Measuring the 3D Dynamics of Multiple Colloidal Particles with Digital Holographic Microscopy

We discuss digital holographic microscopy (DHM), a 3D imaging technique capable of measuring the positions of micron-sized colloidal particles with nanometer precision and sub-millisecond temporal resolution. We use exact electromagnetic scattering solutions to model holograms of multiple colloidal spheres. While the Lorenz-Mie solution for scattering by isolated spheres has previously been used to model digital holograms, we apply for the first time an exact multisphere superposition scattering model that is capable of modeling holograms from spheres that are sufficiently close together to exhibit optical coupling.Physic

Intensive care unit versus high-dependency care unit admission on mortality in patients with septic shock: a retrospective cohort study using Japanese claims data

[Background] Septic shock is a common and life-threatening condition that requires intensive care. Intensive care units (ICUs) in Japan are classified into ICUs and high-dependency care units (HDUs), depending on presence of full-time certified intensivists and the number of assigned nurses. Compared with other developed countries, there are fewer intensive care beds and certified intensivists in Japan; therefore, non-intensivists often treat patients with septic shock in HDUs. It is unknown where we should treat patients with septic shock because no studies have compared the clinical outcomes between ICU and HDU treatment. This study aimed to elucidate which units should admit patients with septic shock by comparing mortality data and resource use between ICU and HDU admissions. [Methods] In this retrospective cohort study, we used a nationwide Japanese administrative database to identify adult patients with septic shock who were admitted to ICUs or HDUs between January 2010 and February 2021. The patients were divided into two groups, based on admittance to ICU or HDU on the day of hospitalization. The primary outcome was 30-day all-cause mortality adjusted for covariates using Cox regression analyses; the secondary outcomes were the length of ICU or HDU stay and length of hospital stay. [Results] Of the 10, 818 eligible hospitalizations for septic shock, 6584 were in the ICU group, and 4234 were in the HDU group. Cox regression analyses revealed that patients admitted to the ICUs had lower 30-day mortality (adjusted hazard ratio: 0.89; 95% confidence interval: 0.83–0.96; P = 0.005). Linear regression analyses showed no significant difference in hospital length of stay or ICU or HDU length of stay. [Conclusions] An association was observed between ICU admission and lower 30-day mortality in patients with septic shock. These findings could provide essential insights for building a more appropriate treatment system

Failure of Hem-o-lok clips

Hem-o-lok clips are commonly used for renal artery ligation in laparoscopic renal surgery. However, failure of the renal artery ligation clips is potentially fatal. A 61-year-old man underwent hand-assisted laparoscopic nephroureterectomy using a retroperitoneal approach for left ureteral carcinoma. One hour postoperatively, he was diagnosed with hemorrhagic shock. An immediate laparotomy revealed two closed, undamaged Hem-o-lok clips around the left renal artery. Pulsatile bleeding was observed, and the renal artery was immediately ligated with non-absorbable thread. We determined that the failure of the Hem-o-lok clips on the renal artery was caused by the lack of space between the two Hem-o-lok clips and the distal renal artery cuff beyond the distal clip. To prevent a potentially fatal failure of the renal artery ligation clips, one should maintain a sufficient space between the Hem-o-lok clips and an adequate distal renal artery cuff beyond the distal clip

Idiopathic Chondrolysis of the Hip Treated by Immunosuppressive Therapy and Arthroscopic Intervention

Idiopathic chondrolysis of the hip (ICH), a very rare disorder of unknown etiology, occurs mainly in female adolescents. Characterized by pain, limp, stiffness and radiological narrowing joint space from the rapid destruction of the articular cartilage, ICH sometimes results in ankyloses. We present the case of a 10-year-old girl diagnosed with ICH based on arthroscopic inspection and synovium biopsy. The femoral deformity appeared gradually, like a cam-type femoroacetabular impingement. She was treated with intensive rehabilitation and immunosuppressive drug. We later performed an arthroscopic bumpectomy for residual symptoms. She achieved a favorable outcome as a 15-year-old at the latest follow-up

15-keto-PGE2 acts as switched agonist of EP receptors

Prostaglandin E2 (PGE2) is well-known as an endogenous proinflammatory prostanoid synthesized from arachidonic acid by the activation of cyclooxygenase-2. E type prostanoid (EP) receptors are cognates for PGE2 that have four main subtypes: EP1 to EP4. Of these, the EP2 and EP4 prostanoid receptors have been shown to couple to Gαs-protein and can activate adenylyl cyclase to form cAMP. Studies suggest that EP4 receptors are involved in colorectal homeostasis and cancer development, but further work is needed to identify the roles of EP2 receptors in these functions. After sufficient inflammation has been evoked by PGE2, it is metabolized to 15-keto-PGE2. Thus, 15-keto-PGE2 has long been considered an inactive metabolite of PGE2. However, it may have an additional role as a biased and/or partial agonist capable of taking over the actions of PGE2 to gradually terminate reactions. Here, using cell-based experiments and in silico simulations, we show that PGE2-activated EP4 receptor–mediated signaling may evoke the primary initiating reaction of the cells, which would take over the 15-keto-PGE2–activated EP2 receptor–mediated signaling after PGE2 is metabolized to 15-keto-PGE2. The present results shed light on new aspects of 15-keto-PGE2, which may have important roles in passing on activities to EP2 receptors from PGE2-stimulated EP4 receptors as a “switched agonist.” This novel mechanism may be significant for gradually terminating PGE2-evoked inflammation and/or maintaining homeostasis of colorectal tissues/cells functions

Compartment Syndrome after Prostatectomy

Robot-assisted laparoscopic prostatectomy (RALP) for prostate cancer was introduced in 2000 and rapidly gained popularity. The Da Vinci Surgical System® can ensure improved local control of cancer and fewer perioperative complications. However, RALP is performed in the steep-Trendelenburg position (a combination of lithotomy and head-down tilt position / Lloyd-Davies position) to obtain a good surgical view, and as a result, well leg compartment syndrome (WLCS) can become a serious complication of RALP. Here, we report a case of WLCS after RALP. A 75-year-old man underwent surgery for prostate cancer and immediately complained of pain and numbness after surgery. The pressure of the four leg compartments increased. Ultimately, we diagnosed the patient with WLCS in his right leg, and an emergency fasciotomy was performed. He completely recovered with no permanent disability and was discharged one month after rehabilitation. Although WLCS after RALP is a rare and severe complication, the patient recovered completely with early diagnosis and intervention. Measuring the compartment pressure is useful when the patient is drowsy immediately after recovery from anesthesia. Preventing WLCS requires identifying this condition as a potential complication of RALP and all urologic surgeries performed in the lithotomy position