Implication of efflux pumps and ERG11 genes in resistance of clinical Trichosporon asahii isolates to fluconazole

Introduction. Trichosporon asahii has been recognized as an opportunistic agent having a limited sensitivity to antifungal treatment.Hypothesis/Gap Statement. Molecular mechanisms of azole resistance have been rarely reported for Trichosproron asahii. Similar to other fungi, we hypothesized that both ERG11 gene mutation and efflux pumps genes hyper-expression were implicated.Aim. The current work aimed to study the sensitivity of clinical T. asahii isolates to different antifungal agents and to explore their resistance mechanisms by molecular methods including real-time PCR and gene sequencing.Methods. The sensitivity of T. asahii isolates to fluconazole, amphotericin B and voriconazole was estimated by the Etest method. Real-time PCR was used to measure the relative expression of Pdr11, Mdr and ERG11 genes via the ACT1 housekeeping gene. Three pairs of primers were also chosen to sequence the ERG11 gene. This exploration was followed by statistical study including the receiver operating characteristic (ROC) curve analysis to identify a relationship between gene mean expression and the sensitivity of isolates.Results. In 31 clinical isolates, the resistance frequencies were 87, 16.1 and 3.2 %, respectively, for amphotericin B, fluconazole and voriconazole. Quantitative real-time PCR demonstrated that only Mdr over-expression was significantly associated with FCZ resistance confirmed by univariate statistical study and the ROC curve analysis (P <0.05). The ERG11 sequencing revealed two mutations H380G and S381A in TN325U11 (MIC FCZ=8 µg ml^-1) and H437R in TN114U09 (MIC FCZ=256 µg ml^-1) in highly conserved regions (close to the haem-binding domain) but their involvement in the resistance mechanism has not yet been assigned.Conclusion. T. asahii FCZ resistance mechanisms are proven to be much more complex and gene alteration sequence and/or expression can be involved. Only Mdr gene over-expression was significantly associated with FCZ resistance and no good correlation was observed between FCZ and VCZ MIC values and relative gene expression. ERG11 sequence alteration seems to play a major role in T. asahii FCZ resistance mechanism but their involvement needs further confirmation.

Blood CD9+ B cell, a biomarker of bronchiolitis obliterans syndrome after lung transplantation

Bronchiolitis obliterans syndrome is the main limitation for long-term survival after lung transplantation. Some specific B cell populations are associated with long-term graft acceptance. We aimed to monitor the B cell profile during early development of bronchiolitis obliterans syndrome after lung transplantation. The B cell longitudinal profile was analyzed in peripheral blood mononuclear cells from patients with bronchiolitis obliterans syndrome and patients who remained stable over 3 years of follow-up. CD24^hi CD38^hi transitional B cells were increased in stable patients only, and reached a peak 24 months after transplantation, whereas they remained unchanged in patients who developed a bronchiolitis obliterans syndrome. These CD24^hi CD38^hi transitional B cells specifically secrete IL-10 and express CD9. Thus, patients with a total CD9⁺ B cell frequency below 6.6% displayed significantly higher incidence of bronchiolitis obliterans syndrome (AUC = 0.836, PPV = 0.75, NPV = 1). These data are the first to associate IL-10-secreting CD24^hi CD38^hi transitional B cells expressing CD9 with better allograft outcome in lung transplant recipients. CD9-expressing B cells appear as a contributor to a favorable environment essential for the maintenance of long-term stable graft function and as a new predictive biomarker of bronchiolitis obliterans syndrome-free survival.

Use of FreeStyle Libre Flash Monitor Register in the Netherlands (FLARE-NL1): Patient Experiences, Satisfaction, and Cost Analysis

