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Biomedical subjects

J H Peters

Publications and source records attributed to J H Peters.

At least 145 records · Page 8Linked to original sources
PubMed1994

Diagnosis and management of bile leaks following laparoscopic cholecystectomy.

Laparoscopic cholecystectomy is now the standard of care for the elective management of gallstone disease. Recent studies have shown the morbidity of laparoscopic cholecystectomy to be similar to that of open cholecystectomy. Postoperative bile leaks have been recognized to be a troublesome problem following laparoscopic cholecystectomy. We present a retrospective review of 854 patients undergoing laparoscopic cholecystectomy at a single institution. Records were reviewed of all patients identified as having postoperative bile leaks. Between January 1990 and April 1991, we have cared for, or been referred, 15 patients with postlaparoscopic cholecystectomy bile leaks (9/854, 1.1% index patients and 6 referred). The location of bile leakage was determined to be the common bile duct (CBD) in two, cystic duct in five, and small accessory ducts located close to the gallbladder bed in the remaining eight. Most patients presented in the first week following laparoscopic cholecystectomy (mean 4.3 +/- 0.7 days, range 2-10) with worsening abdominal pain (13/13, 100%), nausea, and low-grade fever (mean 99.6 +/- 0.3 degrees F, range 96.8-102.2). Eleven of fifteen (66.7%) patients underwent technectium-99m imidodiacetic acid scanning (Tc-99m IDA) to determine the presence of a possible bile leak. All eleven scans were positive, indicating the presence of a bile leak. Thirteen patients underwent endoscopic cholangiography confirming the presence of biliary leakage (the remaining two patients underwent prompt laparotomy). Five patients were taken to the operating room for management of their leaks (two with common bile duct injuries, two cystic duct leaks, one accessory duct leak).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The effect of symptoms and nonspecific motility abnormalities on outcomes of surgical therapy for gastroesophageal reflux disease.

The outcome of Nissen fundoplication in patients with a nonspecific motility abnormality compared with the outcome in patients with normal motility is unknown. One hundred consecutive patients who underwent primary Nissen fundoplication were evaluated before and a median of 50 months after operation, with emphasis on the presence of a preoperative motility disorder and its relationship to preoperative and postoperative symptoms. Compared with patients who had normal motility, patients with a nonspecific motility abnormality had a greater prevalence and severity of heartburn and regurgitation before operation. These patients also had a greater esophageal exposure to gastric juice on pH monitoring as a result of poorer esophageal clearance function. The prevalence and severity of preoperative dysphagia was not related to the presence of a motility disorder. A 90% or a 95% actuarial success rate was achieved in the relief of heartburn and regurgitation over a 96-month period in patients with and without a motility abnormality. The overall actuarial success rate was 93%. Dysphagia was rarely caused or made more severe by the procedure; if present before the operation, it was relieved in most patients. The prevalence of persistent postoperative dysphagia was similar in patients with and without a motility abnormality. The success of Nissen fundoplication in properly selected patients is not affected by the presence of a nonspecific motility disorder.

Deglutition Disorders↗
PubMed1993

Signals required for differentiating dendritic cells from human monocytes in vitro.

Human peripheral blood monocytes (Mo) can quantitatively be differentiated into potent accessory cells which exhibit dendritic cell (DC) function and phenotype. This alternative differentiation of Mo into DC rather than into macrophages (M phi) will be triggered when signals leading to M phi differentiation are omitted from the culture. Serum contains such stimulatory signals and was therefore omitted from the cultures. The cells were cultured on solid agarose surfaces. This newly developed technique allows for the attachment-free differentiation of DC. In the absence of signals, Mo do not survive in culture. IL-1 and IL-6 are endogenously produced by Mo and create an autokrine stimulatory milieu which increases the accessory function. However, also mature Mph will respond by an increased accessory activity upon stimulation by these cytokines. Cyclic AMP is the most likely second messenger to trigger an increase in accessory activity. IL-4 plus GM-CSF further act to upregulate dendritic cell properties and function. By action of these mediators, virtually all markers and functions of Mo/M phi are lost, and the cells convert to the phenotype and function of dendritic cells.

