The expression of nectin-1alpha in normal human skin and various skin tumours

BACKGROUND

A novel cell-cell adhesion system that consists of nectin and afadin has been identified at cadherin-based cell-cell adherens junctions. Nectin is a Ca2+-independent homophilic and heterophilic cell adhesion molecule that belongs to the immunoglobulin superfamily. Nectin has recently been shown to serve as an alpha-herpesvirus entry and cell-cell spread mediator. In spite of the ubiquitous expression of nectin-1alpha, its detailed localization in human skin has not been examined so far.

OBJECTIVES

To investigate the localization of nectin-1alpha in normal human skin and the alteration of its expression in malignant skin tumours.

METHODS

Immunohistochemistry was employed to determine the expression of nectin-1alpha and other adhesion molecules.

RESULTS

We detected nectin-1alpha in normal human epidermis, follicles and eccrine ducts. Nectin-1alpha was colocalized with E-cadherin at cell-cell adherens junctions of the epidermis. The concentration of the nectin-afadin system at cell-cell adherens junctions was reduced in the early stage of malignant transformation of keratinocytes, such as in basal cell carcinomas and squamous cell carcinomas, where the cadherin-catenin system was preserved. Nectin-1alpha at cell-cell adherens junctions was reduced in human epithelial cancer cells located at the advancing border of the tumour.

CONCLUSIONS

Our results showed that nectin-1alpha is located at cell-cell adherens junctions in human skin and that reduction of nectin-1alpha at cell-cell adherens junctions may be involved in the invasion of squamous cell tumours.

Congenital sinus of the upper lip with idiopathic precocious puberty

An extremely rare case of congenital sinus of the upper lip is presented in a 22-year-old woman with idiopathic precocious puberty. The sinus has a pin-like orifice located in the midline of the upper lip philtum just below the base of the columella. Sexual precocity was found out when she was 7 years old. A series of exact examinations had been performed at that time. Neither neurogenic lesions of the central nervous system nor other systemic abnormalities were observed. Oral Diseases

Nano-area electron diffraction pattern reconstructed from three-dimensional Fourier spectrum

A method to obtain a nano-area electron diffraction pattern in transmission electron microscopy (TEM) was proposed, based on three-dimensional (3D)) image formation theory. This method allows us to reconstruct an electron diffraction pattern from a 3D Fourier spectrum of high-resolution through-focus images. As a test case, an electron diffraction pattern from a tilted Si single crystal was reconstructed using the proposed method and compared with the conventional selected-area electron diffraction pattern. The intensity distribution of the reconstructed electron diffraction pattern was confirmed to be qualitatively equal to that of the selected-area electron diffraction pattern, though the degree of the equivalency between these patterns reduces at the high frequency region and the reproducibility of the intensity degrades when the number of images used in the image processing was decreased. By selecting areas in a reconstructed exit wave field, some electron diffraction patterns were obtained from the nano-areas without the influence of spherical aberration.

Pilt, a novel peripheral membrane protein at tight junctions in epithelial cells

Tight junctions (TJs) serve as a barrier that prevents solutes and water from passing through the paracellular pathway, and as a fence between the apical and basolateral plasma membranes in epithelial cells. TJs consist of transmembrane proteins (claudin, occludin, and JAM) and many peripheral membrane proteins, including actin filament (F-actin)-binding scaffold proteins (ZO-1, -2, and -3), non-F-actin-binding scaffold proteins (MAGI-1), and cell polarity molecules (ASIP/PAR-3 and PAR-6). We identified here a novel peripheral membrane protein at TJs from a human cDNA library and named it Pilt (for protein incorporated later into TJs), because it was incorporated into TJs later after the claudin-based junctional strands were formed. Pilt consists of 547 amino acids with a calculated M(r) of 60,704. Pilt has a proline-rich domain. In cadherin-deficient L cells stably expressing claudin or JAM, Pilt was not recruited to claudin-based or JAM-based cell-cell contact sites, suggesting that Pilt does not directly interact with claudin or JAM. The present results indicate that Pilt is a novel component of TJs.

