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Biomedical subjects

P Hoang

Publications and source records attributed to P Hoang.

At least 37 records · Page 2Linked to original sources
PubMed1995

Eosinophilic gastroenteritis presenting with colitis and cholangitis.

Eosinophilic gastroenteritis (EG) is a rare condition that most commonly affects the stomach and intestine. Large bowel involvement has also been described. We report a case of EG presenting with colitis and cholangitis. This is the first case of associated cholangitis demonstrated radiologically and histologically. Simultaneous biliary and gastrointestinal tract involvement suggest a common link between EG and hypereosinophilic syndrome (HES). However, HES requires high peripheral hypereosinophilia and several organs including gastrointestinal tract, lung, heart, infiltrated with eosinophils. The patient's condition improved with corticosteroids.

Adult↗
PubMed1994

[An unusual cause of chronic diarrhea: lymphocytic colitis].

We report a case of lymphocytic colitis in a 74-year-old woman presenting with watery diarrhea since 1 year and in whom previous extensive investigations were normal. The diagnosis could be made on the basis of typical pathological pattern in colonic biopsies. The outcome was favourable with salazopyrine therapy. The clinical, histological and pathophysiological aspects of lymphocytic colitis are discussed.

Aged↗
PubMed1994

[Anal surgery in Crohn disease].

For twenty years, opinions concerning local surgery of anal lesions in Crohn's disease have changed in practice and in the literature. We have reviewed 209 patients, usually in remission of disease, with at least 6 months' follow-up, who underwent local surgery for various anal lesions from 1974 to 1992. In this study, our indications and results are discussed and compared to the literature. Results of partial haemorrhoidectomy are successful. In anorectal stenosis, with rectal involvement, surgery improves the symptoms and can avoid or delay proctectomy. Results of surgery for simple fistulas appear to be identical in cases with or without Crohn's disease. In complex and suprasphincteric fistulas, seton management improves chronic suppuration, occasionally cures the lesion and reduces the number of tracts. After seton drainage, transanal rectal advancement flaps can be performed, but the results of this procedure have yet to be confirmed.

Anus Diseases↗
PubMed1994

[Ileo-anal anastomosis in hemorrhagic-ulcerative rectocolitis and familial adenomatous polyposis: is it mandatory to perform resection of the endo-anal mucosa?].

The aim of this study was to assess the clinical outcome after ileal pouch-anal anastomosis with mucosectomy for ulcerative colitis and for familial adenomatous polyposis, and to characterize the histology of the stripped endoanal mucosa with particular reference to the ulcerative colitis activity, adenomatous polyps and dysplasia. Twenty-eight patients were operated, 16 for ulcerative colitis (group I) and 12 for familial adenomatous polyposis (group II). In group I, there were no intraoperative complications, but mucosectomy was tedious in 10 patients (62%) and the anastomosis was performed under some degree of tension in 10 patients (62%). In group II, there was a direct injury of the internal sphincter by a posterior tear during the mucosal stripping in one case. Mucosectomy was easy to perform in 8 patients (67%) and 10 anastomoses (84%) were performed under tension. In both groups, there were no postoperative complications related to the mucosectomy or to the anastomosis itself. Functional results were good, with a normal continence in 80% of ulcerative colitis patients and 92% of familial adenomatous polyposis patients. Review of histological sections of the stripped anal mucosa in group I showed chronic active ulcerative colitis in 8 patients (50%), chronic non-active ulcerative colitis in 4 (25%) and quiescent ulcerative colitis in 4 (25%). There was only one case of moderate dysplasia in a patient with a Dukes A carcinoma. In group II, anal mucosa showed micropolyps in all cases with mild dysplasia in 3 cases (25%) and moderate dysplasia in 9 (75%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenomatous Polyposis Coli↗
PubMed1993

Human colonic intraepithelial lymphocytes from patients with inflammatory bowel disease fail to down-regulate proliferative responses of primed allogeneic peripheral blood mononuclear cells after rechallenge with antigens.

