Application of the Sinter-HIP Method to Manufacture Cr–Mo–W–V–Co High-Speed Steel via Powder Metallurgy

1.2C–4Cr–4Mo–10W–3.5V–10Co–Fe high-speed steel (JIS SKH57; ISO HS10-4-3-10) is often manufactured via casting and forging. By applying powder metallurgy, the properties of the abovementioned material can be improved. In this study, the effects of sintering conditions on the formation of precipitates and pores are evaluated. Additionally, strength with and without hydrostatic pressure during sintering is evaluated via static bending and impact tests. Sintering via hot isostatic pressing (HIP) at 1463 K can effectively eliminate pores and prevent the coarsening of precipitates. Toughness and strength improved by 50% by applying HIP.     

Hepatic resection for colorectal metastases

PURPOSE: Hepatic resection affords the best hope of survival for patients with colorectal carcinoma metastatic to the liver. However, recurrences are observed in about 60 percent of patients after curative hepatic resection. The purpose of this study was to examine the prognostic factors of patients undergoing curative hepatic resection for colorectal metastases. METHODS: Between April 1984 and September 1997, 168 patients underwent curative hepatic resection for colorectal metastases. The clinicopathologic factors studied for prognostic value were gender, age, primary site, nodal status of primary tumor, time of metastases, preoperative serum level of carcinoembryonic antigen, hepatic tumor size and distribution, number of metastases, type of hepatic resection, resection margin, presence of micrometastases in resected specimen and microscopic fibrous pseudocapsule between the hepatic tumor and surrounding hepatic parenchyma, nodal status of hepatoduodenal ligament, adjuvant regional chemotherapy, and perioperative transfusion. RESULTS: The overall survival was 42 percent at three years and 26 percent at five years, including a 3.5 percent 60-day surgical mortality rate. Thirty-one percent of patients had micrometastases located at a median distance of 3 mm from the metastatic tumor edge. Presence of microscopic fibrous pseudocapsule was observed in 28 percent of patients. Univariate and multivariate analyses showed that significant prognostic factors for survival were nodal status of primary tumor, number of metastases, resection margin, microscopic fibrous pseudocapsule, and adjuvant regional chemotherapy. CONCLUSIONS: We conclude that 1) hepatic resection is effective in select patients with colorectal metastases; 2) adequate resection margin and adjuvant regional chemotherapy can improve outcome; and 3) microscopic fibrous pseudocapsule may offer additional postoperative information as an independent prognostic factor.Presented at the 11th Biennial Scientific Meeting of the Asian Pacific Association for the Study of the Liver, Perth, Western Australia, February 16 to 20, 1998.     

Minimally invasive surgery for single valvular heart disease]

Two patients underwent valve surgery using the minimally invasive approach. A 51-year-old man underwent mitral valve repair for chronic mitral regurgitation due to prolapse of the posterior mitral leaflet. The left-half of his sternum was cut in "C" shape below the level of the second intercostal space, and all of the arterial or venous cannulas were inserted via this single access. A 37-year-old man underwent aortic valve replacement for aortic valve regurgitation due to infective endocarditis. Right upper partial sternotomy between the first and fourth intercostal space was selected for this aortic valve surgery. The median skin incisions were as small as 12 and 9 cm. Postoperative recovery was very smooth. Minimally invasive approach using selected partial sternotomy provides acceptable results with a good exposure, and is an alternative approach to valve surgery.     

Serum angiotensin I-converting enzyme is reduced in Crohn's disease and ulcerative colitis irrespective of genotype

OBJECTIVES: Crohn's disease (CD) is recognized to be a vascular endothelial-associated disease. Angiotensin I-converting enzyme (ACE) exists mainly in endothelial cells. There are some reports on serum ACE levels in patients with CD, but the ACE level is still controversial. Recently, genetic control of serum ACE levels by ACE gene polymorphisms (classified as II, ID, and DD) has been suggested. Although we must consider such polymorphisms to elucidate ACE levels in patients with CD, there is no report about this. METHODS: We studied 341 healthy controls (male/female = 178/162), 39 patients with CD (31/8), 43 patients with ulcerative colitis (UC) (22/21) and 19 patients with infectious enterocolitis (8/11). The polymorphism in intron 16 of the ACE gene was examined by PCR. Serum ACE levels were measured by the method of Kasahara. RESULTS: Serum ACE levels in patients with CD and UC were significantly lower than in healthy controls, irrespective of the genotype of ACE (genotype II: CD 7.0+/-2.5 [mean +/- SD], UC 7.1+/-3.3, controls 11.8+/-2.9, genotype ID: CD 9.7+/-4.1, UC 11.4+/-4.6, controls 15.2+/-3.6, genotype DD: CD 13.9+/-5.8, UC 10.7+/-3.6, controls 19.3+/-3.9 IU/L, controls vs CD, UC; p < 0.01, 0.05). However, there was no significant difference in serum ACE levels between CD and UC. CONCLUSIONS: Considering ACE gene polymorphism, serum ACE levels in patients with inflammatory bowel disease are lower than in controls. Serum ACE levels reflect a part of the pathogenesis of inflammatory bowel disease.     

