Neural precursor proliferation and newborn cell survival in the adult rat dentate gyrus are affected by vitamin E deficiency

The adult hippocampal neurogenesis is affected by vitamin E deficiency. In the present investigation we examined if neural precursor proliferation, newborn cell survival or both are altered by vitamin E deficiency. 5-Bromo-2'-deoxyuridine (BrdU) was employed as a marker of proliferating cells. BrdU-labelled cells were revealed 1 and 30 days after BrdU administration in order to evaluate proliferation and newborn cell survival, respectively. Cell proliferation decreased in controls from juvenile to adult age, and the decrease was lesser in vitamin E deficiency. Thus we found a higher number of proliferating cells in vitamin E-deficient rats than in age-matched controls at 5 months of age. Comparing the number of BrdU-positive cells between 1 and 30 days after the last BrdU injection revealed a remarkable decrease in all groups; this is the greatest in vitamin E-deficient rats and the lowest in control rats. Consistently cell death in the dentate gyrus, assessed by TUNEL technique, was found to decrease from 1 to 5 months of age, but at 5 months it was significantly higher in vitamin E-deficient rats than in age-matched controls. These data show that vitamin E deficiency enhances neural precursor proliferation and cell death during adult neurogenesis.     

Absolute CD4 T-cell counting in resource-poor settings: direct volumetric measurements versus bead-based clinical flow cytometry instruments

Flow cytometry is an accurate but expensive method to determine absolute CD4 cell counts. We compared different methods to measure absolute CD4 counts in blood samples from HIV-infected and uninfected subjects using a research/clinical flow cytometer (FACScan); a dedicated clinical instrument (FACSCount); and a volumetric, mobile, open-system flow cytometer equipped with 3 fluorescence and 2 light scatter detectors (Cyflow SL blue). The FACScan and Cyflow were used as single-platform instruments, but they differ in running cost, which is a central factor for resource-poor settings. Direct volumetric and bead-based CD4 measurements on the Cyflow were compared with 2 bead-based single-platform CD4 measurements on the FACSCount and on FACScan (TruCount) in "Le Dantec" Hospital, Dakar, Senegal, using whole blood samples from 102 HIV+ and 28 HIV- subjects. The agreement between the various measurement methods was evaluated by Bland-Altman analysis. Volumetric CD4 measurements on the Cyflow using a no-lyse-no-wash (NLNW) procedure and a lyse-no-wash (LNW) procedure correlated well with each other (R2 = 0.98) and with CD4 measurements on the FACSCount (R2 = 0.97) and FACScan (R2 = 0.97), respectively. Red blood cell lysis had no negative effect on the accuracy of absolute CD4 counting on the Cyflow. An excellent correlation was observed between bead-based CD4 measurements on the Cyflow and CD4 measurements on the FACSCount (R2 = 0.99) and FACScan (R2 = 0.99). Rigid internal and external quality control monitoring and adequate training of technicians were considered essential to generate accurate volumetric CD4 measurements on the Cyflow.     

Antigenicity and specificity of selected glycolipid fractions from Mycobacterium tuberculosis

Antigenicity of Mycobacterium tuberculosis glycolipids polyphthienoyl trehalose (PPTR), phenolic glycolipid (PGL-Tb1), tetraacyl trehalose-2'-sulphate (SL-I) and diacyl trehalose-2'-sulphate (SL-IV) was examined in rabbits. PPTR did not induce production of IgG antibodies in rabbits, while PGL-Tb1, SL-I and SL-IV glycolipids were efficient in this respect. Immune sera raised in rabbits immunoreacted exclusively with the corresponding antigens, which indicated that they were remarkably specific. Specificity of the immune sera was further examined using crude extracts of representative strains of 39 mycobacterial species, and the data showed that these immune sera reacted only with extracts of M. tuberculosis and M. africanum. An antiserum raised against whole cells of M. leprae immunoreacted with the purified SL-IV antigen from tubercle bacilli.     

Single nucleotide polymorphisms in alcohol dehydrogenase genes among some Indian populations.

Seven ADH genes, identified until now, located in the long arm of human chromosome 4, produce seven different isozymes involved in the metabolism of ethanol to acetaldehyde. Of the more than 500 SNPs reported in the coding and non-coding regions of these genes in the world databases, 11 are more extensively studied. Three SNPs, ADH1B Arg47His (Exon3), ADH1B Arg369Cys (Exon9) and ADH1C Val349Ile (Exon8), are functionally validated in terms of phenotype-genotype correlations and are in specific linkage disequilibrium (LD) with non-coding SNPs. However, the frequency of each SNP and configuration of LD varies among populations. The Indian populations studied were conspicuous by the complete absence of African specific allele ADH1B*369Cys, the negligible frequency of East Asian specific ADH1B*47His allele and the presence of a novel SNP ADH1B A3529G (Intron3). The ADH1C*349Ile was the only functional allele polymorphic with a strong LD block in all the populations studied and the high F(st) value observed for the non-coding ADH1B Rsa1 variant was in conformity with world populations.     

