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Biomedical subjects

T G Wilson

Publications and source records attributed to T G Wilson.

At least 55 records · Page 3Linked to original sources
PubMed1996

Coordination of biliary and upper gastrointestinal motility in the fasted conscious pig.

A chronic pig model was developed which permits the simultaneous measurement of integrated biliary motility as resistance to flow (CBD inflow), gallbladder, duodenal and gastric motility in addition to collection of venous blood samples for gut hormones estimations. Animals displayed a duodenal interdigestive cycle of 55.4 +/- 3.4 min (mean +/- SEM, n = 6), consisting of phase I, II and III (21.2 +/- 2.1, 70.5 +/- 2.0, 8.7 +/- 0.5% of the cycle, respectively). A gastric interdigestive cycle of 60.2 +/- 6.5 min (n = 4) was similarly demonstrated consisting of three phases which corresponded to the three duodenal phases. The gastric phases I, II and III comprised 26.3 +/- 3.0, 71.2 +/- 2.7 and 2.5 +/- 0.8% of the cycle, respectively. The gastric phase III immediately preceded the onset of the duodenal phase III. The gallbladder likewise displayed an interdigestive cycle of 54.5 +/- 7.2 min (n = 6) consisting of a quiescent period (37.2 +/- 3.7% of the cycle) corresponding temporally to duodenal phase III and phase I. This quiescent phase was followed by a period of rhythmic contractions (64.5 +/- 4.1% of the cycle) which corresponded temporally to duodenal phase II. The onset of the gallbladder quiescent period coincided with the onset of duodenal phase III. The CBD inflow similarly demonstrated an interdigestive cycle of 53.4 +/- 9.6 min (n = 4) duration, consisting of three phases. The initial phase was evident as a period of rapid inflow, the onset of which coincided with the onset of duodenal phase III and the gallbladder quiescent period, and occupied 12.0 +/- 0.8% of the cycle. The second phase which occupied 18.0 +/- 7.4% of the cycle, was typified as a period of declining inflow which reached a relatively stable level at a time corresponding to the end of duodenal phase I. The third phase consisted of the maintenance of the inflow rate achieved at the end of the previous phase (60% of maximum inflow), corresponding in onset and duration with duodenal phase II and occupied 70.0 +/- 8.6% of the cycle. Plasma motilin levels fluctuated in relation to the duodenal interdigestive cycle, peaking during phase III relative to phase I (36.9 +/- 8.5 vs 25.4 +/- 7.7 pg mL-1, respectively, n = 5, P < 0.05). Cholecystokinin levels did not fluctuate, remaining low (2.3 +/- 2.1 pM cholecystokinin octapeptide equivalents, n = 5) throughout the duodenal interdigestive cycle, but increased about two fold after ingestion of solid food. Feeding disrupted the gastric, duodenal, gallbladder and CBD inflow cycles.

Animals↗
PubMed1996

The social costs of inadequate contraception.

This study examines, on a per-case basis, the social costs associated with contraceptive failures and resulting term pregnancies. To combat unintended pregnancy and escalating health care costs, the public sector needs to provide greater access to highly effective methods of contraception.

Contraception↗
PubMed1995

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↗
PubMed1995

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↗
PubMed1995

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↗
PubMed1995

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↗
PubMed1995

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↗
PubMed1995

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↗
PubMed1995

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↗
PubMed1994

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↗
PubMed1994

Late complications of the modified Indiana pouch.

The modified Indiana pouch is currently an accepted and widely used form of continent cutaneous urinary diversion. However, results of long-term followup and potential late complications are still being established. We report our experience with 130 modified Indiana pouches performed between September 1987 and September 30, 1991. In 16 patients (12%) late complications developed between 1 and 16 months after the pouch procedure. Ureteral obstruction developed in 9 of these patients (7%), including bilateral obstruction in 4. Balloon dilation with or without incision of ureteral strictures in 6 patients resulted in an 83% failure rate, while ureteral reimplantation was successful in 91% (10 of 11 cases). Reservoir dysfunction was the late complication in the remaining 7 patients. Urodynamic evaluation was essential in determining appropriate treatment for incontinence with either replication of the ileal segment or pouch augmentation with an ileal patch. Of the 16 late complications 56% occurred in patients who received between 3,000 and 6,500 rad of pelvic radiation before the urinary diversion. We conclude that the modified Indiana pouch is a successful form of urinary diversion with an acceptable complication rate. Ureteral balloon dilation with or without endoscopic incision of ureteral strictures has not been successful. However, patients can usually undergo successful ureteral reimplantation via an extraperitoneal approach with minimal morbidity. Previously radiated patients are at higher risk for complications and require shorter ureteral tunnels to avoid stricture, in addition to an ileal patch at initial construction.

Adult↗
PubMed1994

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↗
PubMed1994

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↗