Expression of type V secretory phospholipase A in myocardial remodelling after infarction

AIMS

Secretory phospholipase A2 is associated with ischaemic injury in the human heart, but the distribution of type V secretory phospholipase A2 (sPLA2-V) remains unknown. The significance of sPLA2-V in myocardial infarction was investigated histopathologically.

METHODS

Sequential changes in the localization of sPLA2-V and its mRNA in myocardial tissues obtained from 30 autopsied hearts were examined by immunohistochemistry and in situ hybridization and compared with those of fibronectin, vascular endothelial growth factor (VEGF), interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, and cyclooxygenase-2 (COX-2).

RESULTS

No expression of sPLA2-V was observed in normal heart, but it was promptly expressed in wavy myofibres positive for fibronectin just after the onset of infarction. sPLA2-V was subsequently expressed in ischaemic cardiomyocytes around the lesion. The expression decreased at the granulation tissue and disappeared at the chronic stage with scar formation. The distribution of the signal for sPLA2-V mRNA paralleled that of the protein. Ischaemic myocytes around the lesion expressed VEGF, IL-1beta, TNF-alpha and COX-2 at all stages.

CONCLUSIONS

sPLA2-V production in myocardium is limited to the acute phase of infarction. sPLA2-V may play a dual role, acting both to remove degraded cell-membrane through cooperative activity with COX-2 in necrotic areas and to attack ischaemic myocytes around the lesion via degradation of membrane phospholipids.

[Intraoperative frozen section diiagnosis of small peripheral lung adenocarcinoma for limited operation]

Sixty-two cases of peripheral lung adenocarcinoma 2 cm or less in diameter were diagnosed as type A, B, or C according to Noguchi classifications by intraoperative frozen section diagnosis. Four of 19 type A were changed finally to type B by postoperative pathologic examination. Likewise 10 of 34 type B were changed finally to 1 type A, 8 type C, and 1 type D. Three of 9 type C were changed finally to 2 type B and 1 type D. Frozen section diagnosis for small peripheral lung adenocarcinoma has some special problems and limitations. Only cases of type A diagnosed by frozen section diagnosis should be permitted to undergo limited surgical resection.

Stereochemistry of 1,2-dichloroethane adsorbed on Pt(111)

The rotational isomerism of 1,2-dichloroethane (DCE, CH2ClCH2Cl) adsorbed on Pt(111) was studied in the temperature range of 35-100 K using high-resolution electron energy loss spectroscopy and metastable atom electron spectroscopy. In the coverage below monolayer the physisorbed and chemisorbed species coexist at 35 K in the gauche and slightly distorted trans form, respectively. Owing to the direct Pt-Cl interactions, the nonbonding Cl 3p states of the chemisorbed DCE are split off, giving rise to degradation in symmetry from the pure trans form (C2h). The physisorbed gauche conformers are arranged with the C2 axis parallel (or heavily tilted) to the substrate and converted irreversibly to the pseudo-trans form by heating at 70 K. In the multilayer, the trans and gauche conformers exist at 35 K, where the former population is increased with increasing layer thickness. Upon annealing the bilayer at 80 K, the irreversible conversion takes place to yield a higher population of the gauche conformer in the topmost layer. The conformational stabilities and mutual changes of DCE adsorbed on a metal surface are discussed in terms of intramolecular rotational potential.

Electron acceleration by a nonlinear wakefield generated by ultrashort (23-fs) high-peak-power laser pulses in plasma

We study experimentally the interaction of the shortest at present (23-fs) , relativistically intense (20-TW), tightly focused laser pulses with underdense plasma. MeV electrons constitute a two-temperature distribution due to different plasma wave-breaking processes at a plasma density of 10(20) cm(-3). These two groups of electrons are shown numerically to constitute bunches with very distinctive time durations.

