Body composition as a predictor of oncological outcome in patients with non-muscle-invasive bladder cancer receiving intravesical instillation after transurethral resection of bladder tumor

Introduction

Body status, categorized as sarcopenia or obesity and assessed using body mass index and body composition, affects the outcome of bladder cancer patients. However, studies comparing disease progression, recurrence, or overall survival in patients with non-muscle-invasive bladder cancer (NMIBC) with different body compositions are lacking. Therefore, we conducted a retrospective study to identify the impact of body composition, sarcopenia, and obesity on the oncological prognosis of patients with NMIBC who underwent transurethral resection of bladder tumor (TURBT) with Bacillus Calmette-Guerin (BCG) intravesical instillation (IVI).

Methods

Patients with NMIBC who had undergone TURBT with adjuvant IVI with BCG from March 2005 to April 2021 were included. Body composition parameters were evaluated using computed tomography images of the third lumbar vertebrae and further categorized by sarcopenia and obesity. Oncological outcomes including recurrence-free survival (RFS), progression-free survival, and overall survival (OS) after treatment were analyzed.

Results

A total of 269 patients were enrolled. Subcutaneous adipose tissue (SAT) density was a significant predictor of RFS, whereas psoas muscle density was a significant predictor of OS in the multivariate analysis. Patients with sarcopenia but without obesity tolerated significantly fewer BCG IVIs than patients without sarcopenia or obesity. Patients with sarcopenia had poorer RFS and OS than those without sarcopenia. In contrast, patients with obesity had better OS than those without obesity.

Discussion

Body composition parameters, including SAT density and psoas muscle density, emerged as significant predictors of OS and RFS, respectively. Hence, our findings indicate that body composition is a helpful measurement to assess the oncological outcomes of patients with NMIBC.

Recognition of Postoperative Cystography Features by Artificial Intelligence to Predict Recovery from Postprostatectomy Urinary Incontinence: A Rapid and Easy Way to Predict Functional Outcome

Purpose: Post-operative cystography has been used to predict the recovery of postprostatectomy urinary incontinence (PPI) in patients with localized prostate cancer. This study aimed to validate the predictive value of cystography for PPI and utilize a deep learning model to identify favorable and unfavorable features. Methods: Medical records and cystography images of patients who underwent robotic-assisted radical prostatectomy for localized prostate cancer were retrospectively reviewed. Specific cystography features, including anastomosis leakage, a downward bladder neck (BN), and the bladder neck angle, were analyzed for the prediction of PPI recovery. Favorable and unfavorable patterns were categorized based on the three cystography features. The deep learning model used for transfer learning was ResNet 50 and weights were trained on ImageNet. We used 5-fold cross-validation to reduce bias. After each fold, we used a test set to confirm the model’s performance. Result: A total of 170 consecutive patients were included; 31.2% experienced immediate urinary continence after surgery, while 93.5% achieved a pad-free status and 6.5% were still incontinent in the 24 weeks after surgery. We divided patients into a fast recovery group (≤4 weeks) and a slow recovery group (>4 weeks). Compared with the slow recovery group, the fast recovery group had a significantly lower anastomosis leakage rate, less of a downward bladder neck, and a larger bladder neck angle. Test data used to evaluate the model’s performance demonstrated an average 5-fold accuracy, sensitivity, and specificity of 93.75%, 87.5%, and 100%, respectively. Conclusions: Postoperative cystography features can predict PPI recovery in patients with localized prostate cancer. A deep-learning model can facilitate the identification process. Further validation and exploration are required for the future development of artificial intelligence (AI) in this field.

Instillation Strategies for Non-Muscle-Invasive Bladder Cancer in the Bacillus Calmette-Guerin Shortage Era: A Simple Solution for BCG Discontinuation

Objective

Among intravesical instillation protocol in patients with non-muscle-invasive bladder cancer (NMIBC), chemotherapy agents have been widely used during the bacillus Calmette-Guérin (BCG) shortage era since the patient might under the risk of BCG discontinuation. This study evaluates the efficacy of incomplete BCG instillation compared with pure chemotherapy instillation protocol.

Materials and Methods

Patients newly diagnosed with intermediate- and high-risk NMIBC who received incomplete BCG intravesical instillation or chemotherapy instillation were retrospectively included. Patients were divided into three groups according to different intravesical instillation schedules: [BCG only], [BCG + Chemo], and [Chemo only]. Comparisons between these three groups were performed. Bladder recurrence-free survival (RFS) was analyzed as the primary endpoint.