In patients with diabetes mellitus (DM), adequate glucose control is of major importance. When treatment schemes become more complicated, proper self-management through intermittent self-measurement of blood glucose (SMBG), among others, becomes crucial in achieving this goal. In the last decade, continuous glucose monitoring (CGM) has been on the rise, providing not only intermittent information but also information on continuous glucose trends. The FreeStyle Libre (FSL) Flash CGM system is a CGM system mainly used for patients with DM and is designed based on the same techniques as early CGMs. Compared with earlier CGMs, the FSL is factory calibrated, has no automated readings or direct alarms, and is cheaper to use. Although less accurate compared with the gold standard for SMBG, users report high satisfaction because it is easy to use and can help users monitor glucose trends. The Flash Monitor Register in the Netherlands (FLARE-NL) study aims to assess the effects of FSL Flash CGM use in daily practice. The study has a before-after design, with each participant being his or her own control. Users will be followed for at least 1 year. The endpoints include changes in HbA1c, frequency and severity of hypoglycemias, and quality of life. In addition, the effects of its use on work absenteeism rate, diabetes-related hospital admission rate, and daily functioning (including sports performance) will be studied. Furthermore, cost-benefit analysis based on the combination of registered information within the health insurance data will be investigated. Ultimately, the data gathered in this study will help increase the knowledge and skills of the use of the Flash CGM in daily practice and assess the financial impact on the use of the Flash CGM within the Dutch healthcare system.

Human Leukocyte Antigen Sensitization in Solid Organ Transplantation: A Primer on Terminology, Testing, and Clinical Significance for the Apheresis Practitioner

The human leukocyte antigen (HLA) system is an important immunologic barrier that must be considered for successful solid organ transplantation. Formation of donor-specific HLA antibodies in solid organ transplantation is an important cause of allograft injury and may contribute to recipient morbidity and mortality. Therapeutic plasma exchange is often requested to lower HLA antibody levels prior to or after transplantation and for management of HLA antibodies in the context of organ rejection. In this review, we summarize the current terminology, laboratory testing, and clinical significance of HLA sensitization in the solid organ transplant population. Furthermore, to illustrate applications of HLA testing in clinical practice, we summarize our own lung and kidney institutional protocols for managing HLA antibodies in the peri-transplant setting.

Young Sprague Dawley rats infected by Plasmodium berghei: A relevant experimental model to study cerebral malaria

Cerebral malaria (CM) is the most severe manifestation of human malaria yet is still poorly understood. Mouse models have been developed to address the subject. However, their relevance to mimic human pathogenesis is largely debated. Here we study an alternative cerebral malaria model with an experimental Plasmodium berghei Keyberg 173 (K173) infection in Sprague Dawley rats. As in Human, not all infected subjects showed cerebral malaria, with 45% of the rats exhibiting Experimental Cerebral Malaria (ECM) symptoms while the majority (55%) of the remaining rats developed severe anemia and hyperparasitemia (NoECM). These results allow, within the same population, a comparison of the noxious effects of the infection between ECM and severe malaria without ECM. Among the ECM rats, 77.8% died between day 5 and day 12 post-infection, while the remaining rats were spontaneously cured of neurological signs within 24-48 hours. The clinical ECM signs observed were paresis quickly evolving to limb paralysis, global paralysis associated with respiratory distress, and coma. The red blood cell (RBC) count remained normal but a drastic decrease of platelet count and an increase of white blood cell numbers were noted. ECM rats also showed a decrease of glucose and total CO2 levels and an increase of creatinine levels compared to control rats or rats with no ECM. Assessment of the blood-brain barrier revealed loss of integrity, and interestingly histopathological analysis highlighted cyto-adherence and sequestration of infected RBCs in brain vessels from ECM rats only. Overall, this ECM rat model showed numerous clinical and histopathological features similar to Human CM and appears to be a promising model to achieve further understanding the CM pathophysiology in Humans and to evaluate the activity of specific antimalarial drugs in avoiding/limiting cerebral damages from malaria.

Molecular basis of pyruvate kinase deficiency among Tunisians: description of new mutations affecting coding and noncoding regions in the PKLR gene

INTRODUCTION

Pyruvate kinase (PK) deficiency is one of the most common hereditary nonspherocytic hemolytic anemias worldwide with clinical manifestations ranging from mild to severe hemolysis. However, investigation of this enzymopathy is lacking in Tunisia. We report here a pioneer investigation of PK deficiency among Tunisian cases referred to our laboratory for biological analysis of unknown cause of hemolytic anemia.

METHODS

Two hundred and fifty-three patients with unknown cause of hemolytic anemia have been addressed to our laboratory in order to investigate for red blood cells genetic disorders. Red cell enzyme activities were measured by standard methods, and molecular analysis was performed by DNA sequencing. The interpretation of mutation effect and the molecular modeling were performed by using specific software.

