A study of the electronic structure of FeSe(1-x)Te(x) chalcogenides by Fe and Se K-edge x-ray absorption near edge structure measurements

Fe K-edge and Se K-edge x-ray absorption near edge structure (XANES) measurements are used to study the FeSe(1 - x)Te(x) electronic structure of chalcogenides. An intense Fe K-edge pre-edge peak due to Fe 1s --> 3d (and admixed Se/Te p states) is observed, showing substantial change with Te substitution and x-ray polarization. The main white line peak in the Se K-edge XANES due to Se 1s --> 4p transition appears similar to the one expected for Se(2-) systems and changes with Te substitution. Polarization dependence reveals that unoccupied Se orbitals near the Fermi level have predominant p(x, y) character. The results provide key information on the hybridization of Fe 3d and chalcogen p states in the Fe-based chalcogenide superconductors.

Splenic artery embolization before laparoscopic splenectomy in children

BACKGROUND

This study assessed the safety and utility of preoperative splenic artery embolization before laparoscopic splenectomy in children.

METHODS

Five young girls with a mean age of 13.2 years underwent laparoscopic splenectomies at the authors' institution from August 1998 to April 2003. Three of the patients had idiopathic thrombocytopenic purpura, and two had hereditary spherocytosis. Preoperative splenic artery embolization was performed the day before the surgery in all cases. The laparoscopic splenectomy was performed using traditional laparoscopic procedures and standard laparoscopic instruments with the patient in the right semilateral position.

RESULTS

The mean spleen weight was 252.6 g, and the mean length was 11.6 cm. All the patients reported postembolic pain, but not to a level unmanageable by intravascular narcotics. There were no severe complications in the splenic artery embolization. The laparoscopic splenectomies were completed in a mean of 211 min, with a mean estimated blood loss of 9 ml. None of the operations required conversion to traditional open laparotomy, and none of the patients died or experienced operative complications.

CONCLUSION

The authors concluded that splenic artery embolization is safe and useful as an adjuvant procedure performed before elective laparoscopic splenectomy in children.

Acute cholecystitis caused by a cholesterol polyp

A 39-year-old man hospitalized with upper abdominal pain had been found to have a 3mm polyp in the body of the gallbladder 3 years previously. Laboratory tests on admission showed mild liver dysfunction. Ultrasonography depicted a dilated gallbladder with increased wall thickness; the polyp could no longer be seen. Computed tomography with drip infusion cholangiography again showed a dilated gallbladder, and also stenosis of the distal cystic duct. The resected specimen obtained by laparoscopic cholecystectomy showed disappearance of the polyp from the body of the gallbladder. A cholesterol stone was incarcerated in the cystic duct, representing an impacted detached cholesterol polyp causing acute cholecystitis. Spontaneous detachment of a cholesterol polyp from the gallbladder mucosa, then, can result in acute cholecystitis.

Incidentally discovered giant renal arteriovenous malformation

A case is presented of giant renal arteriovenous malformation (AVM). A 61-year-old woman was admitted to the National Defense Medical College Hospital for further evaluation of a renal cyst. Doppler ultrasonography and magnetic resonance imaging revealed a giant renal AVM, although the patient had no history nor clinical sign suggesting an AVM. Under the diagnosis of a right renal AVM, the patient underwent AVM resection.

Inverted papilloma arising in a juvenile

A 15-year-old man presented with painless, gross hematuria. Excretory pyelography showed a filling defect in the bladder and ultrasonography revealed a solitary bladder tumor. Cystoscopy showed a solitary, papillary tumor on the bladder neck. Transurethral resection was then performed and histological examination showed an inverted papilloma. In addition, the expression of proliferative cellular nuclear antigen and p53 in the surgical specimen were 37.1 and 0%, respectively. Since an inverted papilloma arising during the first two decades of life is quite rare, we herein report the above case and review previous reports.

Measurement of birefringence in integrated optical waveguides by use of a microwave-modulated optical wave

We present a technique for measuring birefringence (B) in integrated optical waveguides by use of a microwave-modulated optical wave. It is shown that the technique is able to yield an accurate measurement of birefringence. In addition, an approximate estimate of birefringence dispersion (dB/dlambda) can be achieved by means of tuning the wavelength of the light source and measuring the dependence of the birefringence on the wavelength. As an example of the use of the technique, we show how to evaluate an innovative Ti:LiNbO (3) waveguide. The results show that such a Ti:LiNbO (3) waveguide has a birefringence of 0.0783+/-0.0001 and a birefringence dispersion of 0.05+/-0.01mum (-1) when the optical wavelength is approximately 1.560mum .