Cell Differentiation↗
PubMed1993

Down-regulation and release of CD14 on human monocytes by IL-4 depends on the presence of serum or GM-CSF.

IL-4 induces down-regulation of CD14 expression on human monocytes only when the cells are cultured with serum. In serum-free cultures we failed to down-regulate CD14 by IL-4. Instead of serum, GM-CSF was required as a co-factor to restore the regulatory effect of IL-4 on CD14-expression. After 4 days of culture human monocytes were quantitatively CD14-negative as determined by flow-cytometry. On day 6, high amounts of CD14 molecules were detected in the SUP of these cultures, whereas intracellular immunofluorescence staining revealed no detectable CD14 in cytokine-treated monocytes. Thus, CD14 is lost by down-regulation (as shown by others) as well as by delivery into the medium. We previously hypothesized that dendritic cells may originate from monocytes. Our present finding support that one of the key markers, distinguishing monocytes/macrophages from dendritic cells, can be lost upon physiological stimuli.

Antigens, CD↗
PubMed1993

Fat-stimulated cholecystokinin release following transplantation of the entire small bowel or of different intestinal segments in rats.

This study presents data on the fat-stimulated release of cholecystokinin (CCK) in conscious rats 11 and 84 days after one-stage transplantation of the entire small bowel, or of jejunal, jejunoileal, or ileal segments, under syngeneic and allogenic conditions. After allotransplantation, ciclosporin (CsA) was administered for graft acceptance. The results were compared with those in unoperated controls and in animals that had undergone small-bowel resections leaving jejunal, jejunoileal, or ileal remnants. When the entire small bowel was grafted under syngeneic (92.5 +/- 8.3; 106.6 +/- 7.5) or allogeneic (110.5 +/- 5.5; 101.2 +/- 6.9) conditions, CCK release (pg/ml per 60 min) was similar (P > 0.05) to that of the controls (110.3 +/- 9.0; 94.7 +/- 6.8) at both measurement points. Recipients of jejunal or ileal segmental isografts showed a significantly elevated (P < 0.05) output of CCK (jejunal graft: 176.4 +/- 18.5; 125.5 +/- 10.1 -ileal graft: 55.9 +/- 9.0; 30.1 +/- 5.4) compared with corresponding small-bowel resections (jejunal remnant: 69.0 +/- 7.9; 93.5 +/- 3.9-ileal remnant: 16.7 +/- 3.7; 6.6 +/- 1.3). In contrast, the difference was not significant (P > 0.05) when jejunoileal segments were grafted (jejunoileal graft: 74.4 +/- 19.6; 47.0 +/- 10.4-jejunoileal remnant: 50.7 +/- 11.0; 47.0 +/- 11.9). All recipients of jejunal allografts died between day 8 and day 10 after transplantation, due to functional impairment. Two-stage segmental jejunal allotransplantation, with insertion of the graft into the continuation of the gastrointestinal tract in an accessory, non-functional position after 28 days was successful. Due to this technique, we could gather data on day 84. Recipients of jejunal (118.2 +/- 7.6), jejunoileal (87.1 +/- 19.7; 48.6 +/- 9.3), or ileal (48.1 +/- 6.7; 21.6 +/- 4.6) allografts showed no significant (P < 0.05) differences in CCK output compared with isografts, either on day 11 or on day 84. Our data indicate that transplantation of the entire small bowel affects the fat-stimulated CCK release neither in the early postoperative period nor 3 months after transplantation. In contrast, transplantation of jejunal or ileal segmental isografts caused a significantly elevated output of CCK compared with corresponding resection remnants. Immunosuppression with CsA did not affect CCK release after transplantation, but led to functional impairment with fatal outcome when a short jejunal segment was grafted. This could be prevented by applying the two-stage technique.