RESULTS

Six different PKLR mutations were found (c.966-1G>T; c.965+1G>A; c.721G>T; c.1163C>A; c.1456C>T; c.1537T>A), among which four are described for the first time. Genotype-phenotype correlations for the novel missense mutations were investigated by three-dimensional structure analysis.

CONCLUSION

This study provides important data of PK deficiency among Tunisians. It might be followed by a large neonatal screening to determine the spectrum of PK mutations and identify potential deficient patients for an early medical follow-up.

Performance of the FreeStyle Libre Flash glucose monitoring system in patients with type 1 and 2 diabetes mellitus

OBJECTIVE

To evaluate the performance of the FreeStyle Libre Flash continuous glucose monitoring (FSL-CGM) system against established central laboratory methods.

RESEARCH DESIGN AND METHODS

20 subjects (8 type 1 diabetes mellitus, 12 type 2 diabetes mellitus) were analyzed. FSL-CGM sensor measurements (inserted in arm and abdomen) were compared with capillary blood glucose results analyzed with StatStrip as semigold standard. The glucose response after a standardized oral glucose load was measured by FSL-CGM and capillary samples analyzed by perchloric acid hexokinase (PCA-HK) method, StatStrip and FSL test strip (FSLC), and a commonly used CGM system (iPro2).

RESULTS

FSL-CGM arm sensor readings showed 85.5% of paired readings falling within Clarke Error Grid (ISO 15197:2013) zone A when compared with StatStrip. For FSL-CGM abdomen and FSLC, these percentages were 64% and 98%, respectively. The overall correlation of FSL-CGM in the arm and the StatStrip indicates a performance with lower results with the FSL-CGM in the arm than expected based on the StatStrip in the lower glucose ranges, and higher results than expected in the higher ranges. Following a standardized glucose load, a slower rise in glucose level was observed for FSL-CGM arm as compared with PCA-HK, StatStrip, FSLC, and iPro2 during the first 45-60 min after glucose load ingestion.

CONCLUSIONS

Certain matters need attention while using the FSL-CGM in daily life including the observed lower values in the lower ranges, and the underestimation of the effect of a meal on glucose response. These effects of such deviations can partly be overcome by optimizing the available user instructions.

TRIAL REGISTRATION NUMBER

TC5348; results.

Early Lung Computed Tomography Scan after Allogeneic Hematopoietic Stem Cell Transplantation

A lung computed tomography (CT) scan is essential for diagnosing lung diseases in hematopoietic stem cell transplantation (HSCT) recipients. As a result, lung CT scans are increasingly prescribed in the early phase after allogeneic HSCT, with no assessment of the added value for global patient management. Among 250 patients who underwent allogeneic HSCT in our center over a 2-year period, we evaluated 68 patients who had at least 1 lung CT scan within the first 30 days post-transplantation. The median interval between allogeneic HSCT and lung CT scan was 8.5 days. Patients who underwent an early lung CT scan were more immunocompromised and had a more severe course. Fever was the main indication for the CT scan (78%). The lung CT scan was abnormal in 52 patients, including 17 patients who had an abnormal pre-HSCT CT scan. A therapeutic change was noted in 37 patients (54%) within 24 hours after the lung CT scan. The main changes included the introduction of corticosteroids (n = 23; 62%), especially in patients with a normal CT scan (89%). In univariate models, we found that a normal pretransplantation CT scan (P = .002), the absence of either dyspnea (P = .029) or hypoxemia (P = .015), and a serum C-reactive protein level <10 mg/L (P = .004) were associated with a normal post-HSCT lung CT scan. We found that the association of these variables could predict the normality of early post-HSCT lung CT scans. Pretransplantation lung CT scans are useful for the interpretation of subsequent lung CT scans following allogeneic HSCT, which are frequently abnormal. Early post-HSCT lung CT scans are helpful in patient management, but prescriptions could be more targeted.

