A Novel Gene, fudoh, in the SCCmec Region Suppresses the Colony Spreading Ability and Virulence of Staphylococcus aureus

Staphylococcus aureus colonies can spread on soft agar plates. We compared colony spreading of clinically isolated methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). All MSSA strains showed colony spreading, but most MRSA strains (73%) carrying SCCmec type-II showed little colony spreading. Deletion of the entire SCCmec type-II region from these MRSA strains restored colony spreading. Introduction of a novel gene, fudoh, carried by SCCmec type-II into Newman strain suppressed colony spreading. MRSA strains with high spreading ability (27%) had no fudoh or a point-mutated fudoh that did not suppress colony spreading. The fudoh-transformed Newman strain had decreased exotoxin production and attenuated virulence in mice. Most community-acquired MRSA strains carried SCCmec type-IV, which does not include fudoh, and showed high colony spreading ability. These findings suggest that fudoh in the SCCmec type-II region suppresses colony spreading and exotoxin production, and is involved in S. aureus pathogenesis.     

Sewing needles in the abdominal cavity assumed to have been ingested and to have penetrated the GI tract 40 years ago: A case report

A 60‐year old woman had been hospitalized in a psychiatric hospital for 40 years for schizophrenia. An X‐ray was performed when she fell, which showed needles in the abdominal field. After additional examinations and questioning, the patient was diagnosed with needles in the abdominal cavity, which were assumed to have been ingested and to have perforated the GI tract 40 years ago. They were removed by laparoscopic surgery. The needles were found in the omentum and near the left ovary. There were no inflammatory reactions around them. There have been previous reports about the removal of intra‐abdominal foreign bodies, but foreign body reaction occurred in most of the reports. Our case had the longest period from ingestion of the foreign bodies to their removal. Laparoscopy and intraoperative fluoroscopy are useful for removing intra‐abdominal foreign bodies because of their ability to help discriminate between structures and to navigate in real time.     

Robotic surgery for the upper gastrointestinal tract: Current status and future perspectives

More than 4000 da Vinci Surgical Systems have been installed worldwide. Robotic surgery using the da Vinci Surgical System has been increasingly performed in the last decade, especially in urology and gynecology. The da Vinci Surgical System has not become standard in surgery of the upper gastrointestinal tract because of a lack of clear benefits in comparison with conventional minimally invasive surgery. We initiated robotic gastrectomy and esophagectomy for patients with upper gastrointestinal cancer in 2009, and we have demonstrated the potential advantages of the da Vinci Surgical System in reducing postoperative local complications after gastrectomy and recurrent laryngeal nerve palsy after esophagectomy. However, robotic surgery has the disadvantages of a longer operative time and higher costs than the conventional approach. In this review article, we present the current status of robotic surgery for gastric and esophageal cancer, as well as future perspectives on this approach, based on our experience and a review of the literature.     

Evaluation of various deformable image registration algorithms for thoracic images

We evaluated the accuracy of one commercially available and three publicly available deformable image registration (DIR) algorithms for thoracic four-dimensional (4D) computed tomography (CT) images. Five patients with esophagus cancer were studied. Datasets of the five patients were provided by DIR-lab (dir-lab.com) and consisted of thoracic 4D CT images and a coordinate list of anatomical landmarks that had been manually identified. Expert landmark correspondence was used for evaluating DIR spatial accuracy. First, the manually measured displacement vector field (mDVF) was obtained from the coordinate list of anatomical landmarks. Then the automatically calculated displacement vector field (aDVF) was calculated by using the following four DIR algorithms: B-spine implemented in Velocity AI (Velocity Medical, Atlanta, GA, USA), free-form deformation (FFD), Horn–Schunk optical flow (OF) and Demons in DIRART of MATLAB software. Registration error is defined as the difference between mDVF and aDVF. The mean 3D registration errors were 2.7 ± 0.8 mm for B-spline, 3.6 ± 1.0 mm for FFD, 2.4 ± 0.9 mm for OF and 2.4 ± 1.2 mm for Demons. The results showed that reasonable accuracy was achieved in B-spline, OF and Demons, and that these algorithms have the potential to be used for 4D dose calculation, automatic image segmentation and 4D CT ventilation imaging in patients with thoracic cancer. However, for all algorithms, the accuracy might be improved by using the optimized parameter setting. Furthermore, for B-spline in Velocity AI, the 3D registration error was small with displacements of less than ∼10 mm, indicating that this software may be useful in this range of displacements.     

Stenotrophomonas maltophilia infection during allogeneic hematopoietic stem cell transplantation: a single‐center experience

To examine risk factors for Stenotrophomonas maltophilia (S. maltophilia) infection during allogeneic hematopoietic stem cell transplantation (allo‐HSCT), we retrospectively analyzed 259 patients who underwent allo‐HSCT. Not only S. maltophilia infection but also S. maltophilia colonization was associated with mortality during allo‐HSCT. Among 52 episodes in 39 patients in whom S. maltophilia was detected, documented infection developed in 33 episodes (25 patients). The onset of S. maltophilia infection in the period from the conditioning regimen to engraftment was associated with a high mortality rate. Breakthrough S. maltophilia infection developed in 24% of the patients during prophylactic administration of fluoroquinolones, to which S. maltophilia is sensitive. Reinsertion of a central venous catheter (CVC) immediately after removal was suggested to be a risk for persistent S. maltophilia infection in the period of neutropenia. Our results indicated that (i) onset of S. maltophilia infection in the period from the conditioning therapy to engraftment and (ii) removal and immediate reinsertion of a CVC as treatment after the onset of S. maltophilia infection are possible risk factors for S. maltophilia‐related mortality during allo‐HSCT.     

