Smoothing orientation data is a fundamental task in different fields of research. Different methods of smoothing time series in quaternion algebras have been described in the literature, but their ...application is still an open point. This paper develops a smoothing approach for smoothing quaternion time series to obtain good performance in classification problems. Starting from an existing method which involves an angular velocity transformation of unit quaternion time series, a new method which employ the logarithm function to transform the quaternion time series to a real three-dimensional time series is proposed. Empirical evidences achieved on real data set and artificially noisy data sets confirm the effectiveness of the proposed method compared with the classical approach based on angular velocity transformation. The R functions developed for this paper will be provided in a Github repository.
Solutions to assess walking deficiencies are widespread and largely used in healthcare. Wearable sensors are particularly appealing, as they offer the possibility to monitor gait in everyday life, ...outside a facility in which the context of evaluation biases the measure. While some wearable sensors are powerful enough to integrate complex walking activity recognition models, non-invasive lightweight sensors do not always have the computing or memory capacity to run them. In this paper, we propose a walking activity recognition model that offers a viable solution to this problem for any wearable sensors that measure rotational motion of body parts. Specifically, the model was trained and tuned using data collected by a motion sensor in the form of a unit quaternion time series recording the hip rotation over time. This time series was then transformed into a real-valued time series of geodesic distances between consecutive quaternions. Moving average and moving standard deviation versions of this time series were fed to standard machine learning classification algorithms. To compare the different models, we used metrics to assess classification performance (precision and accuracy) while maintaining the detection prevalence at the level of the prevalence of walking activities in the data, as well as metrics to assess change point detection capability and computation time. Our results suggest that the walking activity recognition model with a decision tree classifier yields the best compromise in terms of precision and computation time. The sensor that was used had purposely low computing and memory capacity so that reported performances can be thought of as the lower bounds of what can be achieved. Walking activity recognition is performed online, i.e., on-the-fly, which further extends the range of applicability of our model to sensors with very low memory capacity.
To investigate the safety and clinical utility of the sentinel node procedure in early-stage vulvar cancer patients.
A multicenter observational study on sentinel node detection using radioactive ...tracer and blue dye was performed in patients with T1/2 (< 4 cm) squamous cell cancer of the vulva. When the sentinel node was found to be negative at pathologic ultrastaging, inguinofemoral lymphadenectomy was omitted, and the patient was observed with follow-up for 2 years at intervals of every 2 months. Stopping rules were defined for the occurrence of groin recurrences.
From March 2000 until June 2006, a sentinel node procedure was performed in 623 groins of 403 assessable patients. In 259 patients with unifocal vulvar disease and a negative sentinel node (median follow-up time, 35 months), six groin recurrences were diagnosed (2.3%; 95% CI, 0.6% to 5%), and 3-year survival rate was 97% (95% CI, 91% to 99%). Short-term morbidity was decreased in patients after sentinel node dissection only when compared with patients with a positive sentinel node who underwent inguinofemoral lymphadenectomy (wound breakdown in groin: 11.7% v 34.0%, respectively; P < .0001; and cellulitis: 4.5% v 21.3%, respectively; P < .0001). Long-term morbidity also was less frequently observed after removal of only the sentinel node compared with sentinel node removal and inguinofemoral lymphadenectomy (recurrent erysipelas: 0.4% v 16.2%, respectively; P < .0001; and lymphedema of the legs: 1.9% v 25.2%, respectively; P < .0001).
In early-stage vulvar cancer patients with a negative sentinel node, the groin recurrence rate is low, survival is excellent, and treatment-related morbidity is minimal. We suggest that sentinel node dissection, performed by a quality-controlled multidisciplinary team, should be part of the standard treatment in selected patients with early-stage vulvar cancer.
