Extended Endoscopic Endonasal Transplanum and Transdorsum Sellar Approach for the Resection of Retroinfundibular Craniopharyngioma With Two-Piece Dural Opening: A Technical Case Report.

The surgical treatment of retroinfundibular craniopharyngiomas is challenging due to their location and the surrounding neurovascular structures. In this report, the transdorsum sellar approach with posterior clinoidectomy, the efficacy of direct cyst puncture, and the suitability of a two-piece dural opening are presented. A 56-year-old male with visual and cognitive disturbances was referred to our hospital. Preoperative CT and MRI demonstrated a mostly cystic lesion with calcifications in the suprasellar and retroinfundibular areas. The imaging findings were suspected craniopharyngioma, and an extended endoscopic endonasal transdorsum sellar approach with posterior clinoidectomy was performed for direct access to the lesion. Two pieces of the dura were opened to prevent postoperative CSF leakage. The patient's postoperative course was uneventful. The endoscopic transdorsum sellar approach gives direct access to the posterior cranial fossa. A direct puncture of the cyst without CSF drainage is helpful for large cystic lesions. A two-piece dural opening is easy to suture and can reduce the chance of postoperative CSF leakage.

Synergistic effect of combining two nondestructive analytical methods for multielemental analysis.

We developed a new analytical technique that combines prompt gamma-ray analysis (PGA) and time-of-flight elemental analysis (TOF) by using an intense pulsed neutron beam at the Japan Proton Accelerator Research Complex. It allows us to obtain the results from both methods at the same time. Moreover, it can be used to quantify elemental concentrations in the sample, to which neither of these methods can be applied independently, if a new analytical spectrum (TOF-PGA) is used. To assess the effectiveness of the developed method, a mixed sample of Ag, Au, Cd, Co, and Ta, and the Gibeon meteorite were analyzed. The analytical capabilities were compared based on the gamma-ray peak selectivity and signal-to-noise ratios. TOF-PGA method showed high merits, although the capability may differ based on the target and coexisting elements.

Deep-sea record of impact apparently unrelated to mass extinction in the Late Triassic.

The 34-million-year (My) interval of the Late Triassic is marked by the formation of several large impact structures on Earth. Late Triassic impact events have been considered a factor in biotic extinction events in the Late Triassic (e.g., end-Triassic extinction event), but this scenario remains controversial because of a lack of stratigraphic records of ejecta deposits. Here, we report evidence for an impact event (platinum group elements anomaly with nickel-rich magnetite and microspherules) from the middle Norian (Upper Triassic) deep-sea sediment in Japan. This includes anomalously high abundances of iridium, up to 41.5 parts per billion (ppb), in the ejecta deposit, which suggests that the iridium-enriched ejecta layers of the Late Triassic may be found on a global scale. The ejecta deposit is constrained by microfossils that suggest correlation with the 215.5-Mya, 100-km-wide Manicouagan impact crater in Canada. Our analysis of radiolarians shows no evidence of a mass extinction event across the impact event horizon, and no contemporaneous faunal turnover is seen in other marine planktons. However, such an event has been reported among marine faunas and terrestrial tetrapods and floras in North America. We, therefore, suggest that the Manicouagan impact triggered the extinction of terrestrial and marine organisms near the impact site but not within the pelagic marine realm.

Comparison of multiple prompt γ-ray analysis and prompt γ-ray analysis for the elemental analysis of geological and cosmochemical samples.

Multiple prompt γ-ray analysis (MPGA) and conventional neutron-induced prompt γ-ray analysis (PGA) are nondestructive analytical methods for bulk chemical compositions, and their analytical capabilities were compared for elemental analyses of geological and cosmochemical samples. Detection sensitivities of PGA are often restricted by poor signal-to-noise ratios and interferences from different origins. MPGA can substantially reduce the background level, especially for hydrogenous samples, relative to PGA, which opens up a possibility to use lower energy prompt γ-rays of some trace elements. Although it is one of the major constituent elements of rock samples, Mg is hard to be determined by PGA. With MPGA, Mg contents could be determined with reasonable consistency with their corresponding recommended values in geological and cosmochemical samples by carefully selecting suitable coincident prompt γ-ray energy pairs without interference correction. MPGA was applied to a hydrogenous meteorite, Ivuna, which contains H at 2% mass level. MPGA detection limits for most of the elements studied can be reduced up to 1 order of magnitude when compared with PGA detection limits under the present experimental conditions.

A feasibility study on image-based control of surgical robot using a 60-GHz wireless communication system.

