Posture analysis in predicting fall-related injuries during French Navy Special Forces selection course using machine learning: a proof-of-concept study.

INTRODUCTION: Injuries induced by falls represent the main cause of failure in the French Navy Special Forces selection course. In the present study, we made the assumption that probing the posture might contribute to predicting the risk of fall-related injury at the individual level. METHODS: Before the start of the selection course, the postural signals of 99 male soldiers were recorded using static posturography while they were instructed to maintain balance with their eyes closed. The event to be predicted was a fall-related injury during the selection course that resulted in the definitive termination of participation. Following a machine learning methodology, we designed an artificial neural network model to predict the risk of fall-related injury from the descriptors of postural signal. RESULTS: The neural network model successfully predicted with 69.9% accuracy (95% CI 69.3-70.5) the occurrence of a fall-related injury event during the selection course from the selected descriptors of the posture. The area under the curve value was 0.731 (95% CI 0.725-0.738), the sensitivity was 56.8% (95% CI 55.2-58.4) and the specificity was 77.7% (95% CI 76.8-0.78.6). CONCLUSION: If confirmed with a larger sample, these findings suggest that probing the posture using static posturography and machine learning-based analysis might contribute to inform risk assessment of fall-related injury during military training, and could ultimately lead to the development of novel programmes for personalised injury prevention in military population.

Presence of zinc and calcium permeant channels in the inner membrane of the nuclear envelope.

The nuclear envelope possesses specific ion channels that regulate the ionic traffic between the cytoplasm or the perinuclear space and the nucleoplasm. Using the patch-clamp technique to isolated rat nuclei exhibiting only the inner membrane of the nuclear envelope, we report the existence of calcium and zinc permeant channels. These channels displayed similar characteristics (conductance : 8 and 11 pS respectively, open time constant (3.5 ms and 3.7 ms) and close time constant (5.1 ms and 4.8 ms)) and were insensitive to different types of calcium channels blockers and to calcium concentration in the bathing solution. The exact role of these channels remains to define, but they may contribute to the regulation of intranuclear Ca++ or Zn++ dependent processes as important as cell proliferation or programmed cell death. Moreover, this work demonstrates that our nuclei preparation provides a way to study the inner membrane of the nuclear envelope.

Comparison of anti-fading agents used in fluorescence microscopy: image analysis and laser confocal microscopy study.

To ascertain the ability of commercial and home-made anti-fading media to reduce the decrease of fluorescein isothiocyanate (FITC) fluorescence, we studied the bleaching characteristics of FITC-stained Reh 6 cells mounted in buffered glycerol and in anti-fading media. We measured the intensity of fluorescence over time with a confocal laser scanning microscope and a standard epifluorescence microscope coupled to an image analysis system. Most of the anti-fading media effectively retard fading but each has drawbacks. Better results were obtained with media containing p-phenylenediamine (solutions in buffered glycerol, Vectashield, Fluorstop). However, Mowiol, Slowfade, n-propyl gallate (20 g/liter) were also effective in retarding fading. Most of them, except Mowiol, reduced fluorescence intensity. We concluded that the choice of anti-fading medium would depend on the desired results: a slower decay of fluorescence despite an initial quenching of fluorescence or a lower retardant effect with no decrease in initial fluorescence intensity. Moreover, the combination of Mowiol with another anti-fading medium may be a useful compromise when a strong retardant effect is required without marked quenching of the initial fluorescence.

Studies of monoclonal antibody BL2-10D1 as a marker for the detection of the urothelial origin of tumors.