Human colonic intraepithelial lymphocytes from control subjects down-regulate the proliferative responses of primed allogeneic peripheral blood mononuclear cells on rechallenge with antigens or phytohaemagglutinin (PHA). In contrast, human colonic intraepithelial lymphocytes from patients with inflammatory bowel disease fail to down-regulate the proliferative responses of primed allogeneic peripheral blood mononuclear cells on rechallenge with antigens. These findings may be important in the development and maintenance of the mucosal immunological activation of inflammatory bowel disease.

Aged↗
PubMed1993

Human colonic intraepithelial lymphocytes suppress in vitro immunoglobulin synthesis by autologous peripheral blood lymphocytes and lamina propria lymphocytes.

Human colonic intraepithelial lymphocytes have been shown to suppress the proliferation of autologous lamina propria lymphocytes and allogeneic peripheral blood mononuclear cells. This study has shown that, in vitro, intraepithelial lymphocytes suppress IgA and total immunoglobulin synthesis (but not IgG or IgM production) by autologous peripheral blood and lamina propria lymphocytes. This down regulation of IgA production is mediated by a soluble factor secreted by the intraepithelial lymphocytes. There is no difference in immunoglobulin down regulation by intraepithelial lymphocytes of control subjects and patients with inflammatory bowel disease.

Adolescent↗
PubMed1993

Cap polyposis--an unusual cause of diarrhoea.

'Cap polyposis' is a poorly recognised condition with distinct clinical, sigmoidoscopic, and pathological features that may be confused with other inflammatory conditions of the large intestine including pseudomembranous colitis and idiopathic chronic inflammatory bowel disease. The pathogenesis is unknown but on the basis of the characteristic histological appearances, which are similar to those seen in situations where mucosal prolapse is the underlying mechanism, it has been suggested that the latter may be an important aetiological factor. Two cases are described. Histological features in the first (presence of intramucosal elastin) and clinical features in the second (rectal prolapse) support the above hypothesis.

Aged↗
PubMed1992

Phenotypic characterization of isolated intraepithelial lymphocytes in patients with ulcerative colitis and normal controls.

A method was developed to isolate colonic intraepithelial lymphocytes in patients with ulcerative colitis (N = 8) and normal controls (N = 13) in order to characterize their phenotype using a panel of monoclonal antibodies and flow cytometry. In both groups, the majority of the cells are of the CD3+CD8+ phenotype associated with cytotoxic/suppressor function. The CD4/CD8 ratios were similar. Virtually no B cells or macrophages were found. An increase in cells coexpressing the CD3 and HLA-DR molecules and a decrease in natural killer cells (CD3, CD16+CD56+) were found in ulcerative colitis, but this was not significant. There were no differences in the proportions of CD8+ and CD4+ cells expressing the Leu8 antigen between ulcerative colitis and controls. Thus a population of colonic intraepithelial lymphocytes has been isolated and, although they may be functionally different in ulcerative colitis compared with controls, this cannot be explained in terms of phenotypic characteristics.

Adult↗
PubMed1992

Acute localized diverticulitis: optimum management requires accurate staging.

Between 1977 and 1989, 151 patients were treated in our institution for acute sigmoid diverticulitis. Thirty-one patients were operated on for diffuse peritonitis, and were excluded from the study. One hundred twenty patients had localized disease. There were 59 men and 61 women, with a mean age of 60 years (range, 30 to 87 years). Thirteen were under 40 years of age. A "phlegmonous" diverticulitis (no pericolic abscess) was diagnosed in 78 cases (group I). A pericolic abscess was identified in 42 cases (group II). The medical treatment was successful in 97% of the patients of the group I. Only 15 patients required a delayed elective resection for recurrence or chronic complications, within the next 24 months. There were no operative deaths. All the other patients were doing well after a mean follow-up of 5 years (9-144 months), without any disease-related death. Patients presenting with a localized pericolic abscess (group II, n = 42) were initially treated either conservatively (n = 22) or by a more or less extensive drainage (n = 20). There were two deaths in the "conservative" group. Primary or delayed colonic resection was indicated in 34 cases because of uncontrolled sepsis, recurrence or secondary chronic complications. It is concluded that accurate classification of the disease is essential. If no peritonitis has developed, the presence of an abscess is the main determinant in both prognosis and treatment. Most patients who develop an acute phlegmonous diverticulitis do well with conservative treatment, and prophylactic resection is not indicated. Curative colectomy is reserved for patients developing persistent complications over the next few months.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1992

Salicylates used in inflammatory bowel disease and colchicine impair interferon-gamma induced HLA-DR expression.

