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Biomedical subjects

H Gerdes

Publications and source records attributed to H Gerdes.

At least 19 recordsLinked to original sources
PubMed1993

Preoperative endoscopic ultrasound can predict the risk of recurrence after operation for gastric carcinoma.

PURPOSE: Endoscopic ultrasonography (EUS) has been shown to determine accurately the depth of invasion of the stomach wall in gastric carcinoma. We undertook this study to determine if T (tumor) stage as determined by EUS correlated with recurrence after resection and could be used to identify patients preoperatively at high risk for recurrence. MATERIALS AND METHODS: We reviewed the surgical pathology and obtained follow-up data from the first 50 patients who underwent preoperative EUS for staging of gastric carcinoma. Rotating sector-scan ultrasound endoscopes were used with switchable frequencies of 7.5 MHz and 12 MHz. RESULTS: Of 50 patients, 43 underwent resection with curative intent and were available for follow-up. The concordance of EUS T stage with pathologic T stage in these patients was 86%. At a median follow-up duration of 25 months, only two of 13 patients with preoperative EUS stage T1 or T2 disease were found to have recurrence, while 23 of 30 patients with EUS stage T3 or T4 disease had recurrence (P = .0002) and 22 died. CONCLUSION: We conclude that patients with a preoperative EUS stage T1 or T2 are at low risk for postoperative recurrence, while patients with EUS stage T3 or T4 are at high risk for early postoperative recurrence. The latter patients are reasonable candidates for controlled trials of alternative preoperative management programs, such as chemotherapy, in an effort to improve their poor prognosis.

Adult↗
PubMed1992

Ultrasound directed extrahepatic bile duct intraluminal brachytherapy.

Intraluminal brachytherapy with a transcatheter Iridium-192 (Ir-192) wire, as a method to deliver a boost to patients with tumors of the extrahepatic bile ducts, has been well described. A major limitation of current imaging techniques is the inability to accurately define the proximal, distal, and most importantly the lateral extent of the tumor. We have found endoluminal ultrasound, which to this date has been used primarily to measure arterial wall layers, can successfully determine tumor volume in the bile ducts. The small diameter of these ultrasound probes allows easy insertion into a biliary duct drainage tube. Given the uncertainties in the determination of tumor size in the bile ducts, ultrasound is an ideal method by which to obtain the measurements. We present a case of recurrent islet cell carcinoma treated with external beam radiation therapy and an Ir-192 intraluminal brachytherapy boost in which the ultrasound probe was used to determine the tumor volume and response to therapy.

Adenoma, Islet Cell↗
PubMed1991

Preoperative staging of esophageal cancer: comparison of endoscopic US and dynamic CT.

Fifty patients with esophageal cancer proved by means of biopsy underwent preoperative staging with endoscopic ultrasonography (US); in 42 of the patients, dynamic CT of the chest and abdomen was also performed. All results were compared with the findings at pathologic examination of resected specimens. In staging the depth of tumor growth, endoscopic US was significantly more accurate (46 of 50 tumors [92%]) than CT (25 of 42 tumors [60%]) (P less than .0003). In staging regional lymph nodes, it was more accurate (44 of 50 patients [88%]) than CT (31 of 42 patients [74%]), but this was not statistically significant. In staging distant metastases, however, CT was more accurate (38 of 42 patients [90%]) than endoscopic US (35 of 50 patients [70%]) (P less than .016). The highest concordance with surgical and pathologic findings in overall stage (36 of 42 tumors [86%]) occurred with the combined use of CT and endoscopic US, which was significantly more accurate than use of CT alone (27 of 42 tumors [64%]) (P less than .008).

Adenocarcinoma↗
PubMed1991

Preoperative staging of gastric cancer: comparison of endoscopic US and dynamic CT.

Fifty consecutive patients with gastric adenocarcinoma proved by means of biopsy underwent preoperative staging with endoscopic ultrasonography (US). Dynamic computed tomography (CT) of the chest and abdomen was performed before surgery in 33 of the patients. In all 50 patients, the TNM classification of the American Joint Committee on Cancer was used to compare the imaging findings with pathologic findings in specimens resected at surgery. When the depth of tumor penetration was evaluated, the findings at endoscopic US and those at pathologic examination were concordant in 46 of 50 patients (92%), and the findings at dynamic CT and those at pathologic examination, in 14 of 33 patients (42%) (P less than .00042). Evaluation of regional lymph node metastases showed a concordance of 78% with endoscopic US and 48% with dynamic CT (P less than .038). Overall determination of stage with both dynamic CT and endoscopic US showed a concordance of 73%, compared with a concordance of 45% for dynamic CT alone (P less than .028).

Adenocarcinoma↗
PubMed1989

Percutaneous endoscopic gastrostomy and jejunostomy for long-term feeding in patients with cancer of the head and neck.