Complementing yeast rho1 mutation groups with distinct functional defects

Saccharomyces cerevisiae is a multifunctional molecular switch involved in establishment of cell morphogenesis. We systematically characterized isolated temperature-sensitive mutations in the RHO1 gene and identified two groups of rho1 mutations (rho1A and rho1B) possessing distinct functional defects. Biochemical and cytological analyses demonstrated that mutant cells of the rho1A and rho1B groups have defects in activation of the Rho1p effectors Pkc1p kinase and 1,3-beta-glucan synthase, respectively. Heteroallelic diploid strains with rho1A and rho1B mutations were able to grow even at the restrictive temperature of the corresponding homoallelic diploid strains, showing intragenic complementation. The ability to activate both of the essential Rho1p effector proteins was restored in the heteroallelic diploid. Thus, each of the complementing rho1 mutation groups abolishes a distinct function of Rho1p, activation of Pkc1p kinase or 1,3-beta-glucan synthase activity.

The participation of pharmacists in a team to introduce a clinical pathway to laparoscopic cystectomy in obstetrics and gynecology

In the Department of Obstetrics and Gynecology at our hospital, a team of doctors, pharmacists, nurses, and other medical staff was established to prepare a clinical pathway for laparoscopic cystectomy. Various data on clinical charts including the use of drugs were collected from 57 patients by pharmacists and nurses. Based on the analysis of these data, hospitalization period, method of preoperative bowel preparation, time to initiation of food intake, duration of antibiotic administration, and time and content of pharmaceutical instructions to patients of dosage and administration were determined. Criteria for variances requiring the doctor's directions were determined for fever, wound pain, and vomiting. The clinical pathway established here allows of not only the efficient and uniform care of patients, but also the active exchange of opinions among members of the medical team. Moreover, most patients who replied to a questionnaire said that they were at ease during hospitalization because they had received detailed information about the clinical pathway including the use of drugs before surgery. Thus, the participation of pharmacists on a medical team that is introducing a clinical pathway is particularly important because the use of drugs and pharmaceutical care are an important part of good patient care.

Wave field restoration using three-dimensional Fourier filtering method

A wave field restoration method in transmission electron microscopy (TEM) was mathematically derived based on a three-dimensional (3D) image formation theory. Wave field restoration using this method together with spherical aberration correction was experimentally confirmed in through-focus images of amorphous tungsten thin film, and the resolution of the reconstructed phase image was successfully improved from the Scherzer resolution limit to the information limit. In an application of this method to a crystalline sample, the surface structure of Au(110) was observed in a profile-imaging mode. The processed phase image showed quantitatively the atomic relaxation of the topmost layer.

Demonstration of angiogenin in human endometrium and its enhanced expression in endometrial tissues in the secretory phase and the decidua

Angiogenesis is thought to be crucial for normal physiology of the endometrium, where dynamic vascular remodeling occurs during the menstrual cycle and pregnancy. We investigated the presence of angiogenin, a potent inducer of angiogenesis, and the regulatory mechanisms of its production in the human endometrium. Western blot analysis demonstrated that angiogenin protein expression increased by 3- to 4-fold in the endometrium in the mid and late secretory phases and in early gestation relative to that during the proliferative phase. Quantitative mRNA analysis showed the similar tendency in the expression of angiogenin mRNA in the endometrium, with the highest levels observed in the mid and late secretory phases and early gestation. An immunohistochemical study showed that angiogenin was expressed in both stromal cells and epithelial cells, with indistinguishable intensity between these cells regardless of phases of the menstrual cycle. In support of the Western blot analysis, the intensity of staining appeared to be highest in the mid to late secretory phases relative to other phases. Consistent with these in vivo results, decidualized cultured stromal cells, after treatment with progesterone or progesterone plus E2, exhibited the capacity to secrete significantly increased amounts of angiogenin compared with untreated or E2 alone-treated control group. Both the treatment with (Bu)2cAMP and hypoxic conditions stimulated angiogenin secretion by stromal cells. For isolated epithelial cells, hypoxia stimulated angiogenin secretion, whereas (Bu)2cAMP had no appreciable effect. In summary, we demonstrated the presence of angiogenin in human endometrium and its possible local regulatory factors, such as progesterone, cAMP, and hypoxia. These findings along with its enhanced expression in the endometrium in the secretory phase and in decidual tissues raise the possibility that angiogenin may play a role in establishing pregnancy.

