Involvement of the cerebellar dorsal vermis in vergence eye movements in monkeys

Frontal-eyed primates use both smooth pursuit in frontoparallel planes (frontal pursuit) and pursuit-in-depth (vergence pursuit) to track objects moving slowly in 3-dimensional (3D) space. To understand how 3D-pursuit signals represented in frontal eye fields are processed further by downstream pathways, monkeys were trained to pursue a spot moving in 3D virtual space. We characterized pursuit signals in Purkinje (P) cells in the cerebellar dorsal vermis and their discharge during vergence pursuit. In 41% of pursuit P-cells, 3D-pursuit signals were observed. However, the majority of vermal-pursuit P-cells (59%) discharged either for vergence pursuit (43%) or for frontal pursuit (16%). Moreover, the majority (74%) of vergence-related P-cells carried convergence signals, displaying both vergence eye position and velocity sensitivity during sinusoidal and step vergence eye movements. Preferred frontal-pursuit directions of vergence + frontal-pursuit P-cells were distributed in all directions. Most pursuit P-cells (73%) discharged before the onset of vergence eye movements; the median lead time was 16 ms. Muscimol infusion into the sites where convergence P-cells were recorded resulted in a reduction of peak convergence eye velocity, of initial convergence eye acceleration, and of frontal-pursuit eye velocity. These results suggest involvement of the dorsal vermis in conversion of 3D-pursuit signals and in convergence eye movements.     

Intrahepatic cholangiojejunostomy for unresectable malignant biliary tumors with obstructive jaundice

We reviewed our experience with intrahepatic cholangiojejunostomy as a palliative therapy for patients with unresectable malignant diseases involving the ductal confluence or the common hepatic duct. Fifteen patients with malignant biliary obstruction were treated by cholangiojejunostomy at our hospital. Two patients had intrahepatic cholangiocarcinoma, 7 had gallbladder carcinoma, 5 had bile duct carcionoma, and 1 had pancreatic carcinoma. Segment III cholangiojejunostomies were performed in 14 patients and segment V cholangiojejunostomy in 1. Contraindications for surgical resection were locoregional invasion of tumors involving the proper and/or common hepatic artery and portal vein in 15 patients and the presence of hepatic metastases in 6 patients. Liver metastases were detected in 5 of the 7 patients with gallbladder carcinoma. Postoperative complications occurred in 2 patients (13%), but there was no leakage of the cholangioenteric anastomosis in our series. There was no operative mortality after cholangiojejunostomy. Of the 9 patients who survived for more than 6 months after surgery, 7 showed a significant improvement in performance status (PS) (82 ± 10%) 3 months after the surgery compared with the preoperative PS (70 ± 7%). Four of the 9 patients had recurrent cholangitis as a late complication, but 4 were completely free from jaundice. Median survival after cholangioenteric bypass was 9 months (range, 2–25 months). With respect to tumor location, the median survival time was 4 months (range, 2–25 months) in patients with gallbladder carcinoma and 15.5 months (range, 12–22 months) in those with bile duct carcinoma. While the median survival period after surgery was only 3 months (range, 2 to 8 months) in the 5 patients with hepatic metastases from gallbladder carcinoma, 2 patients without liver metastasis survived for 9 and 25 months after segment III cholangioenteric bypass. In conclusion, cholangiojejunostomy can provide useful palliation for malignant biliary obstruction when combined with careful patient selection. Received: September 5, 2000 / Accepted: November 8, 2000     

Roles of Carbon Monoxide in Leukocyte and Platelet Dynamics in Rat Mesentery during Sevoflurane Anesthesia

Background: Heme oxygenase 1 (HO-1), induced by a variety of stressors, provides endogenous carbon monoxide (CO) and bilirubin, both of which play consequential roles in organs. The current study aimed to examine whether induction of HO-1 and its by-products modulated endothelial interaction with circulating leukocytes and platelets evoked by sevoflurane anesthesia in vivo.

Methods: Rats, pretreated with or without hemin, were anesthetized with sevoflurane in 100% O2, and lungs were mechanically ventilated. Platelets labeled with carboxyfluorescein diacetate succinimidyl ester and leukocyte behavior in mesenteric venules were visualized during sevoflurane anesthesia at 1,000 frames/s using intravital ultrahigh-speed intensified fluorescence videomicroscopy. To examine the mechanisms for the effects of HO-1 on leukocyte and platelet behavior, these studies were repeated with superfusion of either CO, bilirubin, or N[omega]-nitro-l-arginine methyl ester (l-NAME).

Results: As reported previously, the elevation of sevoflurane concentration evoked adhesive responses of leukocytes, concurrent with platelet margination and rolling. Pretreatment with hemin, a HO-1 inducer, prevented such sevoflurane-elicited changes in the microvessels. These changes were restored by zinc protoporphyrin IX, a HO inhibitor, and repressed by CO but not by bilirubin. During sevoflurane anesthesia, however, nitric oxide suppression by l-NAME deteriorated microvascular flows irrespective of the presence or absence of the HO-1 induction.     

