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Biomedical subjects

M Perrin

Publications and source records attributed to M Perrin.

At least 73 records · Page 4Linked to original sources
PubMed1995

Dental injuries among schoolchildren aged from 6 to 15, in Rennes (France).

A representative sample of 2020 schoolchildren, aged 6 to 15 years, was randomly selected from 85 state and private schools in Rennes and distributed in 10 groups, according to their age. Type and prevalence of dental injuries were determined in each group, using Ellis & Davey's classification, giving rise to a subset of 345 subjects. Simple enamel fracture was the predominant injury (59.4%), occurring most often on maxillary central incisors. Most time (77.1%), the trauma affected only one tooth. Mean prevalence of dental injuries was 13.6% from 2020 subjects. Boys showed a higher prevalence than girls (respectively 17% and 10.2%), but this difference was only significant for age-groups 12 and 13 (p < 0.001) and for the whole group of 6-15 (p < 0.001).

Adolescent↗
PubMed1994

Distribution of corticotropin-releasing factor receptor mRNA expression in the rat brain and pituitary.

Corticotropin-releasing factor (CRF) is a major hypophysiotropic peptide regulating pituitary-adrenal response to stress, and it is also widely expressed in the central nervous system. The recent cloning of cDNAs encoding the human and rat CRF receptors has enabled us to map the distribution of cells expressing CRF receptor mRNA in rat brain and pituitary by in situ hybridization. Receptor expression in the forebrain is dominated by widespread signal throughout all areas of the neo-, olfactory, and hippocampal cortices. Other prominent sites of CRF receptor mRNA expression include subcortical limbic structures in the septal region and amygdala. In the diencephalon, low levels of expression are seen in a few discrete ventral thalamic and medial hypothalamic nuclei. CRF receptor expression in hypothalamic neurosecretory structures, including the paraventricular nucleus and median eminence, is generally low. In the brainstem, certain relay nuclei associated with the somatic (including trigeminal), auditory, vestibular, and visceral sensory systems, constituted prominent sites of CRF receptor mRNA expression. In addition, high levels of this transcript are present in the cerebellar cortex and deep nuclei, along with many precerebellar nuclei. In the pituitary, moderate levels of CRF receptor mRNA expression were detected throughout the intermediate lobe and in a subset of cells in the anterior lobe identified as corticotropes by concurrent immunolabeling. Overall, the central distribution of CRF receptor mRNA expression is similar to, though more expansive than, that of regions reported to bind CRF, and it shows limited overlap with loci expressing CRF-binding protein. Interestingly, CRF receptor mRNA is low or undetectable in several cell groups implicated as central sites of CRF action.

Adrenocorticotropic Hormone↗
PubMed1994

[Normal and pathological anatomy and physiology of the veins of the lower limbs].

Veins of the lower limbs are divided into two regions: 1) the superficial region, composed of two saphenous veins, internal and external, and of their tributaries; 2) the deep region, composed of veins that are satellites (and homonyms) of the arteries (anterior and posterior tibial; peroneal; popliteal; superficial, deep and common femoral; external, epigastric and common iliac). The two networks are linked by perforating (or communicating) veins and by the arches of the two saphenous veins. Valvules are found in the venous network below the inguinal ligament; their number decreases with increasing proximity to the inferior vena cava. The function of the valves is the main factor in the physiology of venous circulation, in association with the force essentially provided by the "muscle pump" of the calf. The various forms of venous insufficiency are due to obstruction or incontinence of the veins.

Blood Circulation↗
PubMed1994

Mixed cryoglobulinemia and hepatitis C virus.

