Regulation of hematopoietic stem cells using protein transduction domain-fused Polycomb

The Polycomb-group complex is a chromatin regulatory factor that is classified into two different complexes: Polycomb repressive complex 1 and 2. Components of Polycomb repressive complex 1 are involved in the self-renewal of hematopoietic stem cells. Bmi1, one of these components, maintains the immaturity of neural and cancer stem cells as well as that of hematopoietic stem cells. We constructed recombinant protein transduction domain (PTD)-Polycomb proteins and transduced them into murine bone marrow (BM) cells. We designed and fused the PTD-protein transduction domain to three proteins (i.e., green fluorescent protein, Bmi1, and Mel18). Murine BM cells were incubated for 48 h and each PTD-Polycomb protein was added. Then, we analyzed the function of hematopoiesis using the colony assay and transplantation. BM cells exposed to PTD-Bmi1 showed an increased number of colonies. In contrast, BM cells exposed to PTD-Mel18 or to both proteins showed a decreased number of colonies. Hematopoietic cells derived from PTD-Bmi1-transduced BM cells were significantly increased in the peripheral blood at 6 weeks after transplantation. Moreover, 80% of mice transplanted with PTD-Bmi1-transduced BM cells died at 8 to 24 weeks after transplantation. However, only a few early deaths were observed in the mice transplanted with BM cells exposed to both PTD-Bmi1 and PTD-Mel18. We expect that hematopoietic stem cells could proliferate after transduction with PTD-Bmi1, but this may generate undesirable effects, e.g., tumorigenesis. Thus, Bmi1 and Mel18 have opposing functions and are present in distinct complexes.     

Early awareness of cerebrospinal fluid hypovolemia after craniotomy for microsurgical aneurysmal clipping

Background

Mild cerebrospinal fluid (CSF) hypovolemia is a well-known clinical entity, but critical CSF hypovolemia that can cause transtentorial herniation is an unusual and rare clinical entity that occurs after craniotomy. We investigated CSF hypovolemia after microsurgical aneurysmal clipping for subarachnoid hemorrhage (SAH).

Method

This study included 144 consecutive patients with SAH. Lumbar drainage (LD) was inserted after general anesthesia or postoperatively as a standard perioperative protocol. CSF hypovolemia diagnosis was based on three criteria.

Results

Eleven patients (7.6 %) were diagnosed with CSF hypovolemia according to diagnostic criteria in a postoperative range of 0–8 days. In all patients, signs or symptoms of CSF hypovolemia improved within 24 hours by clamping LD and using the Trendelenburg position.

Conclusions

As a cause of acute clinical deterioration after aneurysmal clipping, CSF hypovolemia is likely under-recognized, and may actually be misdiagnosed as vasospasm or brain swelling. We should always take the etiology of CSF hypovolemia into consideration, and especially pay attention in patients with pneumocephalus and subdural fluid collection alongside brain sag on computed tomography. These patients are at higher risk developing of pressure gradients between their cranial and spinal compartments, and therefore, brain sagging after LD, than after ventricular drainage. We should be vigilant to strictly manage LD so as not to produce high pressure gradients.     

Propofol Drip Infusion Anesthesia for MRI Scanning: Two Case Reports

The magnetic resonance imaging (MRI) room is a special environment. The required intense magnetic fields create unique problems with the use of standard anesthesia machines, syringe pumps, and physiologic monitors. We have recently experienced 2 oral maxillofacial surgery cases requiring MRI: a 15-year-old boy with developmental disability and a healthy 5-year-old boy. The patients required complete immobilization during the scanning for obtaining high-quality images for the best diagnosis. Anesthesia was started in the MRI scanning room. An endotracheal intubation was performed after induction with intravenous administration of muscle relaxant. Total intravenous anesthesia via propofol drip infusion (4–7 mg/kg/h) was used during the scanning. Standard physiologic monitors were used during scan pauses, but special monitors were used during scanning. In MRI scanning for oral maxillofacial surgery, general anesthesia, with the added advantage of having a secured airway, is recommended as a safe alternative to sedation especially in cases of patients with disability and precooperative chidren.Key Words: Magnetic resonance imaging (MRI), General anesthesia, Propofol drip infusion, Children, Developmental disability patientsThe magnetic resonance imaging (MRI) scanning room is a special environment. The required intense magnetic fields create unique problems with the usage of standard anesthesia machines, syringe pumps, and physiologic monitors (electrocardiogram, pulse oximeter, capnograph, and noninvasive blood pressure).^1–3 Moreover, the scanning procedure lasts around 1 hour. In addition, there is high-level acoustic noise in the MRI room. For the best quality of magnetic resonance imaging and diagnosis, complete immobilization of the patient is needed during scanning, often assisted by general anesthesia or sedation.³ However, special anesthesia instruments made of nonmagnetic materials needed for MRI scanning are not available at our university dental hospital.In this paper, we report 2 general anesthesia cases for MRI scanning in our dental hospital using alternative equipment.     

