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Biomedical subjects

A Mahé

Publications and source records attributed to A Mahé.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Dry skin and black skin: what are the facts?].

We present a review of the data in the literature on the potential specificities of the stratum corneum of so-called "black" skin, together with the afferent cutaneous hydration regulation process. The methodology of the studies is often debatable, not only for basic (absence of definition of "black skin") but also for technical reasons. Their results are often contradicting. Other than certain subtle differences, related to potentially enhanced preservation of the epidermis of dark skin from heliodermal xerosis, we conclude in the similarity of the physicochemical characteristics of the stratum corneum in the different color of skin. Moreover, the data available do not suggest a predisposition of certain skin colors to the occurrence of pathological states involving the stratum corneum. However, dark skin is characterized by its semiologic capacity of taking on a "ashy" aspect related to a better assessment of normal or xerotic stratum corneum because of melanic pigmentation.

Black People↗
PubMed2001

Bacterial skin infections in a tropical environment.

The subject of bacterial skin infection in the tropics has shown some significant advances in the past few years, although it is still relatively understudied. Of special interest is the emerging concern about the public health aspects of pyoderma, either primary or secondary to scabies, in developing countries. In addition, certain more unusual agents, such as Bacillus anthracis and Corynebacterium diphtheriae, continue to cause significant problems in some areas, while incidence of other tropical diseases, such as endemic treponematoses, has largely dropped.

Bacillus anthracis↗
PubMed2000

Characterization of two members of the maize gene family, Incw3 and Incw4, encoding cell-wall invertases.

Two maize putative cell-wall invertase genes (Incw3 and Incw4) have been isolated by screening a genomic DNA library (Zea mays L. W22) using the cDNA probes encoding the two maize cell-wall invertases Incw1 and Incw2. The Incw3 and Incw4 genes contain six exons/five introns and five exons/four introns, respectively. The protein sequences deduced from both genes revealed a beta-fructosidase motif and a cysteine catalytic site known to be conserved in invertase genes. A detailed analysis of the protein and nucleotide sequences provides evidence that the Incw3 and the Incw4 genes encode putative cell-wall invertases. Furthermore, the isoelectric point deduced from the INCW4 protein sequence suggested that the Incw4 gene may encode a unique type of cell-wall invertase unbound in the apoplast. Gene expression studies using RT-PCR and in-situ RT-PCR hybridization showed that the Incw3 expression is organ/tissue-specific and developmentally regulated. In contrast, the Incw4 gene is constitutively expressed in all vegetative and reproductive tissues tested.

Amino Acid Sequence↗
PubMed2000

Evidence against a direct cytotoxic effect of alpha interferon and zidovudine in HTLV-I associated adult T cell leukemia/lymphoma.

The combination of the anti-viral agents, zidovudine (AZT) and interferon-alpha (IFN), is a potent treatment of HTLV-I-associated adult T cell leukemia/lymphoma (ATL). In this study we investigate the possible mechanism of action of this combination by examining several cellular parameters including cell proliferation, cell cycle distribution and apoptosis. The ATL-derived T cell lines HuT-102 and MT-2 served as models. HTLV-I negative T cell lines (CEM and Jurkat) were used as controls. No significant modification of cell growth was observed except at suprapharmacological doses of AZT and IFN. Moreover, these effects were less pronounced in HTLV-I-infected cell lines compared to control cell lines. AZT and IFN treatment did not induce any significant modification of the expression of bcl-2 and p53. Interestingly no in vitro cytotoxic effect of AZT/IFN combination was observed on fresh leukemic cells derived from an acute ATL patient at diagnosis despite achievement of in vivo complete remission using the same therapy. These results suggest that the therapeutic effect of AZT and IFN is not through a direct cytotoxic effect of these drugs on the leukemic cells.

Aged↗
PubMed2000

A maize vacuolar invertase, IVR2, is induced by water stress. Organ/tissue specificity and diurnal modulation of expression.

The expression of invertases was analyzed in vegetative organs of well-watered and water-stressed maize (Zea mays) plants. Early changes in sucrose metabolism and in acid soluble invertase expression were observed in vegetative sink and source organs under mild water stress. The organ-specific induction of acid invertase activity was correlated with an increase in the Ivr2 gene transcripts and in the vacuolar invertase proteins. In addition diurnal changes in activity and Ivr2 transcripts for vacuolar invertase were noted in shoots. Hexoses (glucose and fructose) accumulated in all organs examined from water-stressed plants. In situ localization studies showed that glucose accumulation, vacuolar invertase activity, invertase protein, and the Ivr2 transcripts colocalized specifically in bundle sheath and vascular tissue cells of mature stressed leaf; in primary roots the stress-induced increase of Ivr2 transcripts was detected only in root tips. Based on these results different regulatory roles are proposed in sink and source organs for the stress induced Ivr2 vacuolar invertase.