Radiation therapy for loco-regionally recurrent esophageal cancer after surgery

PURPOSE

To evaluate the treatment outcome of radiation therapy for 33 loco-regionally recurrent esophageal cancer patients.

METHODS

Between 1988 and 1997, 33 patients with loco-regional recurrence of esophageal cancer after curative surgery received radiation therapy at an average total dose of 61 Gy. The site of recurrence was the supraclavicular region in 14 patients, the mediastinal region in 13 patients, and both the supraclavicular and mediastinal regions in six patients. If patients had ether distant metastasis or malignant pleural effusion, they were excluded from analysis. Patients who received prophylactic postoperative irradiation were also excluded from analysis.

RESULTS

The median survival period was 7 months. The survival rates at 1, 2, and 3 years were 33, 15, and 12%, respectively. In univariate analysis, patients with a short time interval between surgery and recurrence (P=0.0098) and patients with recurrence in both the supraclavicular and mediastinal regions (P=0.036) had a worse prognosis. In multivariate analysis, the time interval between surgery and recurrence (P<0.001) and age (worse prognosis in younger patients, P=0.019) were the significant prognostic factors. Complete or partial responses were observed in nine (27%) and 21 (64%) of the patients, respectively. Changes in clinical symptoms, such as dysphagia, chest pain and back pain, could be evaluated in 11 patients, and improvement in symptoms was obtained in eight (73%) patients.

CONCLUSIONS

The prognosis of patients who received radiation therapy for postoperative loco-regional recurrence of esophageal cancer is poor. However, there is symptomatic relief in a significant proportion of such patients, and long-term survival is possible in some patients.

Combinatorial evaluation of the chiral discrimination of permethylated carbohydrates using fast-atom bombardment mass spectrometry

The chiral discrimination abilities of several variously permethylated carbohydrates toward various amino acid 2-propyl esters were combinatorially evaluated from the relative peak intensity of the 1:1 diastereomeric complex ions with the deuterium-labeled L-amino acid 2-propyl ester protonated ion and with the unlabeled D-amino acid 2-propyl ester protonated ions in FAB mass spectrometry. The chiral discrimination abilities evaluated using FAB mass spectrometry approximately corresponded to the ratio of the association constants (K(R)/K(S)) toward each enantiomer in the solution. Therefore, this evaluation method is very useful for the screening of the chiral discrimination abilities of carbohydrates and their derivatives.

Regulation of Ras and Rho small G proteins by SHP-2

BACKGROUND

Hepatocyte growth factor/scatter factor (HGF/SF) induces cell scattering through the tyrosine kinase-type HGF/SF receptor, c-Met. We have previously shown that SHP-2, a protein tyrosine phosphatase, positively regulates the HGF/SF-induced cell scattering through modulating the activity of Rho to form stress fibres and focal adhesions. To further investigate the role of SHP-2 in HGF/SF-induced cell scattering, we have now examined the effect of a dominant active mutant of SHP-2 (SHP-2-DA).

RESULTS

Expression of SHP-2-DA markedly increased the formation of lamellipodia with ruffles, while it decreased the accumulation of E-cadherin and beta-catenin at cell-cell adhesion sites in MDCK cells. In addition, expression of SHP-2-DA markedly enhanced cell scattering of MDCK cells in response to HGF/SF. Expression of SHP-2-DA induced the activation of MAP kinase without HGF/SF stimulation, whereas an inhibitor of MEK partly reversed the SHP-2-DA-induced morphological phenotypes. Furthermore, expression of either a dominant-active mutant of Rho or Vav2 also reversed the SHP-2-DA-induced morphological phenotypes.

CONCLUSION

These results indicate that SHP-2 plays a crucial role in the HGF/SF-induced cell scattering through the regulation of two distinct small G proteins, Ras and Rho.

