Mediastinoscopic extended thymectomy for pediatric patients with myasthenia gravis.

BACKGROUND: Extended thymectomy is indicated for children with myasthenia gravis (MG) when drug-resistance or dependence is seen. We have employed a technique for mediastinoscopic extended thymectomy (MET) on children with MG. METHOD: A total of 14 children underwent MET at Kanagawa Children's Medical Center between 2005 and 2013. A mediastinal operation field was made by a V-shaped hook infrasternally to extirpate the thymus with adipose tissue around the thymus. RESULTS: The operation time and the amount of blood loss were 182±44 minutes and 34±43 ml, respectively. Postoperative complications, in the form of transient paralysis of the right recurrent nerve, occurred in 2 patients. The median length of postoperative hospital stay was 4.5 days. After MET, 6 patients achieved complete remission and 7 patients achieved steroid dose reduction, but no improvement was seen in 1 patient. CONCLUSIONS: This procedure offers the advantage of good surgical access for dissection around the bilateral phrenic nerves in extended total thymectomy, while achieving good cosmetic results.

Identification of AFLP makers linked to non-seed shattering locus (sht1) in buckwheat and conversion to STS markers for marker-assisted selection.

Shattering habit in buckwheat has two forms: brittle pedicel and weak pedicel. Brittle pedicel is observed in wild buckwheat, but not in cultivated buckwheat. Brittle pedicel in buckwheat is produced by two complementary, dominant genes, Sht1 and Sht2. The sht1 locus is linked to the S locus; almost all common buckwheat cultivars possess the allele sht1. To detect molecular makers linked to the sht1 locus, we used amplified fragment-length polymorphism (AFLP) analysis in combination with bulked segregant analysis of segregating progeny of a cross between a non-brittle common buckwheat and a brittle self-compatible buckwheat line. We screened 312 primer combinations and constructed a linkage map around the sht1 locus by using 102 F2 plants. Five AFLP markers were linked to the sht1 locus. Two of these, e54m58/610 and e55m46/320, cosegregated with the sht1 locus without recombination. The two AFLP markers were converted to STS markers according to the sequence of the AFLPs. The STS markers are useful for marker-assisted selection of non-brittle pedicel plants and provides a stepping-stone for map-based cloning and characterization of the gene encoding non-brittle pedicel.

Laparoscopic cholecystectomy: a report on the community hospital experience in Hokkaido.

We analyzed the outcome of 1408 patients who underwent laparoscopic cholecystectomy (LC) between February 1991 and October 1993 in affiliated community hospitals around Hokkaido, Japan. LC was performed for symptomatic gallstones (68%) and asymptomatic gallstones (29%) using the pneumoperitoneum (96%) or abdominal wall lift (4%) techniques. Intraoperative and postoperative complications occurred in 105 patients (10%), including bile duct injuries in 9 patients (0.9%). Conversion to open surgery or reoperation was required in 89 patients (8%) mainly because of unclear anatomy, difficulties with hemostasis, or bile duct injury. One patient died of congestive heart failure, resulting in a mortality rate of 0.07%. The patients were discharged after an average of 8 days, and returned to work after an average of 14 days. The complication and conversion rates were high; however, the incidences of reoperation, bile duct injuries, postoperative bile leaks, and deaths were low. In conclusion, LC was performed with acceptable safety in our community hospitals. The reason for this is most likely that conventional cholecystectomy was preferred to LC in difficult cases during this early period.

[The limits of resection in hepatopancreatectomies in rats].

Hepatopancreatectomy (HPx), one of the most stressful surgeries, is occasionally the only curative resection for widely spreading biliary cancer. Little is known about the pathophysiology after HPx. This study was undertaken to investigate the limits of resection and to compare HPxs with respect to morphological and biochemical findings in order to establish reasonable models of HPxs in rats. Male Wistar rats underwent 6 kinds of HPxs. The HPxs performed were a combination of one of 3 degrees of hepatectomy (70%, 80%, or 90%) and one of 2 degrees of pancreatectomies (60% or 90%). Hepatectomy (Hx) alone and pancreatectomy (Px) alone were used as the controls. The animals were observed with checks on mortality, body weight, and blood sugar level. On day 28, they were sacrificed in order to obtain the liver and pancreas tissue and systemic blood. According to direct survival rate on day 28, the six kinds of HPxs were classified into four as follows: safe HPx (70% Hx + 60% Px, survival rate 100%; and 70% Hx + 90% Px, survival rate 88.2%); critical HPx (80% Hx + 60% Px, survival rate 52.9%); poor HPx (80% Hx + 90% Px, survival rate 31.3%; and 90% Hx + 60% Px, survival rate 25.0%); and fatal HPx (90% Hx + 90% Px, survival rate 0%). In the rats which underwent HPxs, 46 out of 49 deaths (95.8%) occurred in the first three postoperative days. In survivors receiving the critical and poor HPxs, morphological and biochemical values were within permissible ranges, comparable with those of the rats receiving 70% Hx or 60% Px. In conclusion, 70% Hx + 90% Px was considered to be a safe limit for HPx, and 80% HX + 60% Px was considered to be a borderlining limit for HPx; sufficient recovery after operation would be expected since some rats survived even after critical and poor HPxs. Vitally physiological changes would be expected to occur in the early postoperative period.