BACKGROUND: Mixed cryoglobulinemia (MC) is frequently associated with clinical and biological evidence of liver disease and has recently been reported in cases of hepatitis C virus (HCV) infection. The aim of this study was to assess prospectively in a large series of MC patients: (1) the prevalence of HCV markers (anti-HCV antibodies and HCV RNA in serum and cryoprecipitate); (2) the main clinical, biologic and liver histologic features in patients with or without HCV infection. PATIENTS: One hundred fifteen consecutive unselected MC patients were studied: 45% had well-defined underlying diseases ("nonessential" MC). Fifty-five percent with no cause of MC were considered to have "essential" MC and were subjected to in-depth examination. METHODS: Patients were considered to have MC if two successive determinations of their serum cryoglobulin level were above 0.05 g/L. Anti-HCV antibodies (Ab) were detected in all patients by second-generation tests (ELISA, RIBA). We also looked for HCV RNA sequences amplified by polymerase chain reaction (PCR) in the sera and cryoprecipitates of 39 patients; HBs antigen, anti-HBs Ab and anti-HBc Ab in all patients; and HBV DNA in 20 sera and 17 cryoprecipitates. Quantitative HCV Ab and RNA studies were performed on whole serum, cryoprecipitates, and supernatants. Clinical features were recorded retrospectively for each patient. Liver biopsies from 23 anti-HCV Ab-positive and 7 anti-HCV Ab-negative patients were examined histologically, with qualitative and quantitative analysis. RESULTS: Anti-HCV Ab were found in 47/115 (41%) patients by ELISA and RIBA: 33/63 (52%) essential MC and 14/52 (27%) nonessential MC. Among the 63 essential MC patients, the 33 anti-HCV Ab-positive (Group 1) were compared to the 30 anti-HCV Ab-negative patients (Group 2). Group 1 patients had more cutaneous involvement (Raynaud's phenomenon, purpura, livedo, distal ulcers, or gangrenous changes) (17 versus 5: p = 0.004), higher alanine aminotransferase levels (110 +/- 22 versus 41 +/- 10 IU; p < 0.005), higher serum cryoglobulin levels (0.35 +/- 0.07 versus 0.12 +/- 0.04 g/L; p = 0.01), lower CH50 (28 +/- 3 versus 44 +/- 2 CH50/mL; p = 0.0001) and lower C4 levels (0.20 +/- 0.02 versus 0.29 +/- 0.03 g/L; p < 0.04). The prevalence of HBV serum markers was low in both groups, and HBV DNA was never detected in any of the sera and cryoprecipitates tested. HCV RNA sequences were detected in 10/16 (63%) sera and 12/16 (75%) cryoprecipitates from Group 1 patients, whereas they were not in the sera or cryoprecipitates from 23 Group 2 patients. Using quantitative PCR, HCV RNA in cryoprecipitates was concentrated 20 to 100 times despite the absence of significant anti-HCV Ab concentration in these samples. Histologic examination of liver biopsies revealed a spectrum of lesions ranging from chronic active hepatitis to cirrhosis, but Knodell's score did not differ between the groups. CONCLUSION: (1) About 50% of the essential MC patients had anti-HCV Ab, and these patients had more severe cryoglobulinemia-associated clinical and biological signs; (2) HCV RNA sequences were found in the large majority of sera and cryoprecipitates from patients with essential MC and anti-HCV Ab and were more concentrated in cryoprecipitates than in supernatants. These results suggest a role for HCV in the pathogenesis of MC and indicate that many cases of essential MC may be secondary to HCV infection and thus nonessential.

Adult↗
PubMed1994

Cryoglobulinemia in chronic liver diseases: role of hepatitis C virus and liver damage.

BACKGROUND/AIMS: Mixed cryoglobulinemia is frequently associated with liver diseases. The respective role of hepatitis C virus (HCV) and liver damage in the pathogenesis of cryoglobulinemia is investigated in this study. METHODS: The prevalence of cryoglobulinemia in 226 consecutive patients with chronic liver diseases (hepatitis C, 127; hepatitis B, 40; other diseases, 59) was studied, and the epidemiological, biological, histological, and virological features in these three groups were analyzed. Anti-HCV antibodies, HCV proteins, and HCV RNA were searched in the cryoprecipitates. RESULTS: The prevalence of mixed cryoglobulinemia was high (41.5%) in patients with liver diseases and higher in patients with hepatitis C (54.3%) than in patients with hepatitis B (15%) or other causes of liver disease (32%). Patients with cryoglobulinemia had cirrhosis more frequently and had a longer history of hepatitis. In patients with hepatitis C, HCV RNA sequences and HCV proteins were detected in the cryoprecipitate. Cryoglobulins became undetectable in 21 of 43 patients treated with interferon. CONCLUSIONS: These findings suggest that HCV is a major cause of cryoglobulinemia. Besides viral infection itself, multiple factors appear to be responsible for the production of cryoglobulins, including cirrhosis and duration of liver disease.

Adult↗
PubMed1994

Evidence for a short-term stimulatory effect of insulin on cholesterol synthesis in newly insulin-treated diabetic patients.

