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R Gomis

Publications and source records attributed to R Gomis.

At least 19 recordsLinked to original sources
PubMed1992

Analysis of islet cell antibodies reactivity to a human islet cell line.

A human pancreatic beta cell line (HP62) was tested for reactivity with islet cell antibodies (ICA) as compared with previously-established methods. Using indirect immunofluorescence test, we found that HP62 cell line failed to react in a specific way with ICA from type 1 (insulin-dependent) diabetic patients since sera from normal controls showed a reactivity similar to that found in the patients. So, the usefulness of this human beta cell line as a tool of immunological purpose is questioned when indirect immunofluorescence procedures are used.

Autoantibodies↗
PubMed1992

Symptomatic and hormonal hypoglycaemic responses to human and porcine insulin in patients with type I diabetes mellitus.

In recent years there has been great concern that human insulin (HI) may induce fewer hypoglycaemic warning symptoms than porcine insulin (PI). We addressed this issue in eight patients aged 25.6 +/- 3.3 (SEM) years with Type I (insulin-dependent) diabetes mellitus of 15.1 +/- 3.7 years duration who complained that hypoglycaemia unawareness had appeared after transferring from PI to HI. Acute induction of hypoglycaemia was induced on two occasions with semisynthetic HI and purified PI under double-blind conditions. Blood glucose was first clamped for 2 h at 4.4-6.7 mmol l-1 with an intravenous infusion of HI or PI at 50 mU kg-1 h-1 and 20% glucose at a variable rate. Thereafter, insulin infusion alone was maintained for 100 minutes. Heart rate, arterial pressure, reflex times, autonomic and neuroglycopenic signs and symptoms were assessed every 10 min. Arterialized venous blood samples were taken to measure blood glucose every 10 min and catecholamines, insulin, glucagon, growth hormone, and cortisol every 20 min. Autonomic symptoms first appeared at a plasma glucose level of 2.92 +/- 0.21 mmol l-1 with HI vs 2.92 +/- 0.48 mmol l-1 with PI (NS). There were no significant differences between the two studies concerning any of the above mentioned clinical parameters or the counterregulatory hormone responses. A differential effect of insulin species on the ability to perceive hypoglycaemia in patients who ascribed diminished perception of hypoglycaemia to the use of HI was thus not observed.

Adult↗
PubMed1992

Reevaluation of autoantibodies to islet cell membrane in IDDM. Failure to detect islet cell surface antibodies using human islet cells as substrate.

Since their demonstration in 1975, ICSAs have been proposed as serological markers and pathogenic elements in IDDM. ICSAs are detected in the sera of most newly diagnosed IDDM patients by indirect IFL that uses viable preparations of rat islet or insulinoma cells as substrate, but they also can be detected by using human insulinoma or fetal islet cells. We have tried to demonstrate ICSAs in the sera of 31 newly diagnosed diabetic patients, including 6 positive samples on human fetal islet cells, which used their natural target for the first time: normal human islet cells. In spite of using different types of preparations of these cells (i.e., freshly dispersed cell suspensions, monolayer cultures, or dispersed islets after culture), ICSAs could not be detected by IFL under the UV microscope, nor by flow cytometry. In contrast, 9 of 29 of the sera gave a positive staining on the RIN rat insulinoma cells. In an attempt to establish whether the putative ICSA autoantigen is present in the surface of human islet cells in the diabetic pancreas, the insulitis microenvironment was emulated by exposing the islets to three types of stress: 1) cytokines (IFN-gamma and TNF-alpha); 2) heat shock; and 3) hyperglycemia. However, diabetic sera failed again to recognize membrane antigens on the islet cells after either of these treatments. Neither were islet cells from a newly diagnosed diabetic patient stained by its autologous serum (ICA titer > 80 JDF U). These results suggest that ICSA autoantigen is not expressed in the membrane of human islet cells and therefore raises doubts about their proposed pathogenic role.