Blotting, Northern↗
PubMed1999

Ivr2, a candidate gene for a QTL of vacuolar invertase activity in maize leaves. Gene-specific expression under water stress.

Water shortage produced an early and large stimulation of acid-soluble invertase activity in adult maize leaves whereas cell wall invertase activity remained constant. This response was closely related to the mRNA level for only one of the invertase gene (Ivr2), encoding a vacuolar isoform. In parallel, four quantitative trait loci (QTLs) were detected for invertase activity under control and nine under stressful conditions. One QTL in control and one in stressed plants was located near to the Ivr2 gene on chromosome 5. Other QTLs for invertase activity were found close to carbohydrate QTLs; some of them formed 'stress clusters'.

DNA, Plant↗
PubMed1999

Dermatological practice in Guadeloupe (French West Indies).

Guadeloupe is a French Caribbean island, with a population of mainly African ancestry, and a high standard of living. We recorded the dermatological diagnoses in 5000 new patients attending dermatologists. The main diagnoses were acne (16.4%), superficial mycoses (12.8%), and eczema (10.5%). Diseases considered to be specific to the tropics were scarce. The main dermatoses attributable to a tropical environment were superficial mycoses, and prurigo. Concerning ethnicity, the majority of Afro-Caribbeans and resident Caucasians visited dermatologists for the same diseases. The main difference attributable to ethnicity was a high rate of visits by Caucasians for melanocytic naevus and malignant/premalignant neoplasms. Dermatoses restricted to Afro-Caribbeans were only secondary ailments. The spectrum of diseases registered in our study was similar to that in Northern countries; this probably reflects the influence of the high standard of life in Guadeloupe.

Adult↗
PubMed1998

[Mucocutaneous manifestations of dengue].

CHANGING EPIDEMIOLOGY: During the last half of the 20th century, dengue has spread to most countries in the inter-tropical zone and today is the most common cause of human arbovirus infection. In tropical zones, dengue is a frequent cause of fever and can be observed in travellers returning from an endemic zone. SKIN AND MUCOSAL MANIFESTATIONS: Though variable, skin and mucosal manifestations are important to recognize. Exanthema occurs late after constitutional symptoms and is suggestive. Minimal hemorrhagic lesions involving the skin and mucosa are observed in common dengue. They usually do not signal progression to authentic hemorrhagic dengue or shock. DIAGNOSIS: Skin manifestations of dengue raise the more general problem of diagnosis in travellers returning from tropical zones who develop fever and rash.

Dengue↗
PubMed1998

Skin diseases in Bamako (Mali).

BACKGROUND: Skin diseases have only recently been considered as a possible public health problem in developing countries. Data supporting this matter are scarce. The aim of this study is to report the experience of a specialized dermatologic center in Bamako (Mali) in order to complete two previous studies conducted in the Bamako area: a prevalence study in the general population and a study in nonspecialized health centers of Bamako. It is our intention to provide a comprehensive picture of the problem of skin diseases in an African developing country. METHODS: We retrospectively collected all cases of skin diseases diagnosed during consultations provided at the Institut Marchoux in Bamako, the only center specializing in dermatology in Mali, during the year 1993. RESULTS: A total of 10,575 new outpatients were seen with 10,889 skin diseases. The main skin diseases registered were as follows: infectious dermatoses (41% of all diagnoses, including scabies (16.6%), superficial mycoses (13.6%), and primary pyoderma (5.6%)), dermatitis (20.4%), papular urticaria (4.4%), acne (4.2%), pityriasis alba (3.6%), keratoderma (3.6%), and urticaria (3%). Typical tropical infectious diseases accounted for only 1% of all diagnoses. CONCLUSIONS: It appears that certain skin diseases (mainly scabies and pyoderma) are an important health problem for the population of the Bamako area. Public health policies should be implemented in order to manage this problem rationally.

Acquired Immunodeficiency Syndrome↗
PubMed1997

[Primary Vibrio vulnificus septicemia. 1st documented case in the French West Indies].

BACKGROUND: Vibrio vulnificus is a non-choleric halophilic vibrion widely distributed in marine environments. Contamination in humans is uncommon except in coastal areas of the United States and Asia. We report the first documented case in the French West Indies. CASE REPORT: A 57-year-old native with alcoholic cirrhosis was hospitalized for septic shock. The infectious syndrome began suddenly a few hours earlier with fever, diarrhea, and intense pain in the calf muscles. In the absence of a suspected agent, a wide spectrum antibiotic was prescribed. On day 3, bullae developed over the legs and progressed, despite early surgical debridement, to bilateral rapidly extensive necrosing cellulitis. An above the knee amputation was required but did not prevent death on day 9 due to irreversible multiple organ failure. Blood cultures were positive for V. vulnificus. DISCUSSION: Primary septicemia due to V. vulnificus is mainly observed in subjects with an underlying liver disease and usually occurs after ingestion of contamined raw halieutic products such as oysters. The clinical presentation is characteristic with secondary necrotic ulcerations on the lower limbs. Improvement in the extremely poor prognosis of these infections depends on early initiation of an effective antibiotic with wide exeresis of necrotic tissue. Physicians should be aware of this severe infection despite its low frequency.