Glucose-6-phosphate dehydrogenase deficiency in Mali. Epidemiology and pathological aspects

I,858 semi quantitative G6PD determinations were done in Mali (mostly in the Point G Hospital, in Bamako). 15.7% of the men and 4.5% of the women had a G6PD deficiency. The age did not affect the incidence of the disease. G6PD deficiency was more frequent among the Sonrais than among the other ethnic groups tested. It did not occur more frequently among subjects having the sickling trait of AC hemoglobinopathy but no G6PD was found among subjects having a major hemoglobinopathy (SS or SC). Severe hemolytic anemia was rather infrequent among adults subjects. Hemolysis was induced by drugs--such as dapsone or niridazole--but it was usually mild and time-limited.     

Distribution of acid alpha-naphthyl acetate esterase among human T lymphocyte subsets

Human T lymphocyte subsets, identified by means of OKT3, 4 and 8 monoclonal antibodies, were isolated by a fluorescence activated cell sorter (FACS IV) and analyzed for distribution of alpha-naphthyl acetate esterase (ANAE) activity. As compared to OKT8⁺ lymphocytes a higher proportion of OKT4⁺ lymphocytes was ANAE-positive exibiting a spot or dot-like pattern in the cytoplasm. OKT8 and 4 positive subsets showed a similar ANAE distribution in diffuse granular form. Although OKT4 and OKT8 populations presented a different ANAE dot-like reactivity, this marker did not allow as clear a distinction between them as that reported for T_G and T_M lymphocytes.     

Use of photodynamic therapy in the palliation of massive advanced rectal cancer

Photodynamic therapy (PDT) is a relatively new form of cancer therapy utilizing a photosensitizer such as hematoporphyrin derivative. We conducted a pilot study to determine the efficacy of its use in palliating advanced rectal cancer, to determine toxicity, and to establish objective outcome criteria. Six patients with very advanced, usually recurrent rectal cancer were treated with PDT after being photosensitized with Photofrin II^®. A protocol was established to measure clinical and radiologic response to therapy. A new intraluminal delivery system was incorporated. Five patients had both clinical and radiologic responses to therapy. In two patients we observed such significant responses that they cannot be accounted for on a photobiologic basis alone. One patient developed a significant sunburn after discharge. There was no major toxicity of bleeding or sepsis even at maximum doses (200 J/cm²). We are confident that PDT has a role to play in rectal cancer and speculate as to future applications.     

Early splenectomy and polychemotherapy versus polychemotherapy alone in chronic myeloid leukemia

The effect of early splenectomy and of polychemotherapy with hydroxyurea, busulfan, and alternate bimonthly courses of arabinosyl cytosine and vincristine plus prednisone, was evaluated in 139 previously untreated patients with chronic myeloid leukemia (CML), consecutively admitted to 18 hospitals from March 1973 to October 1974. Fifty-six patients were splenectomized and 83 patients were not splenectomized. Splenectomy did not influence the duration of chronic and blastic phase, and did not prolong survival. The prognosis of high risk patients was not improved. During the chronic phase, high platelet counts were more frequent in splenectomy group, and five patients developed thrombotic or thromboembolic complications, 5 to 19 months after the operation. The median survival of the whole group was 50 months, with 32 of 139 patients (actuarial proportion 30%) remaining alive 72 months after diagnosis, but the slope of the survival curve was similar to that of historical controls. The results of this trial suggests that new strategies should be developed for the therapy of CML.     

Aminopenicillin allergy

Eight two children with histories of maculopapular or urticarial rashes during aminopenicillin treatment underwent skin tests, patch tests, radioallergosorbent assays and, in some cases, oral challenges. Hypersensitivity was diagnosed in eight (9.8%): immediate in four with urticarial reactions and delayed (that is cell mediated) in four with maculopapular rashes. In 49 children (38 with maculopapular eruptions, 11 with urticarial/angiooedematous reactions), negative allergologic findings were confirmed using oral challenges with the suspected drug. Maculopapular rashes may reflect delayed hypersensitivity to aminopenicillins, which can be diagnosed on the basis of late intradermal reactions and/or patch test positivity. The allergen panel must include the suspected aminopenicillin itself, as many cases are side chain specific. Most patients with urticarial reactions (more typical of immediate hypersensitivity) will also react to penicilloyl polylysine and minor determinant mixture. The time elapsed between the reaction and testing must be considered if negative results emerge, because IgE mediated sensitivity (unlike cell mediated forms) declines in the absence of antigen exposure.