Serum autotaxin measurement in haematological malignancies: a promising marker for follicular lymphoma

Autotaxin (ATX) is a tumour cell motility-stimulating factor originally isolated from melanoma cell supernatants. ATX is identical to lysophospholipase D, which produces a bioactive lipid mediator, lysophosphatidic acid (LPA), from lysophosphatidylcholine. ATX is overexpressed in various malignancies, including Hodgkin lymphoma, and ATX may stimulate tumour progression via LPA production. The present study measured the serum ATX antigen levels in patients with haematological malignancies using a recently developed automated enzyme immunoassay. The serum ATX antigen levels in patients with B-cell neoplasms, especially follicular lymphoma (FL), were higher than those in healthy subjects. Serum ATX antigen levels in FL patients were associated with tumour burden and changed in parallel with the patients' clinical courses. The serum ATX antigen levels were little affected by inflammation, unlike the soluble interleukin-2 receptor and beta2-microglobulin levels. As expected, the plasma LPA levels in FL patients were correlated with the serum ATX antigen levels. Given that leukaemic tumour cells from FL patients expressed ATX, the shedding of ATX from lymphoma cells probably leads to the elevation of serum ATX antigen levels. Our results suggest that the serum ATX antigen level may be a promising and novel marker for FL.     

Aromatase-knockout mouse carrying an estrogen-inducible enhanced green fluorescent protein gene facilitates detection of estrogen actions in vivo

Aromatase is an enzyme that converts androgen to estrogen in the gonads and also at extragonadal sites, including the brain. In this study we developed a transgenic mouse that carries an enhanced green fluorescent protein (EGFP) gene inducible by estrogen through an estrogen response element to facilitate detection of estrogen actions in vivo. The expression of EGFP in aromatase-deficient (Ar(-/-)) female mice was significantly suppressed at the pituitary gland, ovary, uterus, and gonadal fat pad and was induced by dietary 17beta-estradiol to wild-type (Ar(+/+)) levels or higher. These results demonstrate that the expression of the EGFP gene is tissue selective and estrogen dependent in vivo. Employing this transgenic mouse, we examined whether estrogen synthesis in the extragonadal sites is necessary for reproduction in female mice. When ovaries of Ar(-/-) mice were replaced with Ar(+/+) ovaries, a significant induction of EGFP expression in the pituitary gland and uterus was observed. Histological examinations showed the presence of antral follicles in the replaced ovaries, indicating that the transplants are functional in Ar(-/-) mice. After crossing with males, three of 10 Ar(-/-)females with Ar(+/+) ovaries became pregnant and fed their pups. Collectively, these observations indicate that estrogen synthesis in the ovary is sufficient for supporting female reproduction, and that infertility of Ar(-/-) females is primarily due to a defect in estrogen synthesis in the ovary.     

Superficial elevated-type early gallbladder carcinoma treated by laparoscopic cholecystectomy

A 60-year-old woman was admitted to our department for detailed examination of a polypoid lesion of the gallbladder detected at the time of a mass survey by ultrasound. Endoscopic ultrasonography (EUS) demonstrated a broad-based mass lesion, about 10 mm in size, with an irregular surface, at the peritoneal side of the body of the gallbladder. The layer structure of the gallbladder wall had not been destroyed by the mass. Computed tomography showed no direct invasion of the liver or other evidence of metastasis. Type-IIa (superficial elevated-type) early gallbladder cancer was suspected and laparoscopic cholecystectomy was performed. Histologically, the tumor proved to be a papillo-tubular adenocarcinoma, 9×8 mm in size, confined to the mucosa and without lymphatic permeation, vascular involvement, perineural invasion, or other signs of metastasis. Laparoscopic cholecystectomy for gallbladder cancer can be indicated only when a lesion is a pedunculated protruded-type (type-Ip) cancer, or a broad-based cancer 10 mm or less in size located on the peritoneal side with no destruction of the layer structure of the wall demonstrated by EUS. This strategy is justified only with precise evaluation of the lesion by EUS.     

Effects of betazole hydrochloride and cyclic AMP on the pepsinogen secretion by rabbit gastric mucosa in organ culture

The effects of betazole hydrochloride, dibutyryl cyclic AMP (DB-cyclic AMP) and betazole hydrochloride plus aminophylline on pepsinogen secretion by rabbit gastric mucosa were studied in organ culture. Betazole hydrochloride alone did not stimulate pepsinogen secretion at the concentrations of 10(-8), 10(-6), 10(-5) and 10(-4) M. However, 10(-3) M DB-cyclic AMP produced a significant stimulation of pepsinogen secretion into the culture medium when compared with the control. In the presence of 3 x 10(-3) M aminophylline, betazole hydrochloride in the concentration of 10(-5) and 10(-4) M stimulated pepsinogen secretion into the culture medium, and the magnitude of this increase was 2.0- and 2.8-fold, respectively, compared with the control. Aminophylline alone could not change pepsinogen secretion into the culture medium. These results suggested that the pepsinogen secretion, stimulated by betazole hydrochloride, was mediated by cyclic AMP in the chief cells.     

Molecular cloning and characterization of a gonadotropin-releasing hormone receptor in the guinea pig, Cavia porcellus

Guinea pig gonadotropin-releasing hormone (gpGnRH) is predicted to have a unique structure among all known forms of GnRH molecule [Endocrinology 138 (1997) 4123] and it is of great interest to determine whether the unique structure of gpGnRH is manifested in the characteristics of the guinea pig GnRH receptor. In the present study, we isolated a full-length cDNA for a GnRH receptor from the pituitary gland of the guinea pig. The putative guinea pig GnRH receptor protein has an amino acid identity of 79-87% with mammalian type I GnRH receptors. The amino acid residues which have been demonstrated to be important for ligand binding and signal transduction were conserved in the guinea pig GnRH receptor. However, there are several specific amino acid substitutions among mammalian type I GnRH receptors. Moreover, though the guinea pig has generally been classified as a rodent, the putative GnRH receptor protein did not have some rodent-specific characteristics. Total IP assays demonstrated that the cloned guinea pig GnRH receptor is a functional GnRH receptor and that it shows different preference of ligand sensitivities from the rat GnRH receptor.     

Rectal submucosal tumor-like lesion originating from intestinal tuberculosis

We present the case of a 55-year-old man who underwent transsacral local excision for a rectal submucosal tumor-like lesion suspected to originate from tuberculosis. The lesion, 2 cm in size, was found incidentally in the posterior wall of the lower rectum during anal fistulectomy. The lesion was apart from the primary crypt of the anal fistula. Barium enema and colonoscopy revealed a protuberant submucosal growth with a shallow depression of the overlying mucosa. Although computed tomography and magnetic resonance imaging showed a well defined round mass within the rectal wall, digital rectal examination suggested extramural origin. Since repeated endoscopic biopsies were negative, we selected the transsacral approach for excisional biopsy to achieve histological diagnosis. The lesion was confined to the rectal wall and the full-thickness rectal wall was excised. Histologically, a foreign-body granuloma with acute inflammation was the main component of the lesion. Caseating granulomas and Langhans' giant cells, consistent with tuberculosis, were also found.