Animals↗
PubMed1993

Laparoscopic cholecystectomy in patients admitted with acute biliary symptoms.

Laparoscopic cholecystectomy has become the standard of care for the elective management of cholelithiasis. Little information exists, however, regarding the appropriateness of this procedure in the setting of acute symptomatology. We retrospectively reviewed our experience with 516 laparoscopic cholecystectomies performed at a single institution from May 1990 to May 1991. Seventy-five (14.5%) of these patients were admitted from the emergency department with acute abdominal pain (100%), fever (4 of 75, 5%), and/or an elevated white blood cell count (22 of 75, 29%). There were 54 females and 21 males, with a mean age of 50.0 +/- 2.4 years (range: 17 to 89 years). Laparoscopic cholecystectomy was attempted in all patients, and was successful in 68 of 75 patients (91%). Seven procedures were converted to open cholecystectomy because of the difficulty in dissection precluding safe laparoscopic cholecystectomy. The time from admission to surgery (mean: 3.4 +/- 0.3 days), as well as the total hospital stay (mean: 5.5 +/- 0.6 days), was much longer than in the elective circumstance. Mean laboratory values for the group as a whole were as follows: white blood cell count (mean: 9.6 IU/L +/- 0.4 IU/L, range: 4.1 IU/L to 19.5 IU/L), alkaline phosphatase (mean: 97.0 IU/L +/- 13.7 IU/L, range: 27 IU/L to 375 IU/L), and alanine aminotransferase (mean: 78.3 IU/L +/- 13.7 IU/L, range: 15 IU/L to 701 IU/L). Patients requiring open cholecystectomy were older (mean: 61.4 +/- 4.4 versus 48.8 +/- 2.6), were more likely to be febrile (3 of 7, 42%, versus 1 of 68, 1%), and were more likely to have a significant leukocytosis (mean: white blood cell count 12.9 +/- 1.8 x 10(3) cells/mm3 versus 9.2 +/- 0.4 x 10(3) cells/mm3) than were those undergoing successful laparoscopic cholecystectomy. Laparoscopic cholecystectomy can be performed safely in the majority of patients presenting with acute biliary symptoms. Patients with a triad of acute abdominal pain, fever, and elevated white blood cell count, particularly elderly patients, are more likely to require conversion to open cholecystectomy, however.

Acute Disease↗
PubMed1993

Gastroesophageal reflux.

Gastroesophageal reflux is a common disease that accounts for approximately 75% of esophageal pathology. Motility abnormalities of the esophagus and stomach, including an incompetent lower esophageal sphincter, are responsible for pathologic reflux in the majority of patients. Surgical treatment offers the only chance for long-term cure. Obtaining optimal results following surgery of the esophagus is one of the most challenging aspects of modern surgical therapy. Given a precise diagnosis, careful patient selection, critical attention to detail in the perioperative period, and the meticulous performance of the appropriate anti-reflux procedure, long-term success can be assured in more than 90% of patients.

Gastroesophageal Reflux↗
PubMed1993

1,25-Dihydroxyvitamin D3 exerts opposing effects to IL-4 on MHC class-II antigen expression, accessory activity, and phagocytosis of human monocytes.

To investigate the differentiation and activation of monocytes, the combined effects of 1,25-dihydroxyvitamin D3 (D3) and IL-4 on human blood monocytes were examined with respect to expression of MHC class-II antigens, accessory activity, and phagocytic capacity. IL-4 was reported to upregulate the expression of MHC class-II antigens and accessory activity of monocytes. The experiments described here demonstrate that D3 inhibits the expression of all three subtypes of MHC class-II antigens (HLA-DR, -DP and -DQ) as well as the accessory activity of monocytes, both in a dose- and time-dependent manner. However, D3 enhances the immunoglobulin- and complement-dependent phagocytosis by monocytes in a dose- and time-dependent manner. When monocytes are treated with both IL-4 and D3, the effects of D3 are reverted by IL-4, suggesting that IL-4 induces the development of monocytes into accessory cells, whereas D3 stimulates differentiation of monocytes into classical macrophages. These findings provide further evidence for the contention that, depending on defined stimuli, monocytes may develop either into accessory cells or into classical macrophages.

