Ultrafast interaction of the angular momentum of photons with spins in the metallic amorphous alloy GdFeCo

Ultrashort laser pulses have been used to study the effect of circularly polarized light on spins in the ferrimagnetic metal GdFeCo. By turning the sample into a multidomain state and thereby suppressing the observation of the heating effect of light, we have been able to demonstrate an ultrafast nonthermal excitation of spin waves with a phase that depends on the angular momentum of the photons. These results demonstrate the possibility of ultrafast coherent control of the magnetization in this metallic system.

Confocal endomicroscopy for the diagnosis of gastric cancer in vivo

BACKGROUND AND STUDY AIMS

Advances in endoscopy have led to imaging of the details of the gastric mucosa, but the histological diagnosis usually has to be confirmed by endoscopic biopsy. A method of confocal endomicroscopy that has recently been developed allows the observation of living cells in vivo. Several investigators have reported that the technique is of value, but there have as yet been no studies describing its application in gastric cancer.

PATIENTS AND METHODS

Twenty-seven patients with early gastric cancer underwent confocal endomicroscopy (Pentax EG-3870CIK; Pentax, Tokyo, Japan). After intravenous administration of fluorescein sodium, confocal images obtained from the normal mucosa and from cancerous lesions were interpreted by two pathologists independently and compared with the histological findings, including CD34 immunostaining of biopsy specimens or resected specimens from the same sites.

RESULTS

Fluorescein yielded high-quality confocal images of the gastric mucosa; if cancer could be targeted (59%) images were mostly graded good. The images corresponded to the hematoxylin-eosin staining of transverse sections of specimens from the same sites. In the results for the interpretation by the two pathologists, the accuracy for the diagnosis of gastric cancer was 94.2% (pathologist A), and 96.2% (pathologist B), respectively. The accuracy decreased substantially when poor images and inaccessible lesions were included.

CONCLUSIONS

Confocal endomicroscopy is useful in the diagnosis of gastric cancer but good quality images cannot always be obtained. In the future, it may allow virtual biopsy and help reduce unnecessary biopsies.

Preliminary comparison of capsule endoscopy and double-balloon enteroscopy in patients with suspected small-bowel bleeding

BACKGROUND AND STUDY AIMS

Capsule endoscopy (CE) and double-balloon enteroscopy (DBE) have been introduced as modalities for examining the entire small bowel. The aim of the present study was to assess the clinical effects of CE and DBE to consider the roles of CE and DBE and the indications for the procedures in patients with suspected small-bowel bleeding.

PATIENTS AND METHODS

Between June 2004 and January 2005, 32 patients in whom a site of bleeding in the gastrointestinal tract had not been identified were enrolled in the study. Twenty-eight patients were examined with both methods. Bleeding sources were categorized as either A1 lesions (immediate hemostatic procedures required) or A2 lesions (close observation required). CE and DBE were evaluated with regard to whether or not they were capable of accessing the entire small bowel and provided a diagnosis, and the access and diagnostic rates were calculated.

RESULTS

On CE, 13 patients were diagnosed with A1 lesions and six with A2 lesions; on DBE, 11 had A1 lesions and one had an A2 lesion. The access rate for the entire small intestine on CE was 90.6 % (29 of 32), significantly higher than with DBE at 62.5 % (10 of 16; P < 0.05). The diagnostic rate on CE was 59.4 % (19 of 32), higher than with DBE at 42.9 % (12 of 28; P = 0.30), but not significantly different. Among patients with A1 lesions who were diagnosed with DBE, histological diagnoses were obtained in six of the 11, and three patients were treated.

CONCLUSIONS

In many suspected small-bowel bleeding cases, CE should be selected for the initial diagnosis and DBE for treatment or histopathological diagnosis after detection of the bleeding site on CE.

Quantitative analysis of the microvascular architecture observed on magnification endoscopy in cancerous and benign gastric lesions

BACKGROUND AND STUDY AIMS

Gastric cancer remains a common malignant tumor in Japan. The aim of this study was to attempt a quantitative evaluation of the microvascular architecture observed by magnification endoscopy using image analysis, and to investigate whether this method is able to distinguish between gastric cancers and benign lesions.

PATIENTS AND METHODS

A total of 132 patients were studied using magnification endoscopy, and image analysis was performed in 71 patients (32 patients with early gastric cancer, 39 patients with benign lesions). Analysis was not possible in the other 61 patients because the quality of the image was not good enough. A square region of interest was selected from the magnified images of the gastric mucosa. From this we extracted the vascular images corresponding to microvessels and calculated the mean caliber of vessels in the region of interest.

