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Biomedical subjects

J Rahier

Publications and source records attributed to J Rahier.

At least 37 records · Page 2Linked to original sources
PubMed2001

Unusual evolution of an Epstein-Barr virus-associated leiomyosarcoma occurring after liver transplantation.

We report the case of a child who developed, 2 yr after orthotopic liver transplantation (OLTx) for biliary atresia, a multi-focal hepatic tumor with lymphonodular metastases, identified as an Epstein-Barr virus (EBV)-associated leiomyosarcoma. Chemotherapy was given without tumor response. Subsequently, slow growth of the tumor was observed. Immunosuppression was tapered and stopped 9 yr after transplantation. At the present time, 12 yr after the discovery of the first hepatic lesions, the patient is alive and completely symptom-free, the abdominal masses are stable, and liver function tests are completely normal. Smooth muscle tumors are increasingly recognized in children with various immunodeficiencies occurring after organ transplantation. This unusual evolution of a clinically aggressive tumor into a stable disease after restoration of immunity confirms that the immune status of the patient is a crucial factor.

Biliary Atresia↗
PubMed2001

Tolbutamide stimulation of pancreatic beta-cells involves both cell recruitment and increase in the individual Ca(2+) response.

Individual pancreatic beta-cells are functionally heterogeneous. Their sensitivity to glucose is variable, so that the proportion of active cells increases with the glucose concentration (recruitment). We have investigated whether sulphonylureas also recruit beta-cells, by measuring cytoplasmic Ca(2+) ([Ca(2+)](i)) - the triggering signal of insulin secretion - in single cells and clusters of cells prepared from mouse islets. In 4 mM glucose, the threshold concentration of tolbutamide inducing a [Ca(2+)](i) rise was variable (5 - 50 microM). The proportion of responsive cells and clusters therefore increased with the tolbutamide concentration, to reach a maximum of 90% of the cells and 100% of the clusters. This recruitment occurred faster when the glucose concentration was increased from 4 to 5 mM (EC(50) of approximately 14 and approximately 4 microM tolbutamide respectively). Within responsive clusters little recruitment was observed; when a cluster was active, all or nearly all cells were active probably because of cell coupling. Thus, tolbutamide-induced [Ca(2+)](i) oscillations were synchronous in all cells of each cluster, whereas there was no synchrony between clusters or individual cells. Independently of cell recruitment, tolbutamide gradually augmented the magnitude of the [Ca(2+)](i) rise in single cells and clusters. This increase occurred over a broader range of concentrations than did recruitment (EC(50) of approximately 50 and 25 microM tolbutamide at 4 and 5 mM glucose respectively). Tolbutamide (10 microM) accelerated the recruitment of single cells and clusters brought about by increasing glucose concentrations (range of 3 - 7 mM instead of 4 - 10 mM glucose), and potentiated the amplification of the individual responses that glucose also produced. In conclusion, both metabolic (glucose) and pharmacologic (sulphonylurea) inhibition of K(+)-ATP channels recruits beta-cells to generate a [Ca(2+)](i) response. However, the response is not of an all-or-none type; it increases in amplitude with the concentration of either glucose or tolbutamide.

Animals↗
PubMed2001

An unusual metastatic motilin-secreting neuroendocrine tumour with a 20-year survival. Pathological, biochemical and motility features.

Motilin-secreting neuroendocrine tumours have been rarely described. Immunohistochemical, biochemical and motility investigations were performed in a 62-year-old man with liver and bone metastases of a motilin-secreting neuroendocrine tumour originating from a rectal polyp removed 14 years previously. Symptoms related to liver metastases were reduced by a right hepatectomy whereas plasma motilin levels were decreased. The patient also underwent two operations for spinal cord decompression and survived 6 more years under medical treatment, mainly octreotide. Immunohistochemistry revealed predominant expression of motilin-containing cells, with rare cells expressing somatostatin and pancreatic polypeptide, and staining for only one panendocrine marker, neurone-specific enolase. A liver tumour extract contained 17.9 microg motilin per gram of tissue, which permitted to isolate and characterize human motilin, which was identical to porcine motilin. Plasma column gel chromatography revealed a main peak corresponding apparently to porcine motilin. The patient had no symptoms of disturbed motility. Gastric emptying and gastroduodenojejunal motility were found within normal limits. The absence of alterations of gut motility was perhaps related to sustained autonomous motilin production. The long evolution of this type of tumour suggests that plasma motilin determination should be added to the investigations for neuroendocrine tumours.