Role of Rab3 GDP/GTP exchange protein in synaptic vesicle trafficking at the mouse neuromuscular junction

The Rab3 small G protein family consists of four members, Rab3A, -3B, -3C, and -3D. Of these members, Rab3A regulates Ca(2+)-dependent neurotransmitter release. These small G proteins are activated by Rab3 GDP/GTP exchange protein (Rab3 GEP). To determine the function of Rab3 GEP during neurotransmitter release, we have knocked out Rab3 GEP in mice. Rab3 GEP-/- mice developed normally but died immediately after birth. Embryos at E18.5 showed no evoked action potentials of the diaphragm and gastrocnemius muscles in response to electrical stimulation of the phrenic and sciatic nerves, respectively. In contrast, axonal conduction of the spinal cord and the phrenic nerve was not impaired. Total numbers of synaptic vesicles, especially those docked at the presynaptic plasma membrane, were reduced at the neuromuscular junction approximately 10-fold compared with controls, whereas postsynaptic structures and functions appeared normal. Thus, Rab3 GEP is essential for neurotransmitter release and probably for formation and trafficking of the synaptic vesicles.

Identification of splicing variants of Frabin with partly different functions and tissue distribution

Frabin is a GDP/GTP exchange protein for Cdc42 small G protein with actin filament-binding activity. Frabin consists of the actin filament-binding domain, the Dbl homology domain, the first pleckstrin homology domain, the FYVE-finger domain, and the second pleckstrin homology domain in this order from the N-terminus. Frabin forms filopodia through direct activation of Cdc42 and lamellipodia through indirect activation of Rac small G protein. We isolated here two smaller splicing variants of frabin and named the original one, middle-size one, and smallest one frabin-alpha, -beta, and -gamma, respectively. Frabin-beta lacked the second pleckstrin homology domain and frabin-gamma lacked the FYVE-finger domain and the second pleckstrin homology domain. These three variants were expressed in all of the tissues examined but their expression levels are different depending on tissues. In L fibroblasts, all the three variants formed filopodia. As to lamellipodia, frabin-alpha formed them; frabin-beta formed them to a small extent; and frabin-gamma did not. In MDCK epithelial cells, frabin-alpha formed microspikes but frabin-beta or -gamma did not.

Dynamic observation of an atom-sized gold wire by phase electron microscopy

A single-atom-sized gold wire was successfully observed in real time by a newly developed defocus-image modulation processing electron microscope. Because of phase retrieval processing with spherical aberration correction, the single-atom strand wire was observed with high contrast and without contrast blurring. By carefully looking at the atomic distance, the contrast, and the dynamic behavior of the wire, we recognized that there are two stages of the wire. In the first stage the wire maintained the atomic distance in the bulk crystal, but in the second stage the wire showed the atomic distance of the nearest-neighbor atoms with weaker contrast. The gold wire was rather stable for a few seconds under strong electron beam illumination.

Metabolic characterization of sciadonic acid (5c,11c,14c-eicosatrienoic acid) as an effective substitute for arachidonate of phosphatidylinositol

Sciadonic acid (20:3 Delta-5,11,14) is an n-6 series trienoic acid that lacks the Delta8 double bond of arachidonic acid. This fatty acid is not converted to arachidonic acid in higher animals. In this study, we characterized the metabolic behavior of sciadonic acid in the process of acylation to phospholipid of HepG2 cells. One of the characteristics of fatty acid compositions of phospholipids in sciadonic acid-supplemented cells is a higher proportion of sciadonic acid in phosphatidylinositol (PtdIns) (27.4%) than in phosphatidylethanolamine (PtdEtn) (23.2%), phosphatidylcholine (PtdCho) (17.3%) and phosphatidylserine (PtdSer) (20.1%). Similarly, the proportion of arachidonic acid was higher in PtdIns (35.8%) than in PtdEtn (29.1%), PtdSer (18.2%) and PtdCho (20.2%) in arachidonic-acid-supplemented cells. The extensive accumulation of sciadonic acid in PtdIns resulted in the enrichment of newly formed 1-stearoyl-2-sciadonoyl molecular species (38%) in PtdIns and caused the reduction in the level of pre-existing arachidonic-acid-containing molecular species. The kinetics of incorporation of sciadonic acid to PtdEtn, PtdSer and PtdIns of cells were similar to those of arachidonic acid. In contrast to sciadonic acid, neither eicosapentaenoic acid (20:5 Delta-5,8,11,14,17) nor juniperonic acid (20:4 Delta-5,11,14,17) accumulated in the PtdIns fraction. Rather, these n-3 series polyunsaturated fatty acids, once incorporated into PtdIns, tended to be excluded from PtdIns. In addition, the level of arachidonic-acid-containing PtdIns molecular species remained unchanged by eicosapentaenoic-acid-supplementation. These results suggest that sciadonic acid or sciadonic-acid-containing glycerides are metabolized in a similar manner to arachidonic acid or arachidonic-acid-containing glyceride in the biosynthesis of PtdIns and that sciadonic acid can effectively modify the molecular species composition of PtdIns in HepG2 cells. In this regard, sciadonic acid will be an interesting experimental tool to clarify the significance of arachidonic acid-residue of PtdIns-origin bioactive lipids.