Adolescent↗
PubMed1991

Metabolic and secretory response of parotid cells to cationic amino acids. Uptake and catabolism of L-arginine and L-ornithine.

L-Arginine and L-ornithine, which stimulate amylase release, are taken up by rat parotid cells. L-Arginine is converted, in an NADPH-dependent manner and to a limited extent to L-citrulline in parotid cell homogenates, despite the absence of ornithine transcarbamylase activity. L-Arginine is largely converted to urea and L-ornithine. The generation of putrescine and polyamines from L-ornithine occurs at a very low rate, relative to the cell content in performed amines. The major fate of exogenous or arginine-derived ornithine consists in its conversion to L-glutamate, which is then further metabolized. These findings raise several hypotheses for the secretory response of the parotid cells to cationic amino acids, including their accumulation as positively charged molecules inside the cell and the generation of either NO, amines, substrates for a transglutaminase-catalyzed reaction, or ATP through oxidative catabolism. However, each of these hypotheses meets with objections, the modality for the stimulation of amylase release by cationic amino acids being eventually considered as an unsettled matter.

Amylases↗
PubMed1991

Effects of single dose irradiation on pancreatic beta-cell function.

We have irradiated abdominal cavity of 23 rats with 10 Gy irradiation-induced hypoglycemia on the fourth day after intervention. Islets collected at this time showed an impaired insulin secretion without affecting insulin content. This impairment persisted after one month follow-up with reduced number of beta-cells in morphological examination.

Abdomen↗
PubMed1991

Auditory function in young patients with type 1 diabetes mellitus.

Comprehension of the effect of diabetes mellitus on auditory function has been hindered by the fact that previous studies have evaluated hearing function in heterogeneous groups of patients with diabetes mellitus, thus giving conflicting results. We have performed audiometric studies in 46 consecutive patients. 13 with newly diagnosed type 1 diabetes mellitus (group 1) and 33 with type 1 diabetes mellitus of more than 3 years of duration (group 2), of 14 to 40 years of age. The results were compared to an age-matched control group. Pure-tone auditory thresholds were significantly higher in all frequencies 250-8,000 Hz in both groups when compared to the control subjects. Ten patients, all of which belonged to group 2, had auditory thresholds above 30 dB in at least one frequency, showing a conversational hearing loss that ranged between 11 and 44%. However, none of them referred subjective hypoacusia. Univariate analysis revealed significant associations between auditory thresholds and age, duration of disease as well as retinopathy, but not with neuropathy, HbA1c or hypoglycaemic episodes. Only age and duration of disease independently correlated with an auditory threshold using multiple regression. We conclude that type 1 diabetes mellitus can cause mild sensorineural hearing impairment which correlates with age and duration of disease.

Adult↗
PubMed1991

[Segmental arterial sympathectomies at the level of the fingers].

The authors relate their experience of thirty digital artery sympathectomies in twenty-four fingers. Ten men and two women were operated: six crush injuries to fingers, three Raynaud's disease and two Buerger disease and one scleroderma. All presented digital vascular insufficiency. The pre-operative arteriogram always revealed more extensive thrombosis than suspected by the clinical symptoms. In this way we performed a segmental arterial sympathectomy depending on the site of the thrombosed artery. The follow-up was five years. The immediate postoperative results were excellent. Five years later the results depended on the nature of the initial disease.

Angiography↗
PubMed1991

[The inguinal pedicle flap in emergency traumatic hand surgery: value of the long pedicle permitting an early rehabilitation].

The main drawbacks of the use of a groin pedicle flap in emergency surgery for hand injuries are the declivitous position of the upper limb with a tendency towards oedema and the difficulty of instituting early rehabilitation because of the fact that the injured hand is fixed to the abdomen. Based on an extensive experience of 76 emergency flaps out of more than 100 flaps performed over the last ten years, the authors describe their flap raising technique which allows the formation of a long, closed tube compatible with early rehabilitation and also allowing the possible use of splints.

Emergencies↗
PubMed1991

Increased CD5-positive B lymphocytes in type I diabetes.