RESULTS

Image analysis provided good-quality images of microvessels and enabled evaluation of the microvascular architecture. The mean caliber of vessels was 4.454 pixels in 17 differentiated adenocarcinomas, 4.319 pixels in 15 undifferentiated adenocarcinomas, and 4.034 pixels in the 39 benign lesions. This represented a significant difference between gastric cancers and benign lesions (P<0.0001). Histopathological investigation of surgically resected tumors demonstrated the mean caliber of microvessels in cancerous lesions to be greater than that of microvessels in the surrounding mucosa.

CONCLUSIONS

Image analysis was useful for evaluating the microvascular architecture of the gastric mucosa, and calculation of the mean caliber of the vessels may prove helpful in the differential diagnosis of gastric cancers. However, analysis was not possible in 61 of the 132 patients studied because of inadequate image quality, and this represents a significant limitation of this diagnostic method.

Intravenous myocardial contrast echocardiography predicts regional and global left ventricular remodelling after acute myocardial infarction: comparison with low dose dobutamine stress echocardiography

OBJECTIVE

To assess the role of intravenous myocardial contrast echocardiography (MCE) in predicting functional recovery and regional or global left ventricular (LV) remodelling after acute myocardial infarction (AMI) compared with low dose dobutamine stress echocardiography (LDSE).

METHODS

21 patients with anterior AMI and successful primary angioplasty underwent MCE and LDSE during the subacute stage (2-4 weeks after AMI). Myocardial perfusion and contractile reserve were assessed in each segment (12 segment model) with MCE and LDSE. The 118 dyssynergic segments in the subacute stage were classified as recovered, unchanged, or remodelled according to wall motion at six months' follow up. Percentage increase in LV end diastolic volume (%DeltaEDV) was also calculated.

RESULTS

The presence of perfusion was less accurate than the presence of contractile reserve in predicting regional recovery (55% v 81%, p < 0.0001). However, the absence of perfusion was more accurate than the absence of contractile reserve in predicting regional remodelling (83% v 48%, p < 0.0001). The number of segments without perfusion was an independent predictor of %DeltaEDV, whereas the number of segments without contractile reserve was not. The area under the receiver operating characteristic curve showed that the number of segments without perfusion predicted substantial LV dilatation (%DeltaEDV > 20%) more accurately than did the number of segments without contractile reserve (0.88 v 0.72).

CONCLUSION

In successfully revascularised patients with AMI, myocardial perfusion assessed by MCE is predictive of regional and global LV remodelling rather than of functional recovery, whereas contractile reserve assessed by LDSE is predictive of functional recovery rather than of LV remodelling.

The use of endoscopic ultrasound-guided fine-needle aspiration for investigation of submucosal and extrinsic masses of the colon and rectum

BACKGROUND AND STUDY AIM

Ensdoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been reported as a useful technique for histological diagnosis of submucosal or extrinsic gastrointestinal and pancreatic lesions. The aim of this study was to evaluate the use of EUS-FNA for the diagnosis of lesions either within or adjacent to the wall of the colon and rectum.

PATIENTS AND METHODS

A total of 22 patients with a lesion within the wall of, or adjacent to, the colon or rectum underwent EUS-FNA. They were divided into two groups: patients who had previously had a malignancy (the "previous +ve" group, n = 11), and patients who had not previously had a malignancy (the "previous -ve" group, n = 11). In the four patients who had lesions located proximal to the sigmoid colon, EUS-FNA was performed using a guide wire and overtube. The success rates for adequate tissue sampling and for detecting malignant and benign masses by EUS-FNA were evaluated and the success rate for detection was compared with the success rate of EUS and computed tomography.

RESULTS

Sufficient tissue for evaluation was obtained from 21 of the 22 patients (95.5 %). The overall rate of detection of malignant and benign masses was 95.5 % (21/22) for EUS-FNA and 81.8 % (18/22) for pre-EUS-FNA imaging investigations. Of the 11 patients in the previous +ve group, ten were diagnosed with recurrences of primary malignancies; of the 11 patients in the previous -ve group, four were diagnosed with primary malignancies and seven were diagnosed with benign lesions. There were no complications related to the EUS-FNA procedure.

CONCLUSIONS

EUS-FNA is a safe technique which is useful in the planning of treatment for patients who have a mass within the wall or adjacent to the wall of the entire length of the colon or rectum.

