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Biomedical subjects

J L Perret

Publications and source records attributed to J L Perret.

At least 37 records · Page 2Linked to original sources

[The new poor expatriates in the third world].

This report describes four cases involving French expatriates who developed serious health problems while living destitute in Senegal. A 37-year-old man presented with embolism-like symptoms in relation with lung involvement due to spreading of untreated staphylococcal skin infection. A 64-year-old man was admitted for high output cardiac failure secondary to severe anemia caused by malnutrition. A 50-year-old man presented recurrent fever with loss of consciousness after successful treatment of neuromalaria and finally attributed to delirium tremens. A 25-year-old man was hospitalized with presumed meningoencephalitis that had been ongoing for two weeks. All four patients had been in Senegal for several months and had cut all ties to mainland France. Being jobless and homeless, they had been unable to obtain proper nutrition or medications. With minimal entry requirements and low-cost air travel, Senegal has been come a common sight-seeing destination and has developed a small but apparently growing population of destitute travelers. Alienation from the home community and resulting seclusion enhance clinical consequences and delay intervention by foreign service officials.

Adult↗

Evidence for differences in MT2 cell tropism according to genetic subtypes of HIV-1: syncytium-inducing variants seem rare among subtype C HIV-1 viruses.

Non-syncytium-inducing (NSI) variants seem to be more readily transmitted than syncytium-inducing (SI) variants, and the switch from NSI to SI during HIV-1 infection seems to be a key determinant to the evolution of AIDS. We investigated eventual differences in the SI capacity on MT-2 cells according to genetic subtypes of HIV-1 and correlated this observations with CD4 counts and duration of HIV infection. In total, 86 patients, most with known date of HIV contamination and infected with different genetic subtypes, have been studied: 11 subtype A, 46 subtype B, 22 subtype C, and 7 subtype E. Multivariate analysis used a Cox's proportional hazards regression. The number and percentage of patients infected with an SI strain were as follows: 3 of 11 (27%) for subtype A, 15 of 46 (33%) for subtype B, 0 of 22 (0%) for subtype C, and 5 of 7 (71%) for subtype E. After adjustment for time after seroconversion and CD4 counts, significantly fewer SI variants were observed in patients infected with subtype C (p < .002) and it was found that subjects infected with subtype E had a higher risk of being infected with an SI strain (rate ratio [RR] = 12.39%; 95% confidence interval [CI] 1.55-98.67; p < .001). Most of the subtype E-infected patients from our study switched from an NSI to SI phenotype early after seroconversion (<4 years). To predict the in vitro presence of SI variants, we scanned V3-loop sequences for mutations at positions 11 and/or 25. Overall, 54 of 55 (98.2%) NSI strains in vitro were predicted NSI, and only 4 of 12 (33.3%) of SI viruses were predicted SI. For patients in whom a switch from an NSI to an SI virus was observed, the SI phenotype could be detected earlier in vitro than by the corresponding V3-loop sequence. No SI strains were observed among patients infected with subtype C; however, longer follow-up is needed to see whether the appearance of SI variants in subtype E or the absence of SI variants in subtype C-infected patients is also associated respectively with a faster or slower progression to AIDS as described for subtype B.

Amino Acid Sequence↗

Genetic characterization of the nef gene from human immunodeficiency virus type 1 group M strains representing genetic subtypes A, B, C, E, F, G, and H.

Most efforts to characterize sequence variation of HIV isolates has been directed toward the structural envelope gene. Few studies have evaluated the sequence variability of auxiliary genes such as nef. In this study 41 new HIV-1 strains, representing the majority of the described envelope subtypes of HIV-1 (A to H), were genetically characterized in the nef region. Phylogenetic analysis showed that 34 strains could be classified in the same subtype in nef and env, and 7 (19%) of the 41 new viruses were recombinants. For two of the seven strains, recombination occurred upstream of the nef gene, whereas for five of the seven strains recombination occurred within the nef gene with a crossover close to the 5' end of the LTR (long terminal repeat). The low intersubtype distance between subtype B and D in the nef gene confirms previous observations in the pol, env, and gag genes, which suggest a common ancestor for these subtypes. The majority of all the previously described functional domains in the nef gene were relatively conserved among the different subtypes, with only minor differences being observed. The myristoylation signal among the different subtypes, with only minor differences being observed. The myristoylation signal was less conserved for subtype C, with one or more amino acid changes being observed at positions 3, 4, and 5. The highly conserved acidic region (positions 62 to 65), critical for the enhancement of viral synthesis with an increased virus growth rate, was less conserved among the subtype G strains from our study. At least three epitopic regions of the nef gene have been defined and each can be recognized by CTLs under a variety of HLA restrictions; all were also relatively well conserved between the different genetic subtypes. Despite the relatively important genetic variation in nef sequences obtained among the different genetic subtypes, functional domains and CTL epitopes were relatively well conserved. In vitro and/or in vivo studies are necessary to study the relevance of the observed differences.