To gain further insight into the effects of insulin on cholesterol synthesis in humans, 19 newly insulin-treated diabetic patients were studied before any insulin treatment (study day 1) and after a few days of optimized glycemic control with a continuous intravenous insulin infusion (study day 2). The patients were divided into two groups according to their clinical characteristics and laboratory disorders. Groups I and II consisted, respectively, of 10 newly diagnosed type I diabetic patients and nine type II diabetic patients with secondary failure to oral antidiabetic drugs. Cholesterol synthesis was estimated from the determination of serum lathosterol, a metabolic precursor in the cholesterol pathway, and from the serum lathosterol to cholesterol ratio. Serum cholesterol (millimolar, mean +/- SEM) remained unchanged in both groups. After insulin therapy (study day 2), serum lathosterol (micromolar) and the serum lathosterol to cholesterol ratio (molar ratio x 10(3)) were significantly increased as compared with baseline (study day 1). Serum lathosterol levels were as follows: 9.9 +/- 2.0 versus 4.1 +/- 0.4 (P < .02) in group I, and 9.9 +/- 0.8 versus 5.7 +/- 0.7 (P < .005) in group II; serum lathosterol to cholesterol ratios were 2.10 +/- 0.39 versus 0.86 +/- 0.11 (P < .005) in group I, and 1.92 +/- 0.12 versus 0.98 +/- 0.10 (P < .001) in group II. The data indicate that in newly insulin-treated diabetic patients, short-term intensive insulin therapy has a stimulatory effect on cholesterol synthesis and even results in cholesterol overproduction.

Adolescent↗
PubMed1994

Venous valve repair: early results in fifty-two cases.

PURPOSE: Chronic deep venous insufficiency, usually secondary to the postthrombotic syndrome, is due to primary valve failure in approximately 15% of cases. In these cases surgical repair of the valvular mechanism may be indicated. METHODS: Fifty-two limbs in 42 patients were treated with superficial femoral vein valvuloplasty after appropriate investigation. Adjunctive operations on the superficial or perforating veins were performed on 49 limbs during the same hospital admission. RESULTS: Of the 27 patients who have completed one year of follow-up, 85% are free of reflux on duplex scanning and 68% have had normalization of venous refilling times. Of 11 limbs with venous ulceration followed up for more than 1 year, only one has had a recurrent ulcer (9%). In patients without ulceration the procedure has been successful in alleviating symptoms of venous insufficiency. CONCLUSIONS: We conclude that the procedure, in conjunction with appropriate superficial venous operation, is effective in selected patients with deep vein reflux whose conditions remain uncontrolled by conservative measures. At 1 year, 85% of valvuloplasties in this series remained competent.

Adult↗
PubMed1994

[Understanding the poor results after surgery for superficial venous insufficiency].

Effectiveness and value of surgical treatment in varicose veins remains difficult to assess for many reasons. They are discussed in details in front of this general review devoted to poor results after varicose vein surgery. An other pathology is often associated with venous insufficiency and is frequently missed and responsible of poor results. Many factors contribute to make uneasy assessment of poor results. The lack of objective criteria to appreciate the natural evolution of varicose disease different from one patient to another. The difficulty to grade clinical disease severity. Results published before the use of modern preoperative investigations make their report obsolete. Precise data of surgical treatment undertaken are often not detailed. The quality of therapists (surgeon or phlebologist) is uneasy to check. The difficulty to assess results after treatment: subjective results (patient) vs objective results (audit). Duration of follow-up. Imprecise vocabulary to qualify results. Clinical assessment remains the cornerstone but supplementary investigations must be undertaken. Duplex-Scan is currently accepted as the gold standard investigation. Phlebography or (and) plethysmography can be helpful in some cases. After detailed assessment patients can be classified in different groups. This classification allows to determinate the most adequate treatment. In some selected patients redosurgery is strongly recommended. Prevention of recurrence after surgical treatment of varicose veins can not be complete. Strict respect of several rules can however reduce it. They can be summarised as follows: Respect of temporary of definitive contraindications to surgical treatment. Thorough investigation before surgery. Preoperative precise aim of what must be treated by the surgical procedure. Correct operative procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Follow-Up Studies↗
PubMed1994

[Prevalence and significance of non-specific anti-organelle antibodies of the liver in chronic viral hepatitis C].

OBJECTIVES: The aim of this study was to evaluate the prevalence and the clinical signification of non organ specific autoantibodies in chronic hepatitis C. METHODS: We studied retrospectively 158 consecutive patients (97 with chronic hepatitis C, 24 with chronic hepatitis B, 67 with alcoholic cirrhosis) and 100 blood-donors. RESULTS: The prevalence of anti-nuclear and anti-smooth muscle antibodies was lower in blood donors than in patients (P < 0.001), but was comparable among the 3 groups of patients. The anti-liver-kidney microsome type 1 antibodies were detected only in patients with chronic hepatitis C (6%). The serum gammaglobulin level was significantly higher in patients with hepatitis C and anti-nuclear antibody titers > or = 1/50. The anti-smooth muscle antibodies detected in patients with hepatitis C had no anti-actin specificity. The response to interferon was not related to the detection of non organ specific autoantibodies before treatment. CONCLUSION: Anti-nuclear or anti-smooth muscle antibodies are not characteristic of hepatitis C virus infection.