Bone Neoplasms↗
PubMed2001

Human type 2 diabetes: morphological evidence for abnormal beta-cell function.

The exact nature of the beta-cell defect in type 2 diabetic patients is still unclear. beta-Cell mass reduction has been reported but remains controversial. A preliminary study of a large series of patients has demonstrated that in most, the beta-cell defect is not related to a decreased beta-cell mass. Amyloid deposits are observed in the islets of some type 2 diabetic patients but also in normoglycemic subjects. Because it has been claimed that these deposits interfere with beta-cell function, we evaluated in situ the effect of insular amyloid deposits on beta-cell transcription and translation. Pancreases were obtained at autopsy from 28 normoglycemic patients and 41 type 2 diabetic patients. Staining with hemaluneosin and Congo red was used to analyze the general features of the islets and the presence of amyloid deposits, respectively. Immunohistochemistry for proinsulin was performed with an antibody recognizing the junction between B-chain and C-peptide, thus specifically labeling the Golgi area where proinsulin is produced. In seven patients, we evaluated insulin gene transcription by in situ hybridization of proinsulin mRNA combined with Congo red staining, and we evaluated insulin storage by double immunostaining for insulin and amylin. In many type 2 diabetic patients, the islets appeared entirely normal. Amyloid deposits were found in 57% of diabetic subjects and 33% of normoglycemic age-matched control subjects. The percentage of amyloid-infiltrated islets varied from 0.4 to 74%. beta-Cells from amyloid-containing islets still had specific Golgi proinsulin labeling. In obese type 2 diabetic patients, the number of beta-cells with abnormal expression of proinsulin in the whole cytoplasm was significantly higher than in normoglycemic control subjects. Proinsulin mRNA was significantly reduced in islets with amyloid deposits when compared with amyloid-free islets, but the mean reduction did not exceed 16%. Insulin was still present in the beta-cells of amyloid-containing islets, and its amount, estimated by measurement of the insulin-labeling optical density, was not statistically different from that in amyloid-free islets. In conclusion, even in amyloid-containing islets, beta-cells maintain active insulin transcription and translation and normal insulin storage. Taking into account that in most cases only a small proportion of islets are infiltrated by amyloid, the limited reduction in proinsulin mRNA is unlikely to play a major role in the pathogenesis of diabetes.

Amyloid↗
PubMed2000

Orbital metastasis as primary manifestation of thyroid carcinoma.

A 59-year-old woman with unknown primary tumor developed progressive painless left upper eyelid swelling and exophthalmos. Computed tomography (CT) showed a well-circumscribed left orbital mass producing bone lysis. Immunohistologic staining of the incisional biopsy specimen was positive for thyroglobulin, suggesting an orbital metastasis from thyroid carcinoma. At this time, thyroglobulin was high (1400 ng/dL). Total thyroidectomy with lymph node dissection disclosed a follicular carcinoma with microscopic foci of papillary variant follicular carcinoma. Two months after radioiodine treatment, the CT showed a regression of the orbital tumor mass with concomitant decrease in thyroglobulin (428 ng/dL). Although orbital metastases of thyroid carcinoma are uncommon, thyroid carcinoma has to be considered as a potential primary tumor in a patient with an orbital metastasis.

Carcinoma, Papillary, Follicular↗
PubMed2000

Loss of imprinted genes and paternal SUR1 mutations lead to focal form of congenital hyperinsulinism.

Persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) is a heterogeneous disorder characterized by profound hypoglycaemia due to inappropriate hypersecretion of insulin. An important diagnostic goal is to distinguish patients with a focal hyperplasia of islet cells of the pancreas (FoPHHI) from those with a diffuse abnormality of islets (DiPHHI), because the management differs significantly. The intriguing similarity between islet cell hyperplasia and tumourigenesis prompted us to investigate whether the imprinted genes in the 11p15 region are involved. Results showed that diffuse forms are caused by constitutional homozygous or compound heterozygous mutations of the SUR1 gene. In contrast, focal forms are caused by loss of the maternally inherited 11p15 region, resulting in both loss of the maternally expressed tumour suppressor genes accounting for hyperplasia and somatic reduction to hemizygosity or homozygosity of the paternally inherited SUR1, limited to the lesion. Thus, this somatic disorder, which leads both to beta-cell proliferation and to hyperinsulinism, can be considered the somatic equivalent, restricted to a microscopic focal lesion, of constitutional uniparental disomy associated with unmasking of a heterozygous parental mutation.

