The usability of daytime and night-time heart rate dynamics as digital biomarkers of depression severity.

BACKGROUND: Alterations in heart rate (HR) may provide new information about physiological signatures of depression severity. This 2-year study in individuals with a history of recurrent major depressive disorder (MDD) explored the intra-individual variations in HR parameters and their relationship with depression severity. METHODS: Data from 510 participants (Number of observations of the HR parameters = 6666) were collected from three centres in the Netherlands, Spain, and the UK, as a part of the remote assessment of disease and relapse-MDD study. We analysed the relationship between depression severity, assessed every 2 weeks with the Patient Health Questionnaire-8, with HR parameters in the week before the assessment, such as HR features during all day, resting periods during the day and at night, and activity periods during the day evaluated with a wrist-worn Fitbit device. Linear mixed models were used with random intercepts for participants and countries. Covariates included in the models were age, sex, BMI, smoking and alcohol consumption, antidepressant use and co-morbidities with other medical health conditions. RESULTS: Decreases in HR variation during resting periods during the day were related with an increased severity of depression both in univariate and multivariate analyses. Mean HR during resting at night was higher in participants with more severe depressive symptoms. CONCLUSIONS: Our findings demonstrate that alterations in resting HR during all day and night are associated with depression severity. These findings may provide an early warning of worsening depression symptoms which could allow clinicians to take responsive treatment measures promptly.

Predictors of engagement with remote sensing technologies for symptom measurement in Major Depressive Disorder.

BACKGROUND: Remote sensing for the measurement and management of long-term conditions such as Major Depressive Disorder (MDD) is becoming more prevalent. User-engagement is essential to yield any benefits. We tested three hypotheses examining associations between clinical characteristics, perceptions of remote sensing, and objective user engagement metrics. METHODS: The Remote Assessment of Disease and Relapse - Major Depressive Disorder (RADAR-MDD) study is a multicentre longitudinal observational cohort study in people with recurrent MDD. Participants wore a FitBit and completed app-based assessments every two weeks for a median of 18 months. Multivariable random effects regression models pooling data across timepoints were used to examine associations between variables. RESULTS: A total of 547 participants (87.8% of the total sample) were included in the current analysis. Higher levels of anxiety were associated with lower levels of perceived technology ease of use; increased functional disability was associated with small differences in perceptions of technology usefulness and usability. Participants who reported higher system ease of use, usefulness, and acceptability subsequently completed more app-based questionnaires and tended to wear their FitBit activity tracker for longer. All effect sizes were small and unlikely to be of practical significance. LIMITATIONS: Symptoms of depression, anxiety, functional disability, and perceptions of system usability are measured at the same time. These therefore represent cross-sectional associations rather than predictions of future perceptions. CONCLUSIONS: These findings suggest that perceived usability and actual use of remote measurement technologies in people with MDD are robust across differences in severity of depression, anxiety, and functional impairment.

A computer-aided approach to detect the fetal behavioral states using multi-sensor Magnetocardiographic recordings.

We propose a novel computational approach to automatically identify the fetal heart rate patterns (fHRPs), which are reflective of sleep/awake states. By combining these patterns with presence or absence of movements, a fetal behavioral state (fBS) was determined. The expert scores were used as the gold standard and objective thresholds for the detection procedure were obtained using Receiver Operating Characteristics (ROC) analysis. To assess the performance, intraclass correlation was computed between the proposed approach and the mutually agreed expert scores. The detected fHRPs were then associated to their corresponding fBS based on the fetal movement obtained from fetal magnetocardiogaphic (fMCG) signals. This approach may aid clinicians in objectively assessing the fBS and monitoring fetal wellbeing.

Removal of interference from fetal MEG by frequency dependent subtraction.

Fetal magnetoencephalography (fMEG) recordings are contaminated by maternal and fetal magnetocardiography (MCG) signals and by other biological and environmental interference. Currently, all methods for the attenuation of these signals are based on a time-domain approach. We have developed and tested a frequency dependent procedure for removal of MCG and other interference from the fMEG recordings. The method uses a set of reference channels and performs subtraction of interference in the frequency domain (SUBTR). The interference-free frequency domain signals are converted back to the time domain. We compare the performance of the frequency dependent approach with our present approach for MCG attenuation based on orthogonal projection (OP). SUBTR has an advantage over OP and similar template approaches because it removes not only the MCG but also other small amplitude biological interference, avoids the difficulties with inaccurate determination of the OP operator, provides more consistent and stable fMEG results, does not cause signal redistribution, and if references are selected judiciously, it does not reduce fMEG signal amplitude. SUBTR was found to perform well in simulations and on real fMEG recordings, and has a potential to improve the detection of fetal brain signals. The SUBTR removes interference without the need for a model of the individual interference sources. The method may be of interest for any sensor array noise reduction application where signal-free reference channels are available.