Adult↗
PubMed1993

Post-transfusional anti-HCV-negative, non-A, non-B hepatitis. (I) a prospective clinical and epidemiological survey.

Despite the identification of hepatitis C virus (HCV) and the detection of anti-HCV antibodies in the serum of infected individuals, a sizeable proportion of patients who develop transfusion-associated acute non-A, non-B hepatitis following surgery do not develop anti-HCV antibodies. The cause of this disease remains unknown. To assess the role of homologous blood transfusion in anti-HCV-positive and -negative, non-A, non-B hepatitis following surgery, patients receiving homologous blood, autologous blood alone, or no transfusions were prospectively studied. Consumption of potentially hepatotoxic drugs was also quantified. Anti-HCV antibodies were tested retrospectively when commercial assays became available. Of the 181 patients who received homologous blood which tested negative for surrogate markers of infectivity, 19 (10.5%) developed non-A, non-B hepatitis, associated with anti-HCV seroconversion in three cases. Of the 90 autologous blood recipients, non-A, non-B hepatitis developed in one (1.1%), who did not seroconvert to anti-HCV. Of the 64 untransfused patients, non-A, non-B hepatitis developed in one (1.6%), who was anti-HCV-positive before surgery. Logistic regression analysis showed that the occurrence of non-A, non-B hepatitis was associated with homologous blood transfusion, but not with the consumption of potentially hepatotoxic drugs. The 16 homologous-blood recipients who developed anti-HCV-negative, non-A, non-B hepatitis had received blood from 70 donors, none of whom had detectable anti-HCV antibodies but six of whom had minimal elevations of serum aminotransferase activity. Anti-HCV-negative, non-A, non-B hepatitis is mainly transfusion-transmitted in the surgical setting. Known hepatotropic agents may be involved despite the absence of usual serum markers, but our results are also consistent with the involvement of an unidentified non-A, non-B, non-C agent.

Adult↗
PubMed1993

Hepatitis C virus and essential mixed cryoglobulinaemia.

Clinical and laboratory evidence of liver involvement are frequently found in essential mixed cryoglobulinaemia (EMC). We looked for evidence of hepatitis C virus (HCV) infection in 37 patients with EMC. Anti-HCV antibodies (Ab) were found in 16/37 (43%) patients with EMC using the ELISA 2 test and the RIBA 2 test. The 16 anti-HCV-Ab positive patients (group 1) were compared to the 21 anti-HCV-Ab negative patients (group 2). Group 1 patients had more frequent cutaneous involvement (P = 0.02), clinical, biological and histologic hepatic involvement (P < 0.01), higher serum cryoglobulin and lower CH50 levels (P < 0.001). Serum hepatitis B virus markers were infrequent in both groups and no patient from either group had detectable serum HBV DNA. These preliminary results suggest that HCV may be another cause of mixed cryoglobulinaemia.

Adult↗
PubMed1993

A European comparative study of serological methods for the diagnosis of infectious bovine rhinotracheitis.

A comparison is made of serological diagnostic procedures used for infectious bovine rhinotracheitis in the European Community. A panel of 65 sera, including positive, doubtful, negative and diluted samples was dispatched to nine different European laboratories and tested by neutralisation, enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence and passive haemagglutination, according to the methods used in each laboratory. The results showed good agreement between the various tests for positive and negative sera. However, considerable variability between tests was noted in the "doubtful" category of sera. The highest test sensitivity, as judged by the detection limit for samples serially diluted in negative serum, was found with the blocking ELISAs. A need was identified for international standard reference sera to be made available.

Animals↗
PubMed1993

[Effectiveness of combined repeat surgery and sclerotherapy after failure of surgical treatment of varicose veins].

UNLABELLED: From January 1985 to December 1986 one hundred and five patients (145 lower limbs) have been treated by redosurgery followed by sclerotherapy. It is a selected group because redosurgery decision was taken both by surgeon and angiologists on the basis that a significant reflux between the profunda system and the superficial system was present. The aim of this retrospective study was to assess results obtained by this therapeutic association with a follow-up from 5 to 6 years. Failure mechanisms of initial treatment, symptoms, preoperative investigations, redosurgery procedures are analysed. Results were estimated both by a questionnaire and an independent audit. Patient estimation: symptoms improvement 65%; cosmetics improvement 68%. Audit estimation: SYMPTOMS: excellent or good results: 78%, fair results: 12%, poor results: 10%. Cosmetics: excellent or good results: 30%, fair results: 53%, poor results: 17%. 82% of patients plebiscited redosurgery in cooperation with sclerotherapy.