[Establishment of an optimum bowel preparation method before gynecologic laparoscopic surgery]

OBJECTIVE

To establish a new method for preoperative bowel preparation that facilitates nursing care and minimizes the patient's discomfort during the clinical pathway of laparoscopic surgery.

METHOD

A randomized controlled trial was conducted for the following two preparation methods. Twenty cases were assessed with Method 1 and 18 cases with Method 2. Method 1 (the conventional procedure): oral magnesium citrate is given in the afternoon of the day before surgery, followed by a glycerin enema in the night of the day before surgery and in the morning of the day of surgery. Method 2 (a new procedure): oral magnesium citrate is given in the afternoon of the day before surgery, followed by oral picosulfate in the night before the day of surgery and a bisacodyl suppository in the morning of the day of surgery. To evaluate the two methods we sent questionnaires to the surgeons (blinded to the method used), nurses, and patients.

RESULTS

No statistical difference existed between the two methods in their effectiveness as a preoperative treatment. Facilitation of nursing care was significantly better in Method 2, and patients had considerably reduced discomfort with Method 2.

DISCUSSION

Patients who received oral picosulfate and a bisacodyl suppository experienced much less discomfort and nursing care was easier when compared with the conventional method of administering a glycerin enema. Since an enema is disliked by young women and an effect comes out with discomfort very shortly after the administration, the degree of discomfort of patients would have become high. Picosulfate is an oral medicine and thereby the effect comes out mildly. That would be the reason why the degree of discomfort of patients was low. In the nursing care, an enema requires time for preparation and administration, while picosulfate is easy to administer, making the nursing care easier. Therefore, Method 2 was chosen as a preoperative bowel treatment for the clinical pathway. Thus, we could establish a new evidence-based method useful for the preoperative bowel preparation in the clinical pathway of laparoscopic surgery.

Real-time observation of spherical aberration-free phase image using high-speed image processing CCD video camera

Spherical aberration-free phase images have been observed at a time resolution of 1/30 s for the first time by using a defocus-image modulation processing electron microscope (DIMP-EM) combined with a newly developed high-speed image processing CCD video camera. In a profile image of the Au (011) crystal surface, no extra interference fringes were observed outside the crystal region, which clearly demonstrates successful correction of spherical aberration in real-time. The novel real-time DIMP-EM enabled the dynamic observation of surface and interface phenomena at an atomic level.

[Simple method of stereotactic radiotherapy without stereotactic body frame for extracranial tumors]

Thirty-five patients with metastatic lung cancer(46 lesions) and twenty patients with primary lung cancer (21 lesions) have been treated with a simple method of stereotactic radiotherapy (SRT) without stereotactic body frame. Tumor size ranged from 1-4 cm in diameter. We used Vac-Lok cushion(Med-Tek) as a immobilization system. To be sure to include the respiratory movement of tumor to planning target volume(PTV), every patients were examined by fluoroscopy and radio-opaque catheters with the same length of tumor movement were attached on the anterior and lateral chest wall before CT simulation. A gold grain was implanted into a tumor that was invisible on fluoroscopy, as a radiomaker. Protocol of 60 Gy/8 fractions/2 weeks and 45 Gy/3 fractions/3-6 days were mainly used. The median follow-up period was 15 months for primary lung cancer and 19 months for metastatic lung cancer. Local control rates were 91% for metastatic lung cancer, 89% for primary lung cancer and 85% for T1, 2N0M0 cases. All patients developed mild pneumonitis or fibrosis about 4.5 months after SRT just in the treatment volume. Only three patients was symptomatic.