Amino Acid Sequence↗

Efficiencies of four versions of the AMPLICOR HIV-1 MONITOR test for quantification of different subtypes of human immunodeficiency virus type 1.

Three versions of a commercial human immunodeficiency virus (HIV) type 1 (HIV-1) load test (the AMPLICOR HIV-1 MONITOR Test versions 1. 0, 1.0+, and 1.5; Roche Diagnostics, Branchburg, N.J.) were evaluated for their ability to detect and quantify HIV-1 RNA of different genetic subtypes. Plasma samples from 96 patients infected with various subtypes of HIV-1 (55 patients infected with subtype A, 9 with subtype B, 21 with subtype C, 2 with subtype D, 7 with subtype E, and 2 with subtype G) and cultured virus from 29 HIV-1 reference strains (3 of subtype A, 6 of subtype B, 5 of subtype C, 3 of subtype D, 8 of subtype E, 3 of subtype F, and 1 of subtype G) were tested. Detection of subtypes A and E was significantly improved with versions 1.0+ and 1.5 compared to that with version 1. 0, whereas detection of subtypes B, C, D, and G was equivalent with the three versions. Versions 1.0, 1.0+, and 1.5 detected 65, 98, and 100% of the subtype A-infected samples from patients, respectively, and 71, 100, and 100% of the subtype E-infected samples from patients, respectively. Version 1.5 yielded a significant increase in viral load for samples infected with subtypes A and E (greater than 1 log10 HIV RNA copies/ml). For samples infected with subtype B, C, and D and tested with version 1.5, only a slight increase in viral load was observed (<0.5 log10). We also evaluated a prototype automated version of the test that uses the same PCR primers as version 1.5. The results with the prototype automated test were highly correlated with those of the version 1.5 test for all subtypes, but were lower overall. The AMPLICOR HIV-1 MONITOR Test, version 1.5, yielded accurate measurement of the HIV load for all HIV-1 subtypes tested, which should allow the test to be used to assess disease prognosis and response to antiretroviral treatment in patients infected with a group M HIV-1 subtype.

Evaluation Studies as Topic↗

[Thyroid cardiac diseases in the African hospital milieu: experience of the Principal Hospital of Dakar, Senegal].

The incidence of cardiomyopathy associated with hyperthyroidism in black Africa is unclear. A prospective study was carried out at the Principal Hospital in Dakar, Senegal to systematically screen for thyrocardiac disease using cardiologic examinations including electrocardiography and ultrasound in a series of 15 men and 35 women with hyperthyroidism. Cardiac manifestations were detected in 3 men and 8 women including right ventricular insufficiency in 9 cases, left ventricular insufficiency and angor in one. After treatment of hyperthyroidism, atrial fibrillation disappeared in two cases and angor in one. Isolated dilated hypokinetic cardiomyopathy observed in 6 patients was the most common ultrasound finding and disappeared after treatment of thyroid dysfunction in 5. Manifestations occurred in two patients with mitro-aortic valve disease and one patient with isolated aortic valve disease. Based on these findings, the incidence of cardiomyopathy in patients with hyperthyroidism in Senegal was estimated to be 22 per 100 cases. This is similar to the incidence reported in industrialized countries. However the age of occurrence is lower and rheumatic valve disease was the most common associated cardiopathy.

Adolescent↗

Short- and long-term action of multiple doses of ivermectin on loiasis microfilaremia.

