Mycophenolate mofetil monotherapy for severe side effects of calcineurin inhibitors following liver transplantation

Withdrawal of calcineurin inhibitors (CNI) followed by mycophenolate mofetil (MMF) monotherapy after liver transplantation (LT) remains controversial due to the increased risk of acute rejection and graft loss. The aim of the present study, performed in a large cohort of liver-transplanted patients with severe CNI-induced side effects, was to assess renal function recovery, and safety in terms of liver function, of complete CNI withdrawal and replacement by MMF monotherapy. Fifty-two patients treated with MMF monotherapy for CNI-induced toxicity were analyzed. Mean estimated glomerular filtration rate (eGFR) increased significantly during the period of MMF monotherapy, from 37 +/- 10 to 44.7 +/- 15 mL/min/1.73 m(2) at 6 months (p = 0.001) corresponding to a benefit of +17.4% in renal function. eGFR stabilized or improved in 86.5%, 81% and 79% of cases, and chronic renal dysfunction worsened in 13.5%, 19% and 21% of cases, at 6, 12 and 24 months after CNI withdrawal, respectively. Only two patients experienced acute rejection. MMF monotherapy may be efficient at reversing/stabilizing CRD, and appears relatively safe in terms of liver graft function in long-term liver-transplanted patients. However, clinicians must bear in mind the potential risk of rejection and graft loss, and should be very cautious in the management of such 'difficult-to-treat patients'.

[Myxomatous mitral valve degeneration: biochemical aspects and physiopathological considerations]

Mitral valve is a complex structure which is submitted to repeated mechanical constraints. In clinical practice, an increasing incidence of mitral insufficiency resulting from myxomatous degeneration is observed. Since myxomatous degeneration is also observed in defined genetic diseases of connective tissues, we propose the hypothesis that idiopathic mitral insufficiency might result from a minor alteration of the interstitial valvular cells and/or their interactions with their support. After a brief review of the role of the extracellular matrix in the heart, some histopathological and biochemical aspects of myxomatous degeneration are presented. Our data and those of the literature will be summarized and a physiopathological hypothesis proposed for myxomatous mitral valve degeneration.

Evaluation of the new heterogeneous ACMIA immunoassay for the determination of whole-blood cyclosporine concentrations in bone marrow, kidney, heart, and liver transplant recipients

Cyclosporine (CyA) has a narrow therapeutic index. Determination of CyA concentrations correlate with rejection or adverse effects like nephropathy. Cyclosporine is assayed based on either chromatographic or many different immunoenzymologic techniques. The investigators evaluated a new heterogeneous immunoassay of CyA on RxL Dimension. The pretreatment step is automatically performed in the apparatus. Linearity, intra- and interday precision, limit of quantification, dilutions, and stability of the equipment were compared with the EMIT method for patient determinations. The heterogeneous immunoassay showed a good linearity between 0 and 500 ng/mL, and intra- and inter-day precision with a coefficient of variation below 9.2%. The investigators observed reproducible and accurate dilutions of high concentrations (500 to 2000 ng/mL). The correlation with the EMIT technique was valid: ACMIA = 0.964 EMIT + 0.156 (r = .96) for different types of transplant (n = 116). Finally, this new system improves the determination of CyA concentrations.

[Evaluation of the heterogeneous immunoassay (ACMIA) for the measurement of blood cyclosporin on the Behring dimension RXL clinical chemistry analyzer]

We propose an evaluation of a new heterogeneous immunoassay of cyclosporin on RXL HM Dimension (Dade Behring) for therapeutic cyclosporin monitoring in whole-blood patients transplant. The pretreatment step is performed automatically into the apparatus while it is a manual step with EMIT. Linearity, intra- and inter-day precision, limit of quantification, precision and accuracy of dilution steps and stability into the equipment were studied. We realized the comparison between ACMIA and EMIT methods on whole-blood patients transplant recipients. Heterogeneous immunoassay showed a good linearity between 0 and 500 ng/mL, intra- and inter-day precision with coefficient of variation inferior to 7.2%. We observed reproducible and accurate dilutions of high concentrations (500 to 2,000 ng/mL). The correlation with EMIT technique was correct for different type of transplant (n=55).

