Mild Hypercapnia Induces Vasodilation via Adenosine Triphosphate-sensitive K+ Channels in Parenchymal Microvessels of the Rat Cerebral Cortex

Background: Carbon dioxide is an important vasodilator of cerebral blood vessels. Cerebral vasodilation mediated by adenosine triphosphate (ATP)-sensitive K+ channels has not been demonstrated in precapillary microvessel levels. Therefore, the current study was designed to examine whether ATP-sensitive K+ channels play a role in vasodilation induced by mild hypercapnia in precapillary arterioles of the rat cerebral cortex.

Methods: Brain slices from rat cerebral cortex were prepared and superfused with artificial cerebrospinal fluid, including normal (Pco2 = 40 mmHg; pH = 7.4), hypercapnic (Pco2 = 50 mmHg; pH = 7.3), and hypercapnic normal pH (Pco2 = 50 mmHg; pH = 7.4) solutions. The ID of a cerebral parenchymal arteriole (5-9.5 [mu]m) was monitored using computerized videomicroscopy.

Results: During contraction to prostaglandin F2[alpha] (5 x 10-7 m), hypercapnia, but not hypercapnia under normal pH, induced marked vasodilation, which was completely abolished by the selective ATP-sensitive K+ channel antagonist glibenclamide (5 x 10-6 m). However, the selective Ca2+-dependent K+ channel antagonist iberiotoxin (10-7 m) as well as the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (10-4 m) did not alter vasodilation. A selective ATP-sensitive K+ channel opener, levcromakalim (3 x 10-8 to 3 x 10-7 m), induced vasodilation, whereas this vasodilation was abolished by glibenclamide.     

Heat-shock preconditioning protects fatty livers in genetically obese Zucker rats from microvascular perfusion failure after ischemia reperfusion

Reduced tolerance of steatotic livers to ischemic injury is considered to correlate with impaired microcirculation. The aim of this study was to investigate the impact of heat-shock preconditioning (HSPC) on microcirculatory failure after ischemia/reperfusion (I/R) in steatotic livers by means of intra-vital fluorescence microscopy. Obese Zucker rats were used. In the HS group, rats underwent whole-body hyperthermia followed by 60-min partial liver ischemia. In group IR, rats were exposed only to ischemia. Microcirculation parameters (sinusoidal perfusion rate, sinusoidal diameter, leukocyte-endothelial interaction) were significantly better preserved in the HS group than in the IR group. Liver enzymes, oxygenated glutathione/reduced glutathione (GSSG/GSH) ratio, and electron microscopy showed less damage in the HS group. A marked expression of heat shock protein 72 (HSP72) and heme oxygenase (HO-1) was found only in the livers of group HS. HSPC mitigated the I/R injury of steatotic livers by preventing post-ischemic failure of microcirculation. This beneficial effect was found to be associated with the induction of HSP72 and HO-1.     

Surgical management of trabecular ventricular septal defects: the sandwich technique

