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Biomedical subjects

A Bonnin

Publications and source records attributed to A Bonnin.

At least 73 records · Page 4Linked to original sources
PubMed1994

Cross-sectional study of the susceptibility of Candida isolates to antifungal drugs and in vitro-in vivo correlation in HIV-infected patients.

OBJECTIVES: To investigate (1) the frequency of clinical resistance to oral polyenes or azole treatment for oral candidiasis, (2) the frequency of resistant in vitro Candida strains, (3) the relationship between the susceptibilities of in vitro Candida species and in vivo status in HIV patients. DESIGN: Prospective cross-sectional study. SETTING: Tertiary care clinic at Bocage Hospital, Dijon, France. PATIENTS: HIV-infected patients with and without oral candidiasis. INTERVENTIONS: Clinical examination, oral swab for mycologic investigations. MAIN OUTCOME MEASURES: Clinical diagnosis of oral candidiasis, identification of the antifungal treatment given within the previous month, identification of Candida species, antimycogramm and determination of the minimal inhibitory concentration (MIC) for fluconazole, and measurement of T-helper cell count. RESULTS: Within a 2-month period, 154 HIV-infected patients were studied: 46 heterosexuals, 51 intravenous drug users (IVDU), 52 homosexuals and five blood transfusion recipients. The percentages of patients with oral candidiasis were: 41, 80, 44 and 20%, respectively (P < 0.05); the mean T-helper cell counts were 200, 135, 210 and 238 x 10(6)/l cells, respectively (P < 0.05). Twenty-two patients (14.3%) had received recent azole treatment and 29 (18.8%) recent oral polyene treatment. Among the 84 patients with and the 70 patients without oral candidiasis, 78 and 28 Candida strains were isolated, respectively. Although Candida albicans represented the majority of Candida species (88 strains, 83%), the non-albicans strains were isolated more frequently in patients who had received recent antifungal treatment. No strains were resistant to ketoconazole, miconazole or econazole; however, six (5.6%), 16 (15%) and 10 (9.5%) were intermediately susceptible to the three drugs, respectively. Twelve (13.6%) of the 88 C. albicans, five of the six C. (Torulopsis) glabrata, one of the five C. tropicalis and all three C. krusei strains were resistant to fluconazole. These resistant strains were separated as follows: 41.1% of C. albicans strains resistant to fluconazole were isolated from patients who had received recent azole therapy, 17.6% from patients who received recent oral polyene, and 3.7% from patients who had not received any recent antifungal treatment (P = 0.004). The mean MIC of these three categories of isolates were 3.6, 1.6 and 0.6 mg/l, respectively (P = 0.06). CONCLUSIONS: Oral candidiasis and fluconazole-resistant Candida isolates are more frequently found in IVDU. Treatments using azoles select non-albicans strains and are associated with decreased susceptibilities of C. albicans strains to fluconazole in particular. These findings show that prolonged azole treatment in severely immunocompromised patients should be avoided.

AIDS-Related Opportunistic Infections↗
PubMed1994

MR imaging and CT of surgical materials currently used in ophthalmology: in vitro and in vivo studies.

PURPOSE: To assess methods of imaging postoperative changes in the eyeball by performing in vitro and in vivo studies of the main solid and fluid materials used in the treatment of cataract and retinal detachment. MATERIALS AND METHODS: The samples were analyzed in vitro with computed tomography (CT) and magnetic resonance (MR) imaging performed at 0.5 T. In vivo studies were performed in seven patients who underwent lens implantation (n = 1), scleral buckling with hydrogel or silicone (n = 6), and retinopexy with gas or silicone oil (n = 6). The attenuation and signal intensity of the materials were compared with values for anatomic structures. RESULTS: Lens implants were difficult to visualize. Each scleral buckling and retinopexy material was easily differentiated from the others and from anatomic structures at both CT and MR imaging. CONCLUSION: Postoperative CT or MR imaging may be useful after retinal detachment surgery, particularly when ultrasound is not reliable after intravitreous gas-fluid interchange.

Eye↗
PubMed1994

Silent necrosis of a pituitary corticotroph adenoma revealed by timely magnetic resonance imaging: a cause of spontaneous remission of Cushing's disease.