Pre-transplant prognostic factors of long-term survival after allogeneic peripheral blood stem cell transplantation with matched related/unrelated donors

Mobilized peripheral blood has become the predominant stem cell source for allogeneic hematopoietic cell transplantation. In this retrospective single center study of 442 patients with hematologic malignancies, we analyzed prognostic factors for long-term survival after peripheral blood stem cell transplantation from HLA-matched related or unrelated donors. To account for disease/status heterogeneity, patients were risk-stratified according to the Disease Risk Index. Five-year overall survival was similar after transplants with matched related and unrelated donors (45% and 46%, respectively; P=0.49). Because donor age ≥60 years impacted outcome during model building, we further considered 3 groups of donors: matched unrelated (aged <60 years by definition), matched related aged <60 years and matched related aged ≥60 years. In multivariate analysis, the donor type/age group and the graft CD34(+) and CD3(+) cell doses impacted long-term survival. Compared with matched unrelated donor transplant, transplant from matched related donor <60 years resulted in similar long-term survival (P=0.67) while transplant from matched related donor ≥60 years was associated with higher risks for late mortality (hazard ratio (HR) 4.41; P=0.006) and treatment failure (HR: 6.33; P=0.009). Lower mortality risks were observed after transplant with CD34(+) cell dose more than 4.5×10(6)/kg (HR: 0.56; P=0.002) and CD3(+) cell dose more than 3×10(8)/kg (HR: 0.61; P=0.01). The Disease Risk Index failed to predict survival. We built an "adapted Disease Risk Index" by modifying risks for myeloproliferative neoplasms and multiple myeloma that improved stratification ability for progression-free survival (P=0.04) but not for overall survival (P=0.82).

Three new mutations account for the prevalence of glucose 6 phosphate deshydrogenase (G6PD) deficiency in Tunisia

A previous study on G6PD deficiency carried out on Tunisian population, led to the finding of seven different mutations with the prevalence of G6PD A- variant. This present study reports 23 new unrelated deficient subjects studied at the molecular level to determine the mutation that causes G6PD deficiency. Using PCR-SSCP of coding regions followed by direct sequencing of abnormal pattern, three new mutations were detected. Two of them are polymorphic intronic mutations. The first is IVS-V 655C-->C/T, found in four female subjects with mild deficiency of class III variant. The second is IVS-VIII 43 G-->A, found in three male subjects with mild deficiency of class III variant. The third mutation is in the exon region so that it changes the primary structure of the molecule. It is cited for the first time and named G6PD Tunisia. This variant affects the exon 7 of the gene at genomic position 15435 G→T. Its cDNA position is 93 G→G/T, it changes arg 246 to leu. This mutation was found in one heterozygote female with deficiency of class II who have had hemolytic anemia due to ingestion of fava beans. Finally, G6PD Med variant, reported before in three cases, was also found in five other cases (four heterozygote females and one male hemizygote). These findings first enlarge the spectre of mutations to be ten variant mutations, characterizing the Tunisian population and also contribute with hemoglobin gene research in our laboratory to trace the whole genetic map of Tunisian population.

Alveolar and blood T lymphocyte profiles in Pneumocystis jirovecii-positive patients: effects of HIV status

BACKGROUND

There are substantial differences in the risk evaluation, clinical presentation, and outcome of Pneumocystis pneumonia between human immunodeficiency virus (HIV)-positive and HIV-negative immunocompromised patients. To compare the host immune defenses against Pneumocystis jirovecii, the blood and alveolar lymphocyte profile was explored in these 2 populations.

METHODS

The total, CD3(+), CD4(+), and CD8(+) T-lymphocyte counts were measured in the blood and alveoli of immunocompromised patients with a P. jirovecii DNA detected in their bronchoalveolar lavage samples, according to their HIV status.

RESULTS

In blood and alveoli, the CD4(+) and CD8(+) T-lymphocyte counts were higher and lower, respectively, in the HIV-negative group. The threshold for initiating prophylaxis in HIV-positive persons, 200 CD4(+) T cells/μL, was not pertinent for HIV-negative patients. The P. jirovecii burden correlated with the blood CD4(+) T-cell counts in the HIV-positive but not in the HIV-negative group. Nevertheless, whatever the HIV status, a correlation was observed between alveolar CD4(+) T cells and the P. jirovecii burden.

CONCLUSIONS

The T-lymphocyte profile was different between HIV-positive and HIV-negative patients with P. jirovecii, suggesting a distinct pathogenesis. Alveolar CD4(+) T cells could be critical to explain the development of Pneumocystis pneumonia but may also be important for evaluation of disease risk, mostly among HIV-negative immunocompromised patients.