Summary Background Currently, all patients with vulvar cancer with a positive sentinel node undergo inguinofemoral lymphadenectomy, irrespective of the size of sentinel-node metastases. Our study ...aimed to assess the association between size of sentinel-node metastasis and risk of metastases in non-sentinel nodes, and risk of disease-specific survival in early stage vulvar cancer. Methods In the GROningen INternational Study on Sentinel nodes in Vulvar cancer (GROINSS-V), sentinel-node detection was done in patients with T1–T2 (<4 cm) squamous-cell vulvar cancer, followed by inguinofemoral lymphadenectomy if metastatic disease was identified in the sentinel node, either by routine examination or pathological ultrastaging. For the present study, sentinel nodes were independently reviewed by two pathologists. Findings Metastatic disease was identified in one or more sentinel nodes in 135 (33%) of 403 patients, and 115 (85%) of these patients had inguinofemoral lymphadenectomy. The risk of non-sentinel-node metastases was higher when the sentinel node was found to be positive with routine pathology than with ultrastaging (23 of 85 groins vs three of 56 groins, p=0·001). For this study, 723 sentinel nodes in 260 patients (2·8 sentinel nodes per patient) were reviewed. The proportion of patients with non-sentinel-node metastases increased with size of sentinel-node metastasis: one of 24 patients with individual tumour cells had a non-sentinel-node metastasis; two of 19 with metastases 2 mm or smaller; two of 15 with metastases larger than 2 mm to 5 mm; and ten of 21 with metastases larger than 5 mm. Disease-specific survival for patients with sentinel-node metastases larger than 2 mm was lower than for those with sentinel-node metastases 2 mm or smaller (69·5% vs 94·4%, p=0·001). Interpretation Our data show that the risk of non-sentinel-node metastases increases with size of sentinel-node metastasis. No size cutoff seems to exist below which chances of non-sentinel-node metastases are close to zero. Therefore, all patients with sentinel-node metastases should have additional groin treatment. The prognosis for patients with sentinel-node metastasis larger than 2 mm is poor, and novel treatment regimens should be explored for these patients. Funding None.
Innovative approaches combining regulatory networks (RN) and genomic data are needed to extract biological information for a better understanding of diseases, such as cancer, by improving the ...identification of entities and thereby leading to potential new therapeutic avenues. In this study, we confronted an automatically generated RN with gene expression profiles (GEP) from a cohort of multiple myeloma (MM) patients and normal individuals using global reasoning on the RN causality to identify key-nodes. We modeled each patient by his or her GEP, the RN and the possible automatically detected repairs needed to establish a coherent flow of the information that explains the logic of the GEP. These repairs could represent cancer mutations leading to GEP variability. With this reasoning, unmeasured protein states can be inferred, and we can simulate the impact of a protein perturbation on the RN behavior to identify therapeutic targets. We showed that JUN/FOS and FOXM1 activities are altered in almost all MM patients and identified two survival markers for MM patients. Our results suggest that JUN/FOS-activation has a strong impact on the RN in view of the whole GEP, whereas FOXM1-activation could be an interesting way to perturb an MM subgroup identified by our method.
Background: The development of a mass in a surgical scar poses a diagnostic dilemma due to similarities in appearance to hernias,
abscesses, hematomas or desmoid tumors. Scar endometriosis is ...uncommon and malignant change within this ectopic tissue is
rare. Case Report: The case of a 55-year-old woman with an isolated clear cell adenocarcinoma in an area of scar endometriosis
more than 17 years after a cesarean section is presented. Initially, this tumor was thought to be a chronic abscess, but was
finally diagnosed as clear cell carcinoma. This case highlights the difficulties in preoperative diagnosis as well as the
poor prognosis of these tumors. Conclusion: Accurate diagnosis of a lump within a scar is important to define the prognosis
and treatment. Further data are needed for the management of this pathology.
Clinical Performance of CGMS in Type 1 Diabetic Patients Treated by Continuous Subcutaneous Insulin Infusion Using Insulin
Analogs
Bruno Guerci , MD, PHD ,
Michèle Floriot , MD ,
Philip Böhme , MD ,
...Danielle Durain , RN ,
Muriel Benichou , MD ,
Stéphanie Jellimann , MD and
Pierre Drouin , MD *
Service de Diabétologie, Maladies Métaboliques et Maladies de la Nutrition, Centre d’Investigation Clinique-INSERM/CHU de
NANCY-Hôpital Jeanne d’Arc, Centre Hospitalo-Universitaire de Nancy, Toul cedex, France
Abstract
OBJECTIVE —Performance criteria have been established for in vitro blood glucose monitoring, particularly for the self-monitoring of
blood glucose using glucose meters. Devices intended for use in the future, such as the continuous glucose monitoring system
(CGMS), should satisfy similar criteria, particularly in diabetic patients under intensive therapy.