Results

A total of 475 patients who received intravesical instillations were enrolled. Compared to the [Chemo only] group, the [BCG + Chemo] group had significantly better bladder RFS (p = 0.027). Multivariate analysis of recurrence revealed the [BCG + Chemo] regimen has a hazard ratio 0.381 (95% CI 0.154–0.941, p = 0.037). The total instillation number >12 was associated with better RFS (p = 0.001) compared with other instillation numbers.

Conclusion

For NMIBC patients facing the risk of unexpected BCG instillation interruption, instead of starting instillation with chemotherapy agents, receiving BCG first till stoppage then shifting to chemotherapy agents is recommended.

Clinical Benefits of Indocyanine Green Fluorescence in Robot-Assisted Partial Nephrectomy

Background: To compare the intraoperative and postoperative outcomes of indocyanine green (ICG) administration in robot-assisted partial nephrectomy (RAPN) and report the differences in the results between patients with benign and malignant renal tumors. Methods: From 2017 to 2020, 132 patients underwent RAPN at our institution, including 21 patients with ICG administration. Clinical data obtained from our institution’s RAPN database were retrospectively reviewed. Intraoperative, postoperative, pathological, and functional outcomes of RAPN were assessed. Results: The pathological results indicated that among the 127 patients, 38 and 89 had received diagnoses of benign and malignant tumors, respectively. A longer operative time (311 vs. 271 min; p = 0.006) but superior preservation of estimated glomerular filtration rate (eGFR) at 3-month follow-up (90% vs. 85%; p = 0.031) were observed in the ICG-RAPN group. Less estimated blood loss, shorter warm ischemia time, and superior preservation of eGFR at postoperative day 1 and 6-month follow-up were also noted, despite no significant differences. Among the patients with malignant tumors, less estimated blood loss (30 vs. 100 mL; p < 0.001) was reported in the ICG-RAPN subgroup. Conclusions: Patients with ICG-RAPN exhibited superior short-term renal function outcomes compared with the standard RAPN group. Of the patients with malignant tumors, ICG-RAPN was associated with less blood loss than standard RAPN without a more positive margin rate. Further studies with larger cohorts and prospective designs are necessary to verify the intraoperative and functional advantages of the green dye.

Changes in prostate-specific antigen kinetics during androgen-deprivation therapy as a predictor of response to abiraterone in chemonaïve patients with metastatic castration-resistant prostate cancer

Purpose

Materials and Methods

Results

Conclusions

Gain of TPPP as a predictor of progression in patients with bladder cancer

The present study investigated the role of tubulin polymerization promoting protein (TPPP) in the regulation of bladder cancer (BC) cell proliferation and migration, in addition to the association between TPPP gene copy number amplification and clinicopathological characteristics of BC. TPPP gene amplification was measured in human BC epithelial cells and samples obtained from 52 patients with BC via fluorescence in situ hybridization. TPPP gain was defined as mean TPPP copy number >2.2 per nucleus (cutoff). The neutrophil-to-lymphocyte ratio (NLR) was also obtained from the preoperative data of the patients. For in vitro assays, BC cell lines were transfected with either TPPP small interfering RNAs or scrambled control, following which cell proliferation and migration were determined using Cell Counting Kit-8 and Transwell migration assays, respectively. The percentage of cells with TPPP copy number amplification in the four BC epithelial cell lines (MGH-U1, -U1R, -U3, -U4) examined (86.0-100.0%) was found to be higher compared with that in the normal human uroepithelial cell lines (3.0 and 9.0%). Patients were divided into one- (1.9%), two- (55.8%), three- (7.7%), four- (26.9%) and five-copy (7.7%) types. Results calculated using Fisher's exact test indicated that the gain of TPPP in patients with BC associated significantly with age (P<0.05), advanced histological grade (P<0.001), tumor stage (P<0.05), histological type (P<0.001) and NLR (P<0.05). In MGH-U1R and MGH-U4 cells, cell proliferation and migration were revealed to be significantly lower following TPPP knockdown compared with those in cells transfected with the scrambled control. In conclusion, findings from the present study suggest that TPPP is important for cell proliferation, cell migration and BC progression, such that TPPP copy number assessment would be advised for preoperative urine cytology for urothelial neoplasia diagnosis.