This paper presents an evaluation study on the feasibility of introducing wireless connection into a neurosurgical robot, which is controlled by an image-based navigation system. The wireless connection introduced into the robotic system is based on amplitude shift keying (ASK) at 60 GHz. With this wireless connection, data transmission at the bit-rate of 1 Gbps or more is possible, and here high-definition video images (1080i/1080p) can be transmitted. Such a wireless connection system is implemented in the surgical robot replaces the cable connection between the digital video camera and the controller. In this study, the wireless robotic surgical system is evaluated in terms of its accuracy of navigation using the transmitted video images. The results of a wireless connection test under a line-of-sight (LOS) environment show that navigation accuracy observed when using this wireless surgical robot is comparable to that when using a wired robotic system.

Gastrobiliary motility is not coordinated in patients with non-ulcer dyspepsia of normal gastric emptying time: simultaneous sonographic study.

BACKGROUND: Disorders of the motor function of the upper gastrointestinal tract have been implicated in the pathogenesis of non-ulcer dyspepsia. Approximately 50% of patients with abdominal symptoms (without ulcer) have normal gastric emptying. Apart from gastric emptying, other mechanisms are very important in the etiology of non-ulcer dyspepsia. METHODS: Gastric emptying and gallbladder motility were simultaneously investigated in 16 patients with non-ulcer dyspepsia and in 15 healthy controls. Fasting blood samples were taken, and pepsinogen levels were assayed. RESULTS: Gastric emptying time, fasting antral diameter, and post-prandial antral diameter were not significantly different between the patients with non-ulcer dyspepsia and the controls. Fasting gallbladder volume, the time required to reach minimal gallbladder residual volume, minimal gallbladder residual volume, and the serum levels of pepsinogen were not significantly different. Simple linear regression was used to summarize the relationship between gastric emptying time and time required to reach minimal gallbladder residual volume. In the controls, the gastric emptying time and time required to reach minimal gallbladder residual volume were linearly related. However, in the patients with non-ulcer dyspepsia, they were not related. CONCLUSIONS: These observations suggest that disturbance of coordination between gastric emptying and gallbladder emptying is a cause of the symptoms of non-ulcer dyspepsia.

Pancreatic enzyme supplement improves dysmotility in chronic pancreatitis patients.

BACKGROUND AND AIMS: Impaired gallbladder contraction and rapid gastric emptying in patients with chronic pancreatitis may be the result of depleted pancreatic exocrine function. The authors tested whether oral pancreatic enzymes can improve the dysmotility or not. METHODS: Study subjects consisted of 15 patients with chronic pancreatitis and 18 healthy controls. The gastric emptying time and gallbladder contraction were studied. All patients were initially studied using a test meal without pancreatic enzymes, followed on separate days by a test meal with a single and a triple dose of pancreatic enzymes. Blood samples were taken before and 2 h after the test meal to determine the pancreatic polypeptide levels. RESULTS: In patients with chronic pancreatitis, gallbladder contraction at 15 min after the meal was impaired. The gastric emptying time was faster and the ratio of pre- to postprandial pancreatic polypeptide levels was enhanced. A single dose and a triple dose of oral enzymes further improved the gastric emptying time and the pancreatic polypeptide ration, but did not improve the gallbladder contraction rate at 15 min. CONCLUSIONS: It was demonstrated that the oral pancreatic enzymes improved the gastric dysmotility, confirming the previous findings that suggested the depleted pancreatic enzyme output caused the dysmotility.

Development and use of a new staging system for severe acute pancreatitis based on a nationwide survey in Japan.

METHODOLOGY: In 1997, a cooperative nationwide survey of 192 patients diagnosed with severe acute pancreatitis in 1996 was carried out. RESULTS: Alcoholic pancreatitis was the major etiology (46%), and the male-to-female ratio was 2.6:1. Overall, the mortality rate was 27%, which was similar to the rate (30%) in the first nationwide survey of 1,219 patients diagnosed between 1982 and 1986 that was performed in 1987. A marked difference between the surveys was the early mortality rate within 2 weeks: 52% in the 1987 survey and 29% in the current survey. We devised a new stage classification system for acute pancreatitis. Stages 0 and 1 are equivalent to mild and moderate conditions, respectively, in the conventional classification, and stages 2 and higher correspond to severe acute pancreatitis. Severity scores of 2-8 are regarded as stage 2, scores of 9-14, as stage 3, and scores of > or =15, as stage 4. The mortality rates were as follows: 0, stages 0 and 1 at hospitalization; approximately 10%, stage 2; approximately 30-40%, stage 3; and approximately 70-100%, stage 4. CONCLUSION: We found that stage at hospitalization reflected the prognosis of acute pancreatitis.