Aneuploidy and DNA fragmentation in sperm of carriers of a constitutional chromosomal abnormality

Among various causes responsible for infertility, it has been admitted for a long time that male infertility can be due to impaired spermatogenesis and/or balanced structural chromosomal abnormalities. Sperm DNA fragmentation is also considered as another cause of infertility. Most of the studies on male infertility have concerned either aneuploidy in the sperm of carriers of constitutional chromosomal abnormalities or sperm DNA fragmentation. This review is aimed at analyzing these 2 parameters in the same patients. Furthermore, we present work on the study of these 2 parameters in the same gametes of 4 carriers of a balanced chromosomal abnormality. Meiotic segregation was analyzed by fluorescent in situ hybridization and DNA fragmentation was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. It was shown that aneuploidy and DNA fragmentation were increased in the sperm of carriers of a balanced chromosomal abnormality. For all 4 carriers of a balanced structural abnormality, there was a 2-5 times higher proportion of spermatozoa with unbalanced chromosomal content and fragmented DNA than among those with normal/balanced content. Moreover, we found a non-random distribution with more gametes with DNA fragmentation when these arose from a particular segregation mode. The mechanism which would tend to explain our results is abortive apoptosis. In conclusion, both meiotic segregation and DNA fragmentation studies should be integrated in the genetic exploration of male carriers of a chromosomal structural abnormality.

Expression of S100A8 in leukemic cells predicts poor survival in de novo AML patients

Cytogenetic stratification remains insufficient for almost half of the acute myeloblastic leukemia (AML) cases, with AML patients requiring subsequent molecular investigation. In our study, we used mass spectrometry (MS)-based proteomic approaches to characterize de novo AML. Fifty-four samples (mononuclear cells from bone marrow or peripheral blood mononuclear cells collected and frozen before treatment) from two independent cohorts of newly diagnosed AML patients were analyzed. We showed that the protein signature of leukemic cells defined two clusters that displayed significant variation for overall and disease-free survival (P=0.001 and 0.0004, respectively). This proteomic classification refines the cytogenetic classes. AML patients with intermediate and unfavorable cytogenetic classifications could be subdivided according to their protein profiles into subgroups with significantly different survival rates. Among the proteins expressed by leukemic cells, we isolated a 10,800-Da marker that retained the highest discriminative value between living and deceased patients. The 10,800-Da marker was identified by MS peptide sequencing as S100A8 (also designated MRP8 or calgranulin A). Western blot analysis confirmed its expression mainly in AML patients with the worst prognosis, arguing for a selective deregulation associated with poor prognosis. These results suggest that the expression of S100A8 in leukemic cells is a predictor of low survival.

Precipitation of Arsenic Trisulfide by Desulfotomaculum auripigmentum

A newly discovered bacterium, Desulfotomaculum auripigmentum, precipitates arsenic trisulfide (As(inf2)S(inf3)). Precipitation of As(inf2)S(inf3) by this organism results from its reduction of As(V) to As(III) and S(VI) to S(-II). At the As(III) concentration range of interest (0.1 to 1 mM), the stability of As(inf2)S(inf3) is highly sensitive to pH and [S(-II)]. Thus, the relative rates at which D. auripigmentum reduces As(V) and S(VI) are critical to its formation of As(inf2)S(inf3). Other As(V)- or S(VI)-reducing bacteria are unable to precipitate As(inf2)S(inf3) either due to their inability to reduce both As(V) and S(VI) or because they reduce S(VI) too rapidly. Electron microscopy of thin sections showed that the precipitate forms both intra- and extracellularly. Microbial As(inf2)S(inf3) formation nucleates precipitation of the mineral in the bulk milieu, whereas heat-killed cells alone do not serve as templates for its formation. Precipitation of As(inf2)S(inf3) by D. auripigmentum suggests that As(inf2)S(inf3) formation may be important in the biogeochemical cycle of arsenic.

45,X/46,XX mosaicism below 30% of aneuploidy: clinical implications in adult women from a reproductive medicine unit

OBJECTIVE

Turner's syndrome (TS) is well known, but prognosis for 45,X/46,XX mosaicism below 30% of aneuploidy has not been established. We evaluated differences in clinical features and biological parameters between patients with numerical sex chromosome mosaicism diagnosed incidentally and control women.

DESIGN

Retrospective observational study of clinical features and biological parameters.

METHODS

Standard endocrinological and gynecological examination was done and early-follicular-phase blood values were collected from the medical records of women aged 21-43, who were referred to our ward from 1996 to 2006 because of infertility and were karyotyped. Seventy-one women with sex chromosome mosaicism (45,X/46,XX) ranging from 4 to 28% were assigned a chromosomally normal woman (46,XX) matched according to age (n=71).

RESULTS

In group 45,X/46,XX, 8% or more of aneuploidy accounted for a smaller height compared to controls (P=0.01). Body mass index was increased from 6% of aneuploidy (P=0.02) and was positively correlated to the percentage of 45,X cells (P=0.0001); menarche occurred earlier from 10% of aneuploidy (P=0.01) and was inversely correlated to the percentage of 45,X cells (P=0.045). No difference was found between the groups for FSH, LH, estradiol, inhibin B, and TSH values. Spontaneous abortions were more frequent in case of mosaicism (P=0.01), and recurrence was positively correlated to the percentage of aneuploidy (P=0.008).

CONCLUSION

Sex chromosome mosaicism is responsible for clinical changes from 6% of aneuploidy, corresponding to the main phenotypical features of TS.