Clinical predictors for biochemical failure in patients with positive surgical margin after robotic-assisted radical prostatectomy

OBJECTIVE

Patients with positive surgical margins (PSMs) after radical prostatectomy for localized prostate cancer have a higher risk of biochemical failure (BCF). We investigated the risk factors of BCF in patients with PSMs after robotic-assisted radical prostatectomy (RARP).

METHODS

We evaluated 462 patients who underwent RARP in a single medical center from 2006 through 2013. Of them, 61 with PSMs did not receive any treatment before BCF. Kaplan-Meier curve and Cox regression analysis were used to compare patients with (n = 19) and without (n = 41) BCF.

RESULTS

Overall, 13.2% of patients had PSMs, and of those, 31.7% experienced BCF during follow-up. The mean follow-up duration was 43.7 months (42.4 [non-BCF] vs 46.35 (BCF], p = 0.51). In univariant analyses, the platelet to lymphocyte ratio (6.26 [non-BCF] vs 8.02 [BCF], p = 0.04) differed statistically. When patients were grouped by pathologic grade ≦2 or ≧3 (p = 0.004), the BCF-free survival rates differed significantly. Seminal vesicle invasion also differed significantly (5 [non-BCF] vs 7 [BCF], p = 0.005). Patients with undetectable nadir prostate-specific antigen (PSA) after RARP (BCF rate 4/34) differed statistically from those with detectable PSA after RARP (BCF rate 15/26) (p < 0.001). In the multivariate analysis, the platelet/lymphocyte (P/L) ratio, pathologic grade, and undetectable nadir PSA remained statistically significant.

CONCLUSIONS

In patients who undergo RARP and have PSMs, P/L ratio >9 preoperatively, pathologic grade ⩾3, and detectable nadir PSA after RARP should be considered adverse features. Early intervention such as salvage radiation therapy or androgen deprivation therapy should be offered to these patients.

Genomic characterization of clear cell renal cell carcinoma using targeted gene sequencing

Kidney cancer is one of the most lethal cancer types worldwide. The most common subtype of kidney cancer is clear cell renal cell carcinoma (ccRCC), and the somatic mutations of ccRCC have been identified through the development of large databases. The present study aimed to validate the status of the associated gene mutations in a Taiwanese cohort. Targeted sequencing was used to validate the mutation status of genes related to ccRCC in Taiwanese patients who had nephrectomy for kidney cancer. The top eight mutated genes in the Catalogue Of Somatic Mutations In Cancer (COSMIC) were selected. These genes were VHL, protein polybromo-1 (PBRM1), histone-lysine N-methyltransferase SETD2, BRCA1-associated protein-1 (BAP1), lysine-specific demethylase 5C (KDM5C), TP53, MTOR and PTEN. The association between the gene mutation status of VHL, PBRM1, SETD2 and BAP1 was validated with clinicopathological parameters as well as overall survival time. Tumor cells from 96 patients with ccRCC were target sequenced. The order of mutation rate of the eight aforementioned genes was similar to that reported within COSMIC. The present Taiwanese cohort exhibited lower PBRM1 and BAP1 mutation rates compared with average, with increased mutation rates for SETD2 and KDM5C. BAP1 mutation was associated with the tumor and cancerous stage. None of these four genes were positively associated with the overall survival of patients. The PBRM1 and SETD2 mutations were mutually exclusive to BAP1 mutation. Overall, the present study provided data confirming gene alteration in Taiwanese patients with ccRCC and showed some differences when compared with Western countries. Further comprehensive genomic and epigenomic studies, as well as downstream validation, are necessary to evaluate the impact of these differences.

Increasing incidence of prostate cancer in Taiwan: A study of related factors using a nationwide health and welfare database

