Separation of the outer membrane and identification of major outer membrane proteins from Porphyromonas gingivalis

The outer membrane of Porphyromonas gingivalis, an oral strict anaerobe, was isolated by sucrose density gradient centrifugation. The outer membrane obtained by the differential detergent extraction method, previously reported, showed an essentially similar protein pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), confirming that the latter method is suitable for the study of outer membrane proteins in this organism. N-terminal amino acid sequence analysis revealed that major outer membrane proteins in this organism included Arg-gingipain, Lys-gingipain, RagA (a TonB-linked receptor), and putative porins that were homologous to Escherichia coli OmpA.

Prospect of a stanniocalcin endocrine/paracrine system in mammals

Stanniocalcin (STC) is a calcium- and phosphate-regulating hormone produced in bony fish by the corpuscles of Stannius, which are located close to the kidney. It is a major antihypercalcemic hormone in fish. As the corpuscles of Stannius are absent, and antihypercalcemic hormones are basically not necessary, in mammals, the discovery of a mammalian homolog, STC1, was surprising and intriguing. STC1 displays a relatively high amino acid sequence identity (approximately 50%) with fish STC. In contrast to fish STC, STC1 is expressed in many tissues, including kidney. More recently, a human gene encoding the second stanniocalcin-like protein, STC2, was identified. STC2 has a lower identity (approximately 35%) with STC1 and fish STC. Similar to STC1, STC2 is also expressed in a variety of tissues. Research into the functions of STCs in mammals is still at an early stage, and the ultimate physiological and pathological roles of STCs have not yet been established. A few studies indicate that STC1, similar to fish STC, stimulates phosphate absorption in the kidney and intestine, but the function of STC2 is still unknown. However, several interesting findings have been reported on their cellular localization, gene structure, and expression in different physiological and pathological conditions, which will be clues in elucidating the functions of STCs in mammals. STC1 expression is enhanced by hypertonicity in a kidney cell line or by ischemic injuries and neural differentiation in the brain. STC1 expression in the ovary is also enhanced during pregnancy and lactation. Calcitriol upregulates STC1 and downregulates STC2 expression in the kidney. Interestingly, STC1 and STC2 are expressed in many tumor cell lines, and the expression of STC2 is enhanced by estradiol in breast cancer cells. STC2 is also expressed in pancreatic islets. These results suggest that the biological repertoires of STCs in mammals will be considerably larger than in fish and may not be limited to mineral metabolism. This brief review describes recent progress in mammalian STC research.

Analysis of NaCl transport in thin ascending limb of Henle's loop in CLC-K1 null mice

To characterize the nature of NaCl transport in the thin ascending limb (tAL), we examined the transport properties of Na(+) and Cl(-) using in vitro microperfusion of the tAL in CLC-K1 null mice. In the presence of a transmural NaCl concentration gradient (100 mM higher in the lumen), the transepithelial diffusion voltage (V(d)) was 15.5 +/- 1.0 and -7.6 +/- 1.4 mV in CLC-K1(+/+) and CLC-K1(-/-) mice, respectively. Neither Cl(-) transport inhibitor 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB) nor acidification of the bathing fluid changed the V(d) values in CLC-K1(-/-) mice. The addition of 300 microg/ml protamine, a selective blocker of paracellular conductance, to the bath increased the V(d) values by 5.6 +/- 0.7 and 12.6 +/- 1.5 mV (P < 0.001) in CLC-K1(+/+) and CLC-K1(-/-) mice, respectively. Although efflux coefficients of (36)Cl were significantly decreased in CLC-K1(-/-) mice (188.3 +/- 25.6 in 4 tubules vs. 17.2 +/- 7.0 x 10(-5) cm/s in 6 tubules), those of (22)Na were not different between CLC-K1(+/+) and CLC-K1(-/-) mice. These results clearly indicate that the major component of Cl(-) transport sensitive to NPPB or pH is mediated by CLC-K1 in the tAL.