Candida glabrata strain relatedness by new microsatellite markers

We investigated six microsatellite markers to type 85 unrelated and 118 related isolates of Candida glabrata from 36 patients. Three new markers were selected from the complete sequence of CBS138 and three previously described markers, RPM2, MTI and ERG3 were used. We found a genetic diversity of 0.949 by combining four of them. By applying the new microsatellite markers GLM4, GLM5 and GLM6 we were able to discriminate 29 isolates, originally identified by the more established markers, RPM2, MTI and ERG3. When epidemiologically closely related isolates from 36 patients were typed, 25 patients (72%) exhibited identical or highly related multilocus genotypes. We noted a microvariation in 4 of the patients. This minor change of one locus could be explained by a single step mutation. Since one of these patients had not received antifungal treatment; thus, the relationship between genome variation and antifungal therapy remains controversial. We can conclude from our analysis of these new microsatellite markers that they are highly selective and therefore should be considered as a useful typing system for differentiating related and unrelated isolates of C. glabrata, as well as being able to detect microvariation.

A review of molecular techniques to type Candida glabrata isolates

Candida glabrata has emerged as a common cause of fungal infection causing mucosal and systemic infections. This yeast is of concern because of its reduced antifungal susceptibility to azole antifungals such as fluconazole. A clear understanding of the epidemiology of Candida infection and colonisation required a reliable typing system for the evaluation of strain relatedness. In this study, we discuss the different molecular approaches for typing C. glabrata isolates. Recent advances in the use of molecular biology-based techniques have enabled investigators to develop typing systems with greater sensitivities. Several molecular genotypic approaches have been developed for fast and accurate identification of C. glabrata in vitro. These techniques have been widely used to study diverse aspects such as nosocomial transmission. Molecular typing of C. glabrata could also provide information on strain variation, such as microvariation and microevolution.

[Polymorphisms of the UDP-glucuronosyltransferase 1-A1 gene in Tunisian population]

The UDP-glucuronosyltransferase 1A1 gene that encode the enzyme UGT1A1 responsible for glucuronidation undergoes several variations that may affect the enzymatic activity or expression and which are the cause of metabolic disorders related to the glucuronidation of bilirubin, such as Gilbert's syndrome and Crigler Najjar's syndrome. Among the most common variations, there is the repeat polymorphism A (TA) n TAA in TATA box and biallelic mutation G211A in exon 1. We consider in this work to determine their frequencies in a healthy population. The polymorphism A (TA) n TAA showed that genotype [TA7/TA7] was described as being associated with Gilbert's syndrome and was encountered in 11% of the population studied. This percentage is close to the value described in the Caucasian population, estimated at 10%. Concerning the polymorphism G211A, our results show that the mutated allele is encountered in 15.7% of our study population. This frequency differs greatly from that reported for Caucasians and Afro-Americans but it is similar to that perceived at the Japanese. All these results suggest that the Tunisian population appears to be heterogeneous view UGT1A1 gene mutation status. Regarding the origins and distribution of such polymorphisms in our population, the study reveals a high haplotypic haplotype (TA) 6-G considered ancestral. The comparison of the haplotype structure generally leads to the development of a hypothetical tree of the origin and spread of different haplotypes.

A silent composite hemoglobinopathy characterized by gene sequencing

We report the case of a 35-year-old Tunisian women with a chronic anemia non investigated for a long time. Laboratory analysis using advanced technology of DNA sequencing revealed a compound heterozygote for Hb O Arab and cd 39 beta degrees-thalassemia. It's the first time that such a genotype has been characterized by gene sequencing.

Microsatellite analysis and susceptibility to FCZ of Candida glabrata invasive isolates in Sfax Hospital, Tunisia