Acute kidney injury: novel biomarkers and potential utility for patient care in urology.

Urologists are integrally involved in the management of acute kidney injury (AKI), which is common after renal surgery or secondary to postrenal (obstructive) etiologies. The measurement of serum creatinine is a suboptimal indicator of AKI because it lags behind acute changes in renal function. Recent advances indicate that serum/urine biomarkers will prove useful for early detection of AKI, analogous to the use of cardiac enzymes for acute myocardial infarction. These serum/urine markers may guide future therapy, facilitate research efforts to reduce the severity of AKI, such as after partial nephrectomy, and allow for more accurate prognostication for patients with AKI.

A novel approach to track fetal movement using multi-sensor magnetocardiographic recordings.

Changes in fetal magnetocardiographic (fMCG) signals are indicators for fetal body movement. We propose a novel approach to reliably extract fetal body movements based on the field strength of the fMCG signal independent of its frequency. After attenuating the maternal MCG, we use a Hilbert transform approach to identify the R-wave. At each R-wave, we compute the center-of-gravity (cog) of the coordinate positions of MCG sensors, each weighted by the magnitude of the R-wave amplitude recorded at the corresponding sensor. We then define actogram as the distance between the cog computed at each R-wave and the average of the cog from all the R-waves in a 3-min duration. By applying a linear de-trending approach to the actogram we identify the fetal body movement and compare this with the synchronous occurrence of the acceleration in the fetal heart rate. Finally, we apply this approach to the fMCG recorded simultaneously with ultrasound from a single subject and show its improved performance over the QRS-amplitude based approach in the visually verified movements. This technique could be applied to transform the detection of fetal body movement into an objective measure of fetal health and enhance the predictive value of prevalent clinical testing for fetal wellbeing.

Complications of open primary and post-chemotherapy retroperitoneal lymph node dissection for testicular cancer.

OBJECTIVE: Treatment decisions regarding the use of retroperitoneal lymph node dissection (RPLND) for low-stage and advanced testicular cancer may be influenced by the morbidity of the procedure. We sought to compare the complication profile of primary (P-) and post-chemotherapy (PC-) RPLND using a standardized complication grading scale. MATERIALS AND METHODS: A retrospective analysis was conducted of 112 and 96 patients who underwent P-RPLND and PC-RPLND, respectively, between 1982 and 2007 for perioperative outcomes and late complications. Postoperative complications were graded using a 5-tiered scale based on the severity and/or level of intervention required for resolution. RESULTS: P-RPLND patients had rates of 5%, 24%, and 7% for intraoperative, postoperative, and late complications, respectively. For PC-RPLND, these rates were 12%, 32%, and 7%, respectively (P = 0.11, 0.19, and 1, respectively). Major postoperative complications (grades III-V) were observed in 3 (3%) P-RPLND and 8 (8%) PC-RPLND patients (P = 0.15), including 1 fatal pulmonary embolus in a PC-RPLND patient. Ileus accounted for 63% and 45% of postoperative complications of P-RPLND and PC-RPLND, respectively. PC-RPLND was associated with significantly greater operative times, blood loss, and transfusion rates (P < 0.001). Compared with PC-RPLND after first-line chemotherapy for advanced NSGCT, there were no significant differences in perioperative outcomes for PC-RPLND performed in other settings. CONCLUSIONS: P-RPLND and PC-RPLND are associated with low rates of serious short- and long-term complications and negligible mortality, without significant differences between the 2 procedures. The safe morbidity profile of RPLND performed by fellowship-trained urologic oncologists should be considered during treatment decision-making for low-stage and advanced testicular cancer.

Risk factors for compartment syndrome in traumatic brachial artery injuries: an institutional experience in 139 patients.

