Changes in the expression and cytological localization of betacellulin and its receptors (ErbB-1 and ErbB-4) in the trophoblasts in human placenta over the course of pregnancy

OBJECTIVE: Betacellulin (BTC), purified and cloned from mouse beta cell tumor (BTC-JC10), is regarded as a new member of the epidermal growth factor family. The present study was conducted to clarify the expression of BTC and its receptors, ErbB-1 and ErbB-4, in the trophoblasts in the human placenta over the course of pregnancy. DESIGN AND METHODS: Human placental tissues were obtained from 4 pregnant women at the 4th to 5th week of pregnancy (very early placentas), 10 women at the 6th to 12th week (early placentas), 5 women at the 18th to 21st week (mid placentas) and 8 women at the 38th and 40th week (term placentas). The mRNA expressions of BTC, erbB-1 and erbB-4 were evaluated by quantitative RT-PCR with Southern blotting and the expression of the soluble form of BTC was determined by western immunoblot with a specific antibody to BTC protein. Immunohistochemical staining of BTC, ErbB-1 and ErbB-4 was also performed. RESULTS: The levels of BTC mRNA expression in early and mid placentas were significantly higher than those in term placentas. The soluble form of BTC protein with an estimated molecular mass of 9.5 kDa was expressed in early and mid placentas, whereas the soluble form was not detected in term placentas. BTC from very early placentas until mid placentas was immunolocalized in syncytiotrophoblasts (S-cells), and was most abundant in early placentas. In contrast, BTC was immunolocalized in extravillous trophoblasts (EVTs), but not in villous trophoblasts in term placentas. The levels of erbB-1 mRNA in the early and mid placentas were significantly higher than those in term placentas, whereas the levels of erbB-4 mRNA in early placentas were significantly lower than those in mid and term placentas. ErbB-1 was immunolocalized in cytotrophoblasts in very early placentas, whereas it was immunolocalized in S-cells from early until term placentas. ErbB-4 from very early placentas until mid placentas was immunolocalized in S-cells, whereas ErbB-4 in the term placentas was detected in EVTs, but not in villous trophoblasts. CONCLUSIONS: These findings provide evidence for changes in expression and cytological localization of BTC and its receptors in the trophoblasts in human placenta over the course of pregnancy. BTC may play a pivotal role as a local growth factor in promoting the differentiated villous trophoblastic function via ErbB-1 in early placentas and in contributing to placental growth through the maintenance of EVT cell function via ErbB-4 in term placentas.     

Lack of chemopreventive effects of lycopene and curcumin on experimental rat prostate carcinogenesis

The chemopreventive efficacy of lycopene and curcumin with regard to prostate carcinogenesis was investigated using 3,2'-dimethyl-4-aminobiphenol (DMAB)- and 2-amino-1-methylimidazo[4,5-b]pyridine (PhIP)-induced rat ventral prostate cancer models. Three 60 week experiments with male F344 rats were carried out. In the first DMAB was given for the first 20 weeks and lycopene or curcumin were administered concomitantly or subsequently at dietary doses of 15 and 500 p.p.m., respectively. In the second experiment lycopene and curcumin were given to rats pretreated with DMAB at doses of 5, 15 or 45 p.p.m. or 100 or 500 p.p.m. In the third PhIP was selected as an initiator for prostate carcinogenesis and administered for 20 weeks. Rats were then fed a diet containing lycopene at a dose of 45 p.p.m. or curcumin at a dose of 500 p.p.m. or both together. Chemopreventive effects of lycopene and curcumin on development of DMAB-induced ventral prostate carcinomas were observed only in the first experiment and no confirmation of inhibition potential was obtained in the following studies. Neither summational nor synergistic chemoprevention was evident. It is concluded from the present data that, overall, neither lycopene nor curcumin can consistently prevent rat prostate carcinogenesis.     