Adenosine Triphosphate↗
PubMed2000

Dominantly inherited hyperinsulinism caused by a mutation in the sulfonylurea receptor type 1.

ATP-sensitive potassium channels play a major role in linking metabolic signals to the exocytosis of insulin in the pancreatic beta cell. These channels consist of two types of protein subunit: the sulfonylurea receptor SUR1 and the inward rectifying potassium channel Kir6.2. Mutations in the genes encoding these proteins are the most common cause of congenital hyperinsulinism (CHI). Since 1973, we have followed up 38 pediatric CHI patients in Finland. We reported previously that a loss-of-function mutation in SUR1 (V187D) is responsible for CHI of the most severe cases. We have now identified a missense mutation, E1506K, within the second nucleotide binding fold of SUR1, found heterozygous in seven related patients with CHI and in their mothers. All patients have a mild form of CHI that usually can be managed by long-term diazoxide treatment. This clinical finding is in agreement with the results of heterologous coexpression studies of recombinant Kir6.2 and SUR1 carrying the E1506K mutation. Mutant K(ATP) channels were insensitive to metabolic inhibition, but a partial response to diazoxide was retained. Five of the six mothers, two of whom suffered from hypoglycemia in infancy, have developed gestational or permanent diabetes. Linkage and haplotype analysis supported a dominant pattern of inheritance in a large pedigree. In conclusion, we describe the first dominantly inherited SUR1 mutation that causes CHI in early life and predisposes to later insulin deficiency.

ATP-Binding Cassette Transporters↗
PubMed1999

Preserved vascular homograft for revascularization of pediatric liver transplant: a clinical, histological, and bacteriological study.

BACKGROUND: Arterial or venous homografts are frequently implanted for vascular reconstruction in orthotopic liver transplantation (OLT). When fresh vascular homografts (VH) from the same donor were not available, VH from another donor preserved at 4 degrees C in Terasaki (Ter) solution (modified lymphocyte culture medium) were used. METHODS: The clinical results after implantation of Ter-stored VH versus fresh VH in the revascularization of pediatric OLT were studied retrospectively. Short- and long-term follow-up of vascular patency was carried out by doppler ultrasonography in each case. A histological and bacteriological study of nonimplanted VH stored at 4 degrees C in saline (Sal), Ter and University of Wisconsin (UW) solutions for various time periods (days 0-28) was also undertaken. RESULTS: Between 1989 and 1996, 21 iliac arteries and 21 iliac veins preserved in Ter solution (mean preservation time: 8 days; range 1-26) and 100 fresh VH (68 arteries and 32 veins) (preservation time: 8 hr, range 4-21) were used in pediatric OLT. Thrombosis rates were 0 of 21 for stored arteries vs. 7 of 68 (10%) for fresh arteries (NS) and 3 of 21 (14%) for stored veins vs. 3 of 32 (9%) for fresh veins (NS). Actuarial graft survival rates were similar in both groups. Histological analysis of stored, nonimplanted VH invariably showed endothelial destruction within 24-48 hr after procurement. The bacteriological study showed contamination rates of 14 of 25 (56%) for Sal-stored VH, 5 of 25 (20%) for UW, and 1 of 19 (5%) for Ter (Sal vs. UW and Sal vs. Ter: P<0.01; UW vs. Ter: NS). CONCLUSIONS: Ter-preserved cadaveric VH could be safely used in OLT despite early destruction of endothelium.

Adenosine↗
PubMed1999

Clinical features of 52 neonates with hyperinsulinism.