Spontaneous extraskeletal osteosarcomas of the subcutis in Djungarian hamsters (Phodopus sungorus): report of two cases

Spontaneous subcutaneous extraskeletal osteosarcoma was diagnosed in the subcutaneous tissue of two Djungarian hamsters. Histologically, the tumour was characterized by multiple nests of osseous and cartilaginous components within a proliferation of pleomorphic cells. No abnormality was observed in any skeletal bones and no change suggesting tumorous growth was observed in any other sites. This is the first report of extraskeletal osteosarcomas in Djungarian hamsters.

Effects of IL-1beta, TNF-alpha, and macrophage migration inhibitory factor on prostacyclin synthesis in rat pulmonary artery smooth muscle cells

OBJECTIVE

Cytokines have been implicated in the pathophysiology of pulmonary hypertension. We sought to explore the possibility that prostacyclin is a link.

METHODOLOGY

We tested the effects of the cytokines interleukin-1beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha), and macrophage migration inhibitory factor (MIF) on arachidonic acid metabolism of pulmonary artery smooth muscle cells (PASMCs) with special regard to prostacyclin (PGI2) that protects against pulmonary hypertension. Cultured rat PASMCs were treated with IL-1beta, TNF-alpha, or MIF. Expression of prostacyclin synthase (PGIS) and cyclooxygenase-2 (COX-2) mRNAs, and PGI2 synthesis, were measured.

RESULTS

We found that PGIS mRNA expression was suppressed by high concentrations of TNF-alpha and MIF, while COX-2 mRNA was induced by all three cytokines tested. IL-1beta increased PGI2 production in a dose-dependent manner. TNF-alpha and MIF also increased PGI2 production, but to a far lesser degree at high concentrations. TNF-alpha paradoxically decreased PGI2 production at a low concentration.

CONCLUSIONS

These results suggest that TNF-alpha and MIF are potentially antagonistic to the action of PGI2 in rat PASMCs via down-regulation of PGIS mRNA. Simultaneous induction of COX-2 mRNA may further counteract the action of PGI2 by increasing the levels of eicosanoids other than PGI2.

Pilot study of pancreatoscopic lithotripsy using a 5-fr instrument: selected patients may benefit

BACKGROUND AND STUDY AIMS

Despite advances in endoscopic procedures and extracorporeal shock wave lithotripsy (ESWL), the removal of impacted pancreatic duct stones demands a certain amount of time. The aim of this study was to determine which patient group might suitable for our single-session treatment.

PATIENTS AND METHODS

The study included 17 patients who were symptomatic due to relapsing pancreatitis with pancreatic duct stones. A 5-Fr miniscope was inserted via the papilla to the impacted pancreatic duct stone and pancreatoscopic laser lithotripsy (PSLL) was performed, under direct vision, in only one session. If complete extraction of the pancreatic duct stones was not achieved with PSLL, ESWL was adopted in subsequent sessions.

RESULTS

Complete extraction of the pancreatic duct stones using PSLL in a single session was achieved in eight of 17 patients. Single-session PSLL was only suitable for patients with pancreatic duct stones smaller than 17 mm in diameter and with no severe stricture or sharp bend in the pancreatic duct proximal to the stones.

CONCLUSIONS

Our single-session endoscopic treatment of pancreatic duct stones was useful in a selected patient group.

Partitionings and Kinetic Behaviors of Major-to-Ultratrace Elements between Industrial Waste Incineration Fly and Bottom Ashes as Studied by ICP-AES and ICP-MS

The partitionings of major-to-ultratrace elements between industrial waste incineration fly ash (IWIFA) and industrial waste incineration bottom ash (IWIBA) in industrial waste incinerators were investigated by measuring their concentration distributions, where the incineration ash samples were collected from three different types of industrial waste incinerators. The concentrations of the elements in the incineration ash samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). As a result, ca. 40 elements in the concentration range from mg g(-1) to sub-microg g(-1) could be determined in both IWIFA and IWIBA samples. The concentration ratios of CF/CB (CF, concentration in fly ash; CB, concentration in bottom ash) for analyte elements were used to evaluate the partitionings of the elements between fly and bottom ashes. Then, the correlations between the CF/CB values of the elements and the dissociation energies of their monoxides were examined to evaluate the kinetic behaviors of the elements during the incineration processes. It was found that lithophile and siderophile elements, which have a large affinity with oxygen, were almost equally distributed between fly and bottom ashes, regardless of the dissociation energies of their monoxides. On the other hand, chalcophile elements with rather large volatility provided different behaviors; the elements with the smaller dissociation energies of monoxides were more partitioned in fly ashes than those with the larger ones.