Reduction of EDA(+) fibronectin and its clinical importance on cryofiltration.

Cryofiltration (CRYO) removes cryogel, which is a combination of fibrinogen (Fbg) and fibronectin (FN), containing pathological substances. The purpose of this study was to measure cryogel EDA(+) FN and study the relationship between EDA(+) FN and clinical symptoms in patients with rheumatoid arthritis, SLE and polymyositis. Cryogel contains 51 times more EDA(+) FN than plasma. The patients with rheumatoid arthritis showed a high level of EDA(+) FN in their plasma, and the EDA(+) FN level in plasma corresponded with changes in joint pain. We calculated the clearance level at several points in cryofiltration, and the reduction enabled us to evaluate the CRYO device. The EDA(+) FN clearance was 23.3 +/- 6.4 ml/min, the pFN clearance 16.5 +/- 4.1 ml/min, and the Fbg clearance 22.9 +/- 5.7 ml/min. As the plasma flow in cryofiltration was 30 ml/min, a clearance of EDA(+) FN and Fbg, approximately 23 ml/min, was obviously high. The study of the plasma level change of EDA(+) FN during cryofiltration revealed a temporary elevation. These results suggest that the EDA(+) FN was most efficiently reduced by cryofiltration, would become a good indicator on plasmapheresis, and might move from other tissues into the blood during cryofiltration.

Congenital biliary dilatation with pancreatico-biliary maljunction: a comparative study between children and adults.

A comparative study of congenital biliary dilatation with pancreatico-biliary maljunction in 15 children and 16 adults was undertaken. Cystic and fusiform dilatation of the common bile duct was seen in 9 and 6 cases respectively in the child group, with 8 and 8 cases respectively in the adult group. Cholangiographically, neither the length of the common channel nor the type of pancreatico-ductal union varied significantly between groups. Furthermore the incidence of higher amylase levels of bile showed no apparent variance from group to group. This was also true when looking histologically at the number and distribution of periductal glands surrounding the intra-hepatic bile duct. Therefore, we concluded that there was no essential etiological difference between the two groups.

Surgical treatment of congenital biliary dilatation associated with pancreaticobiliary maljunction.

The excisional surgical treatment of 50 patients with congenital biliary dilatation (CBD) associated with pancreaticobiliary maljunction (PBMJ) was analyzed. There were two patients who had early complications of lesser bile juice leakage with a maximum duration of 21 days, but no pancreatic juice leakage was noticed. As a late complication, two strictures at the anastomotic portion of the hepaticojejunostomy and one intrahepatic gallstone formation were encountered, but no malignant lesion was evident. Both patients with strictures could be predicted using postoperative cholangiography performed two weeks postoperatively and underwent hepaticojejunostomy. Intrahepatic gallstones were treated with lateral segmentectomy of the liver and electrohydraulic lithotripsy through percutaneous transhepatic cholangioscopy. Accordingly, these results suggest that excisional surgical treatment is the most appropriate method for CBD with PBMJ; however, special care must be taken, such as creating a sufficiently wide anastomotic stoma to enable free drainage of bile into the intestine; also, there should be precautions against ischemia at the anastomotic portion. The importance of the postoperative cholangiography to predict the postoperative outcome should be emphasized. Furthermore, causes of intrahepatic gallstone formation should be studied in such instances.

Rays and ray envelopes within stable optical resonators containing focusing media.

In stable resonators any given initially paraxial rays remain close to the axis of the structure and are, in fact, confined within well-defined contours-the envelope of the ray system. Previously, envelopes of rays in empty resonators had been found and their form identified with the variation of the spot size. This geometric optical approach is extended to general resonators, comprising arbitrary arrangements of lenses and convergent or divergent inhomogeneous focusing media. An invariant quadratic form involving parameters descriptive of any of the ray segments that result from a given initial ray segment leads to a differential equation satisfied by the ray segments and their envelope in portions of the resonator. A maximum-minimum problem for the envelope is formulated and solved. In convergent media the envelope function is found to be periodically modulated. The period of the modulation depends only on the properties of the convergent medium; the location of relative maxima and minima, as well as their ratio, depends on both the medium and associated optics. In special cases, results are compared with available solutions of the corresponding electromagnetic problem. A particularly simple resonator is analyzed, and envelope characteristics correlated with the stability limits.