Symptomatic double-channel pylorus. Successful treatment with a biliary sphincterotome

A patient with a previous vagotomy and pyloroplasty was evaluated for symptoms of gastric outlet obstruction. Endoscopy revealed a thick, fibrous bridge that created a dual-channel pylorus. Symptomatic improvement was not achieved with balloon dilatation. Surgery was avoided by dividing the tissue bridge endoscopically with a sphincterotome. Since reestablishing a normal pyloric aperture, the patient's symptoms have been alleviated. This is the first description of this minimally invasive technique in the management of a symptomatic double-channel pylorus.

Aberrant function of the Ras-related protein TC21/R-Ras2 triggers malignant transformation

Although the human Ras proteins are members of a large superfamily of Ras-related proteins, to date, only the proteins encoded by the three mammalian ras genes have been found to possess oncogenic potential. Among the known Ras-related proteins, TC21/R-Ras2 exhibits the most significant amino acid identity (55%) to Ras proteins. We have generated mutant forms of TC21 that possess amino acid substitutions analogous to those that activate Ras oncogenic potential [designated TC21(22V) and TC21(71L)] and compared the biological properties of TC21 with those of Ras proteins in NIH 3T3 and Rat-1 transformation assays. Whereas wild-type TC21 did not show any transforming potential in vitro, both TC21(22V) and TC21(71L) displayed surprisingly potent transforming activities that were comparable to the strong transforming activity of oncogenic Ras proteins. Like Ras-transformed cells, NIH 3T3 cells expressing mutant TC21 proteins formed foci of morphologically transformed cells in monolayer cultures, proliferated in low serum, formed colonies in soft agar, and developed progressive tumors in nude mice. Thus, TC21 is the first Ras-related protein to exhibit potent transforming activity equivalent to that of Ras. Furthermore, mutant TC21 proteins also stimulated constitutive activation of mitogen-activated protein kinases as well as transcriptional activation from Ras-responsive promoter elements (Ets/AP-1 and NF-kappa B). We conclude that aberrant TC21 function may trigger cellular transformation via a signal transduction pathway similar to that of oncogenic Ras and suggest that deregulated TC21 activity may contribute significantly to human oncogenesis.

Safety and efficacy of repetitive adenovirus-mediated transfer of CFTR cDNA to airway epithelia of primates and cotton rats

Gene therapy for cystic fibrosis (CF) will require the safe transfer of CFTR cDNA to airway epithelia in vivo. We showed previously that a recombinant adenovirus, Ad2/CFTR-1, expresses CFTR in vitro. As adenovirus rarely integrates, treatment will require repeated vector administration. We applied Ad2/CFTR-1 to intrapulmonary airway epithelia of cotton rats and nasal epithelia of Rhesus monkeys. In both species we detected CFTR mRNA and protein after repeated administration and in monkeys, protein was detected six weeks after repeat administration. The vector did not replicate and was rapidly cleared. Despite an antibody response, there was no evidence of a local or systemic inflammatory response after repeat administration. These data indicate that repetitive administration of Ad2/CFTR-1 is both safe and efficacious.

Adenovirus-mediated gene transfer transiently corrects the chloride transport defect in nasal epithelia of patients with cystic fibrosis

To evaluate the potential of direct transfer of cystic fibrosis transmembrane conductance regulator (CFTR) cDNA for the treatment of cystic fibrosis (CF), we administered an E1-deficient adenovirus, encoding CFTR, to a defined area of nasal airway epithelium of three individuals with CF. This treatment corrected the Cl- transport defect that is characteristic of CF-affected epithelia. After treatment, there was a decrease in the elevated basal transepithelial voltage, and the normal response to a cAMP agonist was restored. We found no evidence of viral replication or virus-associated adverse effects, even at the highest dose tested (25 MOI). These data represent a small step in achieving long-term improvement of CF lung function by gene therapy.