Over the past decades, the incidence of prostate cancer in Taiwan kept rising. Many possible factors including the utility of prostate specific antigen tests, lifestyle remodeling, and patient's comorbidities may contribute to the increasing of incidence or prostate cancer. We aim to use the nationwide Health and Welfare Database (HWD) to investigate possible associated factors.We used HWD, a nationwide database of medical information, to assess the incidence of prostate cancer, utilization of prostate-specific antigen (PSA) test, and underlying diseases of patients and to evaluate whether there was a common trend among these factors.In total, 32,508 patients with newly diagnosed prostate cancer from 2006 to 2013 were identified. The incidence rate of prostate cancer per 100,000 men increased from 35.47 in 2006 to 52.87 in 2012. The number of patients with prostate cancer and underlying diseases related to metabolic syndrome increased every year. The number of total PSA tests and patients undergoing PSA testing, as well as average times of PSA testing per person in the whole population, increased every year. The average PSA test times of patients with newly diagnosed prostate cancer within 3 years before the diagnosis of prostate cancer also increased every year. There was a high correlation between the average PSA test times and the number of patients with newly diagnosed prostate cancer (r = 0.9734).The trends of incidence of prostate cancer, utilization of PSA testing, and underlying diseases related to metabolic syndrome at the diagnoses of cancer were similar, increasing every year in the study period. The results suggested that increasing use of PSA tests may increase the diagnosis of prostate cancers. Underlying diseases related to metabolic syndrome might also affect the incidence of prostate cancer.

Predictors of Intravesical Recurrence After Radical Nephroureterectomy and Prognosis in Patients with Upper Tract Urothelial Carcinoma

Purpose

We investigate factors that may contribute individually to bladder recurrence and find out the potential candidate to receive postoperative single dose intravesical chemotherapy.

Materials and Methods

A total of 217 patients who were diagnosed with upper tract urothelial carcinoma (UTUC) underwent radical nephroureterectomy (RNU) between 2012 and 2016 in a single hospital. The possible risk factors that may contribute to development of bladder recurrence and overall survival were analysed. In order to find out the relationship between 1st bladder recurrence timing and outcome, we divided the 54 of 56 patients (2 patients with prophylactic intravesical chemotherapy excluded) with bladder recurrence after RNU into 2 groups, using the median time of 1st bladder recurrence and confirmed with the “minimum P-value” approach. The primary endpoint was the development of relapsing high-risk non-muscle invasive bladder cancer (NMIBC). The predictive factors of early recurrence and prognostic factors of survival were also analysed.

Results

Among 217 patients with UTUC under RNU, intravesical recurrence occurred in 56 (25.8%) patients after a median follow-up of 35.2 (1.18–83.34) months. On multivariable analysis, the preoperative ureter manipulation (p=0.009) was a significant predictor for the development of bladder tumours. As for overall survival, renal rein invasion (p=0.017), neutrophil to lymphocyte ratio (p=0.021), and main tumour size (p=0.015) were significant predictors. For 54 patients who developed bladder recurrence, the optimal cut-off point of early recurrence was determined to be 10 months after surgery (p=0.042). Preoperative ureter manipulation (p=0.005) and tumour located both pelvicalyceally and ureterically (P=0.042) were identified as independent factors associated with early recurrence. An end-stage renal disease history and surgical margin positive patient has more late bladder recurrence.

Conclusion

Bladder recurrence was common in UTUC after RNU. Early bladder recurrence was associated with more relapsing high-risk NMIBC and preoperative ureter manipulation was identified as an independent factor associated with early recurrence.

Role Of Robot-Assisted Partial Nephrectomy For Renal Cell Carcinomas In The Purpose Of Nephron Sparing

Introduction

Surgery remains the standard treatment for localized renal cell carcinomas, and partial nephrectomy is considered before radical nephrectomy with the aim of preserving renal function. This study aimed to compare robot-assisted and open partial nephrectomy for the purpose of nephron sparing.

Materials and methods

We retrospectively enrolled consecutive patients who received partial nephrectomy at a single tertiary medical center from January 2008 to January 2015. Medical records and radiographic images were reviewed. We analyzed the patients’ general characteristics, underlying disease, complications, length of hospital stay, renal tumor complexity, surgery type, renal function, and specimen and tumor size. A comparison between open and robot-assisted nephrectomy groups was performed.

Results

A total of 136 patients were enrolled, with a male to female ratio of 2:3 and a mean age of 57.8 years. Of these, 71 and 65 patients received open and robot-assisted surgery, respectively. Compared with the open group, patients who underwent robot-assisted surgery were significantly younger (56.0 versus 60.1 years old), had a longer operative time (303 versus 224 min), and a lower kidney ischemic time (33.4 versus 46.9 min). Given similar tumor sizes, the tumor-to-excision ratio was significantly higher in the robot-assisted group (51.7% versus 39.8%), and the excisional volume loss (EVL) was smaller (12.7 versus 19.6 mL). Preoperative glomerular filtration rate and EVL were significant predictors of long-term renal function preservation in the multivariate analysis.