The giant schwannoma in the pelvic cavity: a case report

A 62-year-old man presented with a giant tumor in the pelvic cavity that was incidentally revealed by abdominal ultrasonography. Abdominal magnetic resonance imaging showed the heterogenous tumor in the pelvis with cystic components. The tumor was 10.8 × 10.5 × 11.7 cm in diameter and adhered to the sacral wall. The tumor was extirpated following diagnosis as a benign neurogenic tumor by needle biopsy. The pelvic cavity was occupied by the tumor rigidly adhered to the sacrum. The histopathological diagnosis of the specimen was benign schwannoma, type Antoni A.     

A case of paracecal hernia

A 63-year-old male patient suddenly suffered right lower abdominal pain. The patient had tenderness and rebound tenderness at the right lower abdomen. Marked small bowel dilatation and an intestinal obstruction were evident upon abdominal X-ray and abdominal computed tomography (CT) imaging. CT imaging also revealed a dilated small bowel cluster in a wrapped round shape in the right lower abdomen. The cecum and the ascending colon were displaced inward. Strangulation in the ileocecal region was suspected, and emergency surgery was performed. A part of the small bowel was incarcerated within the retrocecal recess, and the intestinal tract was strangulated in the hernia orifice, by which paracecal hernia was diagnosed. The strangulated intestinal tract was repositioned, and the orifice to the hernia was closed. Paracecal hernia is a rare disease; an internal hernia should always be considered in patients with ileus without a history of surgery.     

Urinary incontinence after robot‐assisted radical prostatectomy: Pathophysiology and intraoperative techniques to improve surgical outcome

Robot‐assisted radical prostatectomy has been shown to have comparable and possibly improved postoperative continent rates compared with retropubic and laparoscopic radical prostatectomy. However, postoperative urinary incontinence has remained one of the most bothersome postoperative complications. The basic concept of the intraoperative technique to improve postoperative urinary continence is to maintain as normal anatomical and functional structure in the pelvis as possible. Therefore, improved knowledge of the normal structure in the pelvis should lead to a greater understanding of the pathophysiology of urinary incontinence, and further development of intraoperative techniques to improve the outcomes of urinary continence. It might be necessary to carry out three steps to realize improvement of the early return of urinary continence after robot‐assisted radical prostatectomy: (i) preservation (bladder neck, neurovascular bundle, puboprostatic ligament, pubovesical complex, and/or urethral length, etc.); (ii) reconstruction (posterior and/or anterior reconstruction, and/or reattachment of the arcus tendineus to the bladder neck, etc.); and (iii) reinforcement (bladder neck plication and/or sling suspension, etc.). On the basis of these steps, further modifications during robot‐assisted radical prostatectomy should be developed to improve urinary continence and quality of life after robot‐assisted radical prostatectomy.     

Correction of a Deformed Thumb by Distraction of the Phalanx

We used distraction osteogenesis to correct six deformed thumbs in four patients ranging in age from 4 to 7 years. Two of the patients had Apert syndrome (syndromic craniosynostosis with symmetrical syndactyly) and two had polydactyly. We used a small fixator with a ball joint and successfully corrected the angular deformity after lengthening the proximal phalanx by distraction. This single inclusive procedure was extremely useful. We found the optimal distraction regimen for the digital phalanx was a one day waiting period and lengthening at 1 mm/day. The mean healing indexes were 37.2 days/cm (range 24.2 to 41.5) in those with Apert syndrome and 64.3 days/cm in those with polydactyly (62.5 and 66.0). Our results suggest that osteogenesis at the distraction site may be quicker in patients with Apert syndrome than in those with polydactyly.     

Postoperative outcome among elderly patients after general anesthesia

BACKGROUND: Preoperative decision-making for elderly patients requires a long-term perspective. The aim of this study was to identify preoperative risk factors for decreased 1- to 5-year survival rates and to compare the survival rates of stratified risk groups with those of the sex- and age-matched general population. METHODS: Subjects were 406 patients, aged 80 years or older, who underwent surgery with general anesthesia. Higher age, male sex, dependency in daily living, low serum albumin level, malignancy, abdominal surgery, emergency surgery and high ASA class were analyzed for survival using univariate and multivariate analysis with Cox's proportional hazard model. One- to 5-year survival rates were estimated using life table analysis for patients divided by risk factors. The survival data were also compared with the cumulative survival rates of the sex- and age-matched general population. RESULTS: Multivariate analysis identified three factors that were significantly associated with decreased survival rates: male sex, dependency in daily living and abdominal surgery. Long-term survival among patients older than 90 years was comparable to those of the general population. Although improved in recent years, overall survival rates were much lower than expected due to poor outcome among patients dependent in daily living and those who underwent abdominal surgery. CONCLUSIONS: In patients 80 years or older who underwent surgery with general anesthesia, independent risk factors for decreased survival are male sex, dependency in daily living and abdominal surgery. Only patients independent in daily living who underwent non-abdominal surgery had survival rates comparable to those of the general population.