BACKGROUND: Surgical closure of trabecular ventricular septal defects is difficult and often unsuccessful. OBJECTIVE: We performed closure of trabecular ventricular septal defects by sandwiching the septum between 2 polyester felt patches placed in the left ventricle and right ventricle without ventriculotomy. METHODS: Eleven patients (7 boys and 4 girls) underwent a sandwiching closure at a mean age of 4.7 years (range, 0.4-9.7 years) and a mean weight of 16.7 kg (range, 4.6-52 kg). Associated cardiac malformations were present in 9 of the 11 patients. Seven patients had undergone previous operations. The trabecular ventricular septal defects are exposed through the tricuspid valve and also from the left ventricular side through a coexisting large perimembranous ventricular septal defect or through the mitral valve through an interatrial septostomy. Two forceps, one each from the right and left ventricular side, lead a 3F Nelaton catheter through the trabecular defect. An oversized circular polyester felt patch mounted on a 3-0 Nespolen suture attached to the Nelaton catheter is then passed into the left ventricle. The suture ends are then passed through a slightly smaller polyester felt patch on the right ventricular side of the septum. The Nespolen suture is then tied, thereby sandwiching the septum between the 2 patches. RESULTS: Time required for the procedure was less than 20 minutes in each case. There were no hospital deaths, and the postoperative course was uneventful in all patients. There was no residual shunt in 3 patients, and a minimal residual shunt was observed in 5 patients. Mild residual shunt was observed in 3 patients. Cardiac catheterization was performed 1 month postoperatively in 8 patients in whom residual shunt was noted on echocardiography. Five of 8 patients had a minimal residual shunt (pulmonary blood flow/systemic blood flow ratio = 1.0). Three patients had a residual shunt (pulmonary blood flow/systemic blood flow ratio = 2.0, 1.6, and 1.2). The patient with a pulmonary blood flow/systemic blood flow ratio of 2.0 had a "Swiss cheese" ventricular septal defect, and a residual shunt remained around the patch. However, the residual shunt decreased to a pulmonary blood flow/systemic blood flow ratio of 1.6 at examination 16 months postoperatively. Echocardiography showed that the residual shunt had also decreased in another 2 patients. CONCLUSIONS: We conclude that the sandwich technique is safe and easy. Even in cases with a residual shunt present, the shunt is expected to decrease as time passes. Further experience and longer follow-up of these patients are necessary to conclude whether this technique is applicable to neonates and young infants.     

Apparent diffusion coefficients of breast tumors: clinical application.

PURPOSE: To evaluate the usefulness of apparent diffusion coefficient (ADC) for the differential diagnosis of breast tumors and to determine the relation between ADC and tumor cellularity. MATERIALS AND METHODS: One hundred and thirty-six female patients (age range, 17-83 years; average age, 51.7 years) with 140 histologically proven breast tumors underwent diffusion-weighted magnetic resonance (MR) imaging (DWI) using the spin-echo echo-planar technique, and the ADCs of the tumors were calculated using 3 different b values, 0, 500, and 1000 s/mm(2). The diagnoses consisted of fibroadenoma (FA, n=16), invasive ductal carcinoma, not otherwise specified (IDC, n=117), medullary carcinoma (ME, n=3) and mucinous carcinoma (MU, n=4). Tumor cellularity was calculated from surgical specimens. The ADCs of breast tumors and cellularity were compared between different histological types by analysis of variance and Scheffe's post hoc test. The correlation between tumor cellularity and ADC was analyzed by Pearson correlation test. RESULTS: Significant differences were observed in ADCs between FA and all types of cancers (P<0.05) and between MU and other types of cancers (P<0.01) and in cellularity between FA and cancers except MU (P<0.01) and between MU and other types of cancers (P<0.01). There was an inverse correlation between ADC and tumor cellularity (P<0.01, r(2)=0.451). CONCLUSIONS: The ADC may potentially help in differentiating benign and malignant breast tumors. Tumor ADC correlates inversely with tumor cellularity.     

Sentinel lymph node mapping for gastric cancer using a dual procedure with dye- and gamma probe-guided techniques

BACKGROUND: Increasing evidence supports the sentinel lymph node (SN) concept for melanoma and breast cancers. SN biopsy may replace routine lymph node dissection in the treatment of these cancers. But there are little data evaluating this concept in patients with gastric cancer. The objective of this study was to test the feasibility of SN mapping in gastric cancers by using the dual-mapping procedure with dye and radioactive colloid. STUDY DESIGN: Thirty-one consecutive patients preoperatively diagnosed as T1-2 and N0 underwent SN biopsy using the dual-mapping procedure. Distributions of SNs identified by the dye-guided technique (blue nodes; BNs) were compared with those identified by the gamma probe guided technique (hot nodes; HNs). RESULTS: Among the 31 patients, 7 were found to have lymph node metastases. All positive nodes were detected by SN biopsy using the dual method. So, an accuracy rate of 100% was achieved in predicting the status of regional lymph nodes. Both BNs and HNs were identified in 28 of 31 patients (90%), but significant discrepancy of distribution was noted between BNs and HNs. Among the 28 patients with identified BNs, there was one metastasis in a non-BN. So the accuracy rate was 96% for the dye-guided technique. In contrast, among the 28 patients with identified HNs, 2 patients had metastasis in non-HNs, making the accuracy rate 93% for the gamma probe-guided technique. CONCLUSIONS: SN mapping is feasible in gastric cancer, but the dye-guided and gamma probe-guided techniques are complementary. So we recommend the dual-mapping procedure.     