Chromosome testing in children with developmental delay in whom the aetiology is not evident clinically

A review was carried out to establish the value of chromosome testing in children with significant developmental delay, where the aetiology was not evident clinically. During 1990, 315 children had been assessed at a child development clinic and found to be significantly delayed in one or more areas of development; in 256, the aetiology was not evident clinically. Chromosome testing of these children revealed an abnormality in 10 (3.9%). Thirty children had dysmorphic features; six (20%) of these had an abnormal karyotype. Four (2%) of the 226 who had no dysmorphic features had a chromosome abnormality. One hundred and fifty-five children had intellectual disability; eight (5%) of these had an abnormal karyotype. Two (2%) of 101 who had a specific delay in their development had a chromosome abnormality. The advantages of chromosome testing in children with developmental delay in whom the aetiology is not evident clinically are discussed.

Laparoscopic cholecystectomy and common bile duct stones. The utility of planned perioperative endoscopic retrograde cholangiography and sphincterotomy: experience with 63 patients

OBJECTIVE

Planned perioperative endoscopic retrograde cholangiography (ERC) and sphincterotomy (ES) for suspected or proven common bile duct stones (CBDS) has been attempted in 63 of 540 consecutive patients undergoing laparoscopic cholecystectomy (LC). Experience with this intervention has been studied with respect to accuracy, efficacy, and safety.

SUMMARY BACKGROUND DATA

The optimal management of CBDSs in the era of LC is not defined. Methods exist for the laparoscopic manipulation of the common bile duct; however, experience is limited. Until surgeons become comfortable with this more demanding technique, ERC and ES will have a prominent role in the perioperative management of CBDSs.

METHODS

A preoperative group (n = 41) included all candidates for LC with historical, biochemical, or radiologic evidence of CBDSs. A postoperative LC group (n = 22) included patients with stones diagnosed by intraoperative cholangiogram (IOC) (n = 6) or with signs or symptoms of retained, but unproven, CBDSs (n = 16).

RESULTS

Thirty-six (88%) of the preoperative attempts were successful. Stones were identified in 18 cases and ES and duct clearance were achieved in all 18. In the postoperative group, ERC was successful in 21 (95%) cases. Calculi were demonstrated in 5 of 6 patients with a positive IOC and 6 of 16 with clinically suspected retained stones. ES and duct clearance were achieved in all 11 patients with documented CBDSs. Overall, ERC was accomplished in 90% of cases. Stones were identified in 51% of cases and all stones were cleared by ES. Morbidity was confined to four cases of self-limited pancreatitis (6%). There were no deaths.

CONCLUSIONS

The perioperative management of CBDSs is an appealing approach for patients anticipating the benefits of LC, at least until the laparoscopic manipulation of the common bile duct becomes a more widely accepted technique.

The carboxyl-terminal CXXX sequence of Gi alpha, but not Rab5 or Rab11, supports Ras processing and transforming activity

Although the heterotrimeric Gi alpha subunit terminates in an apparent CXXX prenylation signal (CGLF), it is not modified by isoprenylation. To determine if the Gi alpha CXXX sequence can signal prenylation when placed at the carboxyl termini of normally prenylated proteins, we have characterized the processing and biological activity of chimeric oncogenic Ras proteins that terminate in the Gi alpha CXXX sequence (Ras/Gi alpha). Surprisingly, these chimeras were prenylated both in vivo and in vitro, demonstrated significant membrane association, exhibited transforming activity, and induced transcriptional transactivation from Ras-responsive elements. We then extended these studies to determine if, unlike the CC or CXC carboxyl-terminal sequences of other Rab proteins, the carboxyl-terminal CXXX sequences of the Ras-related Rab5 and Rab11 proteins represent conventional CXXX prenylation signals that can support Ras processing and transforming activity. Unexpectedly, these Ras/Rab chimeras were nonprenylated, were cytosolic, and lacked detectable transforming or transcriptional transactivation activity. Taken together, these results suggest that the context within which a CXXX sequence occurs may also critically control the modification of a protein by prenylation, and that the Rab5 and Rab11 carboxyl termini do not possess conventional CXXX sequences. Instead, their CCXX and CCXXX motifs may represent additional classes of protein prenylation signals.

Colonic necrosis following sodium polystyrene sulfonate (Kayexalate)-sorbitol enema in a renal transplant patient. Report of a case and review of the literature

The authors present the case of a patient who developed near total colonic necrosis shortly after renal transplantation. The onset of symptoms was temporally related to the administration of sodium polystyrene (Kayexalate; Sanofi Winthrop Pharmaceuticals, New York, NY)-sorbitol enemas for treatment of hyperkalemia. Three similar cases have been reported in the literature. The presence of uremia and the use of sorbitol appear to be common denominators in the pathophysiology of this complication. It is suggested that Kayexalate-sorbitol enemas be avoided in renal transplant patients.