Bacteremia↗
PubMed1997

The proportion of medical consultations motivated by skin diseases in the health centers of Bamako (Republic of Mali).

BACKGROUND: Skin diseases have recently been identified as a public health problem in developing countries. However, most studies on skin diseases in developing countries, have been conducted in specialized dermatologic centers. Data on the proportion of consultations motivated by skin diseases in nonspecialized health centers in developing countries are scarce. In order to appreciate the request for dermatologic care of the population of a developing African country, we attempted to measure this proportion in health centers of Bamako, the capital of Mali. METHODS: Eight out-patient health centers were randomly selected in Bamako, and the medical registers for the first 6 months of 1993 were consulted. RESULTS: Out of a total of 14,058 consultations given, 1639 (11.7%) were motivated by skin diseases. The main diagnoses registered were pyoderma (42.2% of all the dermatologic diagnoses), eczema (15.5%), scabies (8.5%), and fungal infections (7.9%). CONCLUSIONS: The high proportion of ambulatory consultations in health centers in Bamako motivated by skin diseases suggests that they are an important health problem for the population of this city. Public health policies should be implemented in order to manage this problem.

Ambulatory Care Facilities↗
PubMed1997

[Cutaneo-mucous manifestations of dengue].

OBJECTIVES: To describe muco-cutaneous manifestations of dengue fever, assessing their incidence and histopathological aspects. PATIENTS AND METHODS: During a dengue 2 epidemic, occurring in Guadeloupe in 1994, all patients admitted with a confirmed diagnostic of dengue fever were assessed for dermatological changes by 2 clinicians; 5 patients underwent skin biopsy with immuno-fluorescence staining. RESULTS: Among 39 adult inpatients (Sex ratio 1.1, medium age 41 years) none presented a severe form of the disease, whereas 18/39 (46 p. 100) had some muco-cutaneous changes, associating rash (13 cases (33 p. 100)), mucous membranes involvement (7 cases (18 p. 100)), or minor haemorrhages (6 cases (15 p. 100)). The rash appeared macular, discrete, itching, troncular with peripheral extension, rather than maculo-papular (morbiliform) as usually described. Apart from cases which minor haemorrhagic changes, significatively associated with marked thrombocytopenia (medium 37 x 10(9)/1), dengue cases either with or without muco-cutaneous changes had similar clinical (duration, severity) or biological (neutro-lympho-thrombocytopenia, transaminases) features, and evolution. Histological changes appeared non specific (minor lymphocytic dermal vasculitis, non contributive immuno-fluorescence). DISCUSSION: Clinical and histological features of the rash are unspecific and inconstant: they do not allow an easy and accurate diagnosis. Complete clinical, epidemiological (very recent travel in endemic areas) or biological data should be collected, and early virological or later serological confirmation is needed. As well as travel facilities are growing, the dengue area is extending: dengue fever should therefore be considered in every traveller with fever and rash.

Adolescent↗
PubMed1997

[Skin diseases disclosing human immunodeficiency virus infection in Mali].

INTRODUCTION: Several skin diseases are associated with human immunodeficiency virus (HIV) infection. In Africa, due to the difficult access to medical care and complementary examinations, certain diseases are of particular importance. In the present work, we report the skin manifestations observed in a dermatology unit of a large city in Africa over a 3 year period and which were the revealing signs of HIV infection. PATIENTS AND METHODS: All adult subjects (>15 years) with a positive HIV serology (confirmed by Western blot) that had been revealed by a skin disease seen at the Marchoux Institute at Bamako between June 1991 and September 1994 were included in the study. RESULTS: Two hundred sixty-three skin diseases revealed 233 cases of HIV infection. Diseases observed were: zoster (n = 71), seborrheic dermatitis (n = 43), Kaposi's sarcoma (n = 34), prurigo (n = 31), sexually transmitted diseases (n = 27), extensive dermatophytosis (n = 12), psoriasis (n = 12), molluscum contagiosum (n = 8), acquired ichthyosis (n = 3), cutaneous leishmaniasis (n = 2) and other skin diseases (n = 10). More than one disease were associated in 28 patients. Certain particular features were noted (superinfection of zoster, papular margin in dermatophytosis). DISCUSSION: In Africa, certain skin diseases often reveal HIV infection and some diseases have a high positive predictive value for HIV infection (zoster, seborrheic dermatitis, prurigo, Kaposi's sarcoma, extensive dermatophytotis). For prognosis, frequently associated diseases are signs of AIDS (Kaposi's disease, prurigo, molluscum contagiosum).

Adolescent↗