CD14 expression and Kupffer cell dysfunction in non-alcoholic steatohepatitis: superparamagnetic iron oxide-magnetic resonance image and pathologic correlation

Background and Aim: Kupffer cell (KC) function and CD14 expression contributes to pathogenesis of non‐alcoholic steatohepatitis (NASH). However, these relationships remain unclear. We investigated the relationship of KC function with superparamagnetic iron oxide‐enhanced magnetic resonance imaging (SPIO‐MRI), histopathological severity of NASH, and number of CD14‐positive KCs in NASH. Methods: This retrospective study included 32 patients (24 with NASH and eight with simple steatosis) who had previously undergone SPIO‐MRI with T2‐weighted gradient‐recalled echo sequence. All subjects were diagnosed pathologically and were evaluated for necroinflammation grade, fibrosis stage, and number of CD14‐positive KCs. Patients with NASH and simple steatosis were compared by using the Mann–Whitney test to determine differences in percent reduction of liver‐to‐muscle signal intensity ratio (reduction‐%LMR), as a surrogate parameter of KC function, and number of CD14‐positive KCs. Kruskal–Wallis test and Pearson's correlation coefficient were used to analyze relation among reduction‐%LMR, histopathological severity and number of CD14‐positive KCs. Results: There were statistically significant differences in reduction‐%LMR and number of CD14‐positive KCs between NASH and simple steatosis patients (Mann–Whitney test, P < 0.001 for all comparisons). Reduction‐%LMR decreased with an increase in necroinflammation grade or fibrosis stage. The number of CD14‐positive KCs increased with an increase in necroinflammation grade and fibrosis stage (Kruskal–Wallis test, both, P < 0.001). A high correlation was seen between number of CD14‐positive KCs and reduction‐%LMR (Pearson r = 0.81; P < 0.001). Conclusions: KC phagocytic function evaluated with SPIO‐MRI correlated with histopathological severity and number of CD14‐positive KCs. These results support the concept that KC phagocytic dysfunction contributes to the pathogenesis of NASH.     

Retrospective Study Using the Propensity Score to Clarify the Oncologic Feasibility of Thoracoscopic Esophagectomy in Patients with Esophageal Cancer

Background

The present study aimed to clarify the long-term prognostic impact and oncologic feasibility of thoracoscopic esophagectomy (TSE) in patients with esophageal cancer in comparison with open thoracic esophagectomy (OTE).

Methods

Patients with esophageal cancer underwent surgically curative esophagectomy without neoadjuvant therapy from January 1991 to December 2008 and were analyzed retrospectively. Of 257 patients, 91 underwent TSE and 166 had OTE. Relations between the long-term prognosis after surgery, the surgical procedure, and clinicopathologic parameters were analyzed statistically. The propensity scores were calculated for all patients through a multiple logistic regression model that was optimized with Akaike’s Information Criterion. Using Cox’s proportional hazard model with prognostic variables and the propensity scores, we implemented a multivariate analysis for comparing the performance of two surgical methods.

Results

Patient characteristics and the incidence of perioperative morbidity or hospital death were similar for the TSE and OTE groups. Significantly more lymph nodes were dissected in the TSE group than in the OTE group (total p = 0.013; thoracic p = 0.0094; recurrent laryngeal p < 0.0001). The TSE group exhibited a more favorable prognosis after surgery than the OTE group in terms of overall survival (p = 0.011) and disease-specific survival (DSS) (p = 0.0040). Particularly in subgroup analysis of DSS, the TSE group had a favorable prognosis in upper thoracic esophageal cancer (p = 0.0053), invasive cancer (p = 0.046), node-positive cancer (p = 0.020), progressive cancer (p = 0.0052), cancer with lymphatic vessel invasion (p = 0.0019), and cancer without blood vessel invasion (p = 0.0081). In terms of DSS, the TSE group exhibited a more favorable prognosis than the OTE group regardless of the presence or absence of metastasis to lymph nodes around the thoracic (p < 0.0001) or recurrent laryngeal (p < 0.0001) nerves. TSE (p = 0.0430), lymph node metastasis (p = 0.0382), lymphatic invasion (p = 0.0418), and p stage (p = 0.0047) were independent prognostic parameters in the Cox’s proportional hazard model with the propensity scores.

Conclusions

TSE can contribute to prolonged survival after surgery in patients with esophageal cancer by enabling precise thoracic lymph node dissection based on a magnified surgical field. TSE might have maximum oncologic benefit and minimum invasiveness for patients with esophageal cancer.     

Comparison of the Loss of Renal Function after Cold Ischemia Open Partial Nephrectomy,Warm Ischemia Laparoscopic Partial Nephrectomy and Laparoscopic Partial Nephrectomy Using Microwave Coagulation

Purpose

Nephron sparing surgery is an effective surgical option in patients with renal cell carcinoma. Laparoscopic partial nephrectomy involves clamping and unclamping techniques of the renal vasculature. This study compared the postoperative renal function of partial nephrectomy using an estimation of the glomerular filtration rate (eGFR) for a Japanese population in 3 procedures; open partial nephrectomy in cold ischemia (OPN), laparoscopic partial nephrectomy in warm ischemia (LPN), and microwave coagulation using laparoscopic partial nephrectomy without ischemia (MLPN).