Suburban transmission of Q fever in French Guiana: evidence of a wild reservoir

The annual incidence of Q fever in French Guiana was found to have increased in 1996 and was 37/100,000 population over the last 4 years. Subsequent investigations in Cayenne and its suburbs indicated that a wild reservoir of the bacteria was responsible for the epidemiologic pattern. A case-control study showed that residence near a forest and occupations and activities that result in exposure to aerosols of dusts from the soil are risk factors for Q fever. By means of time-series analysis, a strong positive correlation between rainfall and the incidence of Q fever with a time lag of 1-3 months was found. The spatial distribution of the cases showed that transmission occurs widely throughout greater Cayenne, which is incompatible with a pinpoint source of contamination. Transmission from livestock and dissemination of the bacteria by the wind appeared to be unlikely, which strengthens the hypothesis that a wild reservoir is responsible for transmission.

Association of severe malaria with a specific Plasmodium falciparum genotype in French Guiana

Why severe Plasmodium falciparum malaria occurs in only a small percentage of patients is unclear. The possibility that specific parasite characteristics contribute to severity has been investigated in French Guiana, a hypoendemic area, where parasite diversity is low and all patients with severe cases are referred to a single intensive care unit. Parasite genotyping in geographically and temporally matched patients with mild and severe disease showed that the association of a specific msp-1 allele (B-K1) with a specific var gene (var-D) was overrepresented among patients with severe versus mild disease (47% vs. 3%, respectively; P<.001). Moreover, this genotype combination was consistently observed in the most severe clinical cases. Reverse-transcription polymerase chain reaction demonstrated programmed expression of var-D in vivo, which is consistent with its potential implication in severe disease. These results provide field evidence of an association of severe malaria with specific genetic characteristics of parasites and open the way for intervention strategies targeting key virulence factors of parasites.

Tonate virus infection in French Guiana: clinical aspects and seroepidemiologic study

Two recent cases of human infection with Tonate virus, one of which was a fatal case of encephalitis, have renewed interest in these viruses in French Guiana. The clinical aspects of confirmed and probable cases of infection with this virus indicate that it has pathogenic properties in humans similar to those of other viruses of the Venezuelan equine encephalitis complex. To determine the prevalence of antibodies to Tonate virus in the various ethnic groups and areas of French Guiana, 3,516 human sera were tested with a hemagglutination inhibition test. Of these, 11.9% were positive for the virus, but significant differences in seroprevalence were found by age, with an increase with age. After adjustment for age, significant differences were found between places of residence. The prevalence of antibody to Tonate virus was higher in savannah areas, especially in the Bas Maroni (odds ratio [OR] = 22.2, 95% confidence interval [CI] = 15.2-32.4) and Bas Oyapock areas (OR = 13.4; 95% CI = 9.8-18.4). The ethnic differences observed in this study were due mainly to differences in place of residence, except that whites were significantly less frequently infected than other ethnic groups. This study indicates that Tonate virus infection is highly prevalent in French Guiana, especially in savannah areas.

Multiple African honeybee stings and acute renal failure

In 1956, the Brazilian government brought honeybees <i>(Apis mellifera andansonii)</i> from South Africa. A group of these bees crossed the Amazon and reached Venezuela where they have killed between 30 and 50 people in the last 4 years [1]. In 1993, we observed the first case of rhabdomyolysis, hepatic dysfunction and acute renal failure (ARF) following multiple stings by African bees <i>(A. mellifera andansonii)</i> in French Guiana.