Birt‐Hogg‐Dubé syndrome‐associated renal cell carcinoma: Histopathological features and diagnostic conundrum

Birt‐Hogg‐Dubé (BHD) syndrome is associated with the development of hereditary renal cell carcinoma (RCC) and is caused by a germline mutation in the folliculin gene. Most cases of BHD syndrome‐associated RCC (BHD‐RCC) are less aggressive than sporadic clear cell RCC and multifocal. Therefore, it is critical to distinguish BHD‐RCC from its sporadic counterparts to identify and monitor affected families and to preserve renal function for as long as possible. The World Health Organization/International Society of Urological Pathology consensus classification defined distinct entities for certain hereditary RCC; however, BHD‐RCC was not included in this classification. Although the clinical features and molecular mechanisms of BHD‐RCC have been investigated intensively over the last two decades, pathologists and urologists occasionally face difficulties in the diagnosis of BHD‐RCC that require genetic testing. Affected patients usually have miscellaneous benign disorders that often precede renal carcinogenesis. In the present review, we summarize the current understanding of the histopathological features of BHD‐RCC based on our epidemiological studies of Japanese families and a literature review. Pathological diagnostic clues and differential diagnosis of BHD‐RCC from other hereditary RCC are also briefly discussed.     

Estimation of physiologic ability and surgical stress (E-PASS) for a surgical audit in elective digestive surgery

BACKGROUND: This study was undertaken to establish an equation to estimate mortality with the use of the prediction scoring system designated as the Estimation of Physiologic Ability and Surgical Stress (E-PASS), and to evaluate the system's usefulness in defining quality of care by comparing it with the Physiologic and Operative Severity Score for the enUmeration for Mortality and morbidity (POSSUM) and Portsmouth-possum (P-POSSUM) scoring systems previously generated for surgical audit. METHODS: Patients (n=5212; group A) who underwent elective gastrointestinal surgery were analyzed to establish equations for estimated 30-day and in-hospital mortality rates. The usefulness of E-PASS was evaluated in another series of 1934 patients (group B) who underwent elective digestive surgery in 6 national hospitals. The ratio of observed to estimated mortality rates (OE ratio) of each hospital was defined as a measure of quality. RESULTS: In group A, 30-day and in-hospital mortality rates increased as the Comprehensive Risk Score (CRS) increased, providing equations for estimated mortality rates. There was an excellent correlation between the estimated and observed mortality rates in individual diseases: R=0.958, N=6, P=.0027 for in-hospital mortality; R=0.937, N=6, P=.0059 for 30-day mortality. In all patients of group B, the E-PASS system estimated the 30-day mortality rates by 0.63-fold (linear analysis), whereas the POSSUM score was 11.0-fold (exponential analysis). The E-PASS system estimated the in-hospital mortality rates by 1.2-fold (linear analysis), whereas the P-POSSUM score was 4.5-fold (linear analysis). The OE ratios for 30-day mortality among the 6 hospitals defined by E-PASS correlated well with those defined by POSSUM: R=0.996, N=6, P<.0001. Similarly, the OE ratios for in-hospital mortality defined by E-PASS were also highly correlated with those defined by P-POSSUM:(R=0.929, N=6, P=.0075. CONCLUSIONS: The E-PASS scoring system may be useful in defining surgical quality and may be more accurate than existing systems in evaluating elective digestive surgery.     

A case of solitary bone cyst in the skull increasing in size after trivial head injury

A 12-year-old boy had been known to have a small swelling in the left high vertex for several years. After a trivial head hit to the site of the swelling, the swelling enlarged gradually. A bone window CT scan showed a lesion having bubble-like lytic change in the left parietal bone. Similar changes, but small, were able to be pointed out in a CT scan taken seven years previously. In the following 13 months CT scans eventually revealed sequential increases to 3.5 cm in diameter. Surgical exploratory resection of the mass was performed. Intraoperatively, partial destruction of the outer skull table and a simple cyst with serous yellowish brown colored fluid were identified. There was no finding adherent to the diploic structure. The bone defect after excision was reconstructed by using a titanium plate. The patient was followed up for 2 years after the surgery. Bone window CT showed bony development of normal appearance. Histological examination showed the cyst wall consisted of fibrous connective tissue but there were neither epithelial nor endothelial cells. The histopathological diagnosis of SBC was most likely. SBC is relatively common in long bones, but rarely in flat bones. Only several cases of the SBC of cranial bone have been reported. Although a craniectomy for total excision followed by cranioplasty by resin was common, in cases of children, cyst removal with titanium plate application would be an alterative. SBC increasing in size after head injury is extremely rare, but clinicians may need to be aware of cystic skull bone tumors increasing in size after head injury.     

Pancreatic insulinoma combined with glucagon positive cell: A case report

We present a 70-year-old man who was referred for surgery with uncontrollable hypoglycemia. Ultrasonography and abdominal contrast computed tomography revealed a hypervascular tumor of 1 cm in diameter in the pancreatic tail. With a diagnosis of insulinoma, we performed a distal pancreatectomy. The patient showed a good postoperative course without any complications. The patient’s early morning fasting hypoglycemia disappeared. The respective levels of C-peptide and insulin dropped from 14.9 ng/mL and 4860 μIU/mL preoperatively to 5.3 ng/mL and 553 μIU/mL after surgery. A histopathological examination demonstrated that the tumor was a pancreatic neuroendocrine tumor, grade 1. Immunostaining was negative for insulin and positive for CD56, chromogranin A, synaptophysin and glucagon. These findings suggested that the tumor was clinically an insulinoma but histopathologically a glucagonoma. Among all insulinoma cases reported between 1985 and 2010, only 5 cases were associated with independent glucagonoma. In this report, we characterize and discuss this rare type of insulinoma by describing the case we experienced in detail.