Antigen-Presenting Cells↗
PubMed1993

Laparoscopic antireflux repair and myotomy.

Since 1991, the techniques of endosurgical antireflux repair and myotomy have been developed for the treatment of gastroesophageal reflux disease and esophageal motility disorders. The principles of open surgery for the treatment of these conditions learned over several decades should be incorporated into minimally invasive approaches. Moreover, proper patient evaluation and selection are critical to the success of these procedures. This paper describes the technical aspects of endosurgical antireflux repair and myotomy.

Endoscopes↗
PubMed1993

Characterization of monoclonal antibodies to the envelope proteins of an immunodeficiency virus of African green monkeys, SIVagmTYO-7.

Five monoclonal antibodies (mabs) specific for the envelope proteins of a simian immunodeficiency virus of African green monkeys (SIVagm) have been raised. Two mabs were directed against distinct epitopes on the transmembrane protein gp41. A conformational epitope on the gp130 was recognized by three mabs. This is the first report on mabs specific for SIVagm-gp130. Studies of the cross-reactivities revealed that the epitopes recognized by the env-directed mabs are conserved species-specifically in SIVagm isolates. Therefore, these mabs can be used to distinguish SIVagm strains from other virus groups.

Animals↗
PubMed1993

Value of physiologic assessment of foregut symptoms in a surgical practice.

BACKGROUND: The aim of this study was to evaluate the reliability of symptoms in the diagnosis of gastroesophageal reflux disease and esophageal motility disorders as assessed by functional tests. METHODS: In 365 patients referred for suspected esophageal functional disease, symptomatic assessment was compared with the results of esophageal manometry and ambulatory 24-hour pH monitoring of the distal esophagus. RESULTS: Based on the patients' chief complaint, the symptomatic diagnosis was gastroesophageal reflux (44%), esophageal motor disorder (26%), chest pain of esophageal origin (9%), reflux and aspiration (8%), and abdominal pathology (12%). The symptomatic diagnosis was considerably altered by the results of the esophageal function tests: gastroesophageal reflux and motility disorders were found in all symptomatic diagnostic groups and a large number of patients in each group tested normal. The sensitivity and specificity of symptom-based diagnoses for functional disease were low. CONCLUSIONS: The results of this study showed that symptoms are an unreliable guide of esophageal abnormality, illustrating the need for objective testing in these patients, particularly to avoid inappropriate medical or surgical therapy.

Adolescent↗
PubMed1993

Superiority of extended en bloc esophagogastrectomy for carcinoma of the lower esophagus and cardia.

The belief that transhiatal esophagogastrectomy results in the same survival as a more extensive en bloc resection was tested in 69 patients with carcinoma in the distal esophagus and gastric cardia. Preoperative and intraoperative staging defined three distinct subgroups of patients. Those with apparently limited disease and good general health (group I, n = 30) underwent en bloc resection. Those with apparently limited disease but poor physiologic reserve (group II, n = 16) underwent transhiatal resection, as did those with evidence of more advanced disease (group III, n = 23). Overall, survival was significantly better in the 30 patients who underwent en bloc resection (41%) than in the 39 patients who underwent transhiatal resections (14%; p < 0.001, log-rank). Clinical staging showed apparently limited disease in 46 patients (groups I and II). These groups differed only in the presence of poor physiologic reserve because the percentages of patients with tumors limited to the esophageal wall (group I 13/30, group II 6/16) and four or fewer lymph node metastases (group I 21/30, group II 15/16) at the time of pathologic staging were not significantly different. Survival after en bloc resection was, however, significantly better (41% versus 21%; p < 0.05, log-rank). According to the WNM system of pathologic staging, 19 patients had early lesions defined as intramural lesions associated with four or fewer lymph node metastases, 26 had intermediate lesions defined as either transmural or associated with more than four lymph node metastases, and 24 had late lesions defined as both transmural and associated with fewer than four lymph node metastases. Survival was significantly better in patients with early lesions after en bloc resection compared with transhiatal resection (75% versus 20%, p < 0.01), survival was also significantly better in patients with advanced lesions (27% versus 9%, p < 0.01). For intermediate lesions, the survival was similar (14% versus 20%), although the median survival after en bloc resection was longer (24 months versus 8 months).