Local mechanical properties of mouse outer hair cells: atomic force microscopic study

OBJECTIVES: Outer hair cells (OHCs) are capable of altering their cell length in response to changes in membrane potential. Due to this electromotility, OHCs probably subject the basilar membrane to force, resulting in cochlear amplification. To understand the mechanism of such amplification, knowledge of the mechanical properties of OHCs is required since the force produced by OHC electromotility is thought to depend on such properties. Various studies have been conducted to investigate the mechanical properties of guinea pig OHCs. With regard to mice, however, although various kinds of transgenic and knockout mice possess great potential as research models, the mechanical properties of mouse OHCs have not as yet been reported since the cells and/or tissues in the mouse hearing organ are relatively small and vulnerable to external stimuli, rendering sample preparation difficult. In this study, therefore, to establish indicators of the mechanical properties of OHCs in mice, such properties were measured by atomic force microscopy (AFM). METHODS: CBA/JNCrj strain male mice aged 10-12 weeks (25-30 g) were used. Cochleae were dissected out from the animal and both the basilar membrane and the organ of Corti were simultaneously unwrapped from the modiolus with forceps. Dissected coiled tissue was then incubated with an enzymatic digestion medium for 15 min. After digestion, OHCs were isolated by gently triturating the coiled tissue. Local mechanical properties of the OHCs were then measured by an indentation test using an AFM. RESULTS: Young's modulus and stiffness of the OHC in the apical turn of the mouse cochlea were 2.1+/-0.5 kPa and 4.4+/-1.2 mN/m, respectively. CONCLUSIONS: Young's modulus of the OHC in the apical turn of the cochlea in mice was roughly the same as that in the apical turn of the cochlea in guinea pigs; however, the stiffness of the former was about two times greater than that of the latter because the cell length of the former was shorter than that of the latter.     

Collagenous sprue diagnosed by double balloon endoscopy

Double balloon endoscopy (DBE) is useful for diagnosing many intestinal diseases and for endoscopic procedures. We report a case of chronic diarrhea in a 58‐year‐old Japanese man. He was initially suspected to have malabsorption syndrome. DBE showed reduction of folds, scalloping, mucosal nodularity and granularity. Pathological examinations of biopsies from the jejunum showed severe villous atrophy with subepithelial collagen bands. These findings led to the final diagnosis of collagenous sprue (CS). With1 month of total parenteral nutrition followed by a low‐gluten diet, his symptoms gradually improved. CS has never been reported before in Japan. DBE is useful for making a diagnosis of CS, and may be considered for patients who are suffering from diarrhea of unknown cause.     

A case of focal segmental glomerulosclerosis with myeloid bodies

The presence of myeloid bodies in electron microscopy is a characteristic finding of Fabry's disease. Here, we present a male patient, whose renal biopsy findings suggested the coexistence of focal segmental glomerulosclerosis and Fabry's disease, because of the presence of segmental hyalinosis and/or sclerosis in glomeruli and myeloid bodies in electron microscopy. But finally, Fabry's disease was excluded as a diagnosis because the α-galactosidase A activity in leukocyte and plasma in this patient was within normal limits. After renal biopsy, although he received medication including steroid therapy, his renal function gradually decreased to end-stage renal failure and hemodialysis was initiated. Until now, he does not exhibit any specific symptoms. In conclusion, our case suggests that occasional myeloid bodies in renal biopsy specimens should be interpreted with caution.     

Occult Risk of Broken Instruments for Endoscopy-assisted Surgery

Background

The influence of broken sophisticated surgical instruments on the safety of surgery has yet to be determined, in spite of an assumption that breakage of surgical instruments is not associated with critical incidents. The purpose of the present study was to delineate the risk from breakage of surgical instruments used in surgery assisted by endoscopy.

Methods

A retrospective analysis was conducted to determine the frequency of breakage of instruments used in 39,817 operations from 2007 to 2011. Data of breakage were collected using incident/near-incident reports and the request forms for repair of broken instruments.

Results

During the study period, 441 instruments were reported to be broken intraoperatively, and 7,541 were found to be broken on inspection. The incidence of breakage adjusted by the number of operations and the number of uses suggested that instruments for endoscopy-assisted surgery are broken more frequently intraoperatively than are any other type of instruments (visceral surgery: 0.039 versus 0.017, P = 0.0002, RR = 2.318; obstetrics/gynecology: 0.023 versus 0.0067, P < 0.0001, RR = 3.461; thoracic surgery: 0.019 versus 0.004, P = 0.0772, RR = 5.212). Inappropriate use and wearing out were two major possible causes of breakage of instruments. The predominant adverse events were suggested to be attributable to parts falling off broken instruments because of inappropriate use.

Conclusions

Our results demonstrated that surgery assisted by endoscopy has its own occult risk, which has not been previously highlighted. Minimally invasive surgery is not necessarily safe with respect to breakage of surgical instruments. Our data provide substantial evidence for higher risk of instrument breakage in endoscopy-assisted surgery, as well as its possible detrimental effect on patient safety.