[Induction chemoradiotherapy in small adenocarcinoma of the lung with bulky mediatinal lymph node metastasis]

A 56-year-old man, who visited our hospital due to chest pain, was pointed out a large tumor, 60 mm in diameter, on the left superior mediastinum on the chest computed tomography (CT) scan. He was diagnosed as having mediastinal lymph nodes metastasis of adenocarcinoma through video-assisted thoracoscopic surgery (VATS) biopsy. He received induction chemoradiotherapy: cisplatin and paclitaxel were administered once per week for 2 weeks, and radiotherapy was simultaneously performed. No serious adverse reactions were noted. The ipsilateral mediastinal lymph nodes dissection was performed. Intraoperative frozen section analysis showed a small nodule in the left upper lobe, 5 mm in diameter, was adenocarcinoma. He was finally diagnosed as having mediastinal lymph nodes metastasis from the small adenocarcinoma of the lung, and left upper lobectomy was performed. Histopathological examination of the mediastinal lymph nodes showed no evidence of viable maligmant cell. Induction chemoradiotherapy with cisplatin and paclitaxel might be effective treatment for locally advanced non-small cell lung cancer.

[Aortobronchial fistula after replacement of descending thoracic aorta with ringed graft; report of a case]

A 79-year-old male patient complicated with aortobronchial fistula after replacement of descending thoracic aorta with ringed graft. He underwent replacement of the aortic arch using a four branched vascular graft and open stent grafting to replace the descending thoracic aorta after removing the ringed-graft through median sternotomy. This procedure is useful for patients as the left thoracotomy is risky and the distal anastomotic site of the descending thoracic aorta is too far to anastomose.

Transplantation for accidental acute high-dose total body neutron- and gamma-radiation exposure

Accidental exposure to acute high-dose total body neutron radiation is rare. We report a 35-year-old man exposed to a total body dose of 5.4 Gy neutron- and 8.5-13 Gy gamma-radiation in a radiation criticality accident. He received a blood stem cell transplant from his HLA-identical sister. There was bone marrow recovery with complete donor chimerism. Random chromatid breaks were observed in donor cells suggesting a bystander effect of neutron exposure. The subject died 82 days after the accident (75 days post transplant) from multi-organ failure.

Evaluation of an office-based urine test for detecting Helicobacter pylori: a Prospective Pilot Study

BACKGROUND/AIMS

To ascertain the reliability of a newly developed office-based urine test, the RAPIRUN test, used for detection of H. pylori infection.

METHODOLOGY

Urine specimens from 142 consecutive patients undergoing gastroendoscopy (77 men, 65 women; mean 52.0 years) were tested with RAPIRUN at the same time. The total reaction time for the urine test is 20 min. None of the patients had received any H. pylori eradicating treatment. The H. pylori status was evaluated based on 5 different tests: culture, histology, biopsy urease test, 13C-urea breath test, and the RAPIRUN test. A commercial office-based kit using an immunochromatographic technique was used to examine urine samples for H. pylori antibody. H. pylori status was defined as positive when the culture was positive or if 2 of the other 3 tests (histology, biopsy urease test, and 13C-urea breath test were positive.

RESULTS

Of 93 patients with H. pylori infection, 88 were tested as positive by RAPIRUN (sensitivity 94.6%). Of 48 patients without infection, 43 were found to be negative by RAPIRUN (specificity 89.6%). One case with an invalid urine test was excluded.

CONCLUSIONS

This urine test is a rapid, inexpensive, reliable and easy-to-use tool for the diagnosis of H. pylori infection in untreated patients. It can be used for mass screening of patients' H. pylori status, particularly in children, postgastrectomy patients, uncooperative patients, and patients undergoing bismuth or proton pump inhibitor treatment.

