radiographic assessment has become an accepted if not preferred therapeutic option. Selected injuries, however, including renal artery branch injuries, often require surgical intervention and result in partial or total nephrectomy. We report our experience with 16 renal branch arterial injuries secondary to street stabbing during the last 10 years that were managed with angiography and embolization techniques. Angiography with embolization was the initial treatment in 11 patients, while 5 had undergone emergency surgical intervention initially because of hemodynamic instability. Subsequently, gross hematuria recurred in the latter 5 patients and they were managed angiographically. Overall, 14 of 16 patients had prompt hemostasis documented either on the post-embolization angiogram or by clinical assessment. In 2 patients bleeding was increased but partial nephrectomy ultimately was required. Complications included nontarget embolization in 2 patients: 1 subsequently had hypertension and 1 had no untoward effect as a result of this complication. We conclude that angiography with transcatheter embolization techniques provides a safe and effective means of managing renal artery branch injuries secondary to stab wounds.

Adolescent

The competitive ability and fitness components of the Methoprene-tolerant (Met) Drosophila mutant resistant to juvenile hormone analog insecticides.

The Methoprene-tolerant (Met) mutation of Drosophila melanogaster results in a high (100-fold) level of resistance to the insecticide methoprene, a chemical analog of juvenile hormone. Pest species that are under control with methoprene may therefore have the potential to evolve resistance via a mutation homologous to Met. To evaluate the potential of such mutants to persist in wild populations, we must understand the fitness of flies carrying Met. In the absence of methoprene, Met flies were outcompeted by a wild-type strain both in a multigeneration population cage and in single-generation competition experiments. To determine which fitness component(s) is responsible for the competitive disadvantage, the survival, time of development, and fecundity of flies homozygous for each of five Met alleles were compared with wild type. Small but significant differences were found between the pooled Met alleles and wild type for pupal development time, pupal mortality, and early adult fecundity. These differences result in a large competitive disadvantage. Although Met flies were found to have reduced fitness by these measures, the phenotype is not as severe as might be expected from a knowledge of the disruption of juvenile hormone regulation seen in Met flies. It is concluded that (1) although Met flies have a large advantage under methoprene selection, they will quickly become outcompeted upon relaxation of methoprene usage, (2) even a seemingly severe disruption of juvenile hormone regulation has no drastic effect on the vital functions of the insect and (3) small differences in fitness components can translate into a large competitive disadvantage.

Alleles

Pancreaticojejunostomy for chronic pancreatitis.

The treatment of chronic pancreatitis commonly yields disappointing results. Patients with chronic pancreatitis and a dilated pancreatic duct can be treated by longitudinal pancreaticojejunostomy. In order to evaluate the procedure, 20 patients undergoing pancreaticojejunostomy were followed for a median time of more than 5 years. Their clinical characteristics and outcomes have been compared with a group of 43 patients with chronic pancreatitis and small pancreatic ducts. There were no differences between the two groups in the major epidemiological parameters, except that calcification in the gland was more frequently noted in those with large ducts. The operation of longitudinal pancreaticojejunostomy could be accomplished with an acceptable morbidity. There was one death in the postoperative period. Seventy-six per cent of patients were found to have benefited clinically at five years, compared with 48% of those with small duct disease. This difference was statistically significant. Patients who benefited were defined by four factors; they were carrying out their usual occupation at the time of surgery, they were not narcotic dependent at the time of surgery, they had a pancreatic duct width greater than 7 mm and, they had totally abstained from alcohol from before the operation to the time of follow-up. Longitudinal pancreaticojejunostomy probably remains the best surgical treatment for suitable patients with chronic pancreatitis. The operation should only be performed when the pancreatic duct is greater than 7 mm in width. In such patients the operation produces considerable improvement of pain with minimal metabolic disturbance.

Adolescent