RESEARCH DESIGN AND METHODS —The analysis was conducted on 18 type 1 diabetic patients (not controlled, HbA 1c >7.5%) treated by external pump using insulin analogs. Each patient received a glucose sensor for 3 days during his/her hospitalization
and was instructed in its operation. Medtronic criteria were used to determine the accuracy of the CGMS. In addition, the
data were analyzed according to American Diabetes Association (ADA) criteria, Clarke Error Grid analysis, and method of residuals,
with the glucose oxidase method using a Beckman analyzer used as the reference method. Specificity and sensitivity were evaluated
from the viewpoint of accuracy in the detection of hypoglycemia. For nine patients, two glucose sensors were simultaneously
inserted into an abdominal site to determine the reproducibility of the system.
RESULTS —Among the 33 glucose sensors inserted, 6 (18%) were nonfunctional. The mean duration of CGMS recording was 63 ± 12 h. From
all of the 692 sets of data that paired glucose readings and CGMS, the coefficients of correlation ranged from 0.87 to 0.92
and the mean absolute error ranged from 12.8 to 15.7%. The time experienced in hypoglycemia (<55 mg/dl) was reported at 86
± 62 min/day. Only 39% of the CGMS values satisfied the ADA precision criteria to within ±10%, and 19% of these values satisfied
the future ADA precision criteria of accuracy to within ±5%. The means of difference method showed that the CGMS slightly
underestimated the plasma glucose values (mean = −12 mg/dl). Error grid analysis showed only 77% of the glucose sensor values
were in zone A, and 98.9% were in zones A and B. Two values fell in zone C and a single value fell in zone D. The sensitivity
and specificity of the CGMS to detect hypoglycemia were 33 and 96%, respectively. A total of 6,666 paired sensor values were
recorded with a coefficient of correlation of 0.84 with a coefficient of variation of 8.25%.
CONCLUSIONS —CGMS could be useful in routine clinical practice to provide much more information on the glucose profile than intermittent
self-monitoring of blood glucose (SMBG). However, CGMS cannot be used as a replacement for glucose meters because it does
not satisfy the conventional performance goals set down for in vitro glucose measurements and could therefore lead to clinically
incorrect treatment decisions.
ADA, American Diabetes Association
CGMS, continuous glucose monitoring system
FN, false negative
FP, false positive
SMBG, self-monitoring of blood glucose
TN, true negative
TP, true positive
Footnotes
Address correspondence and reprint requests to Dr. Bruno Guerci, MD, PhD, Service de Diabétologie, Maladies Métaboliques et
Maladies de la Nutrition, Hôpital Jeanne d’Arc, Centre d’Investigation Clinique, Inserm-CHU de Nancy, B.P. 303, 54201 Toul
cedex, France. E-mail: b.guerci{at}chu-nancy.fr .
Received for publication 13 September 2002 and accepted in revised form 10 December 2002.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
*
↵ * Deceased, 21 October 2002.
DIABETES CARE
Abstract Objectives We compared the screening performance of conventional Pap cytology and two human papillomavirus (HPV) DNA assays, the original Hybrid Capture 2 (HC2) and an expanded version that ...tests for 4 additional HPV types (HC2 + 4; Qiagen Corporation), in the detection of cervical neoplasia among unscreened women in a primary care setting in a suburb of Kinshasa, Democratic Republic of the Congo. Methods All women 30 years or older residing in the area were invited to participate, and 1528 were evaluated by Pap cytology and the two HPV assays, conducted at a European and US reference laboratory, respectively, followed by colposcopy. Cervical biopsies were obtained from all women with abnormal colposcopy and from 290 randomly chosen women with normal colposcopy (to correct for verification bias). Results Using a relative light unit of 1 as the cutoff for positivity, 169 and 168 (11%) women tested positive using HC2 and HC2 + 4, respectively. HC2 and HC2 + 4 were in agreement in 98.6% of cases (Kappa = 0.94; 95% confidence interval: 0.91–0.96). Both assays were sensitive (~ 83%) and specific (~ 91%) for the detection of cervical intraepithelial neoplasia-2 or worse disease. Irrespective of the cutoff point used to define positivity, Pap cytology was both less sensitive and more specific than HC2 or HC2 + 4. For instance, cytology was 63% sensitive and 97% specific when a cutoff point of low-grade squamous intraepithelial lesions or worse was used. Conclusions Among unscreened women, HC2 and HC2 + 4 had similar screening accuracy for cervical neoplasia, and both were more sensitive but less specific than Pap cytology.