One hundred nine Gabonese patients infected with Loa loa microfilariae were treated with ivermectin (200 microg/kg of body weight) at the Parasitology, Mycology and Tropical Medicine Department (Faculte de Medecine et des Sciences de la Sante, Libreville, Gabon). Each was given one dose per month for six consecutive months. The peripheral blood microfilaria (mf) count before and after each dose showed an average decrease in the microfilaremia of 87.3% (short-term-single dose). An annual single-dose mass treatment with 200 microg/kg of ivermectin was sufficient to control the parasite in populations with low (< 400/ml) L. loa mf counts. One month after the sixth dose (short-term-multiple doses), the average microfilaremia rate had decreased by 99.2% compared with the initial infection (35 patients). Samples were taken from 28 patients one month after the first dose and one month after the sixth dose. The average mf count decreased by 96.4% after the first dose and by 99.6% after the sixth dose (average residual mf counts = 13.7 and 1.5 mf/ml, respectively). The mf count after the sixth dose was only 11.2% of the count after the first dose. The low mf count persisted for more than six months after the sixth treatment (long-term-multiple doses). Thus, mass treatment with multiple doses is more appropriate for areas where the blood mf count is very high. These results show that the number of the annual treatments used in mass chemotherapy with ivermectin can be adapted to each population to provide efficient protection.

Adolescent↗

[Pulmonary melioidosis].

Melioidosis is most frequently encountered in pulmonary localization. Melioidosis is an infectious disease caused by Burkholderia pseudomallei first described by Whitmore in 1912 in Burma. B. pseudomallei is a Gram negative rod belonging to the Pseudomonadaceae family. Soil and water are the natural reservoirs for the germ which is a specific pathogen for several mammal species. Long endemic in Southeast Asia and several tropical zones, B. pseudomallei has recently been found in temperate zones, including France. Human contamination occurs via the transcutaneous route and often leads to dormant inapparent infection. Many conditions, such as diabetes, renal lithiasis, various circumstances of immunodepression or stress, facilitate clinical manifestations which vary greatly. Pulmonary manifestations may be acute and extensive, producing a torpid pseudo-tuberculous condition or a variety of clinical and radiological features mimicking other diseases. Bacteriological and serological tests may be negative. Exposure in an endemic zone, the notion of a favorable context, weight loss, cavitary images on successive chest x-rays and the presence of extra-pulmonary localizations may be suggestive. Ceftazidime or the amoxicillin-clavulanic acid combination are indicated, but mortality in acute forms still reaches 40%. Relapse can be expected if the treatment duration is too short.

Amoxicillin↗

[Soft tissue eosinophilic granuloma or Kimura's disease: a case report].

Soft tissue eosinophilic granuloma or Kimura's disease is a chronic inflammatory disorder of unknown etiology. It is endemic in the Far East but can occur sporadically in other populations especially Middle Eastern peoples as illustrated by the present case involving a 55-year-old man. Examination 8 years after an initial episode revealed masses in the cheek and submaxillary regions with hypereosinophilia and characteristic histological findings. The usual clinical presentation of Kimura's disease includes subcutaneous nodules with lymph node involvement or presence of tumor in the salivary glands. These clinicopathological findings require differential diagnosis with Hodgkin's lymphoma, dermopathic lymphoma, or Castelman's disease. However, the most difficult distinction involves angiolymphoid hyperplasia with eosinophilia. Final diagnosis requires anatomopathological study. The most frequently encountered histological criteria are preservation of node structure, highly developed germinal centers, eosinophilic infiltration, and presence of numerous postcapillary veinlets. Prognosis is favorable but multiple relapses are possible. Corticosteroid therapy is usually effective but radiation treatment may be necessary in patients with recurrent disease.

Algeria↗

[History of the concept of quarantine].

Quarantine is a concept developed by society to protect against the outbreak of contagious diseases. From its original application in the favorable context of Medieval Europe, the quarantine concept has been driven by three main currents. The first involves the personification of epidemics. Although this personification had superstitious implications and led to many excesses, it did have the merit of establishing a concrete connection between travel and outbreak of disease. The second fundamental aspect of quarantining is the existence of a social organization capable of providing the necessary infrastructure for isolation. Specialized facilities are needed and laws must be made and enforced by competent officials. The last fundamental aspect of the development of the quarantine concept is the role of science. After a long process involving better medical knowledge and international negotiations, epidemic controls has largely outgrown the early stage involving essentially local control measures. In accordance with the development of these three currents, infected individuals have been branded as curse bearers, possible criminals, and innocent victims of natural contamination. While forced quarantine is no longer practiced, several recent examples of heated debates illustrate that strong emotional feelings are still present in societies threatened by epidemic disease outbreak. Since the major responsibility for disease control now rests in their hands, physicians must take these factors into account for management of possible future epidemic crises.

Cholera↗

[Malaria in expatriates in Africa. 154 cases. Clinical problems and therapeutic difficulties].