Conclusion

When performing partial nephrectomy, a robot-assisted procedure could increase the accuracy of excision without increasing the risk of positive surgical margin. Lower EVL could assist in better long-term postoperative renal function preservation.

Demographic characteristics and complications of open and minimally invasive surgeries for renal cell carcinoma: a population-based case-control study in Taiwan

Introduction

Renal cell carcinoma (RCC) is one of the most lethal urological malignancies, and surgeries remain the mainstay for localized RCC. This study aimed to compare the selection of open surgery and minimally invasive kidney surgery for RCCs for the aspects of complication, medical costs, and patient preference.

Materials and methods

We conducted a population-based case-control study by using the National Health Insurance Research Database of Taiwan, which included data from 23 million Taiwanese residents. Patients newly diagnosed with RCC during 2006-2012 were included. We compared the general characteristics, underlying disease, complications, hospital stay, postoperative analgesic dosage, and medical costs between open group and minimally invasive group.

Results

A total of 3,172 patients who received radical nephrectomy (RN) or partial nephrectomy (PN) for RCC were included. The mean age was 61.1 years, with a male to female ratio of 1.88. In the minimally invasive groups, the mean hospital stay was significantly shorter than in open groups (12.4 days in open RN versus 10.3 days in minimally invasive RN, and 9.7 days in open PN versus 8.2 days in minimally invasive PN). There was no significant difference between the medical costs and the incidence of major bleeding complication between the open group and the minimally invasive group. Female patients and patients with higher monthly income were more likely to receive minimally invasive surgery.

Conclusion

During past decades, open RN has gradually been replaced by minimally invasive surgeries and PN. Compared to open surgeries, minimally invasive surgeries could lead to less postoperative pain and faster recovery. Economic status of the patients potentially hinders them from receiving minimally invasive surgeries, which may cost more.

Robot-assisted laparoendoscopic single site adrenalectomy: A comparison of 3 different port platforms with 3 case reports

RATIONALE

Laparoscopic adrenalectomy is currently the standard of care for adrenal lesion. Minimal invasive laparoscopic surgery such as laparoendoscopic single site surgery (LESS) and natural orifice transluminal endoscopic surgery (NOTES) have been developed to improve cosmetic outcomes and reduce postoperative pain. However, there are still some problems related to instruments and port limitation during LESS surgery. Robot-assisted laparoscopic surgery may help to overcome these problems, and port platforms selection is an important issue.

PATIENT CONCERNS

Three cases received robot-assisted LESS adrenalectomy due to adrenal tumor were enrolled. Blood loss, hospital stay, and analgesia injection were compared.

DIAGNOSES

Preoperative evaluations were done in a usual manner. Benign tumors were suspect for two patients, while metastatic tumor could not be excluded for the other patient with prior malignancy history. The pathology reports were all benign adrenal cortical adenoma after operation.

INTERVENTIONS

Three different port platforms, Da Vinci Single-Site Surgical Platform, GelPOINT, and homemade glove port were used. Trans-peritoneal approach was used for two patients, while the other one received trans-retroperitoneal approach. The advantage and disadvantage of different port platforms were discussed.

OUTCOMES

All patients underwent the operation smoothly without major complications or conversion to open surgery. Blood loss amount was small, hospital stay was short, and only one patient received one single dose of opioid analgesia injection after the surgery.

LESSONS

The main problems of LESS are the loss of a working triangle and the limitations of the instruments. Robot-assisted LESS may help surgeons overcome part of these problems. Many different port platforms are available, and based on our initial experience, we believe that the GelPoint may be a more suitable platform, for it maintains the endo-wrist function of the Da Vinci instruments, and allows the surgeon to design the position of ports freely to minimize external and internal collision.

Prognosis of prostate cancer with initial prostate-specific antigen >1,000 ng/mL at diagnosis

Purpose

Prostate cancer patients with surprisingly high prostate-specific antigen (PSA) are encountered clinically. However, descriptions of this group of patients are extremely rare in the published literature. This study reports treatment outcome and long-term prognosis for this group of patients.

Patients and methods

Between January 2007 and December 2012, 2,064 patients with PCa diagnosed at a tertiary medical center were retrospectively reviewed. A total of 90 PCa cases were identified with initial PSA (iPSA) >1,000 ng/mL at diagnosis. A retrospective study was conducted in this cohort, with comparison among stratified patient age groups, PSA, treatment options, and overall survival.