Safety of percutaneous endoscopic gastrostomy in patients with a ventriculoperitoneal shunt

The placement of percutaneous endoscopic gastrostomy tubes in patients with a ventriculoperitoneal shunt implicitly raises concerns about the potential for infection, shunt malfunction, and neurological decompensation. As there is no detailed information on this subject, the safety of percutaneous endoscopic gastrostomy was prospectively studied in 15 consecutive patients who had a ventriculoperitoneal shunt. Ten shunts entered the right upper abdomen, and five were on the left. A percutaneous gastrostomy tube was placed in the left upper abdomen for a minimum of 1 week (mean, 2.2 weeks) after shunt insertion. In the immediate postoperative period, no wound or intra-abdominal complications occurred. One patient developed acute neurological decompensation because of proximal shunt malfunction, and one patient died from cardiopulmonary complications unrelated to the placement of shunts or gastrostomy tubes. Among the 14 survivors, there have been no shunt malfunctions or septic complications during a mean follow-up period of 8.6 months. It would appear that percutaneous endoscopic gastrostomy tubes can be placed in patients with a ventriculoperitoneal shunt without undue concern for short- or long-term infectious or neurological sequelae. In addition, the presence of a shunt on the left side does not necessarily interfere with the safe placement of a percutaneous endoscopic gastrostomy tube.

Detection of bulimia in a primary care setting

OBJECTIVE

To develop a screening tool for the identification of bulimia in ambulatory practice.

DESIGN

Administration of a 112-item questionnaire about eating and weight-control practices to women with known bulimia and to healthy control patients. Questions were compared with DSM-III-R criteria of bulimia as a "gold standard."

SETTING

Self-help group for eating disorders and hospital-based primary care practice.

SUBJECTS

Thirty of 42 women with known bulimia met DSM-III-R criteria for current bulimia, and 124 of 130 control patients met the criterion of no history of an eating disorder.

MAIN RESULTS

Thirteen individual questions discriminated between bulimic subjects and control subjects with a sensitivity and specificity of > 75%. When these questions were entered into a stepwise logistic model, two questions were independently significant. A "no" response to the question "Are you satisfied with your eating patterns?" or a "yes" response to "Do you ever eat in secret?" had a sensitivity of 1.00 and a specificity of 0.90 for bulimia. The positive predictive value, based on a 5% prevalence, was 0.36.

CONCLUSIONS

A set of two questions may be as effective as a more extensive questionnaire in identifying women with eating disorders, and could be easily incorporated into the routine medical history obtained from all women.

Laparoscopic management of acute cholecystitis

The role of laparoscopic surgery in patients presenting with acute cholecystitis remains controversial. From September 1989 through August 1992, a total of 720 patients underwent cholecystectomy. Ninety-six were unplanned admissions with a clinical diagnosis of acute cholecystitis. Laparoscopic surgery was attempted in 83 patients. Thirteen individuals were not offered laparoscopy because of the surgeon's inexperience. Twenty-two (27%) patients required the laparoscopic procedure converted to an open laparotomy. The mean postoperative hospital stay for patients undergoing laparoscopic cholecystectomy was 3.3 days versus 6.8 days for the laparotomy group. There was no mortality and no bile duct or major vascular injuries in either group. The overall operative morbidity rate was 16.9%. Laparoscopic cholecystectomy appears to be a safe and beneficial option in selected patients with acute cholecystitis. A low threshold for conversion to laparotomy appeared to be an important factor in maintaining a low incidence of operative complications. Several modifications to the technique of laparoscopic cholecystectomy have evolved over the 3-year study period and are described.

Endoscopic management of the difficult common bile duct stone

Over the past two decades, endoscopic sphincterotomy has become the primary therapy for retained or recurrent choledocholithiasis. Nevertheless, in about 10% of patients, complete ductal clearance is not possible using standard balloon and basket techniques. A variety of endoscopically guided lithotripsy devices can substantially improve the chances of extracting stones that are resistant to conventional methods. Fiberoptic technology has advanced to the point where these procedures can be performed under direct vision through ultrathin fiberscopes. This paper examines the current experience with these intracorporeal techniques for the difficult common bile duct stone.

