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Biomedical subjects

G Kandel

Publications and source records attributed to G Kandel.

At least 19 recordsLinked to original sources
PubMed2000

Helicobacter and disease: still more questions than answers.

Since the causative role of Helicobacter pylori in peptic ulcer and gastritis was established, a number of advances have been made. Helicobacter virulence factors have been identified, the changes it causes in gastric acid secretion has been elucidated, and the entire genome of H. pylori has been mapped. Multiple lines of evidence indicate a strong link between the bacterium and noncardia gastric cancer. The infection can be confidently diagnosed by noninvasive serologic tests and the urea breath test. Triple therapy is almost always curative, and the infection almost never recurs in Canadian adults, but eradicating the bacteria in the absence of peptic ulcer only rarely leads to resolution of dyspepsia. New studies suggest that treating Helicobacter may increase the risk of peptic esophagitis and adenocarcinoma of the esophagus and cardia.

Anti-Bacterial Agents↗
PubMed1998

PreB1 (CD10-) acute lymphoblastic leukemia: immunophenotypic and genomic characteristics, clinical features and outcome in 38 adults and 26 children. The Groupe dEtude Immunologique des Leucémies.

The less differentiated stage (CD10-) of B-lineage acute lymphoblastic leukaemia (ALL) described as preB1-ALL in the GEIL nomenclature, accounts for less than 10% of ALL. It is classically considered to be associated with translocation (4;11)(q21;q23), and to have a poor prognosis. We report an extensive immunophenotypic, genomic and clinical study of a series of 64 preB-1 ALL patients, representing 6.3% of a cohort of consecutive ALLs. The engagement of preB1-ALL cells in the B-lineage was confirmed by their B-lineage score, equal to or higher than 2. In addition, more than 90% of the cases tested showed rearranged IGH genes. Translocation (4;11) was the most frequent karyotypic anomaly seen, but only accounted for 24% of the preB1-ALL cases tested. Expression of the myeloid associated antigen CD15 was also found with high incidence in this subset. Clinical and biological features at presentation showed more significant differences between preB1- and T-ALL than between preB1- and preB2-ALL (CD10+). However, outcome characteristics of the 22 children with preB1-ALL confirmed the worse prognosis of this entity.

Adolescent↗
PubMed1997

Photodynamic therapy for the treatment of tumor ingrowth in expandable esophageal stents.

BACKGROUND AND STUDY AIMS: Tumor ingrowth through self-expanding metal stents presents a difficult problem for management. The techniques for treating tumor ingrowth have not yet been well described, and the optimal endoscopic approach is not clear. We have recently used photodynamic therapy (PDT) to treat tumor ingrowth through uncovered nitinol mesh stents. PATIENTS AND METHODS: Four patients (mean age 73) with obstructive adenocarcinomas of the distal esophagus had received self-expanding stents for palliation of their dysphagia. After stent placement, tumor ingrowth had caused progressive dysphagia in all of the patients; the dysphagia was graded on a scale from 0 (normal) to 4 (inability to swallow liquids). All of the patients received PDT treatment. RESULTS: After PDT, excellent palliation of the dysphagia was seen in all of the patients, with a mean improvement in the dysphagia score of 2.25 and a mean dysphagia-free interval of 92 days. There were no major complications. CONCLUSION: The use of PDT to treat tumor ingrowth through self-expanding metal esophageal stents is effective and safe.

Adenocarcinoma↗
PubMed1997

Idiopathic colonic inflammation in AIDS: an open trial of prednisone.

OBJECTIVES: Idiopathic colonic inflammation and ulceration have been described in HIV infection, but only as isolated case reports. We have been treating this condition with a uniform corticosteroid protocol and now report our results. METHODS: We describe the cases of eight patients with HIV infection who had diarrhea for more than 4 wk and inflammation and/or ulceration in the colon at endoscopy, confirmed by biopsy, without any invasive pathogens despite extensive evaluation. Each patient was treated with prednisone, starting at 40 mg/day, then tapered according to a standardized protocol. RESULTS: The diarrhea completely resolved in three patients and partially improved in five. One patient had some improvement but was unable to tolerate the prednisone because of a severe exacerbation of anal warts. He responded to subtotal colectomy. After a minimum follow-up of 8 months (mean, 17 months), only one patient (complete response to prednisone) was found to have an enteric pathogen. In this patient, cytomegalovirus colitis was diagnosed 15 months after prednisone was started. CONCLUSION: Idiopathic colonic inflammation or ulceration in HIV infection (1) may respond to corticosteroid therapy without life-threatening side effects and (2) is only rarely followed by the detection of a recognized pathogen. These observations suggest that enteric pathogens are not missed by standard techniques.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Use of continuous-infusion alfentanil for analgesia during spark-gap lithotripsy.