[Molecular genetic approaches to Mycobacterium tuberculosis]

Recent progress of molecular genetics has been providing tools for new approaches to disease treatment and diagnosis of Mycobacterium tuberculosis. In 1998, Cole et al. reported the complete genome sequence of Mycobacterium tuberculosis. The new information will provide us the knowledge and understanding of the biology of Mycobacterium tuberculosis. Further, it will provide us new conception of diagnosis and treatment of the disease. Four topics were selected in this symposium. Dr. Iinuma reviewed and prospected the clinical utility of nucleic acid amplification methods of Mycobacterium tuberculosis. Dr. Suzuki reviewed the molecular mechanism of acquired resistance to anti-TB drugs and reported the early detection of genetic mutation by new designed DNA tip method. Dr. Takahashi reviewed the method of molecular epidemiology and genetic elements as a tool for strain differentiation of tuberculosis. Dr. Mizuguchi interpreted the essential feature of mycobacterial genome maps, and genes and their biological activity. He also reviewed the importance and the utility of the complete genome sequence of tuberculosis in association with pathogenecity. These topics were summarized in this report, based on the symposium of "Molecular genetic approaches to Mycobacterium tuberculosis" in the 75th annual meeting of the Japanese Society for Tuberculosis.

A case of hemangioma accompanied by inflammatory pseudotumor of the spleen

Both hemangioma and inflammatory pseudotumor (IPT) of the spleen are rare benign mass lesions. Moreover, a splenic hemangioma accompanied by IPT is extremely rare. A 61-year-old woman who suffered from liver cirrhosis had a splenic cavernous hemangioma surrounded by granuloma. The literature on IPT of the spleen has described several possibilities of its causes; however, it is still unknown. This case was accompanied by portal hypertension due to liver cirrhosis, which may cause microrupture of hemangioma resulting in an IPT.

Hepatocellular carcinoma responding to chemotherapy with 5-FU

A 69-year-old man with unresectable hepatocellular carcinoma and portal vein tumor thrombus was treated by chemotherapy with 5-fluorouracil. A dose of 500 mg/day of 5-fluorouracil was continuously administered via a central venous catheter. After 4 months, the alpha-fetoprotein level was decreased from 50,000 ng/mL to 4,760 ng/mL. Computed tomography revealed disappearance of the low-density area in the liver parenchyma, but the portal vein tumor thrombus was not changed. After 6 months, pancytopenia appeared and continuous infusion of 5-fluorouracil was stopped. After 8 months, the patient died of pneumonia, at which time the alpha-fetoprotein level was 12,000 ng/mL. Continuous intravenous infusion of 5-Fluorouracil was effective against unresectable primary hepatocellular carcinoma, but had little influence on portal vein tumor thrombus.

Cloning and expression of Der f 6, a serine protease allergen from the house dust mite, Dermatophagoides farinae

House dust mite allergen is thought to be a major cause of asthma. Characterization of these allergen molecules is therefore an important step for the development of effective diagnostic and therapeutic agents against mite-associated allergic disorders. Here we report molecular cloning and expression of the group 6 (chymotrypsin-like) allergen from the house dust mite, Dermatophagoides farinae. Sequencing analysis indicates that cloned cDNA, designated Der f 6, encodes a 279 amino acid polypeptide which conserves a primary structure characteristic for chymotrypsin-like serine proteases found in mammals. Recombinant Der f 6 expressed in Escherichia coli bound IgE in a pool made of 20 sera, and induced histamine release from patients' peripheral blood cells.

[Study of transforming growth factor-alpha expression in duodenal ulcer]

Various growth factors were also reported to promote healing of peptic ulcer. We have used a monoclonal antibody in conjunction with a standard immunohistochemical technique to characterize the expression of transforming growth factor-alpha (TGF-alpha) in duodenal ulcer. TGF-alpha immunoreactivity is found in Brunner's gland, also in immature gland and in duodenal epitheliums, but not in gastric metaplasia of the duodenum. TGF-alpha expression of healing and scar stage was higher than that of active stage. The presence or absence of Helicobacter pylori infection did not affect the expression of TGF-alpha in duodenal ulcer.