Training for laparoscopic surgery

Laparoscopic cholecystectomy has rapidly become the procedure of choice for most patients with symptomatic gallbladder disease. Laparoscopic surgery, however, has not been a required component of most general surgery training programs. The demonstrated efficacy of laparoscopic surgery dictates that this discipline be rapidly incorporated into residency programs. Laparoscopic cholecystectomy and other surgical endoscopic procedures have been an integral part of the training program at the University of Maryland since 1989. Currently, residents who are completing their training have performed on average 50 to 75 laparoscopic procedures as the primary surgeon and 25 to 30 as the first assistant. In addition to training future community and academic physicians, those surgeons currently in practice must receive appropriate instruction in laparoscopic surgery. Most practicing surgeons attend a 2- to 3-day intensive course offering both didactic and hands-on experience. Additional exposure to clinical cases is achieved by working with other surgeons with laparoscopic expertise. Full credentialing in laparoscopic cholecystectomy generally requires proctoring by a surgeon from the local community. Since 1990 faculty from the University of Maryland have been active in the local community serving as proctors to surgeons in 14 hospitals.

Long-term neurologic consequences of nutritional vitamin B12 deficiency in infants

A review of the clinical findings in six infants with nutritional vitamin B12 deficiency seen during the last 10 years was undertaken and an attempt made to obtain long-term neurologic follow-up. There was a consistent clinical pattern in vitamin B12-deficient infants; irritability, anorexia, and failure to thrive were associated with marked developmental regression and poor brain growth. Two of the four patients who qualified for long-term review had a poor intellectual outcome. Although early response to treatment is satisfying, the long-term consequences of nutritional vitamin B12 deficiency in infants emphasize the need for prevention or early recognition of this syndrome.

Gastrocolic and duodenocolic fistulas in Crohn's disease

Crohn's disease is a rare cause of gastrocolic and duodenocolic fistulas. Only 83 examples (27 gastric, 52 duodenal, four both) have been described. Weight loss, abdominal pain, and diarrhea are common features but fail to distinguish a fistula from active inflammatory bowel disease. Fecal vomiting is pathognomic but is present in one third of gastrocolic and only 2% of duodenocolic fistulas. Diagnosis is most readily made by contrast radiography, with barium enema being more sensitive than barium meal. Although several gastrocolic fistulas have been successfully treated with long-term 6-mercaptopurine, surgery is the mainstay of therapy. An isolated duodenocolic fistula should not be regarded as the primary indication for operation because most are asymptomatic. Ileocolonic resection with simple gastric or duodenal repair is safe and effective in most cases. An ileocolonic anastomosis should be positioned away from the stomach or duodenum or protected with omentum to prevent recurrent fistulization. A number of fistulas appear to have arisen from gastric or duodenal Crohn's, but the vast majority originate from diseased colon.

Isoprenoid addition to Ras protein is the critical modification for its membrane association and transforming activity

We have introduced a variety of amino acid substitutions into carboxyl-terminal CA1A2X sequence (C = cysteine; A = aliphatic; X = any amino acid) of the oncogenic [Val12]Ki-Ras4B protein to identify the amino acids that permit Ras processing (isoprenylation, proteolysis, and carboxyl methylation), membrane association, and transformation in cultured mammalian cells. While all substitutions were tolerated at the A1 position, substitutions at A2 and X reduced transforming activity. The A2 residue was important for both isoprenylation and AAX proteolysis, whereas the X residue dictated the extent and specificity of isoprenoid modification only. Differences were observed between Ras processing in living cells and farnesylation efficiency in a cell-free system. Finally, one farnesylated mutant did not undergo either proteolysis or carboxyl methylation but still displayed efficient membrane association (approximately 50%) and transforming activity, indicating that farnesylation alone can support Ras transforming activity. Since both farnesylation and carboxyl methylation are critical for yeast a-factor biological activity, the three CAAX-signaled modifications may have different contributions to the function of different CAAX-containing proteins.

Laparoscopic general surgery: current status and future prospects

The capability of performing major abdominal surgery while avoiding a large abdominal incision has clear benefits for patient care. Laparoscopic cholecystectomy can reduce hospital stays and the length of the recovery period, as well as decrease postoperative pain, diminish scarring, and provide significant cost savings.