Free radial forearm osteocutaneous perforator flap for reconstruction of total nasal defects

A case in which a radial forearm osteocutaneous perforator flap was successfully transferred for one-stage reconstruction of total nasal loss is described. This thin flap consists of vascularized radial bone, superficial adiposal tissue, and no deep fascia. It is nourished by a single perforator of the radial artery and a cutaneous vein. The advantages of this flap are minimal donor-site morbidity, easy reconstruction for preservation of the radial arterial system, and no need for longer dissection through the radial artery. The donor defect can be repaired with a flow-through flap, such as an anterolateral thigh flap or a latissimus dorsi perforator flap.     

Primary signet ring cell carcinoma of the urinary bladder successfully treated with intra-arterial chemotherapy alone

A 65-year-old man presented with the complaint of gross hematuria. Cystoscopy revealed a sessile tumor on the left bladder wall. It was diagnosed as primary signet ring cell carcinoma of the bladder (T3bN0M0). The patient did not want surgical treatment. Therefore, three courses of arterial infusion of carboplatin were administered at 3-week intervals. Complete remission was obtained and has been maintained for 44 months. Our case appears to be the first report of successful treatment with chemotherapy alone of an infiltrating signet ring cell carcinoma of the bladder.     

Feasibility of a new approach for creating a preperitoneal space in transabdominal preperitoneal repair inguinal hernia repair: using a sandwich approach

Purpose

In Japan, transabdominal preperitoneal (TAPP) inguinal hernia repair is performed by firmly pulling the peritoneum inwards to lift it from the underlying deep layer of subperitoneal fascia. It decreases the postoperative pain and discomfort in the inguinal area. The aim of this study was to evaluate the feasibility of the sandwich approach, which is a new technique for creating a preperitoneal space.

Methods

The operation was performed via the sandwich approach. We made sure to protect the preperitoneal fascia areolar layer when making the preperitoneal space.

Results

We performed TAPP in 745 patients (876 hernias) treated between October 2006 and April 2015 at Himeji Medical Center and Kurashiki Central Hospital. Before October 2010, we did not use the sandwich approach, and recurrence was observed in three patients. From October 2010, we always used the sandwich approach and never experienced any cases of recurrence. Clavien–Dindo classification Grade 3 or higher postoperative complications occurred in 6 patients (0.8%) between October 2006 and April 2015. Mesh-related ileus was the most frequently observed morbidity. There were no cases of vas differentia or spermatic vessel injury, postoperative chronic pain, or urinary retention.

Conclusion

The sandwich approach is feasible as another standard dissective procedure for TAPP.

     

Assessment of single-dose regimen for antimicrobial prophylaxis to prevent perioperative infection in urologic surgery

A single-dose ofantimicrobial prophylaxis (AMP) was administered parenterally for prevention of perioperative infection in a total of 206 urologic surgeries including 114 endoscopic-instrumental, 92 clean, and 20 clean-contaminated procedures between January and December, 2007, and surgical site infections (SSI), urinary tract infections (UTI), and remote infections (RI) were prospectively surveyed. The definition of a single-dose of AMP allowed the administration of a second dose of an antimicrobial during a surgical procedure that exceeded 3 hours but not parenteral or oral administration at the end of the procedure, in the recovery room, or at a later time over a period of more than 24 hours. UTI was observed in 3 cases (2.7%) after endoscopic-instrumental procedures and in 1 case (5%) after clean-contaminated procedures while no case was associated with UTI in clean procedures. SSI was seen in 1 case each after clean procedures (1.1%) and after clean-contaminated procedures (5%), and RI was seen in 2 cases (2.2%) after clean procedures. A single-dose regimen of AMP was effective for prevention ofperioperative infections including SSI, UTI, and RI in endoscopic-instrumental, clean, and clean-contaminated surgical procedures in urology.