The painful stimuli produced by a new generation of electrohydraulic/electromagnetic lithotripters are such that continuous infusion analgesia rather than general or regional anesthesia is appropriate. We describe our experience with continuous alfentanil infusion supplemented with intravenous bolus midazolam in caring for patients treated with an unmodified Medstone STS 1050 lithotripter. Ninety consecutive treatments using this technique averaged 63 minutes, compared with 69 minutes for 14 treatments done with general anesthesia and 88 minutes for 58 treatments done with epidural anesthesia. The stone burden, kilovoltage, and number of shocks were similar for the three groups, as was the immediate stone fragmentation rate. Only 2 of 90 patients received inadequate analgesia with the intravenous technique and required the induction of general anesthesia. Continuous-infusion analgesia appears sufficient to blunt the stimulus provided by the unmodified spark-gap lithotripters still in common use.

Alfentanil↗
PubMed1994

Mucinous ductal ectasia: cholangiopancreatographic and endoscopic findings.

Mucinous ductal ectasia (MDE) is an uncommon disease characterized by a patulous duodenal papilla extruding mucus, and a pancreatogram showing dilation with amorphous filling defects, communication of the mass with the pancreatic duct, the mass usually being located in the head of the pancreas. We have recently treated three men and three women, mean age 66 years, with MDE. All had abdominal pain, while 33% had the clinical picture of pancreatic insufficiency. Three patients had recurrent pancreatitis, and three had biliary obstruction. Endoscopic retrograde cholangiopancreatography and imaging studies showed a patulous papilla draining mucus in six, pancreatic duct dilation in six, filling defects in six, and communication between the cystic mass and the pancreatic duct in five. A distinct finding not previously reported was a separate pancreatic and biliary orifice in two. Three patients had cancer, two cases being metastatic and one being found at surgery (not suspected preoperatively). Therapy included endoscopic biliary drainage in two, surgery in three, while one refused surgery. Of the operated patients, two underwent resection, one of whom had benign disease and the other cancer; both patients are doing well 14 and 32 months after surgery, respectively. One patient underwent pancreatojejunostomy without symptomatic relief, and developed cholangitis 18 months after surgery that was successfully treated with endoscopic drainage. The other two patients treated with biliary drainage died one and 13 months later, respectively. We conclude that MDE has characteristic pancreatographic and endoscopic findings, and that it is commonly associated with malignant degeneration. Surgical resection is the treatment of choice, since MDE is premalignant, and surgery may be curative when the malignancy is resectable.

Adenocarcinoma, Mucinous↗
PubMed1992

Comparison of hematopoietic and immune recovery after autologous bone marrow or blood stem cell transplants.

We studied hematopoietic and immune recovery in 40 subjects receiving autologous bone marrow (ABMT) or blood stem cell transplants (ABSCT). Supportive care, transplant-related morbidity, duration of hospitalization and cost were also considered. ABSCT was associated with more rapid recovery of all hematopoietic lineages than was ABMT. However, kinetics of immune recovery were similar between the groups. In the ABSCT group, there was a correlation between numbers of blood progenitor cells infused and the rate of hematopoietic recovery. The accelerated hematopoietic recovery following ABSCT correlated with less morbidity, fewer transfusions, briefer hospitalization and lower cost than ABMT.

Adolescent↗
PubMed1990

Management of nonvariceal upper GI hemorrhage.