Accuracy of an Electrochemical Sensor for Measuring Capillary Blood Ketones by Fingerstick Samples During Metabolic Deterioration
After Continuous Subcutaneous Insulin Infusion Interruption in Type 1 ...Diabetic Patients
Bruno Guerci , MD, PHD 1 ,
Muriel Benichou , MD 1 ,
Michèle Floriot , MD 1 ,
Philip Bohme , MD 1 ,
Sebastien Fougnot , MD 1 ,
Patricia Franck , MD 2 and
Pierre Drouin , MD 1
1 Service de Diabétologie, Maladies Métaboliques & Maladies de la Nutrition, CIC-INSERM, Hôpital Jeanne d’Arc, Nancy, France
2 Laboratoire de Biochimie, Hôpital Central, Nancy, France
Abstract
OBJECTIVE —This study was designed to test the accuracy of capillary ketonemia for diagnosis of ketosis after interruption of insulin
infusion.
RESEARCH DESIGN AND METHODS —A total of 18 patients with type 1 diabetes treated by external pump were studied during pump stop for 5 h. Plasma and capillary
ketonemia and ketonuria were determined every hour from 7:00 a.m. (time 0 min = T0) to 12:00 p.m . (time 300 min = T300). Plasma β-hydroxybutyrate (β-OHB) levels were measured by an enzymatic end point spectrophotometric
method, and capillary β-OHB levels were measured by an electrochemical method (MediSense Optium meter). Ketonuria was measured
by a semiquantitative test (Ketodiastix). Positive ketosis was defined by a value of ≥0.5 mmol/l for ketonemia and ≥4 mmol/l
(moderate) for ketonuria.
RESULTS —After stopping the pump, concentrations of β-OHB in both plasma and capillary blood increased significantly at time 60 min
(T60) compared with T0 ( P < 0.001), reaching maximum levels at T300 (1.30 ± 0.49 and 1.23 ± 0.78 mmol/l, respectively). Plasma and capillary β-OHB
values were highly correlated ( r = 0.94, P < 0.0001). For diagnosis of ketosis, capillary ketonemia has a higher sensitivity and negative predictive value (80.4 and
82.5%, respectively) than ketonuria (63 and 71.8%, respectively). For plasma glucose levels ≥250 mg/dl, plasma and capillary
ketonemia were found to be more frequently positive (85 and 78%, respectively) than ketonuria (59%) ( P = 0.017). The time delay to diagnosis of ketosis was significantly higher for ketonuria than for plasma ketonemia (212 ±
67 vs. 140 ± 54 min, P = 0.0023), whereas no difference was noted between plasma and capillary ketonemia.
CONCLUSIONS —The frequency of screening for ketosis and the efficiency of detection of ketosis definitely may be improved by the use of
capillary blood ketone determination in clinical practice.
β-OHB, β-hydroxybutyrate
CSII, continuous subcutaneous insulin infusion
DKA, diabetic ketoacidosis
MDI, multiple daily injections
Footnotes
Address correspondence and reprint requests to Dr. Bruno Guerci, Service de Diabétologie, Maladies Métaboliques & Maladies
de la Nutrition, CIC-INSERM/CHU Nancy, Hôpital Jeanne d’Arc, Centre Hospitalo-Universitaire de Nancy, B.P. 303, 54201 Toul
Cedex, France. E-mail: b.guerci{at}chu-nancy.fr .
Received for publication 31 July 2002 and accepted in revised form 23 December 2002.
P.D. is deceased.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
DIABETES CARE
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