Materials and Methods

A total of 57 patients underwent partial nephrectomy in Yokohama City University Hospital from July 2002 to July 2008. 18 of these patients underwent OPN, 17 patients received MLPN, and 22 patients had LPN. The renal function evaluation included eGFR, as recommended by The Japanese Society of Nephrology.

Results

There was no significant difference between the 3 groups in the reduction of eGFR. eGFR loss in the OPN group was significantly higher in patients that experienced over 20 minutes of ischemia time. eGFR loss in LPN group was significantly higher in patients that experienced over 30 minutes of ischemia time.

Conclusion

This study showed that all 3 procedures for small renal tumor resection were safe and effective for preserving postoperative renal function.Key Words: eGFR, Partial nephrectomy, Renal function, Laparoscopic partial nephrectomy     

Decreased expression of aquaporin 2 in the collecting duct of mice lacking the vasopressin V1a receptor

Background

Vasopressin V1a receptor null (V1aR^?/?) mice recently showed incomplete urinary concentration due to higher urine volume during control and water diuresis (euhydration), but showed normal response during dehydration (Aoyagi et al., Am J Physiol 295: F100–7, 2008).

Methods

Water balance, plasma vasopressin, plasma and urine osmolality, and aquaporin 2 (AQP2) expression in the kidney of wild-type (WT) and V1aR^?/? mice were therefore further examined using improved methods of urine collection (urinary bladder urine).

Results

V1aR^?/? mice demonstrated a lower urine osmolality (3,360 ± 138 vs. 3,610 ± 47 mOsm/kgH₂O) and a higher plasma osmolality (354.3 ± 1.3 vs. 342.5 ± 1.5 mOsm/kgH₂O) after dehydration for 24 h compared to WT mice (P < 0.05). In contrast, the plasma vasopressin concentration was significantly (P < 0.001) higher in the V1aR^?/? mice (48.8 ± 4.8 vs. 22.1 ± 2.4 pg/ml). On the other hand, although the AQP2 protein expression in the kidney was increased after dehydration, the basal (control) and dehydration-induced AQP2 protein levels were significantly lower in V1aR^?/? mice compared to WT mice (by Western blotting). Staining by an anti-AQP2 antibody in the luminal membrane of the collecting ducts was increased in both V1aR^?/? and WT mice after dehydration, but was relatively weaker in the V1aR^?/? mice (by immunohistochemistry). Moreover, urinary excretion of AQP2 protein, an index of the luminal AQP2 expression, was significantly (P < 0.05) lower in the V1aR^?/? mice.

Conclusion

V1aR signaling may be fundamentally important for the expression of AQP2 in the collecting ducts during control conditions and dehydration.     

The essence of the Japan Radiological Society/Japanese College of Radiology Imaging Guideline

Diagnostic imaging is undoubtedly important in modern medicine, and final clinical decisions are often made based on it. Fortunately, Japan has the highest numbers of diagnostic imaging instruments, such as CT and MRI devices, and boasts easy access to them as well as a high level of diagnostic accuracy. In consequence, a very large number of imaging examinations are performed, but diagnostic instruments are installed in so many medical facilities that expert management of these examinations tends to be insufficient. Particularly, in order to avoid risks, clinicians have recently become indifferent to indications of imaging modalities and tend to rely on CT or MRI resulting in increasing the number of imaging examinations in Japan. This is a serious problem from the viewpoints of avoidance of unnecessary exposure and medical economy. Under these circumstances, the Japan Radiological Society and Japanese College of Radiology jointly initiated the preparation of new guidelines for diagnostic imaging. However, the field of diagnostic imaging is extremely wide, and it is impossible to cover all diseases. Therefore, in drafting the guidelines, we selected important diseases and focused on “showing evidence and suggestions in the form of clinical questions (CQs)” concerning clinically encountered questions and “describing routine imaging techniques presently considered to be standards to guarantee the quality of imaging examinations”. In so doing, we adhered to the basic principles of assuming the readers to be “radiologists specializing in diagnostic imaging”, “simultaneously respecting the global standards and attending to the situation in Japan”, and “making the guidelines consistent with those of other scientific societies related to imaging”. As a result, the guidelines became the largest ever, consisting of 152 CQs, nine areas of imaging techniques, and seven reviews, but no other guidelines in the world summarize problems concerning diagnostic imaging in the form of CQs. In this sense, the guidelines are considered to reflect the abilities of diagnostic radiologists in Japan. The contents of the guidelines are essential knowledge for radiologists, but we believe that they are also of use to general clinicians and clinical radiological technicians. While the number and contents of CQs are still insufficient, and while chapters such as those on imaging in children and emergency imaging need to be supplemented, the guidelines will be serially improved through future revisions. Lastly, we would like to extend our sincere thanks to the 153 members of the drafting committee who authored the guidelines, 12 committee chairpersons who coordinated their efforts, six members of the secretariat, and affiliates of related scientific societies who performed external evaluation.