BACKGROUND: The brachial artery is the most common vascular injury encountered in upper extremity trauma. If not treated promptly, it can result in compartment syndrome (CS) and long-term disability. Here, we report an institutional experience of traumatic brachial artery injuries and establish risk factors for the development of upper extremity CS in this setting. METHODS: A retrospective review of 139 patients with traumatic brachial artery injury from 1985 to 2001 at a single institution. Patients were divided into two cohorts, those with evidence of CS and those without CS (NCS), for comparison. RESULTS: One hundred thirty-nine patients presented with traumatic brachial artery injuries (mean age, 28.4 years). Twenty-nine patients (20.9%) were diagnosed with upper extremity CS, and 28 of these patients underwent fasciotomy on recognition of their CS. Seven patients (6.4%) in the NCS cohort underwent fasciotomy as a result of absent distal pulses on initial examination. Mean follow-up was 51.6 days. Two patients required revision of their arterial repair, and one patient underwent amputation. The risk of CS was increased in the presence of combined arterial injuries (p = 0.03), combined nerve injuries (p = 0.04), motor deficits (p < 0.0001), fractures, and increased intraoperative blood loss (p = 0.001). Multivariate logistic regression performed on these variables revealed that elevated intraoperative blood loss, combined arterial injury, and open fracture were independent risk factors for the development of CS (OR 1.12, 5.79, and 2.68, respectively). CONCLUSION: Prompt evaluation and management of traumatic brachial artery injuries is important to prevent CS, which can lead to functional deficits. In the setting of combined arterial injury, open fracture, and significant intraoperative blood loss, prophylactic fasciotomy should be considered.

Understanding dynamics of the system using Hilbert phases: an application to study neonatal and fetal brain signals.

The Hilbert phase phi(t) of a signal x(t) exhibits slips when the magnitude of their successive phase difference |phi(t(i+1))-phi(t(i))| exceeds pi. By applying this approach to periodic, uncorrelated, and long-range correlated data, we show that the standard deviation of the time difference between the successive phase slips Deltatau normalized by the percentage of slips in the data is characteristic of the correlation in the data. We consider a 50x50 square lattice and model each lattice point by a second-order autoregressive (AR2) process. Further, we model a subregion of the lattice using a different set of AR2 parameters compared to the rest. By applying the proposed approach to the lattice model, we show that the two distinct parameter regions introduced in the lattice are clearly distinguishable. Finally, we demonstrate the application of this approach to spatiotemporal neonatal and fetal magnetoencephalography signals recorded using 151 superconducting quantum interference device sensors to identify the sensors containing the neonatal and fetal brain signals and discuss the improved performance of this approach over the traditionally used spectral approach.

Utility of preoperative renal artery embolization for management of renal tumors with inferior vena caval thrombi.

OBJECTIVES: To review our experience with radical nephrectomy and inferior vena cava thrombectomy (RNIVCT) to determine the utility of preoperative embolization. Preoperative embolization has been used as an adjunctive procedure to facilitate surgical resection of complex renal tumors. METHODS: From 1990 to 2007, 225 patients with renal tumors and inferior vena cava thrombus underwent RNIVCT, including 135 patients who had undergone preoperative renal artery embolization and 90 patients who had not. The effect of embolization on perioperative morbidity and mortality, transfusion requirements, blood loss, and operative time was analyzed by comparing the 2 groups. RESULTS: The mean primary tumor size was similar in both groups; however, 67% of the RNIVCT embolization group vs 48% of the nonembolization group had retrohepatic (level III) or supradiaphragmatic (level IV) thrombus extension (P = .032). The RNIVCT embolization patients had a greater median number of perioperative units transfused (8 vs 4; P = .001), a longer operative time (390 vs 313 minutes; P < .001), more postoperative complications (43% vs 29%; P < .001), a longer intensive care unit stay (2 vs 0.5 days), and increased perioperative mortality (13% vs 3%; P = .017). No differences were found in intraoperative complications or length of hospitalization. Multivariate analysis showed a fivefold greater risk of perioperative death (adjusted odds ratio 5.5; P = .029) and a trend toward increased blood transfusion (regression coefficient 3.9; P = .08) with preoperative embolization. CONCLUSIONS: The results of our study have shown that routine preoperative renal artery embolization in patients undergoing RNIVCT does not provide any measurable benefit in reducing blood loss or complications and was associated with increased major perioperative complications and mortality.

A prognostic model for the risk of development of upper extremity compartment syndrome in the setting of brachial artery injury.

A potentially devastating sequela of brachial artery injury in the setting of upper extremity trauma is the development of compartment syndrome (CS). We performed a retrospective review of 139 trauma patients with brachial artery injury from 1985-2001. Objective characteristics of each case were extracted and analyzed using multivariate logistic regression. Three variables were found to be significant in the final model: estimated intraoperative blood loss as a continuous variable, and presence of a multiple arterial injury and presence of an open fracture as categorical variables. Odds ratio were 1.12, 5.79, and 2.68, respectively. We used these variables to create a summative score for the development of CS with weights assigned proportional to the adjusted odds ratio. Odds of having CS for subjects in group 2 and group 3 are 5.3 and 15.1 times the odds for subjects in group 1, respectively. Applying multivariate regression analysis to the largest series of brachial artery injuries to date, we have developed a predictive scoring model of CS.