Colonic epithelial cells express HLA-DR in inflammatory bowel disease. The effect of drugs used in the treatment of inflammatory bowel disease and colchicine on interferon-gamma (IFN-gamma) induced DR expression has been investigated. HT-29 cells were cultured in 25 cm2 flasks. At 48 hours interferon-gamma (0, 50, or 100 U/ml) +/- drug were added. At 120 hours the cells were stained for HLA-DR and analysed by flow cytometry. 10(-2) M 5ASA reduced DR expression induced by 50 U/ml interferon-gamma from 62 (12)% of cells (mean SD) to 29 (20)% (p less than 0.005). Corresponding figures for 10(-2) M N-acetyl 5ASA were 68 (16)% to 39 (17)% (p less than 0.05); for 10(-2) M 4ASA, 61 (4)% to 57 (4)% (p = 0.6); for 10(-2) M N-acetyl 4ASA, 60 (12)% to 35 (13)% (p less than 0.05); for 10(-2) M olsalazine, 72 (9)% to 3 (1)% (p less than 0.001); for 10(-3) M olsalazine, 72 (9)% to 16 (10)% (p less than 0.001); for 10(-6) M colchicine, 62 (13)% to 5 (3)% (p less than 0.001); and for 10(-7) M colchicine, 62 (13)% to 10 (3)%. Similar results were obtained when DR was induced by 100 U/ml of interferon-gamma except with 10(-2) M 4ASA which reduced expression from 77 (4)% to 68 (3)% (p less than 0.05). Sulphapyridine, prednisolone, indomethacin and cyclosporin A had no effect. Concurrent staining with propidium iodide showed that these results were unchanged when viable cells alone were analysed. Prior incubation of cells with drug, followed by washing, had no effect on interferon-gamma induced DR expression. 5ASA, N-acetyl 5ASA, 4ASA, N-acetyl 4ASA, olsalazine and colchicine reduce interferon-gamma induced HLA-DR expression. In inflammatory bowel disease these compounds may impair antigen presentation by the colonic epithelium.

Aminosalicylic Acid↗
PubMed1992

Antigen induced suppression in peripheral blood and lamina propria mononuclear cells in inflammatory bowel disease.

Using an autologous system, suppressor cell function to a range of mycobacterial antigens and Kunin antigen of peripheral blood mononuclear cells and lamina propria lymphocytes has been investigated in normal subjects and patients with inflammatory bowel disease. In the peripheral blood there was reduced antigen induced suppression in patients with Crohn's disease in remission to Mycobacterium paratuberculosis, purified protein derivative (PPD), M fortuitum, and Kunin antigens (p less than 0.05). In patients with ulcerative colitis in remission there was reduced antigen induced suppression in the peripheral blood to Kunin antigen (p less than 0.001), M avium (p less than 0.01), M nonchromogenecin, and M fortuitum (p less than 0.05). The phenomenon of antigen induced suppression was largely CD8 dependent, as depleting CD8+ cells reduced the effect and the concentration of soluble CD8 in the culture supernatant was directly related to the suppressor index (r = 0.25, p less than 0.05). These results are likely to be a true reflection of the cell mediated response to antigen as patients with a positive Mantoux skin test have a significantly higher suppressor index to PPD than Mantoux negative subjects (p less than 0.05). These findings may have significance in the aetiopathogenesis of inflammatory bowel disease. However, a similar effect could not be shown in the lamina propria lymphocytes of patients having colectomy for active disease.

Adult↗
PubMed1992

Double blind, controlled trial of 4-aminosalicylic acid and prednisolone enemas in distal ulcerative colitis.