Spontaneous necrosis of a corticotroph adenoma is rare and is a very unlikely way of curing Cushing's disease. We report hereafter a case where magnetic resonance imaging of the pituitary provided clear evidence of the event. Successive and timely pituitary magnetic resonance imaging in this patient showed first a typical microadenoma as a well-limited mass with a low signal intensity before the necrosis, then a bright signal before gadolinium injection in the T1-weighted image at the time of the event and, finally, the aspect of an empty sella turcica with a small arachnoidocele 1 year later. The necrosis of a corticotroph adenoma is more frequent in macro- than in microadenomas, and is usually heralded by headache and visual disturbances. In this case, pituitary necrosis was entirely asymptomatic, and cured the patient as well as the surgeon's knife would have. Nevertheless, this exceptional occurrence does not rule out the possibility of a recurrence.

Adenoma↗
PubMed1993

A new antigen of Cryptosporidium parvum micronemes possessing epitopes cross-reactive with macrogamete granules.

Three monoclonal antibodies (mAbs) raised against purified excysted oocysts and sporozoites of Cryptosporidium parvum reacted in an immunofluorescent assay with antigens located at the apical pole of the sporozoites. On Western blots of oocyst extract, an antigen of 100 kDa was recognized by the three mAbs. Periodic acid treatment abolished this reactivity, suggesting that the corresponding epitopes are carbohydrates. As determined by immunoelectron microscopy, the three mAbs reacted with micronemes in sporozoites and merozoites and recognized a heterogeneous population of granules in the developing macrogametes. Gold particles were also detected in the parasitophorous vacuole of the macrogametes and sporulating oocysts. The detection of a microneme antigen in a family of macrogamete granules has not previously been reported in coccidia. The significance of this observation and the nature of these macrogamete inclusions are discussed.

Animals↗
PubMed1993

delta 9-Tetrahydrocannabinol affects mesolimbic dopaminergic activity in the female rat brain: interactions with estrogens.

In this work, we studied the possible estrogenic modulation of the effects of delta 9-tetrahydrocannabinol (THC) on mesolimbic dopaminergic activity, by examining the effects of an acute dose of this cannabinoid: (i) during the estrous cycle; (ii) after ovariectomy, chronic estrogen-replacement and tamoxifen (TMX)-induced blockade of estrogenic receptors; and (iii) combined with a single and physiological injection of estradiol to ovariectomized rats. THC significantly decreased the density of D 1 dopaminergic receptors and non-significantly increased the L-3,4-dihydroxyphenylacetic acid (DOPAC) content in the limbic forebrain of ovariectomized rats chronically replaced with estrogens. The decrease in D 1 receptors was also produced by TMX, whereas the coadministration of both THC and TMX did not lead to a major decrease. In addition to the trend of THC increasing DOPAC content, this cannabinoid was also able to increase the ratio between DOPAC and dopamine, although this last effect only occurred after coadministration of THC and TMX, which had been ineffective administered individually. All these effects were not seen when THC was administered to normal cycling rats during each phase of estrous cycle and to ovariectomized rats without chronic estrogen replacement or only submitted to a single and acute dose of estradiol. This observation might be related to the fact that the density of limbic cannabinoid receptors increased in chronic estrogen-replaced ovariectomized rats versus normal cycling, ovariectomized or acutely estrogen-treated ovariectomized rats. Interestingly, THC administration in ovariectomized rats was followed by a slight, although significant, increase in tyrosine hydroxylase activity, which was also observed after coadministration of THC with a short-time and acute dose of estradiol. In summary, THC stimulated the presynaptic activity of mesolimbic dopaminergic neurons, but accompanied by a decrease in their postsynaptic sensitivity. These effects did not appear in normal cycling rats being only evident after ovariectomy and chronic estrogen replacement, which might be related to changes in binding characteristics of cannabinoid receptors in this area. Moreover, some of them appeared after TMX-induced blockade of estrogenic cytosolic receptors, which likely suggests the existence of a certain estrogenic modulation of the actions of THC on mesolimbic neurons. On the contrary, coadministration of THC with a single and shortly tested dose of estradiol was always ineffective in modifying THC effects.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

Efficacy and tolerance of an amphotericin B lipid (Intralipid) emulsion in the treatment of candidaemia in neutropenic patients.

The efficacy and tolerance of a new amphotericin B lipid emulsion (AmB-IL) in which amphotericin B was diluted in a lipid solution for parenteral nutrition (Intralipid) was assessed in fourteen episodes of candidaemia occurring in neutropenic patients. The strains isolated were Candida krusei (nine cases), Candida albicans (three cases), Candida parapsilosis (one case) and Candida lusitaniae (one case). An AmB-IL was administered at a mean dosage of 1.18 mg/kg/day (range 0.73-1.55) for 22 days (range 6-62). Flucytosine was added to AmB-IL in 12 patients (mean duration 10.6 days). Chills were noted in only 3/306 infusions of AmB-IL. A mild increase of serum creatinine level from 9.3 +/- 3 mg/L (baseline) to 10.9 +/- 3 mg/L (after completion of AmB-IL) and mild decrease of creatinine clearance from 83 +/- 28 mL/min to 56 +/- 21 mL/min were observed. These changes did not correlate with either daily or total dose of AmB-IL or length of therapy. Seven patients were cured and six improved (patients who subsequently died due to nonfungal cause) with AmB-IL. One patient died due to C. krusei pneumonia. In conclusion AmB-IL is a well-tolerated method of amphotericin B administration. It could facilitate the use of amphotericin B without impairing its efficacy for the treatment of candidaemia in neutropenic patients.