[Tubercular fibrosing conjunctivitis associated with facial cutaneous tuberculosis]

BACKGROUND

Tuberculous conjunctivitis has been described only rarely during the course of lupus vulgaris. We report a case of hemifacial cutaneous tuberculosis, diagnosed as atypical lupus vulgaris, associated with homolateral fibrosing tuberculous conjunctivitis.

PATIENTS AND METHODS

An 83-year-old woman presented inflammatory conjunctivitis without bullous involvement in the left eye leading to corneal neovascularisation, symblepharons and ptosis. Erythematous and atrophic papules were seen on the left side of the face. Biopsy of the skin and conjunctiva revealed a tuberculoid granulomatous infiltrate. Bacterial culture and PCR were both positive for Mycobacterium tuberculosis.

DISCUSSION

This case illustrates the need to consider tuberculosis when faced with an atypical facial eruption and ocular involvement.

Apolipoprotein A-I and platelet factor 4 are biomarkers for infliximab response in rheumatoid arthritis

OBJECTIVES

The use of biologicals such as infliximab has dramatically improved the treatment of rheumatoid arthritis (RA). However, factors predictive of therapeutic response need to be identified. A proteomic study was performed prior to infliximab therapy to identify a panel of candidate protein biomarkers of RA predictive of treatment response.

METHODS

Plasma profiles of 60 patients with RA (28 non-responders (as defined by the American College of Rheumatology 20% improvement criteria (ACR20)) negative and 32 responders (ACR70 positive) to infliximab) were studied by surface enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF MS) technology on two types of arrays, an anion exchange array (SAX2) and a nickel affinity array (IMAC3-Ni). Biomarker characterisation was carried out using classical biochemical methods (purification by ammonium sulfate precipitation or metal affinity chromatography) and identification by matrix assisted laser desorption/ionisation time-of-flight (MALDI-TOF) MS analysis.

RESULTS

Two distinct protein profiles were observed on both arrays and several proteins were differentially expressed in both patient populations. Five proteins at 3.86, 7.77, 7.97, 8.14 and 74.07 kDa were overexpressed in the non-responder group, whereas one at 28 kDa was increased in the responder population (sensitivity>56%, specificity>77.5%). Moreover, combination of several biomarkers improved the sensitivity and specificity of the detection of patient response to over 97%. The 28 kDa protein was characterised as apolipoprotein A-I and the 7.77 kDa biomarker was identified as platelet factor 4.

CONCLUSIONS

Six plasma biomarkers are characterised, enabling the detection of patient response to infliximab with high sensitivity and specificity. Apolipoprotein A-1 was predictive of a good response to infliximab, whereas platelet factor 4 was associated with non-responders.

Matrix metalloproteinases and diabetic foot ulcers: the ratio of MMP-1 to TIMP-1 is a predictor of wound healing

AIMS

Matrix metalloproteinases (MMPs) play a major role in wound healing: they can degrade all components of the extracellular matrix. In diabetic foot ulcers there is an excess of MMPs and a decrease of the tissue inhibitors of MMPs (TIMPs). This imbalance is probably one cause of impaired healing. However, little is known about changes in MMPs during wound healing.

METHODS

Sixteen patients with neuropathic diabetic foot ulcers participated. Wound fluid was collected regularly during the 12-week follow-up period, for measurement of MMP-1, MMP-2, MMP-8, MMP-9 and TIMP-1. Results were analysed by the degree of wound healing: good healers (defined by a reduction of at least 82% in initial wound surface at 4 weeks) and poor healers (reduction of less than 82% in wound surface at 4 weeks).

RESULTS

In good healers, levels of MMP-8 and -9 secreted by inflammatory cells decreased earlier. The initial levels of MMP-1 were similar in good and poor healers (P = 0.1) but rose significantly at week 2 in good healers (P = 0.039). There was a significant correlation between a high ratio of MMP-1/TIMP-1 and good healing (r = 0.65, P = 0.008). Receiver Operator Curve (ROC) analysis showed that an MMP-1/TIMP-1 ratio of 0.39 best predicted wound healing (sensitivity = 71%, specificity = 87.5%).

CONCLUSIONS

A high level of MMP-1 seems essential to wound healing, while an excess of MMP-8 and -9 is deleterious, and could be a target for new topical treatments. The MMP-1/TIMP-1 ratio is a predictor of wound healing in diabetic foot ulcers.

A role for T cell-derived interleukin 22 in psoriatic skin inflammation

Interleukin (IL)-22 is a T cell-derived cytokine that has been reported recently to induce cutaneous inflammation in an experimental murine model of psoriasis, and to induce in vitro an inflammatory-like phenotype. In the present study, we assessed the presence of IL-22 and the IL-22 receptor 1 (IL-22R1) in skin lesions, skin-derived T cells, as well as IL-22 levels in sera from patients with psoriasis. IL-22R1 and IL-10R2 transcripts are expressed at a similar level in psoriatic and healthy skin. In contrast, IL-22 mRNA expression was up-regulated in psoriatic skin lesions compared to normal skin, whereas IL-22 mRNA levels in peripheral blood mononuclear cells from psoriatic patients and normal subjects were similar. Circulating IL-22 levels were significantly higher in psoriatic patients than in normal subjects. T cells isolated from psoriatic skin produced higher levels of IL-22 in comparison to peripheral T cells isolated from the same patients. IL-10 was expressed at similar levels in skin biopsies and peripheral blood mononuclear cells of psoriatic patients and normal subjects. Finally, we show here that supernatants of lesional psoriatic skin-infiltrating T cells induce an inflammatory response by normal human epidermal keratinocytes, resembling that observed in psoriatic lesions. Taken together, the results reported in this study indicate that IL-22 is a cytokine produced by skin-infiltrating lymphocytes that is potentially involved in initiation and/or maintenance of the pathogenesis of psoriasis.