Simultaneous high-performance liquid chromatographic determination of the antiretroviral agents amprenavir, nelfinavir, ritonavir, saquinavir, delavirdine and efavirenz in human plasma

This article describes a method for the simultaneous determination of four licensed HIV protease inhibitors (amprenavir, nelfinavir, saquinavir and ritonavir) and two novel non-nucleoside reverse transcriptase inhibitors (efavirenz and delavirdine) in human plasma in a single run. Plasma samples (500 microl) were treated by liquid-liquid extraction with methyl tert.-butyl ether. The compounds were separated by reversed-phase liquid chromatography on a C(18) column with spectrophotometric detection at 260 nm. The method is linear over the specific ranges investigated, accurate (inaccuracy <11.7%) and showed intra-day and inter-day precision within the ranges of 0.9-7.0 and 1.9-8.8%, respectively. The six compounds were stable in plasma after 6 months of storage at -20 degrees C and after five freeze-thaw cycles.

[Antibiotic therapy in cystic fibrosis. I. Pharmacologic specifics of antibiotics]

Antibiotherapy is one of the main treatment in cystic fibrosis. Antibiotic administration schedules are different from normal patients because of pharmacokinetic and pharmacodynamic particularities. In moderate disease, the digestive resorption of antibiotics is delayed and their half-life is reduced due to an increase in total clearance. In severe disease, the volume of distribution of antibiotics is increased due to the higher proportion of lean mass in these malnourished patients. Other particularities limit the action of antibiotics such as thick sputum, which limits drug penetration; the property of Pseudomonas aeruginosa to be surrounded by a biofilm; alteration of local antibacterial defense; and inhibition of antibiotics by local factors. Systematic prescription of a biotherapy beta-lactam-aminoglycoside and obtaining high antibiotic concentration in situ might limit this antagonism. In spite of particular therapeutic schedules such as single daily dose for aminoglycoside and continuous infusion for beta-lactams, the intervals between administrations must be narrowed for time-dependent antibiotics, and the total daily dose increased by 20 to 30% for concentration-dependent antibiotics.

Association of Tonate virus (subtype IIIB of the Venezuelan equine encephalitis complex) with encephalitis in a human

Tonate virus, subtype IIIB of the Venezuelan equine encephalitis (VEE) complex, was first isolated in 1973 in French Guiana, South America. However, very little is known about its pathogenicity; it was considered to be responsible for only mild dengue-like syndromes. In 1998, a 2-month-old boy living along the Oyapock river in French Guiana was hospitalized for fever and generalized status myoclonus, and despite treatment the patient died 72 h after admission. Testing showed the presence of IgM specific for viruses of the VEE complex. A sensitive seminested polymerase chain reaction derived from a previous study was developed to detect viruses from the VEE complex, since no virus could be recovered from clinical specimens cultured on mosquito cells or from intracerebral inoculation into newborn mice. The genome of a virus from the VEE complex was detected in postmortem brain biopsies, and Tonate virus was identified by direct sequencing. This is the first reported case of human encephalitis due to Tonate virus.

Plasmodium falciparum parasites in French Guiana: limited genetic diversity and high selfing rate

The genetic characteristics of Plasmodium falciparum isolates collected in French Guiana, where malaria transmission is low and occurs in isolated foci, were studied. Blood samples were collected from 142 patients with symptomatic malaria and typed using a polymerase chain reaction-based strategy for merozoite surface protein-(MSP-1) block 2, the MSP-2 central domain, and glutamate-rich protein (GLURP) repeat domain polymorphism. This showed that the parasite population circulating in French Guiana presented a limited number of allelic forms (4, 2, and 3 for MSP-1 block 2, MSP-1, and GLURP, respectively) and a small number of mixed infections, contrasting with the large genetic diversity of parasite populations and infection complexity reported for Africa, Asia, and other parts of South America. Two groups of isolates displaying identical 3 loci allele combinations were further studied for the Pf332 antigen, histidine-rich protein-1, thrombospondin-related anonymous protein, and Pf60 multigene family polymorphism. Within each group, most isolates were identical for all markers tested. This suggests a high rate of self-fertilization of P. falciparum parasites in French Guiana, resulting in homogenization of the population. The implications of these findings for malaria control in areas of low endemicity are discussed.