Adult↗
PubMed1993

Presence of cannabinoid binding sites in the brain from early postnatal ages.

The present study demonstrates the presence of cannabinoid receptors in the brain from early postnatal ages. Specific and saturable binding was observed in the forebrain and remaining brain from early postnatal ages (2 and 5 days after birth). Female neonate forebrain exhibited a higher receptor density at 2 days after birth than males, but this trend was inverted at 5 days. From postnatal day 10, the receptors could be measured in more defined brain areas, i.e. the striatum, limbic forebrain and ventral mesencephalon. The ontogeny of the receptors in these three areas was relatively similar, exhibiting a progressive increase which maximised on days 30 or 40 and then subsequently decreased to adult values. Subtle sexual dimorphism was found in the striatum and ventral mesencephalon but not the limbic forebrain.

Aging↗
PubMed1993

Comparison of computerized tomography and magnetic resonance imaging for the examination of the pituitary gland in patients with Cushing's disease.

OBJECTIVE: The vast majority of patients with Cushing's disease have a corticotroph adenoma, the selective removal of which, through the transsphenoidal route, has the potential to offer a definitive and complete cure. This study was designed to compare the diagnostic accuracy of computerized tomography (CT) and magnetic resonance imaging (MRI) to identify the presence, evaluate the size, and assess the topographic characteristics of pituitary corticotroph adenomas. METHODS: Forty-two patients with Cushing's disease were included in this prospective study, of whom 16 were subsequently explored transsphenoidally. Computerized tomography used a CE 12,000 CGR apparatus with 1.5-mm coronal slices and a 2-mm interslice gap. Magnetic resonance imaging used an MR Max 0.5T GE apparatus; adjacent 3-mm slices were obtained with a T1-weighted gradient echo before and after gadolinium injection. RESULTS: Lesions compatible with an adenoma were identified in 29 patients by MRI and in 21 patients by CT (69 vs 50%, P < 0.02). Seven macroadenomas were identified as well by the two methods. Eight of the 22 microadenomas detected by MRI were not identified by CT. Evidence for intracavernous tumour extension was found in nine patients: it was more frequently detected by MRI (8 patients) than by CT (4 patients). Fourteen patients with positive MRI had a pituitary examination: in one case the adenoma could not be reached because of purely suprasellar location; of the other 13 all were found by the surgeon and the surgical outcome was successful in 12 cases. CONCLUSION: MRI is superior to CT for the examination of the pituitary gland in patients with Cushing's disease.

Adolescent↗
PubMed1993

Acute effects of delta 9-tetrahydrocannabinol on tuberoinfundibular dopamine activity, anterior pituitary sensitivity to dopamine and prolactin release vary as a function of estrous cycle.

The effects of delta 9-tetrahydrocannabinol (THC) on the activity of brain dopaminergic neurons might be subject to gonadal influence. In this work, we tested this hypothesis in relation to the effects of THC on tuberoinfundibular dopaminergic (TIDA) activity, the anterior pituitary sensitivity to dopamine (DA) and prolactin (PRL) secretion. To this end, we examined the effects of an acute dose of this cannabinoid administered during different phases of the estrous cycle in the morning or afternoon. The results were as follows. THC, administered during the morning of estrus, stimulated TIDA activity as reflected by increases in DA and L-3,4-dihydroxyphenylacetic acid (DOPAC) contents and tyrosine hydroxylase (TH) activity in the medial basal hypothalamus. This was accompanied by an increase in the responsiveness of the anterior pituitary to DA, as reflected by the increase in the density of D2 receptors and the corresponding decrease in PRL release. By contrast, plasma PRL levels increased when THC was administered on the afternoon of estrus, in parallel with a significant reduction in the number of D2 receptors in the anterior pituitary gland and no effects on TIDA activity. A similar decrease in the anterior pituitary density of D2 receptors, but with no changes in plasma PRL levels, was observed when THC was administered during the morning of diestrus. This effect was not accompanied by changes in TIDA activity either.(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

[Spontaneous unilateral adrenal gland hemorrhage and pregnancy].