We have noted that, during the last few years, there has been a redistribution of the most common Candida species with an increase in non-C. albicans Candida species, particularly Candida glabrata. In many countries, the high frequency of Candida glabrata shows the highest resistance rates. The main objective of this investigation was to analyze the genotypic variability of invasive C. glabrata isolates recovered over a period of six years and assess their in vitro susceptibility to fluconazole to determine the possible existence of relationships between genotype and susceptibility. We collected 50 invasive C. glabrata isolates (21.4%) from January 2001 to December 2007. The in vitro susceptibility profiles as determined by the E-test method showed that 8.3% of the isolates were resistant to fluconazole. The typing with three microsatellite markers RPM2, MTI and ERG3 demonstrated 12 multilocus genotypes distributed irregularly with a predominance of G1 (38%). A cluster (G9) was found among isolates collected in the same ward, at the same time period, suggesting cross transmission. Eleven of 13 patients who had previously been colonized by C. glabrata, were infected by their colonizing strains. However, we noted after prolonged treatment with fluconazole that there was an increase of the MIC for an isolate from one patient and in another patient, the selection of a more resistant variant. In our study, we didn't find an association between genotype and susceptibility to fluconazole. In conclusion, the predominance of some genotypes could be explained by nosocomial transmission or a selective ecological advantage rather than an emergence of a resistant isolate.

Cellular and cytokine changes in the alveolar environment among immunocompromised patients during Pneumocystis jirovecii infection

Limited data exist on the cytokine and cellular changes in the alveolar environment in immunocompromised patients during Pneumocystis jirovecii infection. A cellular and a cytokine analysis were performed on bronchoalveolar lavage (BAL) samples from three groups of patients, i.e., an initial study group of 64 immunocompromised P. jirovecii-positive individuals and two control groups of P. jirovecii-negative patients who had been or not immunosuppressed (65 patients). The results were related to alveolar dilution as determined by urea measurement. Compared with non-infected groups, P. jirovecii-infected patients had a lower level of alveolar macrophages (AM), particularly those with high burdens of P. jirovecii. Alveolar macrophages over-expressed the Dectin-1 receptor, which was largely implicated in P. jirovecii clearance. The alveolar CD8+T and CD4+T lymphocyte counts were increased and an inverse correlation was observed between the alveolar CD4+ cell count and the P. jirovecii burden. Although the alveolar IL-6 level was considerably increased, alveolar IL-17, IL-10, TNF-α, TGF-β concentrations of P. jirovecii patients were not different from the control groups. Changes in the pulmonary environment were also highlighted during P. jirovecii colonization. Our study suggests that there is a correlation between the P. jirovecii burden in the alveolus (from colonization to a high P. jirovecii burden), and the degree of impairment of the alveolar immune response.

Molecular characterization of erythrocyte glucose-6-phosphate dehydrogenase deficiency in Tunisia

Screening of G6PD deficiency was carried out on 79 unrelated subjects (32 females and 47 males), all coming from out consultation. DNA from deficient subject (11 females and 30 males) was analyzed for the presence of G6PD mutation. Known mutations were studied by the appropriate restriction enzyme digestion of fragment amplified by PCR. Where the mutation could not be identified in this way, the samples were subjected to SSCP analysis and abnormal fragments were sequenced. Through these methods, seven different mutations have been identified. Among deficient females, eight had the African variant A-(tow of them were homozygous) and three had the Mediterranean variant, one of them was homozygous and have had a haemolytic crisis after ingestion of fava beans showing at birth manifestation of neonatal jaundice. Among deficient males, four were hospitalized and transfused after a haemolytic crisis due to ingestion of fava beans. All of them have had manifestation of neonatal jaundice. Of them, one carried the Mediterranean variant and three others had the African variant A-. Among the remaining deficient males, 15 had A-variant, two had the Aurès mutation. SSCP analysis of nine mild deficient males, revealed the presence of the association of 1311 CT/93 TC in two subjects, a newly described silent mutation in the exon 12 associated with the polymorphism in the intron 11 93 TC in one subject and tow single intronic base deletion. The first is IVS V 17 (-C) found in two subjects and the second is IVS VIII 43 (-G) encountered in four subjects.

[A clinical respiratory evaluation of dysphagic patients with chronic aspirations]

INTRODUCTION

The basical respiratory state of dysphagic patients with chronic aspirations is not well-known.

OBJECTIVE

to determine if chronic aspirations are associated with chronic clinical respiratory complications.

MATERIALS AND METHODS

A prospective study was performed on 76 patients with swallowing disorders; The patients who aspirate are determined by swallowing videofluoroscopy. All patients answer to a questionnaire analysing their general and respiratory handicap. And a respiratory clinical examination was performed. The clinical symptoms between the group of aspirating patients and non aspirating patients were analysed.