Distributions of Major-to-Ultratrace Elements among the Particulate and Dissolved Fractions in Natural Water as Studied by ICP-AES and ICP-MS after Sequential Fractionation

In order to elucidate the distributions of the elements among the particulate and dissolved fractions in pond water, major-to-ultratrace elements in different sizes of particles as well as in the filtrate passed through the 0.05 microm filter were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The different sizes of particle samples (ca. 100-300 microg each) were collected on the membrane filters with pore sizes of 10, 3.0, 1.2, 0.4, 0.2 and 0.05 microm, respectively, by sequential fractionation. As a result, about 40 elements in different sizes of particles could be determined by ICP-AES and ICP-MS, after acid digestion using HNO3/HF/HClO4. Then, the fractional distribution factors of major-to-ultratrace elements among the particulate and dissolved fractions were estimated from the analytical results. The total contents of Al, Fe, Ti, REEs (rare earth elements), Bi, Pb and Ag in the particulate fractions (larger than 0.05 microm) were more than 80-90%, while those of Ca, Sr, Cs, W, Ba, Mn and Co in the dissolved fraction, which corresponded to the filtrate passed through the 0.05 microm membrane filter, were more than 80%. It was further found that the fractional distributions of Cu and Zn in the dissolved fraction were ca. 50%. In addition, the enrichment factors (EFs) of the elements in the particulate fractions with particle sizes of 3.0-10 microm and 0.05-0.2 microm were estimated to elucidate their geochemical characteristics in natural water.

Differentiation of benign and malignant lymph nodes with contrast-enhanced echolymphography using endoscopic ultrasound-guided puncture

BACKGROUND/AIMS

Although endoscopic ultrasonography is considered the most useful diagnostic modality for the regional staging, the capability of diagnosing lymph node metastasis based on endoscopic ultrasonography images alone is not sufficient. To improve the capability of differential diagnosis of lymph node enlargement, contrast-enhanced echolymphography was performed using endoscopic ultrasonography-guided puncture.

METHODOLOGY

Contrast-enhanced echolymphography was performed in 8 metastatic lymph nodes surgically resected from patients with gastrointestinal cancers (in vitro study) and also in 55 patients in whom abdominal lymph node swelling was indicated by endoscopic ultrasonography (in vivo study). Lymph nodes were punctured under real-time endoscopic ultrasonography guidance, and carbon dioxide microbubbles were injected to evaluate echo features before and after microbubbles injection.

RESULTS

Contrast-enhanced echolymphography of freshly resected metastatic lymph nodes showed nonhomogeneous echo patterns. In regions demonstrating filling defects detected by contrast-enhanced echolymphography, neoplastic infiltration was pathologically observed. In almost all of the malignant lymph nodes studied in vivo, filling defects and heterogeneous enhancements were observed by contrast-enhanced echolymphography. However, contrast-enhanced echolymphography demonstrated uniform patterns in most of the benign group. The sensitivity, specificity, positive and negative predictive value, and accuracy of differential diagnosis by contrast-enhanced echolymphography were 95.8%, 90.3%, 88.5%, 96.6%, and 92.7%, respectively.

CONCLUSIONS

Contrast-enhanced echolymphography is a useful method for help in the differentiation between reactive and malignant alterations of lymph nodes.

Speciation of small molecules and inorganic ions in salmon egg cell cytoplasm by surfactant-mediated HPLC/ICP-MS

The speciation of diverse elements in salmon egg cell cytoplasm was performed by a surfactant-mediated HPLC/ICP-MS hyphenated system. In the present experiment, an ODS column coated with CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate), which is a zwitterionic bile acid derivative, was employed as a surfactant-mediated separation column, and ICP-MS was used as an element-selective detector. The present surfactant-mediated HPLC allowed us to separate large and small molecules within 10 min; large molecules, such as proteins, were eluted within 2.5 min, while small molecules were eluted after 2.5 min, but within 10 min. In the present experiment, Fe, Cu, and Zn in egg cell cytoplasm were observed mostly in species with large molecular weights, indicating that these elements are contained as metalloproteins or metalloenzymes in egg cell cytoplasm. On the contrary, it was found that P, S, Mo, and halogens in egg cell cytoplasm were contained as small molecules or inorganic ions. The major species of P in egg cell cytoplasm was identified as the phosphate ion (PO4(3-)). Molybdenum, Cl, and Br in egg cell cytoplasm were molybdate (MoO4(2-), chloride (Cl-), and bromide (Br-) ions, respectively.