Peptic ulcer disease remains the most common upper GI hemorrhagic diathesis, except, of course, for esophageal varices. But mucosal lesions such as vascular ectasias and superficial ulcers of Dieulafoy's disease are being increasingly recognized. Therapeutic endoscopic techniques, notably laser coagulation and injection sclerotherapy, may obviate surgery.

Endoscopy↗
PubMed1989

Pathogenesis of Shigella diarrhea. XVI. Selective targetting of Shiga toxin to villus cells of rabbit jejunum explains the effect of the toxin on intestinal electrolyte transport.

To examine the mechanism by which Shiga toxin alters intestinal water and electrolyte transport, ligated loops of rabbit jejunum were incubated in vivo with purified toxin and then studied in vivo by single pass perfusion and in vitro by the Ussing chamber voltage-clamp technique. Toxin exposure led to accumulation of water in the jejunal lumen, associated with decreased active basal NaCl absorption. Glucose- and alanine-stimulated Na absorption were also reduced, while toxin had no effect on either basal short-circuit current or the secretory response to theophylline. These observations suggest that Shiga toxin selectively inhibits NaCl absorption without significantly altering active anion secretion. To localize the cellular site of toxin action, populations of villus and crypt cells from rabbit jejunum were isolated and studied. Villus cells had a greater content of the glycolipid Shiga toxin receptor, Gb3, had more toxin binding sites than did crypt cells, and were much more sensitive than crypt cells to toxin-induced inhibition of protein synthesis. These experiments demonstrate that purified Shiga toxin inhibits jejunal fluid absorption without affecting active fluid secretion by a preferential effect on villus cells. The results suggest that this is due to the differential distribution of toxin receptors on villus compared to crypt cells.

Absorption↗
PubMed1988

Collection of circulating stem cells and their use for autograft in adults with acute lymphoblastic leukaemia.

The level of peripheral blood granulocyte-monocytic precursors (PB CFU-GM) was studied serially in 10 adult patients with acute lymphoblastic leukaemia (ALL) in early complete remission after induction chemotherapy. The patients were distributed into 2 main groups according to the morphological French-American-British classification: ALL2 and ALL3. Collection of circulating stem cells (CSC) by cytapheresis was performed in 7 of these 10 patients with satisfactory results, except in 2 ALL2 patients, both of whom had chromosome translocation, which could have been a contributing factor. It appears, moreover, that even with 2 or 3 inductions courses, the more intensive the chemotherapy regimen in previously non-treated patients, the higher the peak of PB CFU-GM and the better the collection of CSC. The measurement of CFU-GM is certainly a less effective indicator of pluripotent stem cells in blood than in bone marrow, and it is probably necessary, but sufficient, to inject 5 times more CFU-GM than normally injected in marrow transplants to allow prompt and stable engraftment. The feasibility of this new graft technique seems for the moment undeniable, the main problem in ALL is the risk of relapse.

Adult↗
PubMed1988

Duodenal perforation by a Linton-Nachlas balloon tube.

In a patient with bleeding esophageal varices, inadvertent inflation of a Linton-Nachlas balloon in the third portion of the duodenum led to bowel perforation and death. This complication emphasizes a potential problem in passing a balloon catheter as far as possible down the nares, a technique that has been suggested to prevent balloon catheter inflation in the esophagus. To the best of our knowledge, this is the first reported case of duodenal rupture from attempted balloon tamponade for variceal hemorrhage.

Balloon Occlusion↗
PubMed1987

5-ASA enemas for refractory distal ulcerative colitis. An open trial.

We conducted an open trial of 5-ASA enemas to determine the role of this drug in idiopathic distal ulcerative colitis resistant to conventional therapeutic approaches. Fifty-one such refractory patients were given 4 g 5-ASA enemas once nightly for 2 weeks, and the response was then assessed clinically and sigmoidoscopically. Overall, 29 patients (57%) had an excellent response, 11 (21%) had a satisfactory response, and a further 11 (21%) had a poor outcome. Two patients developed adverse reactions. Of the 11 patients with a poor response, nine remained dependent on oral prednisone for remission of their colitis. Although the role of 5-ASA enemas in the treatment of refractory distal ulcerative colitis remains to be determined, it appears that the drug appears to be beneficial for only a minority of patients dependent on systemic corticosteroids.

Adult↗