Imaging of large early and early advanced hepatocellular carcinomas of more than 5 cm in diameter: report of two cases

In an attempt to clarify the imaging characteristics of large early and early advanced hepatocellular carcinoma (HCC), we present two such cases which were greater than 5 cm in diameter. One case had four early HCCs and the other had early advanced HCC which was followed for five years and nine months. Multiphasic CT, CT arteriography (CTA), CT arterial portography (CTAP), and MR imaging were performed. Early HCC was shown as a low density mass by multiphasic contrast CT, CTAP and as a hyperintense mass on a T1-weighted image (WI) and isointense on T2WI. Early advanced HCC was demonstrated as a hypodense mass with hyperenhancing interior nodules on CTA, and isodense with hypodense internal foci on CTAP. One follow-up case showed a multi-step progression from early to early advanced HCC, and finally to overtly advanced HCC. Despite the unusually large size of these two tumors, the findings of multiphasic CT, CTA, CTAP, and MR imaging were consistent with those seen in common-sized (less than 2 cm) early and early advanced HCCs. Multi-step progression of hepatocarcinogenesis was observed in one case.

[Usefulness of genotypic analysis for investigation of an epidemic of Shigella sonnei infections in Ooami-shirasato Town, Chiba Prefecture]

In March 1996, an epidemic of Shigella sonnei infection occurred in Ooamishira-sato Town, Chiba Prefecture. Colicine typing, antibiotic resistance patterns, plasmid profiles, pulsed-field gel electrophoresis (PFGE) and random amplified poly-morphic DNA (RAPD) were used for the investigation of the epidemic. Ninety-four isolates from patients exhibited three different colicine types and five different antibiotic resistance patterns. But the patterns of plasmid profile, PFGE and RAPD were uniform among the isolates with different colicine type and antibiotic resistance pattern. It is possible that these isolates belonged to a single bacterial clone and circulated through human to human.

Detection of kanamycin-resistant Mycobacterium tuberculosis by identifying mutations in the 16S rRNA gene

In Mycobacterium smegmatis and a limited number of Mycobacterium tuberculosis strains, the involvement of alterations of the 16S rRNA gene (rrs) in resistance to kanamycin has been shown. To investigate the extent to which mutations in a specific region of the rrs gene and the kanamycin-resistant phenotype in clinically isolated M. tuberculosis strains were correlated, 43 kanamycin-resistant strains (MICs, > or =200 microg/ml), 71 kanamycin-susceptible strains, and 4 type strains were examined. The 300-bp DNA fragments carrying the rrs gene and the intervening sequence between the rrs gene and 23S rRNA (rrl) gene fragments were amplified by PCR and were subjected to PCR-based direct sequencing. By comparing the nucleotide sequences, substitutions were found in 29 of 43 (67.4%) kanamycin-resistant clinical isolates at positions 1400, 1401, and 1483 but in none of the 71 sensitive isolates or the 4 type strains. The most frequent substitution, from A to G, occurred at position 1400. A substitution from C to T at position 1401 was found once. Two clinical isolates carried the double mutation from C to A at position 1401 and from G to T at position 1483. In addition, we found that these mutants can be distinguished from wild-type strains by digestion with the restriction endonucleases TaiI and Tsp45I. Furthermore, we found that the genotypes of kanamycin-resistant strains can be discriminated from each other by digestion with a restriction endonuclease, BstUI or DdeI.

Nonfunctioning islet cell tumors of the pancreas: clinical, imaging and pathological aspects in 16 patients

BACKGROUND

Nonfunctioning islet cell tumors (NFICTs) usually reach a large size prior to detection, at which stage patients have some symptoms or signs. Recently, NFICTs have been discovered in asymptomatic patients with increasing frequency owing to advances in diagnostic imaging techniques. This study investigated clinical, imaging and pathological features in recent cases of NFICT.

METHODS

The medical records, radiographs and pathological specimens of 16 patients with NFICT who were evaluated between April 1991 and March 1996 were reviewed.

RESULTS

Tumor sizes ranged from 0.8 to 17 cm (average, 5.2 cm). Five patients (31%) had some symptoms or signs at the time of diagnosis; however, the other 11 (69%) had no symptoms. Of 10 patients with a tumor of size 5 cm or less, nine were asymptomatic and all tumors were histologically benign. In contrast, in six patients with a tumor larger than 5 cm, four had some symptoms and five tumors were malignant. The detection rates of pancreatic tumor mass on ultrasonography and computed tomography were 94% (15/16) each. All 14 patients in whom the tumor was completely resected survived without recurrence; however, the remaining two patients with liver metastases died following recurrence.

CONCLUSIONS

US and CT are useful in detecting NFICTs even if the tumor is small and the patient is asymptomatic. The detection of NFICTs of small size and their complete removal are essential for a successful cure.