Laparoscopic cholangiography. Results and indications

One hundred sixty-five operative cholangiograms were attempted in 364 patients who underwent laparoscopic cholecystectomy (45%). Laparoscopic cholangiography was successful in 150 of 165 attempts (91%). Eighty-nine per cent of studies were normal (134/150) and 11% were abnormal (16/150). All 134 patients with normal cholangiograms remained asymptomatic (false-negative rate, 0%). False-positive studies occurred in 3 of 150 (2%) total cholangiograms and 3 of 12 (25%) abnormal cholangiograms consistent with choledocholithiasis. A total of 16 of 364 patients had proven common bile duct stones (4.4%). Eight of the sixteen stones were removed by preoperative endoscopic retrograde cholangiopancreatography/sphincterotomy. Five of sixteen stones were found at cholangiography, four of which were unsuspected (4/150, 2.6%). Retained common duct stones were found in 3 of 214 patients not undergoing cholangiography (1.4%). No complications or deaths occurred that were due to cholangiography. One biliary injury occurred (1/364, 0.3%), in a patient with aberrant anatomy who did not undergo cholangiography. Laparoscopic cholangiography is a safe technique with a success rate greater than 90%. Routine cholangiography is presently recommended for prevention of biliary injury, detection of stones in the cystic and common ducts, and for training purposes, especially during the learning phase of laparoscopic cholecystectomy.

Laparoscopic cholecystectomy. Experience with 375 consecutive patients

Three hundred seventy-five consecutive patients underwent laparoscopic cholecystectomy from September 1989 to January 1991. Three hundred forty-one (91%) presented on an elective basis, and the remaining 34 patients (9%) were admitted for acute cholecystitis (24), gallstone pancreatitis (9), and cholangitis (1). Of the 375 patients, 20 were converted to laparotomy and cholecystectomy, for an overall success rate of 95% for patients undergoing laparoscopic cholecystectomy. Three hundred nineteen patients (90%) were discharged within 24 hours of surgery. Operative cholangiography was completed in 141 patients, showing choledocholithiasis in five (managed by postoperative endoscopic retrograde cholangiopancreatography [ERCP] in 4, common bile duct exploration [CBDE] in 1). Two retained stones (0.9%) were detected in 214 patients not undergoing cholangiography. Three patients (0.8%) were reoperated on because of perioperative complications. Overall morbidity for patients undergoing laparoscopic cholecystectomy was 3.5%. Major complications (0.6%) included a single common hepatic duct injury and a delayed cystic duct leak at 10 days. Minor complications occurred in 11 patients (2.9%). The single perioperative death (0.3%) was due to a myocardial infarction on postoperative day 3, after an otherwise uncomplicated laparoscopic procedure. Laparoscopic cholecystectomy appears to offer significant advantages to patient recovery, and these data suggest that it can be performed with an efficacy, morbidity rate, and mortality rate similar to those of open cholecystectomy.

Combined laparoscopic cholecystectomy and selective vagotomy

Laparoscopic surgery offers distinct advantages to traditional surgery, including decreased hospitalization and recovery periods, decreased postoperative discomfort, and improved cosmesis. A feasible laparoscopic approach to the treatment of peptic ulcer disease might confer similar patient benefits. A modified highly selective vagotomy (in combination with cholecystectomy for symptomatic cholelithiasis) has been successfully completed under laparoscopic guidance in a patient with intractable ulcer disease. The patient was discharged on the second postoperative day, tolerating a regular diet. The patient's dyspeptic symptoms disappeared during the immediate postoperative period and further endoscopic evaluation revealed resolution of active ulcer disease. Although experience is still limited in the United States, initial clinical results from Europe would indicate that laparoscopic vagotomy is not only feasible but effective. With further experience, laparoscopic vagotomy may provide a viable alternative to the standard treatment of peptic ulcer disease.

Congenital umbilical arteriovenous malformation: a rare cause of congestive heart failure in the newborn

A newborn presented in congestive heart failure on the second day of life. Cardiac catheterization was normal, but aortic injection showed a congenital umbilical artery to umbilical vein arteriovenous malformation. Three similar cases have been reported. All four patients were successfully treated by complete excision of the malformation.