BACKGROUND: Neonatal hyperinsulinemic hypoglycemia is often resistant to medical therapy and is often treated with near-total pancreatectomy. However, the pancreatic lesions may be focal and treatable by partial pancreatic resection. METHODS: We studied 52 neonates with hyperinsulinism who were treated surgically. The type and location of the pancreatic lesions were determined by preoperative pancreatic catheterization and intraoperative histologic studies. Partial pancreatectomy was performed in infants with focal lesions, and near-total pancreatectomy was performed in those with diffuse lesions. The postoperative outcome was determined by measurements of plasma glucose and glycosylated hemoglobin and by oral glucose-tolerance tests. RESULTS: Thirty neonates had diffuse beta-cell hyperfunction, and 22 had focal adenomatous islet-cell hyperplasia. Among the latter, the lesions were in the head of the pancreas in nine, the isthmus in three, the body in eight, and the tail in two. The clinical manifestations were similar in both groups. The infants with focal lesions had no symptoms of hypoglycemia and had normal preprandial and postprandial plasma glucose and glycosylated hemoglobin values and normal results on oral glucose-tolerance tests after partial pancreatectomy (performed in 19 of 22 neonates). By contrast, after near-total pancreatectomy, 13 of the patients with diffuse lesions had persistent hypoglycemia, type 1 diabetes mellitus developed in 8, and hyperglycemia developed in another 7; overall, only 2 patients with diffuse lesions had normal plasma glucose concentrations in the first year after surgery. CONCLUSIONS: Among neonates with hyperinsulinism, about half may have focal islet-cell hyperplasia that can be treated with partial pancreatectomy. These neonates can be identified through pancreatic catheterization and intraoperative histologic studies.

ATP-Binding Cassette Transporters↗
PubMed1999

HLA association of amoxicillin-clavulanate--induced hepatitis.

BACKGROUND & AIMS: Drug-induced immunoallergic hepatitis typically affects a minority of patients exposed to a particular drug. Its rarity is believed to be due to metabolic or immunologic idiosyncrasy. The presence of an immunologic idiosyncrasy might imply an HLA association. Previous studies reporting an HLA association of drug-induced hepatitis included only small numbers of patients and used serological HLA typing. METHODS: We studied 35 patients with biopsy-documented amoxicillin-clavulanate-induced hepatitis. HLA-A and -B were typed using alloantisera and compared with those of 300 controls (volunteer bone marrow donors). HLA-DRB and -DWB were typed by polymerase chain reaction-line probe assay, with 60 volunteer bone marrow donors serving as controls. RESULTS: The study group was characterized by a higher frequency of DRB1*1501-DRB5*0101-DQB1*0602 haplotype (57.1% vs. 11.7% in controls, P < 0.000005; after correction for the large number of comparisons, P < 0.0002). Patients with DRB1*1501-DRB5*0101-DQB1*0602 haplotype were more likely than patients without it to have a cholestatic (70% vs. 60%) or mixed (30% vs. 13%) than a hepatocellular pattern of hepatitis (0% vs. 27%) (P < 0.05). CONCLUSIONS: Amoxicillin-clavulanate-induced hepatitis is associated with the DRB1*1501-DRB5*0101-DQB1*0602 haplotype. The data support the view that an immunologic idiosyncrasy, mediated through HLA class II antigens, plays a role in the pathogenesis of drug-induced immunoallergic hepatitis. HLA association has a limited impact on the expression of hepatitis.

Adult↗
PubMed1999

Liver transplantation and HBsAg-positive postnecrotic cirrhosis: adequate immunoprophylaxis and delta virus co-infection as the significant determinants of long-term prognosis.