CD5+ B lymphocytes have been implicated in the production of polyspecific and monospecific antibodies that bind self-antigens, and increased proportions of this B cell subset occur in patients with some autoimmune diseases. We investigated the proportion of peripheral blood CD5+ B lymphocytes in type I diabetic patients. Compared with 18 age-matched healthy subjects, 11 out of 28 (39.2%) type I diabetic patients had increased proportions of circulating CD5. B lymphocytes with no alterations in the numbers of circulating B and T lymphocytes. Although all patients with increased CD5 B lymphocytes also had serum islet cell antibodies and/or insulin autoantibodies, the occurrence of increased proportions of CD5+ B lymphocytes and serum autoantibodies was not significantly correlated. Increased proportions of CD5+ B lymphocytes was not related to the time elapsed since the clinical onset of diabetes. In addition, regardless of being increased or normal, the proportion of CD5+ B lymphocytes appeared as a relatively constant phenotype after 1 year of follow-up studies at 3-month intervals in eight patients. Although the significance of these findings remains to be established, the possibility exists that CD5+ cells play a role in the pathogenesis of type I diabetes.

Adolescent↗
PubMed1991

Asymptomatic electronystagmographic abnormalities in patients with type I diabetes mellitus.

Only a few studies have investigated vestibular function in diabetes mellitus (DM), showing contradictory results. We have performed an electronystagmographic (ENG) evaluation of 46 individuals with type I DM and 37 healthy controls. No patient reported subjective vestibular symptoms. Duration of caloric-induced nystagmus (DN) was significantly lower (2.1 +/- 0.7 vs. 2.6 +/- 0.4 min, p less than 0.01), and central nystagmus frequency of caloric response also nonsignificantly tended to be decreased (37.4 +/- 16.5 vs. 41.7 +/- 12.7 beats/30s, p = 0.21) in DM patients, as compared to controls. The latter comparison achieved significance after exclusion of newly diagnosed diabetic patients (33.4 +/- 16.1 vs. 41.6 +/- 12.7 beats/s, p less than 0.05). Depressed caloric reactions were seen in 21.8% of patients. DN was lower in patients with microalbuminuria and retinopathy, but this was not observed after exclusion of newly diagnosed diabetic patients, all of whom had normal ENG responses and no chronic diabetic complications. The existence of a lower DN and central nystagmus frequency should be borne in mind when interpreting ENG tracings in patients with long duration type I diabetes mellitus.

Adolescent↗
PubMed1991

[Current techniques and indications of pedicled groin flap for hand surgery. Apropos of 100 cases].

Based on an analysis of the anatomical and physical data reported in the literature, the authors describe their personal technique based on an experience of 100 pedicled inguinal flaps. The authors define the current indications for this flap in reconstructive hand surgery. The quality of pedicled inguinal flaps makes this procedure a technique of choice in the emergency treatment of wounds of the hand.

Adolescent↗
PubMed1991

Natural history of islet cell antibodies during the clinical period of type 1 diabetes. High titres at diagnosis are associated with longer persistence.

The natural history of islet cell antibodies (ICA), using standardized Juvenile Diabetes Foundation (JDF) units, was studied for two years in 64 type 1 (insulin dependent) diabetic patients, aged 7-45 years prospectively from clinical onset. While ICA were present among 44/64 (68.8%) of the newly diagnosed patients, only 9.3% remained positive at 24 months. The only factor which showed significant predictive value for ICA survival was high initial JDF ICA titres: Maximal persistence of ICA was observed in patients with 80 JDF units at diagnosis (100% at 12 and 24 month). This persistence was lower in patients with 40 JDF units at diagnosis (77% at 12 month, 40% at 24 month) and the lowest for patients with 5 JDF at diagnosis (14% at 12 month, 0% at 15 month). 14/20 (70%) of patients negative for the ICA test at diagnosis became positive during follow-up, but always with a low titre (5-10 JDF units) and for a short period (3-6 months). It is concluded that initial titre is the most important variable in predicting the maintenance of ICA during the first two years of clinical type 1 diabetes.