RESULTS

The global handicap and the respiratory handicap, caused by swallowing dysfunction, are more important for the aspirating patients (p < 0.05). The aspirating patients are more often symptomatic (p < 0.05); They present more functional and physical respiratory signs (p < 0.05); it seems that they present more often respiratory infections.

CONCLUSION

Chronic aspirations are associated with a chronic handicapping respiratory disease, that is still to be described with para-clinical exams.

Haplotype diversity and linkage disequilibrium at human G6PD: recent origin of alleles that confer malarial resistance

The frequencies of low-activity alleles of glucose-6-phosphate dehydrogenase in humans are highly correlated with the prevalence of malaria. These "deficiency" alleles are thought to provide reduced risk from infection by the Plasmodium parasite and are maintained at high frequency despite the hemopathologies that they cause. Haplotype analysis of "A-" and "Med" mutations at this locus indicates that they have evolved independently and have increased in frequency at a rate that is too rapid to be explained by random genetic drift. Statistical modeling indicates that the A- allele arose within the past 3840 to 11,760 years and the Med allele arose within the past 1600 to 6640 years. These results support the hypothesis that malaria has had a major impact on humans only since the introduction of agriculture within the past 10,000 years and provide a striking example of the signature of selection on the human genome.

Two fetal hemoglobin variants affecting the same residue: Hb F-Emirates [G gamma 59(E3)Lys-->Glu] and Hb F-Sacromonte [G gamma 59(E3)Lys-->Gln]

Two fast-moving fetal hemoglobin variants were discovered in hematologically normal newborn babies; the first originated in the United Arab Emirates and the second in France. The structural study, carried out by miniaturized techniques of protein chemistry, showed that these two mutations affected the same residue of the G gamma chain, the lysine at position 59(E3) was replaced by glutamic acid in Hb F-Emirates, and by glutamine in Hb F-Sacromonte.

The spectrum of beta thalassaemia mutations in the UAE national population

The beta thalassaemia alleles in 50 beta thalassaemia heterozygotes originating from many parts of the United Arab Emirates (UAE) have been characterised using the allele specific priming technique of the polymerase chain reaction (PCR). The IVSI-5 (G-->C) mutation was found to be present in 66%, while six other alleles occurred at the much lower frequencies of 2% to 8%. These were codon 8/9 (+G), IVSI-1, 3' end (-25 bp), codon 5 (-CT), IVSII-1 (G-->A), codon 30 (G-->C), and codon 15 (G-->A). The mutation types and percentages are compared with other Mediterranean Arab countries and neighbouring areas. It is proposed that IVSI-5 and other Asian Indian mutations were introduced into the UAE by population migration from the region previously known as Baluchistan. These findings should be useful for genetic counselling and the development of a first trimester prenatal diagnosis programme based on direct detection of mutations in the UAE.

[HbD Iran-beta-thalassemia association in a Tunisian family]

A nine-year-old boy from Béjà (North-Western Tunisia) was found to have both HbD Iran and beta-thalassemia. This patient presented with anemia and slight enlargement of the spleen and had a history of acute episodes of hemolysis. Structural studies on this hemoglobin variant used several miniaturized techniques, mainly carboxy-methyl-cellulose chromatography, reverse-phase high performance liquid chromatography and manual peptide sequencing using Chang's technique. The glutamic acid in position 22 on the beta chain was found to be replaced by a glutamine, establishing the diagnosis of HbD Iran. Concomitant presence of a thalassemia trait was suggested by the finding in the index patient of microcytosis, hypochromia and increased HbA2. The family study confirmed this patient's combined heterozygous anomalies, showing the D trait in the father and the beta thalassemia trait in the mother. The same combination was found in the index patient's sister who was, however, free of clinical symptoms. The explanation of this difference in clinical expression was provided by the ADN study which disclosed deletion of an alpha gene in the girl. The resulting alpha chain deficiency counterbalanced the beta chain deficiency.

HB Al-Ain Abu Dhabi [alpha 18(A16)Gly----Asp]: a new hemoglobin variant discovered in an Emiratee family

During a routine program of hemoglobin screening performed in the United Arab Emirates, we observed an electrophoretically fast-moving variant in a 9-month-old girl and in several members of her family. The structural determination, performed by reversed phase high performance liquid chromatography and amino acid sequencing, revealed a new variant that we named Hb Al-Ain Abu Dhabi [alpha 18(A16) Gly----Asp]. Its functional properties were normal.