BACKGROUND: In previous studies, the authors demonstrated the value of the monoclonal antibody (MoAb) BL2-10D1 in identifying malignant transitional cells. In this study, the authors evaluate the possible diagnostic value of a murine MoAb, BL2-10D1, raised against human bladder cancer in the determination of the urothelial origin of metastases in a series of 29 patients with metastatic bladder or prostatic carcinoma. METHODS: Using an immunoperoxidase method, BL2-10D1 and anti-prostate-specific antigen (anti-PSA) reactivity were studied, using histologic sections from 18 pelvic lymph nodes and 4 other anatomic sites invaded by transitional cell cancer, and from 7 pelvic lymph nodes containing prostatic cancer. RESULTS: All lymph nodes containing metastases of transitional cell carcinoma were positive with BL2-10D1, whereas all metastases of prostatic cancer were negative; the four instances of distant urothelial metastases were positive with BL2-10D1 MoAb. Conversely, anti-PSA reacted only with prostatic metastases. CONCLUSION: Thus, MoAb BL2-10D1 and anti-PSA complement each other in the separation of cancers of prostatic and urothelial origin, and the BL2-10D1 MoAb has potential usefulness in differentiating between urothelial carcinoma and prostate adenocarcinoma. In patients with bladder tumors of uncertain origin, BL2-10D1 may be helpful in confirming that a tumor is a transitional cell carcinoma.

Combination of standard cytology and immunocytology with BL2-10D1 monoclonal antibody for monitoring-treated bladder cancer patients.

Monoclonal antibody BL2-10D1 directed against a tumor-associated antigen of bladder carcinoma was used for monitoring 11 intravesically treated patients. Thirty-three bladder washout specimens were used for standard cytology and immunological staining. Prior to treatment, 9 of 11 cytologic specimens examined with standard cytology were found to be positive. Using BL2-10D1 alone, only 6 were positive but 1 patient negative with standard cytology was positive with the antibody and corresponded to a positive histological control. Thus, before treatment, an increase in positive rate was observed using the combination of the 2 methods from 82 to 91%. At the end of treatment, 9 washout specimens remained positive with standard cytology, whereas 1 case negative in standard cytology was positive in immunocytology. Thus, the positive rate increased from 82 to 91%. One month after the end of treatment, of 11 washout specimens tested, 3 false-negative standard cytologies and 4 false-negative immunocytologies were shown. However, used in combination, the two methods lead to an increase in positive rate from 67 to 89%. In view of these results, BL2-10D1 may be considered as a useful reagent in combination with the standard cytology for the confirmation of the presence of tumor cells before and after immunotherapy.

An image cytometric DNA-analysis in breast neoplasms. Parameters of DNA-aneuploidy and their relationship with conventional prognostic factors.

In this prospective study, an image cytometric DNA-analysis was performed in 86 women with breast neoplasms (72 primary invasive carcinomas and 14 benign lesions). Four DNA ploidy parameters were analysed: histogram type (according to AUER classification), DNA-index, tumor cells with DNA content above the 5n limit and DNA malignancy grade (DNA-MG, calculation according to Böcking). Their correlations with well established prognostic factors in breast carcinomas (tumor size, lymph node status, histologic grade, hormone receptor content) were studied. All but one benign lesions were diploid (13/14 cases), whereas the majority of the primary invasive breast carcinomas were aneuploid (58/72 cases). A predominance of carcinomas with a percentage of cells superior or equal to 1% with DNA content above the 5n limit was observed (54 cases out of 58). Most of the aneuploid tumors had a histogram type III or IV (53 cases) or a high DNA-index (50 cases). Of these 58 aneuploid cases, only 26 tumors had a DNA-MG superior to 1. Interestingly, 26 tumors had the 4 criteria of aneuploidy, 19 had 3 and 9 had 2 and only 4 tumors had one parameter. The DNA-MG was significantly related to hormonal receptors (p less than 0.001) and tumor size (p less than 0.01). The histogram types (Auer classification) and the DNA content above the 5n limit were correlated with histologic grade (SBR or SBRM) (p less than 0.02). Concerning the DNA-index no correlation was observed with well established prognostic factors. On the other hand no significant correlation was found between these new biologic variables and lymph node status.(ABSTRACT TRUNCATED AT 250 WORDS)

A useful monoclonal antibody (BL2-10D1) to identify tumor cells in urine cytology.