Adolescent↗
PubMed1990

Human insulin dosage and distribution at the onset of type 1 diabetes mellitus.

The total insulin dosage and its distribution throughout the day were evaluated in newly diagnosed Spanish IDDM patients treated with semisynthetic human insulin. We assessed the insulin dosage and its distribution modifications related to an inpatient versus outpatient setting. We compared our results with classical theoretical algorithms based on patients treated with animal insulin and with alimentary habits which differ from our geographical area. The initial total daily dose (0.68 +/- 0.27 U/kg per day) did not substantially differ from the usual recommended dose (0.70-0.80 U/kg per day). A substantial decrease in total insulin dose was observed in ambulatory patients (0.55 U/kg per day). The reduction in dosage when we substituted regular insulin for intermediate acting insulin was smaller than what is commonly advised. A very low proportion of patients needed to add extra regular insulin to the pre-dinner intermediate insulin dose to achieve acceptable glucose control. Moreover, in these cases regular insulin comprised only 10% of total daily dosage, a proportion clearly inferior to that recommended. The majority of this group of patients needing regular insulin plus intermediate insulin at pre-dinner were treated with human zinc insulin. Most of our patients were acceptably controlled with a regular insulin dose before breakfast and lunch and an intermediate dose before dinner. Finally, human insulin pharmacokinetics plus our Mediterranean alimentary habits might be the explanation to our findings.

Adolescent↗
PubMed1989

Suppression by insulin treatment of glucose-induced inhibition of insulin release in non-insulin-dependent diabetics.

Although restoration of normoglycemia in non-insulin-dependent diabetic subjects improves insulin release evoked by several secretagogues, conflicting data were reported concerning the effect of intensive insulin therapy on the first-phase response of the B-cell to an intravenous glucose challenge. In the present study, 14 non-insulin-dependent diabetics underwent an intravenous glucose test performed before and after 20 h of glycemic normalization. Before insulin treatment, glucose failed, as a rule, to provoke an early positive secretory response. On the contrary, a paradoxical inhibition of insulin release was observed in most patients. This phenomenon was reproducible when a second test was performed 120 min after the first one. The paradoxical inhibition was not observed any more after glycemic normalization. As judged from the paired difference (delta) between the early increment in insulin release before and after insulin treatment, normoglycemia resulted in an improved secretory response (delta greater than 5.0 microU/ml) in seven patients, whilst the first-phase response remained little affected (delta less than 3.0 microU/ml) in the other seven subjects. These findings suggest that an impaired first-phase response to glucose does not always represent an irreversible primary defect of the pancreatic B-cell in diabetic subjects.

Adult↗
PubMed1989

Effect of nicotinamide therapy upon B-cell function in newly diagnosed type 1 (insulin-dependent) diabetic patients.

This study describes the effects of nicotinamide therapy on B-cell function in Type 1 (insulin-dependent) diabetes. C-peptide secretion was studied in 20 patients newly diagnosed with Type 1 diabetes at basal state and also after an i.v. glucagon stimulus. Patients were randomly allocated according to a single-blind schedule, to one of the following treatments over a 45-day period: Group 1: 10 patients, nicotinamide 1 g/day; Group 2: 10 patients, placebo. The C-peptide secretion tests were performed before treatment and on days 15, 45, 180, 365 of the follow-up. The clinical and metabolic data were similar in the two groups of patients. Basal and stimulated C-peptide levels increased by 45 days in both groups, but the increase in stimulated C-peptide response was greater in the nicotinamide group (p less than 0.01). However, the B-cell function decreased after the period of nicotinamide administration. No difference in the number of clinical remissions or insulin requirement and HbA1 between the groups was observed. These data suggest that treatment of Type 1 diabetes with nicotinamide at diagnosis is associated with a moderate increase of C-peptide secretion recovery.

Adolescent↗