Corticosteroid or 5-aminosalicylic acid enemas are the treatment of choice for distal ulcerative colitis but up to one third of patients may be unresponsive. As an alternative therapy might be advantageous, the efficacy of six weeks' treatment with 2 g 4-aminosalicylic acid (4-ASA) (n = 24) and 20 mg prednisolone enemas (n = 21) were compared in a double blind, randomised trial in patients with acute distal (less than 30 cm from the anus) ulcerative colitis. Baseline demography and clinical severity were similar in both groups. Five of 24 patients receiving 4-ASA and 4 of 21 receiving prednisolone did not complete the trial because of deteriorating symptoms, failure to improve, or side effects. At the time of leaving the trial, 24 hour stool frequency, the presence of blood in the stools, and histological and sigmoidoscopic appearances were similar in both groups. Symptomatic improvement occurred in 17 of 24 patients receiving 4-ASA compared with 11 of 21 receiving prednisolone (chi 2 = 1.62, NS). Complete symptomatic improvement occurred in 9 of 24 patients receiving 4-ASA compared with 5 of 21 receiving prednisolone (chi 2 = 0.98, NS). Histological improvement was seen in 9 of 24 patients on 4-ASA compared with 7 of 21 on prednisolone (chi 2 = 0.08, NS). One patient receiving 4-ASA was considered to have an idiosyncratic reaction to the drug but other side effects were not considered to be drug related. Thus, 4-ASA, previously used in the treatment of tuberculosis (para-aminosalicyclic acid), is as good as prednisolone in the treatment of distal ulcerative colitis and should be considered in patients unresponsive to steroids or in whom steroid treatment is undesirable.

Aminosalicylic Acid↗
PubMed1992

Epithelial cells bearing class II molecules stimulate allogeneic human colonic intraepithelial lymphocytes.

HLA-DR+ gut epithelial cells may present antigen to intraepithelial lymphocytes (IEL). This study aimed to isolate an IEL population from the human colon to activate CD3 + IEL by a human colonic epithelial cell line (HT-29), bearing different concentrations of class II antigen (HLA-DR). IEL were isolated by a mechanical method from six patients with ulcerative colitis (UC) and from 14 control patients. IEL were cocultured with HT-29 which had been induced to express class II molecules by gamma-interferon (IFN-gamma) in a dose dependent manner. The phenotype and the subsequent expression of activation markers by the IEL were determined to two colour flow cytometry. The IEL population had a CD4/CD8 ratio similar to that seen in tissue sections. In the mixed cell culture, the degree of IEL activation showed a positive correlation with the degree of HLA-DR expression by the HT29 cells and the IEL secreted a IFN-gamma like factor that in turn stimulated the HT-29. Thus, depending on their expression of HLA molecules, colonic epithelial cells are able to activate CD3+CD8+IEL.

Adult↗
PubMed1992

[Compression neuropathy of the cubital nerve at the elbow].

Compression neuropathy of the ulnar nerve at the elbow has numerous known etiologies, and the anatomy of the ulnar nerve around the elbow leaves it vulnerable to compression at numerous sites. The compression may be extrinsic such as in occupational neuropathy or in cases of postanesthesia neuropathy. The so-called idiopathic compression may be favored by some anatomic variations. The cubital tunnel retinaculum may be loose, leading to ulnar nerve dislocation or subluxation or tight compression of the nerve during flexion of the elbow. Bulging of the synovium in the floor of the tunnel may be the cause of compression in rheumatoid arthritis, whereas osteophytes may be the cause in degenerative osteoarthritis. Cubitus valgus or instability due to a pseudarthrosis of the lateral epicondyle or to ligamentous injury may stretch the nerve. The choice of a surgical technique must be based on (i) the pathophysiology of chronic nerve compression at the elbow, (ii) an understanding of the etiology of the nerve compression in the particular patient's case, and (iii) the knowledge of the potential technical drawbacks of the various operative procedures. Simple decompression is the first choice in case of minimal compression without instability of the nerve. Decompression of the nerve with a medial epicondylectomy is indicated in case of instability of the nerve and is the first choice in case of pseudarthrosis or malunion of the medial epicondyle. Ulnar nerve transposition is technically the most demanding procedure. Inadequate surgical technique creates new sites of compression.(ABSTRACT TRUNCATED AT 250 WORDS)

Elbow↗