Spontaneous unilateral haemorrhage of the adrenal gland during the third trimester of pregnancy is a rare event. The diagnosis may be suspected on the basis of echographic or MRI explorations. There is no sign of endocrine dysfunction. The pregnancy may be conducted to term when the diagnosis is probable but echographic monitoring shows the absence of further development. Only one analogous observation based on MRI diagnosis was found in the literature.

Adrenal Gland Diseases↗
PubMed1993

[Radiology in the medicolegal identification of cadavers. A new technique of radiography of the maxilla].

After removal, the maxilla and the mandible are placed on a standard radiologic cassette and a X-ray is performed with a low energy beam. Different views can be obtained if required. These radiographic images provide a complete, permanent and detailed record of dental anatomy and restorations, for comparison with antemortem radiographies. Two examples are provided. Moreover, this technique enables the determination of the dental age of children.

Cadaver↗
PubMed1993

[Prognostic value of x-ray computed tomography in acute pancreatitis. Value of a new classification].

CT plays an important role in the screening of complications of acute hemorrhagic pancreatitis. There are three classifications at present, one based on a bioclinical score (Ranson) and the other two consisting of gradual stages of severity and resorting to CT imaging (Balthazar and Hill). The authors report about a study on 34 cases of acute pancreatitis, including 10 that became complicated, to which they applied a new classification including the existence of glandular necrosis, the number of extrapancreatic streaks, related to Ranson's bioclinical score. This classification makes it possible to classify acute pancreatitis into three stages: a mild stage with a favorable outcome, a medium stage requiring close surveillance, and stage 3 involving a high (75%) risk of severe complications.

Acute Disease↗
PubMed1993

[Peritoneal tuberculosis and continuous ambulatory peritoneal dialysis].

Depressed immunity in uremic patients increases by ten the risk of tuberculosis. In such patients, 40% of tuberculosis manifestations are extrapulmonary, and peritoneum is involved in about 6% of the cases. Seventeen cases of peritoneal tuberculosis have been so far reported in CAPD patients, and we add a new case. The prognosis of the disease is severe since 8 patients died. Three deaths out of 8 are directly linked to tuberculosis. Indeed, peritoneal tuberculosis diagnosis is hard and often late, at least for two main reasons: at first, it can be difficult to exclude the other causes of lymphocytic peritonitis (viral, fungal, bacterial, etc.), secondly, growth of mycobacteria in dialysate effluent cultures is late and inconstant. Omental biopsy in lymphocytic peritonitis of unknown origin could be of great value for an early diagnosis. Despite the adaptation of antituberculous drugs doses, side-effects are not so rare: optical neuritis and liver toxicity in our case. In spite of ultrafiltration loss, stopping CAPD is not always necessary, as in the reported case.

Aged↗
PubMed1992

[Bilateral adrenal tumoral formation. Regressive spontaneous evolution].

A case of bilateral adrenal tumoral formation associated with Addison's disease is reported, and the possible cause of this association is discussed. The short-term deleterious course of metastatic malignancies, hemopathies or severe infections when left without specific treatment, and the long-term course of our patient's tumoral pathology excluded these diagnoses. The spontaneous regression of a bilateral pseudotumoral mass was suggestive of 2 causes: haematoma or tuberculosis. Haematoma was unlikely in the absence of causal factors, and this, combined with the slow regression of the adrenals, made tuberculosis the most probable diagnosis. The few similar cases found in the literature are reviewed.

Addison Disease↗
PubMed1992

Clinical evaluation of a new lipid-based delivery system for intravenous administration of amphotericin B.

In a retrospective study a new lipid-based delivery system for administration of amphotericin B was evaluated in 26 treatment courses in 22 patients. Amphotericin B was given by infusion diluted in either the lipid solution (1 mg/kg/d; 13 courses) or dextrose (0.92 mg/kg/d; 13 courses). No differences were noted in the serum pharmacokinetics. Fever or rigors were observed in 6 of 13 courses in the conventional amphotericin B group versus none in the lipid amphotericin B group (p = 0.007). Four of 13 courses of treatment were discontinued due to adverse effects in the conventional amphotericin B group compared to none in the other group (p = 0.048). In the lipid amphotericin B group the decrease in creatinine clearance was significantly lower on the fourth day of treatment (p = 0.04) and significantly fewer patients had a decrease of more than 25% in creatinine clearance on the sixth day (4/12 vs 9/11 p = 0.02). These preliminary findings suggest that this lipid amphotericin B formulation is well tolerated with few nephrotoxic effects.

Adult↗