BACKGROUND/AIMS: The place of liver transplantation in hepatitis B viral (HBV)-related diseases remains controversial because of the high rate of reinfection. The aim of this study was to define the determinants of long-term prognosis after transplantation. METHODS: Fifty-eight patients were transplanted during the period February 1984-September 1996. Six patients died during the early (< 3 months) posttransplant period from causes unrelated to HBV infection. All 52 long-term (> 3 months) survivors were evaluated in relation to the mode of presentation, viral replication at time of transplantation, absence of hepatocellular cancer at time of transplantation and use of adequate immunoprophylaxis (IP). Adequate immunoprophylaxis, defined as maintenance of anti-HBs levels over 100 mUI/ml, was introduced in December 1989. Intention-to-treat IP analysis compared patients transplanted before and after this date. The median follow-up was 74 months (range 4 to 131). Forty-seven patients (90%) had a minimal follow-up of 3 years. RESULTS: Five-year actuarial survival rates of 58 patients and of 52 long-term survivors were 72 +/- 6% and 80 +/- 6%, respectively. Univariate analysis showed that delta co-infection (n = 25) significantly improved survival (p < 0.001) [96 +/- 4% vs 63 +/- 10% in HBV patients (n = 27) at 5 years] as did absence of hepatocellular cancer (n = 36) (p = 0.020) [89 +/- 5% vs 61 +/- 12% in 16 non-cancer patients]. IP, however, significantly influenced 5-year survival in the HBV-patient group (n = 17) (p = 0.001) [85 +/- 10% vs 30 +/- 14% in 10 patients without IP). Multivariate analysis selected delta co-infection (p = 0.002) and IP (p = 0.01) as the significant determinants of prognosis independently influencing survival. Uni- and multivariate analyses showed that survival without reinfection was significantly influenced by IP (p = 0.002) [73 +/- 8% (n = 31) versus 33 +/- 12% in 15 non-treated patients). CONCLUSIONS: Delta virus co-infection and immunoprophylaxis are the most important prognostic factors after transplantation for postnecrotic HBsAg-positive cirrhosis. Transplantation can be proposed as a therapeutic tool only if life-long adequate adjuvant therapy can be achieved. Under this condition good results can even be obtained if there is viral replication at the time of transplantation.

Actuarial Analysis↗
PubMed1999

Diabetes mellitus induces a thickening of the pulmonary basal lamina.

Long-term diabetes mellitus (DM) is characterized by widespread alterations of basal lamina (BL). The purpose of the present work was to verify whether the lung is also a target organ damaged in DM. Electron microscopy was performed on lung and kidney samples (autopsic material) from 6 diabetics and 6 control subjects studying the thickening of BL of different structures (alveolar epithelial BL, endothelial capillary BL, both fused BL, BL of the glomerular capillary endothelium and BL of the renal tubules). The results were as follows: (1) alveolar epithelial BL (mean +/- SD) = 121 +/- 11 nm in controls and 176 +/- 27 nm in diabetics (p < 0.01), (2) endothelial capillary BL = 164 +/- 14 nm in controls and 223 +/- 27 nm in diabetics (p < 0.001), (3) both BL fused = 222 +/- 23 nm in controls and 316 +/- 62 nm in diabetics (p < 0.01), (4) BL of the glomerular capillary endothelium = 374 +/- 44 nm in controls and 626 +/- 249 in diabetics (p < 0.05) and (5) BL of the renal tubules = 602 +/- 94 nm in controls and 1,083 +/- 376 nm in diabetics (p < 0. 05). All parts of the lung are equally affected by DM. The thickening of BL is of the same magnitude in lung and kidney. There is no relationship between the thickening of the lung BL and the known duration and type of DM.

Adult↗
PubMed1999

Pulmonary gas exchange in life-long nonsmoking patients with diabetes mellitus.

In a companion paper, we have found that the alveolar epithelial basal lamina, endothelial basal lamina and both fused were significantly thicker in 6 autopsied diabetics than in 6 control subjects. The purpose of the present work was to assess whether these lesions have detrimental effects on gas exchange. We investigated 20 life-long nonsmoking subjects: 10 healthy subjects and 10 insulin-dependent diabetics. All of them had one to four diabetic complications of the following organs: kidney, retina, nerves or arteries. Their pulmonary gas exchange and their transfer factor were measured at rest and during two levels of submaximal exercise. Spirometric data, specific airway conductance, transfer factor, transfer coefficient, oxygen consumption and arterial blood gases were normal and almost identical in both groups. In conclusion, the thickening of lung basal laminae has no detrimental effect on pulmonary gas exchange in insulin-dependent diabetics with peripheral complications.

Adult↗
PubMed1999

Severe exacerbation of liver disease during pregnancy in a thalassemic GBV-C/HGV-positive patient and neonatal hepatitis in offspring.

The case of a young woman with GB virus C/hepatitis G virus (GBV-C/HGV) infection and with a severe exacerbation of chronic hepatitis of unknown etiology during pregnancy is described. In the offspring, severe neonatal hepatitis with subsequent mild chronic liver disease of at least 16-month duration was followed by the development of antibodies to the envelope protein (E2) of GBV-C/HGV, suggesting that the child was recovering from GBV-C/HGV infection. There was an improvement in clinical and biochemical parameters in the mother following delivery and alpha-interferon therapy was associated with a transient biochemical response.

Adult↗