Partial purification and properties of a cysteine protease from citrus red mite Panonychus citri

Several studies have reported that the citrus red mites Panonychus citri were an important allergen of citrus-cultivating farmers in Jeju Island. The aim of the present study was to purify and assess properties of a cysteine protease from the mites acting as a potentially pathogenic factor to citrus-cultivating farmers. A cysteine protease was purified using column chromatography of Mono Q anion exchanger and Superdex 200 HR gel filtration. It was estimated to be 46 kDa by gel filtration column chromatography and consisted of 2 polypeptides, at least. Cysteine protease inhibitors, such as trans poxy-succinyl-L-leucyl-amido (4-guanidino) butane (E-64) and iodoacetic acid (IAA) totally inhibited the enzyme activities, whereas serine or metalloprotease inhibitors did not affect the activities. In addition, the purified enzyme degraded human IgG, collagen, and fibronectin, but not egg albumin. From these results, the cysteine protease of the mites might be involved in the pathogenesis such as tissue destruction and penetration instead of nutrient digestion.

A completely isolated intestinal duplication cyst mimicking ovarian cyst torsion in an adult

Intestinal duplications are rare congenital anomalies that can occur anywhere in the gastrointestinal tract. They are most commonly located in the ileum and are usually detected in infancy or early childhood. Duplicated segments are usually firmly attached to and sometimes communicate with the normal gastrointestinal tract. Rarely, intestinal duplications are completely isolated, thus not associated at all with any part of the gastrointestinal tract. Such duplications do not share a common blood supply with the adjacent normal intestinal segment, unlike the usual form of duplication, but rather have a separate vascular pedicle. Reports of completely isolated duplication cysts in adults are extremely rare; we found only five such reports in the English-language medical literature. Here, we report a case of a completely isolated duplication cyst 12 cm long in an adult female. The cyst had no connection to any part of the intestinal tract and had a dedicated vascular pedicle.

CEACAM5 and CEACAM6 are major target genes for Smad3-mediated TGF-β signaling

The carcinoembryonic antigen (CEAs) family consists of a large group of evolutionarily and structurally divergent glycoproteins. The transforming growth factor-beta (TGF-beta) signaling pathway has been implicated in the stimulation of CEA secretion in TGF-beta-sensitive colon cells, thereby possibly modulating cell adhesion and differentiation. However, the specific CEAs targeted by TGF-beta signaling or underlying mechanism of the expression of CEAs has not yet been clarified. In this study, we investigated the specific CEAs targeted by the TGF-beta signaling pathway. In nine human gastric cancer cell lines examined, TGF-beta-responsive cell lines showed positive expression of CEAs. Expression patterns of CEA proteins correlated well with the level of CEA (CEACAM5) and CEACAM6 transcripts in these cell lines, but CEACAM1 expression was not observed in all of these cells. To investigate the role of TGF-beta signaling in CEA expression, we selected two TGF-beta unresponsive gastric cancer cell lines; SNU638 cells that contain a mutation in the TGF-beta type II receptor and SNU484 cells that express low to undetectable level of the TGF-beta pathway intermediate protein, Smad3. Restoration of TGF-beta signaling in these cells induced expression of the CEAs and increased activity of both CEA (CEACAM5) and CEACAM6 promoters. CEA expression was observed in the epithelium of the stomach of wild-type mice, but was markedly decreased in Smad3 null mice. These findings suggest that CEA (CEACAM5) and CEACAM6 are major target genes for Smad3-mediated TGF-beta signaling.

Management of postoperative hemorrhage after pancreatoduodenectomy

BACKGROUND/AIMS

Hemorrhage after pancreatoduodenectomy is a severe, life-threatening complication. This study was conducted to determine the guidelines appropriate for the prevention and management of hemorrhagic complications.

METHODOLOGY

We reviewed the medical records of 456 patients who had undergone pancreatoduodenectomy at our hospital between 1991 and 2000.

RESULTS

Significant postoperative bleeding occurred in 21 patients (4.6%). Early bleeding (within the 5th postoperative day) caused by improper intraoperative hemostasis occurred in 5 of these cases; 3 of whom were saved by prompt operation and one by conservative management. The other 16 cases consisted of late bleeding (after the 5th postoperative day), of which 12 patients (75%) experienced pancreatic leaks and 8 pseudoaneurysms of major arteries. "Sentinel bleeding" was evident in 8 cases. Angiographic embolization was performed in 8 cases, 7 of which were successful. Reoperation was tried in 7 cases with complete hemostasis being achieved in 2. As a result, 15 of 21 patients obtained complete hemostasis and the mortality rate from hemorrhage was 28.6% (6/21).

CONCLUSIONS

Rapid decision-making is mandatory when bleeding stigmata such as pseudoaneurysm on CT and sentinel bleeding are noted. Prompt operation for early bleeding and angiographic embolization for late bleeding are recommended. In order to prevent hemorrhage after pancreatoduodenectomy, meticulously performed hemostasis and the avoidance of pancreatic anastomotic leaks are essential.

K-ras oncogene mutation in cancer and precancerous lesions of the gallbladder

BACKGROUND AND OBJECTIVES

To determine whether K-ras mutation plays any role in the development and progression of gallbladder cancer, or has any clinical or pathological significance in gallbladder cancer patients, we investigated the presence and incidence of this mutation in the normal mucosa, and precancerous and cancerous lesions of the gallbladder.

METHODS

DNA was obtained from normal mucosa, dysplastic mucosa, primary cancer tissues, and metastatic lymph nodes that were identified and microdissected from the paraffin blocks of 20 gallbladder cancer cases. K-ras codon 12 mutations were investigated using a modified two-step polymerase chain reaction and the restriction fragment length polymorphism method, and by direct sequencing with an automated sequencer.

RESULTS

K-ras mutations were detected in the tissues of 10 out of the 20 patients. A mutation was present in the dysplastic epithelium associated with the primary carcinoma in 3 out of 12 specimens, in metastatic carcinoma in 1 out of 5 patients, and in primary carcinoma in 8 out of 20 patients. Mutation was found only once in the dysplastic, noncancerous epithelium, and only once in a metastatic tumor although not detectable in the primary cancer. Direct sequencing showed that the mutations were G to C substitutions (GGT-->CGT) at the first site of codon 12, except in two cases (GGT-->TGT). There were no correlations between K-ras mutations and clinicopathological factors.

CONCLUSIONS

K-ras mutations were detected in half of the gallbladder cancer cases. We suggest that K-ras mutation may play a role in the development of premalignant lesions or early carcinogenesis in some gallbladder cancers. We were unable to find any evidence that K-ras mutation plays any role in tumor progression or metastasis, or that it has any clinicopathological significance.