Difference between forward and backward swimming speeds of the single polar-flagellated bacterium, Vibrio alginolyticus

The forward and backward swimming speeds and periods of a Vibrio alginolyticus strain that has a single polar flagellum were measured. The backward swimming speeds were 1.5 times greater than the forward ones on average and the average period of backward swimming was shorter than forward swimming. However, the swimming speed and period were not correlated. Similar results were obtained for a mutant that has a 1.6 times longer flagellum on average.

Upregulation of H(+)-peptide cotransporter PEPT2 in rat remnant kidney

The progression of renal damage resulting from reduced nephron mass has been extensively studied in the 5/6 nephrectomized rat. However, reabsorption of small peptides and D-glucose across the renal proximal tubule in this model remains poorly understood. In this study, we examined the alterations of H(+)-peptide cotransporters (PEPT1 and PEPT2) and Na(+)-D-glucose cotransporters (SGLT1 and SGLT2) in chronic renal failure. Two weeks after surgery, H(+)-dependent [(14)C]glycylsarcosine uptake by the renal brush-border membrane vesicles isolated from 5/6 nephrectomized rats was significantly increased compared with that from sham-operated controls. Kinetic analysis revealed that the maximum velocity value for [(14)C]glycylsarcosine uptake by the high-affinity-type of peptide transporter was increased threefold by 5/6 nephrectomy, without significant changes in the apparent Michaelis-Menten constant value. Competitive PCR analyses indicated that the expression of PEPT2 mRNA was markedly increased in the remnant kidney, but PEPT1, SGLT1, and SGLT2 mRNA levels showed no significant changes. These findings indicated that the high-affinity-type H(+)-peptide cotransport activity is upregulated by 5/6 nephrectomy, accompanied by the increased expression of PEPT2. The upregulation of PEPT2 expression would result in an increase in reabsorption of small peptides and peptide-like drugs across the brush-border membranes in chronic renal failure.

Study of retrieved acetabular sockets made from high-dose, cross-linked polyethylene

Although ultra-high molecular weight polyethylene (UHMWPE) has stable chemical properties, chemical degradation, such as oxidation reaction, progresses with long-term clinical use. The purpose of this study was to investigate the change in properties of polyethylene (PE) in vivo by examining retrieved UHMWPE sockets and high-dose, cross-linked PE (100 Mrad PE) sockets. Twenty retrieved sockets (including 2 100 Mrad PE sockets), which were implanted from 1970 to 1996, were used for analysis. The oxidation index of 100 Mrad PE sockets was approximately the same as that of the normal UHMWPE sockets in worn areas. These long-term clinical results indicate that 100 Mrad PE is sufficiently stable for clinical use and that free radicals would not affect progression of oxidation significantly.

Distinct characteristics of organic cation transporters, OCT1 and OCT2, in the basolateral membrane of renal tubules

PURPOSE

This study was performed to determine the detailed mRNA distribution of organic cation transporters, rOCT1 and rOCT2, along the rat nephron and to distinguish the substrate affinities of these transporters.

METHODS

The distributions of rOCT1 and rOCT2 mRNA were determined by reverse transcriptase polymerase chain reaction analysis of microdissected nephron segments. Using MDCK cells transfected with rOCT1 or rOCT2 cDNA, the inhibitory effects of various compounds on the uptake of [14C]tetraethylammonium were assessed.

RESULTS

rOCT1 mRNA was detected primarily in the superficial and juxtamedullary proximal convoluted tubules, whereas rOCT2 mRNA was detected widely in the superficial and juxtamedullary proximal straight and convoluted tubules, medullary thick ascending limbs, distal convoluted tubule, and cortical collecting duct. The IC50 values for cationic drugs and endogenous cations on [14C]tetraethylammonium uptake across the basolateral membranes in the transfectants indicated that rOCT1 and rOCT2 had similar inhibitor specificity for many compounds but showed moderate differences in the specificity for several compounds, such as 1-methyl-4-phenylpyridinium, dopamine, disopyramide, and chlorpheniramine.