A single amino acid mutation results in a rapid inactivation of epithelial calcium channels

Epithelial Ca(2+) channel (ECaC1 and 2 = CAT1) molecules are characterized by properties including inward rectification and Ca(2+)-dependent fast and slow inactivation. To elucidate the electrophysiological differences based on the amino acid residues, we compared human and rodent ECaC1, and ECaC2 alignments, made mutants, and investigated their function in Xenopus and mammalian cells. Expression of the ECaC1 mutant Q579H and a H587Q mutation in ECaC2 in Xenopus oocytes resulted in a possible change in the rate of fast decay. Currents of H587C and H587N were not detected, and the H587R diminished the rate of rapid decay. Treatment of the oocytes with BAPTA magnified the amplitude of the current and abolished the decay. The expressions of mutants, therefore, implied that H587 in ECaC2 is a position related to the mechanism of the rapid decay rather than the magnitude of the current or the slow decay. Decay measurements were carefully performed in mammalian cells by tight-seal patch clamping. The rapid decay was exaggerated in H587C and H587N mutants but was undetectable in the H587R mutant. The results indicate that the amino acid 579Q of ECaC1, corresponding to 587H of ECaC2, is of primary importance in the structure for the fast inactivation by intracellular Ca(2+).

Medroxyprogesterone acetate therapy for patients with adenocarcinoma of the endometrium who wish to preserve the uterus-usefulness and limitations

BACKGROUND

To determine the effectiveness of medroxyprogesterone acetate therapy for women with endometrial adenocarcinoma who wish to preserve their uterus.

STUDY DESIGN

Fifteen patients with endometrial carcinoma (12 with grade 1 endometrioid adenocarcinoma. 2 with grade 2 adenocarcinoma and 1 with adenoacanthoma) were treated with high-dose medroxyprogesterone acetate alone as primary therapy and their clinical responses evaluated.

RESULTS

Seven of the 12 cases (58%) with grade I adenocarcinoma and one of the two (50%) with grade 2 carcinoma responded initially to medroxyprogesterone acetate. The median length of treatment required for regression was 29 weeks. Three patients who initially responded relapsed. Thirteen patients are alive without evidence of disease as of December 1999 (10 to 146 months, median; 4 years and 11 months) and one is continuing medroxyprogesterone acetate therapy as a final follow-up. One patient was lost to follow-up. Two patients have conceived having three healthy infants.

CONCLUSION

Treatment of endometrial carcinoma with high-dose medroxyprogesterone acetate could be an alternative to hysterectomy, although the successful rate is limited.

[Evaluation of an HIV screening assay kit for the combined detection of anti-HIV-1/2 antibodies and HIV p24 antigen]

We have evaluated a new HIV screening assay kit (Genscreen HIV Ag-Ab) for the HIV antigen-antibody combined test by comparing with two HIV antigen-antibody combined assay kits (VIDAS HIV DUO, Enzygnost HIV integral). Genscreen HIV Ag-Ab is a microwell plate enzyme immunoassay for the detection of HIV infection, based on the detection of anti-HIV-1/2 antibodies and HIV p24 antigen in human serum or plasma. In this study, 90 samples of HIV-1 antibody positive sera and 670 samples of HIV negative sera were examined. The sensitivity was 100% and the specificity was 99.7%. All of HIV-1 group M sera (subtypes A to G and B/D), HIV-1 group O sera and HIV-2 sera in worldwide HIV performance panel-302 were positive with Genscreen HIV Ag-Ab. Ten commercially available HIV-1 seroconversion panels were tested to evaluate sensitivity of three HIV antigen-antibody combined assay kits. Genscreen HIV Ag-Ab detected infection at the same bleeds as VIDAS HIV DUO in 8 of 10 seroconversion panels and 1 to 2 bleeds earlier than Enzygnost HIV integral in 5 of 10 seroconversion panels. However, VIDAS HIV DUO indicated false negative on 5th bleed in panel BB (PRA952). The result of the specimen was positive on 3rd bleed, equivocal on 4th bleed, negative on 5th bleed and again positive on 6th bleed. All of these specimens were positive by Genscreen HIV Ag-Ab. Therefore, Genscreen HIV Ag-Ab that shorten the window period is a useful and reliable for HIV screening test, especially in case of primary infection.