Actuarial Analysis↗
PubMed1993

The physiology of laparoscopic surgery: pulmonary function after laparoscopic cholecystectomy.

Changes in pulmonary function were studied via standard spirometry in 30 patients after laparoscopic cholecystectomy (LC) and compared with those in nine patients after traditional open cholecystectomy (OC). Studies performed presurgery and the morning after surgery included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and forced expiratory flow (FEF25%-75%). Age (43.9 +/- 2.6 years for LC and 42.3 +/- 3.2 for OC), sex, reasons for cholecystectomy, and smoking history were similar in both groups. The mean FVC decreased 23% after LC (3.57 +/- 0.18 L presurgery, range 0.56-5.62, versus 2.68 +/- 0.17 postsurgery, range 0.65-5.14) and 35.2% after OC (mean 3.52 +/- 0.29 presurgery, range 2.38-4.99, versus 2.24 +/- 0.24, range 1.23-3.49 postsurgery). FEV1 showed similar changes, with LC decreasing pulmonary function by 24.3% (2.76 +/- 0.14 L presurgery versus 2.01 +/- 0.12 postsurgery) compared with a 36.2% reduction in FEV1 after OC (2.86 +/- 0.29 L presurgery versus 1.81 +/- 0.21 L postsurgery). Forced expiratory flow decreased by 24.3% after LC and 40% after OC. Laparoscopic cholecystectomy provides less decrement in pulmonary function than traditional open cholecystectomy.

Adult↗
PubMed1992

Expression of CD54, CD58, CD14, and HLA-DR on macrophages and macrophage-derived accessory cells and their accessory capacity.

Human peripheral monocytes can differentiate in vitro into macrophages (Mph) possessing a low accessory activity in T cell stimulation. Mph can be converted into a state of high accessory activity by treatment with dibutyryl cyclic AMP. This finding was used in this study to achieve Mph-derived AC (MphAC). Among the surface antigens on AC which have been shown to participate in accessory events leading to T cell proliferation, MHC class II antigens, CD58 (LFA-3) and CD54 (ICAM-1) seem to be especially important. We show here that the high accessory capacity of MphAC was not correlated with a high level of the surface antigens HLA-DR, CD58, and CD54. The amount of CD54 molecules was, in fact, lower on the MphAC than on the Mph.

Antibodies, Monoclonal↗
PubMed1992

Concentration of refluxed acid and esophageal mucosal injury.

The hallmark of gastroesophageal reflux disease (GERD) is an increase in esophageal exposure to gastric juice. This exposure can result in complications such as esophagitis, stricture, and Barrett's esophagus. The aim of this study is to determine if there are specific pH exposure patterns that are associated with the development of these complications. The 24-hour esophageal pH data for 50 normal subjects and 154 patients with proven GERD were analyzed for time spent at different pH intervals. Increased esophageal acid exposure at a given interval occurred when the cumulative time of exposure exceeded the 95th percentile of that measured in the 50 normal subjects for that interval. The greatest prevalence of mucosal damage was found in the those patients with increased esophageal exposure to pH 0 to 2, corresponding to the known pKa of pepsin. This exposure was not related to a hypersecretory state. In addition, mucosal injury was associated with an increased esophageal exposure to pH 7 to 8. We conclude that mucosal injury in patients with GERD is related to the exposure time to gastric juice with a pH of less than 2 or greater than 7.

Adult↗