CONCLUSIONS

rOCT1 and rOCT2 possess similar but not identical multispecificities for various compounds with distinct distributions along the nephron, indicating that the two transporters share physiologic and pharmacologic roles in the renal handling of cationic compounds.

Multispecific substrate recognition of kidney-specific organic anion transporters OAT-K1 and OAT-K2

We characterized the interactions of various compounds with OAT-K1 and OAT-K2, kidney-specific organic anion transporters. By using Madin-Darby canine kidney cells stably transfected with OAT-K1 or OAT-K2 cDNA, the antitumor drug methotrexate, the mycotoxin ochratoxin A, endogenous organic anions (thyroid hormones, taurocholic acid, and conjugated steroids), and the antiretroviral drug zidovudine were shown to be substrates for these transporters. Although the apparent Michaelis constant (Km) values of methotrexate for OAT-K1 and OAT-K2 were 2.1 and 1.8 microM, respectively, 2.5 mM methotrexate inhibited only 20% of the 125I-thyroid hormones uptake via these transporters. In addition, 100 microM methotrexate did not have any effect on [3H]zidovudine uptake via OAT-K1 or OAT-K2. Similarly, several substrates caused little or no mutual inhibition at concentrations much higher than their Km values for these transporters. Moreover, intracellular methotrexate trans-stimulated the OAT-K1- and OAT-K2-mediated uptake of [3H]folic acid, but not that of other compounds. Organic anion-transporting polypeptide 2 (oatp2), a liver-type homolog of OAT-K1 and OAT-K2, showed similar events. The inhibition constant values of triiodothyronine and taurocholic acid for [3H]digoxin uptake in oatp2-expressing oocytes resulted in 50.4 and 1.48 mM, respectively, which were about 9- and 40-fold higher than their Km values for oatp2, respectively. These findings suggested that several substrates interact with these transporters at different amino acid residue(s). Taken together, these observations suggested that OAT-K1 and OAT-K2 could serve as multispecific transporters, mediating transport of a wide variety of endogenous substances, xenobiotics, and their metabolites in the kidney, presumably via several interaction sites in their molecules.

Transitional cell carcinoma of the renal pelvis in a long-term hemodialysis patient with autosomal dominant polycystic kidney

We present a case of renal pelvic transitional cell carcinoma (TCC) accompanied by autosomal dominant polycystic kidney disease (ADPKD). An 81-year-old woman on long-term hemodialysis for ADPKD visited the Department of Urology at Kouseiren Takaoko Hospital, complaining of asymptomatic macroscopic hematuria. Retrograde pyelogram showed an irregular filling defect in the right renal pelvis, which suggested the right renal pelvic tumor. We performed right nephrectomy and transurethral removal of the right ureter. Histological diagnosis demonstrated renal pelvic TCC.

Role of kidney-specific organic anion transporters in the urinary excretion of methotrexate

BACKGROUND

High-dose folinic acid is used to accelerate methotrexate elimination to avoid renal toxicity of the drug. The present study was carried out to examine the role of the renal organic anion transporters OAT-K1 and OAT-K2 in the urinary excretion of methotrexate, especially in the methotrexate-folinic acid rescue therapy.

METHODS

Madin-Darby canine kidney cells stably expressing OAT-K1 and OAT-K2 were used for the in vitro transport study; 5/6 nephrectomized rats were used to detect changes in mRNA expression levels of OAT-K1 and OAT-K2 and to evaluate methotrexate pharmacokinetics under conditions of renal insufficiency.

RESULTS

Methotrexate efflux mediated by these transporters in stable transfectants was stimulated in the presence of extracellular folic acid and folinic acid, suggesting that they could serve as anion exchangers to enhance the apical efflux of methotrexate. The mRNA expression levels of OAT-K1 and OAT-K2 were markedly diminished after 5/6 nephrectomy, but those of multidrug resistance associated protein 2, which could transport methotrexate, were maintained. Renal clearance of methotrexate was markedly decreased in 5/6 nephrectomized rats compared with that in sham-operated rats. Additional folinic acid treatment resulted in a significant increase in methotrexate renal clearance in sham-operated rats but not in 5/6 nephrectomized rats.