Adult↗
PubMed1992

Gonadotropin-releasing hormone antagonists with N omega-triazolylornithine, -lysine, or -p-aminophenylalanine residues at positions 5 and 6.

In order to be used as fertility regulators in humans, gonadotropin releasing hormone (GnRH) antagonists must be extremely potent and long acting and exhibit negligible side effects such as stimulating histamine release. To this aim, we have recently synthesized a series of analogues with the standard Ac-DNal1-DCpa2-DPal3 substitutions, where the N omega-amino function of ornithine, lysine, or p-aminophenylalanine (Aph) was converted to the aminotriazolyl (atz) derivatives at positions 5 and 6 with further modifications at positions 7 and 10. The analogues were tested for their ability to bind to pituitary cell membranes, to release histamine in a mast cell assay, to inhibit luteinizing hormone (LH) secretion by castrated male rats or cultured pituitary cells, and to interfere with the ovulation in intact female rats. While the subcutaneous (sc) injection of 50 micrograms of Azaline A (7, [Ac-DNal1,DCpa2,DPal3,Lys5(atz),DLys6++ +(atz),ILys8,DAla10]GnRH) dissolved in 0.2 mL of an aqueous media significantly inhibited LH release in the castrated male rat for 24 h, the same dose of Azaline B (11), [Ac-DNal1,DCpa2,DPal3,Aph5(atz),DAph6++ +(atz),ILys8,DAla10]GnRH, inhibited LH release for 72 h. A similar long duration of action was observed for Antide ([Ac-DNal1,DCpa2,DPal3,Lys5(Nic),DLys6(Nic ),ILys8,DAla10]GnRH) but not for Nal-Glu ([Ac-DNal1,DCpa2,DPal3,Arg5,4-(pmethoxybenzoy l)-D-2-Abu6,DAla10]GnRH). In the same paradigm, a 5-fold dilution of the peptide (50 micrograms in 1 mL) and the use of three injection sites rather than one resulted in significantly shorter duration of action for most of the peptides tested. This suggested that long duration of action might be the result of slow release from the injection site(s). In order to investigate this possibility, Nal-Glu and Azaline B were injected intravenously (i.v.) at three doses (10, 50, 250 micrograms) to castrated male rats. At all doses, both peptides significantly lowered LH levels for 8 h. By 24 h, Nal-Glu (250 micrograms) and Azaline B (50 and 250 micrograms) still measurably inhibited LH secretion. Finally, only Azaline B (250 micrograms) was still active at 48 h. These findings demonstrate that subtle structural modifications will yield peptides with different half-lives after iv administration. These findings led us to investigate the effects of other structural modifications on duration of action. We observed that systematic substitutions at positions 7 (NMeLeu) and 10 (Pro9-NHEt, and Gly-NH2) were found to be deleterious. Of interest was the observation that only the DAla10-NH2 substitution led to long duration of action and enzymatic stability under the conditions tested.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Liver/kidney microsome antibody type 1 and hepatitis C virus infection.

Recent studies have shown that hepatitis C virus antibodies are present in a large proportion of patients with autoimmune hepatitis type 2. We have studied 83 patients with liver/kidney microsome antibody-positive type 1 hepatitis. Hepatitis C virus antibodies were sought in every case by second-generation tests (hepatitis C virus enzyme-linked immunosorbent assay and recombinant immunoblot assay). Hepatitis C virus RNA sequences were sought in 22 patients (12 with recombinant immunoblot assay-positive results and 10 with recombinant immunoblot assay-negative results) by means of polymerase chain reaction and by use of primers located in the 5' noncoding region. Sixty-four patients (77%) had positive results for hepatitis C virus antibodies in the enzyme-linked immunosorbent assay test, and 41 (49.3%) were confirmed by recombinant immunoblot assay. Hepatitis C virus RNA sequences were found in all the recombinant immunoblot assay-positive patients but in none of the 10 who were recombinant immunoblot assay-negative. The recombinant immunoblot assay-negative patients were younger than those who were positive (13 +/- 11 vs. 50 +/- 11 years) and had higher gamma-globulin levels and liver/kidney microsome antibody-positive type 1 titers (61% had a titer of 1:1,000 or more, vs. only 17% of the recombinant immunoblot assay-positive patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