Laminar analysis of the origin of the various components of evoked potentials in slices of rat sensorimotor cortex

In slices of rat sensorimotor cortex, extracellular field potentials evoked by electrical stimulation of the white matter were recorded at various cortical depths. In order to determine the nature of the various components, experiments were performed in 3 situations: in a control perfusion medium, in a solution in which calcium ions had been replaced by magnesium ions to block synaptic transmission, and in cortices in which the pyramidal neurons of layer V had been previously induced to degenerate. In the control situation, the response at or near the surface was a positive-negative wave. From a depth of about 150 microns downwards, the evoked response consisted usually of 6 successive components, 3 positive-going, P1, P3 and P6 and 3 negative-going, N2, N4 and N5. P1 and N4 were apparent in superficial layers only. The amplitude of the remaining waves was variable in the cortex but all diminished near the white matter. The early part of the surface positive wave arises from a non-synaptic activation of superficial elements, probably apical dendrites. The late part of the surface positive wave and the negative wave are due to the synaptic activation of neurons located probably in layer III. The large negative wave N2 represents principally the antidromic activation of cell bodies and possibly of proximal dendrites of neurons situated in layers III, IV and V, though the compound action potentials of afferent and efferent fibers may contribute to a reduced part to its generation. The late components N4 to P6 are post-synaptic responses. The negative component N5, the amplitude of which is largest in layers III and IV, represents excitatory responses of neurons located at various depths in the cortex. The nature of the positive component P6 is less clear, although the underlying mechanism might be inhibitory synaptic potentials.

Sickle cell anemia in the Tunisian population: haplotyping and HB F expression

Thirty-three Tunisian patients, homozygous for Hb S, were examined. Haplotyping using nine restriction sites in the beta-globin gene cluster revealed that the most common type is the Benin type [---- + - + - +] which occurs at a frequency of 0.94% (31 cases); only one patient was homozygous for an atypical haplotype which shows some differences with the Benin haplotype at sites 1, 5, 6, and 8 [+ ---- + + + +]; the two remaining patients were assumed to be double heterozygotes for the Benin and atypical haplotypes. The presence of the atypical haplotype suggested a double origin of the beta S gene in Tunisia. Moreover, a heterogeneity in the Hb F production was observed, ranging between 2 to 16%, whereas the G gamma-globin expression was remarkably homogeneous in our patients with a normal amount approaching 40%. These results suggested the presence of a combination of several control factors.

[A case of hemoglobin D Punjab in Tunisia. Characterization and structural study]

Hb D Punjab is a hemoglobin abnormality due to the substitution of a glutamic acid by a glutamic on the hemoglobin beta chain: beta 121 Glu----Gln. Authors report here the first case of this rare variant in a tunisian family.

[Leprosy in South Tunisia. Preliminary study]

One hundred and nine leprosy cases have been recorded by the service of dermatology in Sfax (the only specialised centre in the south of Tunisia) during the last decade. These cases have been essentially assembled in two regions: Sfax and Malloulech. The lag of their finding and the ignorance of some other new cases are due to several factors.

[Discovery of 4 new cases of leprosy in a South Tunisian location]

Having found a new case of leprosy from Beni Khadech, the Sfax Service of dermatology has decided to investigate in two places in this region: Elmenzla and Gattar. Beni Khadech, an endemic region, has 30 cases of leprosy in 1978 over 164 declared in Tunisia. Over 1688 systematically examined patients, 4 new cases have been discovered and 3 of which are contagious ones.

[Contribution of hemoglobin synthesis in vitro to the diagnosis of thalassemia]

The authors show that the, incubation techniques of reticulocytes, are able to appreciate accurately deficiency of the globin chain synthesis, so they allow to apply certainly diagnosis of thalassemias.

[Identification of abnormal hemoglobins by isoelectric focusing]

Using IEF on slabs of acrylamide gel was adapted for screening of abnormal Hemoglobins which are at the same level by electrophoresis on cellulose acetate strips. This method is fast, inexpensive and allowed the simultaneous analysis of 70 samples of whole blood. The characterization technique of IEF allowed us to distinguish some rare variants like Hb O Arab, HbD and T gamma in B 0-thalassemia.