CONCLUSIONS

The decreased expressions of OAT-K1 and OAT-K2 may be attributable to the longer exposure to methotrexate and ineffective folinic acid rescue. In terms of contributing to patient safety, renal clearance of methotrexate, especially folinic acid-stimulated tubular secretion of the drug via these transporters, would be a key factor in methotrexate therapy.

Complete genome sequence of an aerobic thermoacidophilic crenarchaeon, Sulfolobus tokodaii strain7

The complete genomic sequence of an aerobic thermoacidophilic crenarchaeon, Sulfolobus tokodaii strain7 which optimally grows at 80 degrees C, at low pH, and under aerobic conditions, has been determined by the whole genome shotgun method with slight modifications. The genomic size was 2,694,756 bp long and the G + C content was 32.8%. The following RNA-coding genes were identified: a single 16S-23S rRNA cluster, one 5S rRNA gene and 46 tRNA genes (including 24 intron-containing tRNA genes). The repetitive sequences identified were SR-type repetitive sequences, long dispersed-type repetitive sequences and Tn-like repetitive elements. The genome contained 2826 potential protein-coding regions (open reading frames, ORFs). By similarity search against public databases, 911 (32.2%) ORFs were related to functional assigned genes, 921 (32.6%) were related to conserved ORFs of unknown function, 145 (5.1%) contained some motifs, and remaining 849 (30.0%) did not show any significant similarity to the registered sequences. The ORFs with functional assignments included the candidate genes involved in sulfide metabolism, the TCA cycle and the respiratory chain. Sequence comparison provided evidence suggesting the integration of plasmid, rearrangement of genomic structure, and duplication of genomic regions that may be responsible for the larger genomic size of the S. tokodaii strain7 genome. The genome contained eukaryote-type genes which were not identified in other archaea and lacked the CCA sequence in the tRNA genes. The result suggests that this strain is closer to eukaryotes among the archaea strains so far sequenced. The data presented in this paper are also available on the internet homepage (http://www.bio.nite.go.jp/E-home/genome_list-e.html/).

Expression of peptide transporter following intestinal transplantation in the rat

BACKGROUND

The absorptive function of the intestinal graft is one of the most important factors for successful intestinal transplantation. To clarify whether the intestinal H(+)/peptide cotransporter (PEPT1) was expressed in the transplanted intestine, we examined the expression of PEPT1 in an experimental model of rat small intestinal transplantation in comparison with expression of Na(+)/glucose cotransporter (SGLT1).

MATERIALS AND METHODS

Heterotopic intestinal transplantation was performed in allogeneic and syngeneic rat strain combinations. An additional group of allogeneic recipients was treated with tacrolimus (1 mg/kg) prior to transplantation, then daily for 7 days. Intestinal grafts were examined for histopathology and PEPT1 and SGLT1 expression.

RESULTS

In the isografts, the levels of messenger RNA (mRNA) encoding both transporters were not changed, while the amount of SGLT1 protein was decreased and that of PEPT1 protein was increased. In the allografts, mRNA level and protein amount of both transporters and the amount of villin protein were decreased, and microscopic examination revealed histopathological features of rejection on day 7. Tacrolimus treatment ameliorated the histopathological features and prevented the decrease in villin protein expression. However, the decreases in PEPT1 and SGLT1 expression (both mRNA and protein) were partially prevented by tacrolimus treatment.

CONCLUSION

This study indicated that the expression of transporters should be determined to evaluate intestinal graft function in addition to histopathological examination of the mucosa and that the levels of mRNA encoding intestinal nutrient transporters in biopsy specimens may be useful for evaluating the intestinal graft function for intestinal transplant patients.