Enteral feeding is often required in patients with cancer of the head and neck. Percutaneous endoscopic gastrostomies (PEGs) and jejunostomies (PEJs) can facilitate enteral feeding in patients who require this treatment. The endoscopic technique allows for the placement of feeding gastrostomies and jejunostomies without a surgical procedure and eliminates the need for nasal tubes for long-term enteral feeding. Forty-two patients with head and neck tumors were referred for placement of PEGs because of severe dysphagia induced by tumors, surgery, radiation, or chemotherapy. The procedure was performed in the gastroenterology suite. Patients were sedated with intravenous meperidine and diazepam, and local anesthetic with lidocaine was applied to the area of incision. Average procedure time was approximately 20 minutes. The procedure was successful in 39 patients in whom tubes were placed ranging in diameter from 15F to 22F. PEGs were placed in 36 patients with intact stomachs and PEJs in three patients with previous gastrectomies. The remaining three procedures were unsuccessful because of technical reasons. There were three localized skin infections, and all responded to antibiotic therapy. Neither peritonitis nor any other immediate complication occurred. In 16 nonhospitalized patients, the procedure was performed on an outpatient basis. After a mean followup of 4.5 +/- 6 months of enteral feeding in the home, there was only one case of aspiration and subsequent pneumonia, and this case responded to antibiotics. No other long-term complications were noted. Thus feeding gastrostomies and jejunostomies can be placed safely and easily in patients with cancers of the head and neck by endoscopic methods without abdominal surgery. These tubes can be used for enteral feeding and eliminate the need for nasogastric tubes. They are better tolerated, are of a wider diameter, and have a reduced risk for migration, clogging, and aspiration-related complications.

Combined Modality Therapy↗
PubMed1988

Flux of calcium across the sheep rumen wall in vivo and in vitro.

Experiments were carried out in vivo and in vitro to study the flux of Ca2+ across the sheep rumen wall. Buffer solutions with five different Ca2+ concentrations in the range 0.2-3.6 mmol l-1 were introduced into the isolated, emptied and washed reticulo-rumen for 1 h to determine Ca2+ net flux. Phosphate concentrations were either kept constant at 8 mmol l-1, or varied so as to maintain a constant phosphate/Ca2+ ratio of 2:1. Under both conditions there was a Ca2+ net secretion into the rumen at Ca2+ concentrations below approximately 1 mmol l-1 whereas Ca2+ net absorption occurred at higher Ca2+ concentrations and linearly increased with increasing Ca2+ concentrations. When phosphate concentrations were reduced to 4.3 and 0.6 mmol l-1 (Ca2+, 3 mmol l-1) Ca2+ net absorption was reduced by about 50% and completely abolished, respectively. The unidirectional (mucosal-to-serosal or serosal-to-mucosal) Ca fluxes in vitro, JCams and JCasm, were measured in Ussing chambers with computer-controlled voltage clamp. Under short-circuit current conditions (Ca2+ and phosphate, 2 mmol l-1) there was a significant net flux of Ca2+ from the mucosal to the serosal side. This net flux of Ca2+ was abolished when ouabain was added to the serosal solution, indicating that the unidirectional Ca2+ flux JCams and, hence, the net flux of Ca2+ was dependent upon active Na+ transport accomplished by the Na, K-ATPase system. Under voltage clamp conditions, the net flux of Ca2+ was greatly increased at a potential difference PD = -25 mV (serosa negative) but disappeared at PD = +25 mV (serosa positive). Analysis of the unidirectional Ca2+ fluxes JCams and JCasm under varying potential differences indicated that both Ca2+ fluxes consisted of a PD-dependent and a PD-independent component. The results show that the reticulo-rumen participates in Ca2+ absorption in sheep.

Animals↗
PubMed1987

Possible interaction of platelets and adrenaline in the early phase of myocardial infarction.

It is known that in most cases of transmural acute myocardial infarction a platelet clot originates within a coronary artery. In acute myocardial infarction patients increased levels of the plasma catecholamines adrenaline and noradrenaline as well as the platelet release proteins platelet factor 4 and beta-thromboglobulin have been reported. In this study, significantly higher values were found of platelet factor 4 (P less than 0.0001) and beta-thromboglobulin (P less than 0.002) in 17 acute myocardial infarction patients as compared to 17 control patients (on intensive care due to non-cardiac disorders), while the plasma levels of adrenaline and noradrenaline were not different. Positive correlations were obtained between the two catecholamines and the platelet products in the control group and between adrenaline and both platelet factor 4 (r = 0.715, P less than 0.01) and beta-thromboglobulin (r = 0.547, P less than 0.05) in the acute myocardial infarction patients. The data suggest that a stimulation of the platelets by adrenaline may facilitate in vitro activation during sampling in patients with high catecholamine load. On the other hand, a "preactivation" of the platelets by an increase of adrenaline might be of significance for thrombus formation in acute myocardial infarction.

Adult↗
PubMed1986

Typhoid fever: successful therapy with cefoperazone.

We compared cefoperazone with chloramphenicol in a randomized trial involving the treatment of 25 children with severe typhoid fever. The clinical characteristics of the two treatment groups were comparable on entry into the study. Four patients died (three receiving chloramphenicol, one cefoperazone), and an additional two patients received dexamethasone (one per group). Excluding these six patients, the response of the cefoperazone group was comparable or superior to that of the chloramphenicol group in terms of the number of days from initiation of therapy to becoming afebrile (P less than .055) and the number of days until negative blood cultures were obtained (P less than .19). There were no relapses or treatment failures in either group. We conclude that cefoperazone is as effective as chloramphenicol in the treatment of severe typhoid fever.

Adolescent↗