Right-sided intrathoracic renal ectopia with Bochdalek's hernia.

A 23-year-old woman was evaluated for right flank pain of one year duration. Magnetic resonance imaging (MRI) revealed a 6 cm defect in the right hemidiaphragm with herniation of the right kidney, adrenal gland, and posterior right hepatic lobe consistent with a congenital right Bochdalek hernia. Computed tomography (CT) urogram confirmed lack of masses, hydronephrosis, and renal calculi and defined vascular and ureteral anatomy through the diaphragmatic hernia. Intrathoracic kidney is rare and is usually discovered incidentally. In the absence of other renal pathology it requires no surgical intervention.

A case of spermatic cord teratoma in low-stage testicular cancer managed by surveillance.

BACKGROUND: A 25-year-old male presented to his local urologist with new-onset right testicular pain and swelling detected on self examination. A scrotal ultrasound scan showed a right testicular mass, suspicious for neoplasm. Serum levels of alpha-fetoprotein and human chorionic gonadotropin were found to be elevated at 920.2 microg/l and 637.4 U/l, respectively. The patient underwent right inguinal orchiectomy and was diagnosed with nonseminomatous germ cell tumor of the right testis, composed of yolk sac tumor, teratoma, and embryonal carcinoma with no evidence of metastatic disease. He opted to remain under surveillance rather than undergo primary chemotherapy or retroperitoneal lymph node dissection for his clinical stage I disease. Serologic relapse at 4 months after orchiectomy was successfully treated with bleomycin, etoposide and cisplatin (BEP) chemotherapy. INVESTIGATIONS: Surveillance comprised regular clinic visits, measurement of serum levels of alpha-fetoprotein, human chorionic gonadotropin and lactate dehydrogenase, chest X-ray and CT of the abdomen and pelvis. Pathology of the testicular mass was reviewed. DIAGNOSIS: A 1.7 cm nodule anterior to the right psoas muscle suspicious for metastatic disease that was seen on CT 16 months after orchiectomy was pathologically confirmed as recurrent mature teratoma in the spermatic cord. Additionally, one of eleven interaortocaval lymph nodes showed evidence of teratoma. MANAGEMENT: Bilateral nerve-sparing retroperitoneal lymph node dissection with complete excision of the right spermatic cord was performed. The patient has since remained disease-free, with normal levels of serum tumor markers and no evidence of metastasis on chest X-ray and abdominal CT.

Carcinosarcoma of the prostate with multiple metastases: case report and review of the literature.

A case of carcinosarcoma of the prostate in a previously healthy 65-year-old man is reported. The tumor was initially diagnosed as adenocarcinoma, but the prostatectomy specimen showed a 717-g prostate, with evidence of adenocarcinoma and carcinosarcoma without heterologous structures. By 3-month follow-up, local recurrence, and liver, lung, and bone metastases had developed in the patient. He died of disease 10 months postoperatively. Carcinosarcoma of the prostate is a very rare but highly aggressive cancer with limited therapeutic options that should be treated with surgery and managed symptomatically. We believe this article is the forty-second case reported in the literature.

A Study on the nature of genetic divergence in rice from assam and North East Himalayas.

A representative group of 190 rice types collected from North-East India along with four standard varieties, three of which were indicas and one japonica, was studied to understand the nature of genetic divergence. Preliminary grouping was done by canonical analysis and the resultant 42 groups were further classified using the D(2) statistic.The final grouping resulted in nine divergent clusters. The three indica standards were found in three different clusters indicating the wide available variability among them. The japonica standard formed a separate group by itself. A majority of the North-East Indian types formed clusters with indicas, whereas some were intermediate and still others were closer to japonica or indica, thus indicating a series of intergrades bridging indica and japonica.Height followed by leaf area was found to be important for primary and 100-grain weight, followed by amylose content for secondary differentiation. It appears that natural selection as well as human selection might have operated for characters differentiating rice types in Assam and North Eastern Himalayas. Geographical distance was not found to be related to genetic divergence. The study suggests that O. sativa contains innumerable but divergent forms, and its classification into definite varietal groups on an arbitrary basis such as isolation barrier, sexual affinity or geographic distribution would be far from reality.