Effect of decreased fetal perfusion on placental clearance of volatile anesthetics in a dual perfused human placental cotyledon model

Placental transfer of volatile anesthetics is a critical issue in managing fetal distress during cesarean section under general anesthesia. Using dual perfused human placental cotyledons obtained from parturients undergoing elective cesarean section (n = 5), we investigated the effect of decreased fetal perfusion on placental clearance of sevoflurane and isoflurane. Keeping the maternal flow rate fixed, fetal flow rate was consecutively decreased from 3 ml/min (control perfusion) to 2 ml/min (intermediate perfusion) and to 1 ml/min (hypoperfusion). Placental transfer was assessed by the clearance of anesthetics by the placenta, defined by the ratio of anesthetic concentration in fetal vein and maternal artery, multiplied by fetal flow rate. Placental clearance was compared between different fetal perfusion states and anesthetics. Hypoperfusion resulted in a lower clearance of sevoflurane and isoflurane compared with control (P = 0.002, P < 0.001) and intermediate (P = 0.04, P = 0.018) perfusion. Clearances of sevoflurane and isoflurane were comparable during control perfusion (P = 0.93), intermediate perfusion (P = 1.00), and hypoperfusion (P = 0.88). Thus, maintenance of volatile anesthetics at a marginally low concentration may not be necessary when fetal distress is observed during emergency cesarean delivery because placental transfer of volatile anesthetics decreases with decreasing fetal perfusion.     

Joint gap measurement in total knee arthroplasty using a tensor device with the same articulating surface as the prosthesis

Background

We developed a new tensor to measure the joint gap throughout knee flexion during total knee arthroplasty (TKA). This tensor has the same articular shape as that of the tibial liner, including the post structure and the curvature of femorotibial articular surface, to measure the gap intraoperatively under the same conditions as after TKA. The present study aimed to examine the precision of the new tensor for gap measurement after implantation.

Methods

We performed TKA using the modified gap technique in four cadaveric knees and measured the gaps using the new tensor. The intra-observer and inter-observer error of the tensor was analyzed using 168 measurements of the gaps as determined at least twice by two surgeons. In addition, the gaps in rotating-platform posterior-stabilized TKA were measured at seven positions with the knee bending from extension to full flexion.

Results

The inter-observer and intra-observer errors were 0.8 and 0.3 mm, respectively, indicating precise and reproducible gap measurement. The gaps before implantation in reduced patellar position were 12.1 mm at extension and 12.5 mm at 90° flexion. The gaps after implantation were 9.1, 12.9, 13.1, 13.5, 13.8, 13.3, and 10.1 mm at 0°, 30°, 45°, 60°, 90°, 120°, and full flexion, respectively.

Conclusions

The new tensor provides precise and reproducible measurements. Although the joint gap before implantation was parallel and equal at extension and 90° flexion, the joint gap after implantation was variable throughout knee flexion. This feature of the gap should be considered during the operation.     

Congenital disorder of glycosylation type Ic: Report of a Japanese case

Congenital disorders of glycosylation (CDG) are inherited metabolic diseases affecting N-linked glycosylation pathways with variable clinical presentations characterized by psychomotor retardation, seizures, ataxia and hypotonia. CDG-Ic is caused by mutation in the ALG6 gene encoding alpha-1,3-glucosyltransferase. We present a 9-year-old girl diagnosed as having CDG-Ic. She developed severe psychomotor retardation, epileptic seizures, muscle hypotonia, strabismus and some dysmorphic features without inverted nipples or fat pads. She showed a fluctuating serum transaminase level with or without some infection, and a characteristically low level of antithrombin III. MR imaging of the brain at age 2 years demonstrated the lower limit of normal myelination, mild atrophy of the cerebrum, and mild hypoplasia of the brainstem and cerebellum. The patient exhibited a CDG type I pattern of serum transferrin on isoelectric focusing and mass spectrometric profiling. Sequence analysis of the ALG6 gene showed two heterozygous mutations, c.998C>T (A333V) and c.1061C>T (P354L). The patient was diagnosed as having CDG-Ic with a novel mutation, making her the first Japanese case. It was suggested that the severe psychomotor retardation in the patient was due to the existence of multiple mutant ALG6 alleles.     

Coexisting cardiac diseases and pressure recovery phenomenon contribute to discrepancy between the echocardiographic severity of aortic stenosis and left ventricular hypertrophy

Background

Assessing left ventricular (LV) hypertrophy (LVH) is an important step in the echocardiographic diagnosis of aortic stenosis (AS). We aimed to investigate the causes of discrepancies between the degrees of AS and LVH.

Methods

The study subjects consisted of 149 consecutive patients with AS having aortic valve area <2.0 cm² (mean age 72.5 ± 11.9 years, 67 men and 82 women). Coexisting cardiac diseases were determined based on echocardiographic findings and comprehensive clinical judgment. Echocardiographic measurements included LV mass index (LVMI), aortic valve area index (AVAI), transaortic mean pressure gradient (MPG), valvulo-arterial impedance (Zva), energy loss coefficient (ELCo), and energy loss index (ELI).

Results

LVMI was not significantly correlated with AVAI and Zva, and had a weak correlation with MPG (r = 0.305, p = 0.0001). There were 55 patients in group A (non-severe AS without significant LVH), 58 in group B (non-severe AS with significant LVH), 7 in group C (severe AS without significant LVH), and 29 in group D (severe AS with significant LVH). Coexisting cardiac diseases were more frequently observed (p = 0.0003) in group B (50 %) than in group A (18 %). In group C, ELCo and (ELI ? AVAI)/ELI were significantly greater than in group D (p = 0.043 and 0.007, respectively).

Conclusion

Significant LVH seen in less than moderate AS is often due to coexisting cardiac diseases, and there may be an overestimation of AS severity due to pressure recovery among patients with apparently severe AS who do not have significant LVH.