Results

The mean PSA at PCa diagnosis in this cohort was 3,323 ng/mL (1,003–23,126, median: 2,050 ng/mL). Most patients were in the age group 65–79 years (55/90, 61%). Males older than 80 years had a poor prognosis (P<0.001). Forty-six patients (51%) underwent orchiectomy with a median follow-up period of 16.2 (1.3–72.7) months, compared to 44 patients treated with medical castration and a median follow-up of 9.1 (0.3–70.5) months. Kaplan–Meier analysis revealed survival benefit from treatment with orchiectomy (P<0.001). PSA reduction >90% of iPSA following primary androgen deprivation therapy (reaching true nadir) could be a predictor of longer survival (P<0.001). Cox regression revealed the hazard ratio (HR) of variables were age (HR: 4.57, 95% confidence interval [CI]: 1.45–14.37, P=0.009), reaching true nadir (HR: 0.12, 95% CI: 0.03–0.58, P=0.008), and the treatment option with orchiectomy (HR: 0.22, 95% CI: 0.65–0.76, P=0.016).

Conclusion

Age ≥80 years indicated poor overall survival in PCa patients with iPSA >1,000 ng/mL. Reaching a true nadir of PSA following primary androgen deprivation therapy could be a predictor of longer survival. Bilateral orchiectomy is recommended for this group of patients.

Effects of nucleus on leukocyte recovery

The rheological properties of a leukocyte significantly affect its biological and mechanical characteristics. To date, existing physical models of leukocyte are not capable of quantitatively explaining the wide range of deformation and recovery behaviors observed in experiment. However, a compound drop model has gained some success. In the present work, we investigate the effect of nucleus size and position, and the relative rheological properties of cytoplasm and nucleus, on cell recovery dynamics. Two nucleus sizes corresponding to that of neutrophil and lymphocyte are considered. Direct comparison between numerical simulations and experimental observation is made. Results indicate that the time scale ratio between the nucleus and cytoplasm plays an important role in cell recovery characteristics. Comparable time scales between the two cell components yield favorable agreement in recovery rates between numerical and experimental observations; disparate time scales, on the other hand, result in recovery behavior and cell shapes inconsistent with experiments. Furthermore, it is found that the nucleus eccentricity exhibits minimum influence on all major aspects of the cell recovery characteristics. The present work offers additional evidence in support of the compound cell model for predicting the rheological behavior of leukocytes.

Numerical analysis of the deformation of an adherent drop under shear flow

The adhesion of leukocytes to substrates is an important biomedical problem and has drawn extensive research. In this study, employing both single and compound drop models, we investigate how hydrodynamics interacts with an adherent liquid drop in a shear flow. These liquid drop models have recently been used to describe the rheological behavior of leukocytes. Numerical simulation confirms that the drop becomes more elongated when either capillary number or initial contact angle increases. Our results show that there exists a thin region between the drop and the wall as the drop undergoes large stretching, which allows high pressure to build up and provides a lift force. In the literature, existing models regard the leukocyte as a rigid body to calculate the force and torque acting on the drop in order to characterize the binding between cell receptors and endothelial ligands. The present study indicates that such a rigid body model is inadequate and the force magnitude obtained from it is less than half of that obtained using the deformable drop models. Furthermore, because of its much higher viscosity, the cell nucleus introduces a hydrodynamic time scale orders of magnitude slower than the cytoplasm. Hence the single and compound drops experience different dynamics during stretching, but exhibit very comparable steady-state shapes. The present work offers a framework to facilitate the development of a comprehensive dynamic model for blood cells.

Rheological modelling of leukocytes

A three-layer Newtonian model is investigated using a combined Eulerian-Lagrangian computational method to describe the dynamic behaviour of leukocytes. The model, composed of a cell membrane (outer layer), cytoplasm (middle layer) and nucleus (inner layer), can better describe the recovery characteristics because large viscosity and capillarity differences between layers are considered, and both Newtonian and seemingly non-Newtonian behaviours reported in the literature can be reproduced. It is found that, to describe adequately the various rheological characteristics of leukocytes, the presence of the highly viscous nucleus and its deformation/recovery, as well as the surface energy stored in the fluid interfaces, are critical. Photographs from pipette experiments using a fluorescent technique confirm the theoretical finding of the important role played by the nucleus in cell deformation.