The monoclonal antibody (MoAb) BL2-10D1 directed against a tumor-associated antigen of human bladder cancer was used to identify tumor cells obtained by bladder washing or voided urine. The reactivity of BL2-10D1 MoAb was detected by an immunoperoxidase method and evaluated in ten healthy donors and in a series of 65 patients. The 65 patients studied were divided into three groups: ten with nontumor bladder disease (group A); 36 with bladder carcinoma (group B); and 19 with a history of bladder neoplasia but no visible tumor at the time of cytologic sampling (group C). The results were compared with the standard cytologic diagnosis on Papanicolaou-stained preparations. Conventional cytologic study showed a high false-negative rate in low-grade tumors (transitional cell carcinomas [TCC] Grades 1 and 2, 1/4 and 4/17, respectively). All urine from patients with a histologically proved TCC Grade 1 were stained with BL2-10D1 MoAb. Cytologic findings from patients with TCC Grade 2 (17 cases) contained positive cells in 14 cases and failed to react in three cases. Furthermore, whereas urine from patients with TCC Grade 2 or 3 was not always stained with BL2-10D1 MoAb, all patients with dysplastic lesions (three cases) or carcinoma in situ (5 cases) showed a positive reactivity. Such results suggest that BL2-10D1 MoAb may be considered as a valuable adjunct to the classical methods of early detection and follow-up of bladder cancer. However, a larger scale study is needed for MoAb BL2-10D1 to be proposed as an aid to improve the diagnostic sensitivity of urine cytologic investigation in the follow-up of patients treated for recurring bladder cancer, and for the screening of workers exposed to potent bladder carcinogens.

Phenotyping of 76 human bladder tumors with a panel of monoclonal antibodies: correlation between pathology, surface immunofluorescence and DNA content.

Phenotyping of 76 bladder tumors (11 grade I, 33 grade II and 32 grade III) has been carried out by flow cytometry on cell suspensions with simultaneous determination of DNA content and surface immunofluorescence using G4 and 5 new monoclonal antibodies (10D1, 7C12, 6D1, 3C6 and 12F6) directed against bladder tumor cells. Ten normal bladder samples were used as control. Antibodies 6D1 and 12F6 were specific for tumor cells whereas the others also labelled umbrella cells. Cells from grade I tumors were labelled with 10D1, 6D1, 7C12 and 12F6 antibodies, and cells of grade II tumors with 7C12 and to a lesser degree with 12F6 but not with 10D1 and 6D1. Grade III tumor cells were specifically labelled with antibodies 3C6 and G4. Reactivity of antibodies with tissue sections was well correlated with cytometry results, except for the antibody 3C6. Finally, most of the cells stained by 3C6 and G4 were shown to have a DNA index greater than 1.0. In conclusion cells of low grade tumors can be identified with 10D1 and 6D1 antibodies, and antigens recognized by 3C6 and G4 antibodies are mostly expressed by aneuploid cells.

A monoclonal antibody (BL2-10D1) reacting with a bladder-cancer-associated antigen.

A hybridoma cell line secreting an IgM monoclonal antibody (MAb) was produced after immunizing a mouse with RT4 cells and a crude suspension of human bladder carcinoma cells (WHO grades II and III TCC). This MAb reacted with RT4 target cells derived from a human transitional bladder cancer but failed to react with a majority of non-bladder cancer cell lines. Immunohistological studies indicate that this MAb reacts inconstantly with normal bladder: in positive cases only a few superficial cells (5% to 10% umbrella cells) are stained but not intermediate or basal cells of the urothelium. This MAb was evaluated on 118 tumors: it reacted with tumor tissue in a majority of grade I (79.5%) and grade II papillary TCC (77.3%), less with grade III papillary TCC (45%) and very rarely with invasive non-papillary TCC (14%). In cases of flat lesions a strong reactivity of superficial, intermediate and/or basal layer cells was observed in 50% of moderate and severe dysplasia and in all cell layers of carcinomas in situ (CIS)(9/9).