OBJECTIVES: Malaria is a major health priority. The aim of this study was to describe clinical expression, laboratory findings and therapeutic aspects of Plasmodium falciparum malaria observed in a French military population stationed in Gabon. PATIENTS AND METHODS: One hundred fifty-four cases of P. falciparum malaria were observed between July 1, 1994 and February 29, 1996. In 145 cases malarial fever predominated and in 9 others further complications occurred. Mean age of the patients was 23.7 years and mean delay to consultation was 30 hours. Seventy-two percent of the patients stated they took prophylaxis (chloroquine-proguanil) regularly. RESULTS: Pain generally accompanied the episodes of fever. There were 21 atypical cases. Parasitemia was < 25000 HPM in 70% of the cases. Blood counts showed leukopenia, lymphopenia, and thombopenia. Plasma cholesterol was low and lactic acid dehydrogenase levels were elevated. Halofantrine was used for curative treatment (2 doses with a 7 day interval) in 145 cases. Intravenous quinine was used in 9 cases. DISCUSSION: This series demonstrates the importance of malarial morbidity in French military men stationed in Africa and confirmed the performance of the acridine orange test. It also emphasized the importance of indirect laboratory findings for early diagnosis of malaria in foreigners living in Africa. A new dosage of halofantrine is proposed for the second injection due to cardiac toxicity.

Adult↗

Presence of multiple non-B subtypes and divergent subtype B strains of HIV-1 in individuals infected after overseas deployment.

OBJECTIVE: To identify the genetic subtypes and characteristics of HIV-1 strains from individuals infected after overseas deployment. PATIENTS AND METHODS: Sixty-one HIV-1-positive individuals detected between 1986 and 1995 in the French army were included in the study. For each patient, the year and country of HIV infection are known. Genetic subtypes of HIV-1 were determined using the heteroduplex mobility assay (HMA) using ED5/ED12 as outer and ES7/ES8 as inner primers. Strains were further characterized by sequencing and phylogenetic analysis of the C2-V3 region. The amino-acid sequences corresponding to the V3 region were aligned on the basis of the subtyping results and were then compared to the consensus V3 sequences of the corresponding subtypes. RESULTS: Among the 61 patients studied, nine became infected in France, and 52 were HIV-negative before overseas deployment but HIV-positive at their return. The majority (n = 43) deployed in Africa and a limited number of patients deployed in Asia (Cambodia, n = 5) or South America (guyana, n = 4). The nine individuals who were not deployed overseas were all infected with subtype B strains. The majority of the other patients were infected with non-B strains; eight subtype A, 20 subtype B, 16 subtype C, one subtype D, six subtype E and one subtype F. Five of the six subtype E strains were contracted in Cambodia and one in Djibouti, and all subtype C strains were from Djibouti. Phylogenetic analysis revealed a large diversity among the different strains introduced into France. Analysis of the amino-acid sequences of the V3 loop revealed the introduction of uncommon V3-loop patterns. CONCLUSION: In the group of HIV-1-infected individuals that we studied and who were deployed overseas, 63.4% were infected with non-B strains. In addition, the subtype A, B and C viruses in this population were very heterogeneous. Due to the routine occurrence of international travel and deployment, the predominance of subtype B HIV-1 viruses may change in European countries. However, the possible implications on the dynamics of the HIV-1 epidemic needs further follow-up.

Adult↗

[Melioidosis: a tropical time bomb that is spreading].

Melioidosis, an infectious disease that affects many mammals, was first identified in Burma by Whitmore in 1912. It is caused by Burkholderia pseudomallei, a gram negative bacillus of the Pseudomonas family, which is found in soil and water. Long present in Southeast Asia and numerous tropical areas, melioidosis has recently appeared in temperate zones including mainland France. The incidence in endemic areas is between 6% and 20% of the population and short period of exposure is sufficient to be contaminated. In man the contamination occurs mainly through skin wounds and the disease can be clinically inapparent. Diabetes, renal disease, and various forms of immunodepression are triggering factors for the onset of a variety of symptoms ranging from acute septicemia to abscesses involving almost any organ in the body. Ceftazidime alone or a combination of clavulanate and amoxicilline is the treatment of choice but the mortality rate in patients with acute forms is still 40% and relapse can occur if treatment is stopped too soon. Bacteriologic and serologic tests can fail and awareness of a history of geographic exposure is an important diagnostic criteria for this disease which has been expanded with the growth of international travel.

Anti-Bacterial Agents↗