First case of yellow fever in French Guiana since 1902

The first case of yellow fever in French Guiana since 1902 was reported in March 1998. The yellow fever virus genome was detected in postmortem liver biopsies by seminested polymerase chain reaction. Sequence analysis showed that this strain was most closely related to strains from Brazil and Ecuador.

[Staphylococcus aureus septicemia producing Panton-Valentine leukocidin. 3 cases]

BACKGROUND

A strong association has been observed between furuncles and Panton-Valentine leukocidin-producing Staphylococcus aureus.

CASE REPORTS

Within one year, we cared for three men at the Cayenne hospital who had Staphylococcus aureus septicemia with severe pleuropulmonary involvement originating from furuncular lesions. The Staphylococcus aureus strains isolated from the skin lesions and from blood cultures produced Panton-Valentine leukocidin.

CONCLUSION

These cases demonstrate the gravity of S. aureus septicemia in young patients with furunculosis. These cases are the first reported with severe S. aureus infections associated with Panton-Valentine leukocidin producing strains.

Dengue encephalitis in French Guiana

Thousands of cases of dengue fever (DF) and several cases of dengue haemorrhagic fever were recorded in French Guiana during the recent outbreak of dengue-2 virus (1991-1992) and in subsequent years. One case with clinical signs typical of classical DF with neurological complications is reported in this study. The neurological features (encephalitis) appeared during the acute phase, 2 days after the onset of fever. Dengue-2 virus was detected in both the cerebrospinal fluid and blood sample. This case was fatal. This first reported case of classical DF with encephalitis in French Guiana is a new demonstration of the potential neurovirulence of dengue viruses.

[Re-emergence of Venezuelan equine encephalitis virus in French Guiana. Apropos of 1 confirmed case]

Venezuelan equine encephalitis (VEE) is a mosquito-borne viral disease that occurs in equine species and in man. The strains can be grouped epidemiologically into two major categories: enzootic and epizootic. Enzootic strains cause sporadic human disease and are not associated with disease among equines. These strains are found throughout Florida. Central America, northern South America and Brazil. Epizootic strains are associated with enormous morbidity and mortality in equine species. In man, VEE virus infections are largely asymptomatic and in children and young adults there is an increased risk of encephalitis and dead. We report the first case in French Guiana of Venezuelan equine encephalitis. Clinical examination and biological studies showed encephalitis, interstitial pneumonia and acute liver failure. Despite an adequate symptomatic treatment, the young patient died five days after her admission in multiple organ dysfunction syndrome. Diagnosis is establishing by virologic test: VEE virus is isolated from the blood. These example of re-emerging infectious disease vividly illustrate that we remains vulnerable and emphasizes the need for an active surveillance system.

[Post-traumatic intramural hematoma of the duodenum]

A post-traumatic intramural hematoma of duodenum in a 9 year old child was detected during exploratory laparotomy but left undisturbed. Postoperative follow up during parenteral feeding included surveillance by repeated gastrografin follow through examinations, normal transit being restored by the 12th day. Intramural hematoma of duodenum is usually due to injury and often affects male children. Symptomatology is that of upper digestive occlusion. The principal investigation should be gastro-duodenal follow through examinations with gastrografin, because of the risk of an associated perforation, to reveal possible partial or total duodenal obstruction. Conservative treatment is possible, but in case of failure or in adults surgery is indicated with evacuation of the hematoma and in some cases a gastro-jejunostomy.

[An apparatus for the noninvasive automatic measurement of arterial pressure]

An automatic apparatus for the measurement of arterial pressure by a non-invasive technique is compared with direct intra-arterial measurement in patients admitted to a neurosurgical intensive care unit. A good correlation is found between the results of the two methods for the systolic and diastolic pressure.