Intravitreal phacoemulsification with pars plana vitrectomy and posterior chamber intraocular lens suture fixation for dislocated crystalline lenses

This technique to manage a dislocated crystalline lens comprises intravitreal phacoemulsification with transscleral suture fixation of a posterior chamber intraocular lens (IOL). The dislocated lens in the vitreous cavity is removed using a standard phaco handpiece with the assistance of a fiber-optic light pipe. Then, the IOL is implanted. The technique was used in 10 eyes of 8 patients with lens luxation or subluxation. The postoperative best corrected visual acuity was 20/25 or better except in 1 eye, and no serious complications were observed. Increased intraocular pressure before surgery in 4 eyes was normalized in 3 eyes.

Estrogens do not modify MAP kinase-dependent nuclear signaling during stimulation of early G(1) progression in human breast cancer cells

Estrogens are direct mitogens for hormone-responsive human breast cancercells, where they promote cell cycle progression and induce transcriptional activation of "immediate early" and cyclin genes. Nongenomic signaling by estrogens, including rapid changes of mitogen-activated protein(MAP) kinase and other signal-transduction-cascades activity, has been proposed to be essential for the mitogenic actions of these hormones and their nuclear receptors. Because regulation of gene transcription is considered a key step in cell cycle control by mitogenic protein kinase cascades, here we investigated the possibility that estrogen might induce the activation of extracellular signal-regulated kinase (Erk) 1/2-, c-Jun NH(2)-terminal kinase-, p38- or protein kinase A-responsive transcription factors in the cell nucleus during stimulation of early G(1) progression, a timing coincident with the maximum effects of these hormones on such enzyme activity. No significant changes in protein kinase-mediated transcription factor activity could be detected here after estrogen stimulation of either MCF-7 or ZR-75.1 cells. Furthermore, these steroids were able to induce activation of the human CCND1 gene promoter, accumulation of cyclin D1 and pRb phosphorylation, all key events in cell cycle stimulation by mitogens, even in the presence of Erk1/2 activation blockade by a MAP kinase-activating kinase (Mek)1/2 inhibitor. Thus, estrogens do not appear to convey significant protein kinase-dependent signaling to the cell nucleus during the early phases of human breast cancer cell stimulation. Furthermore, hormonal regulation of G(1) gene transcription can occur even without additional activation of the Mek-Erk1/2 pathway by estrogen receptors.

Novel deletion of HIV type 1 reverse transcriptase residue 69 conferring selective high-level resistance to nevirapine

A novel deletion of residue 69 of the HIV-1 reverse transcriptase (RT) gene was detected in combination with mutations V75I/V and F77L/F in a patient with partial virological response to several antiretroviral drug regimens, including stavudine (D4T), didanosine (DDI), lamivudine (3TC), saquinavir (SQV), and nevirapine (NVP). Longitudinal analysis of samples revealed that this deletion emerged upon reinitiation DDI/D4T therapy following a toxicity-induced short discontinuation of all antiretrovirals. Analysis of the resistance phenotype showed a greater than 62-fold increase of the IC50 of NVP, but no significant change in sensitivity to other single nonnucleoside reverse transcriptase inhibitors (NNRTIs). The mutated virus showed only a moderately reduced sensitivity to DDI (6.7-fold) and D4T (4.8 fold). In a subsequent sample 3 months later additional RT mutations were found, including A62V, Y188L, and Q151M, conferring high-level cross-resistance to multiple nucleoside analogs. Our findings provide evidence that the deletion of RT residue 69 selectively confers high-level NVP resistance.

Optical coherence tomography of tractional macular elevations in eyes with proliferative diabetic retinopathy

PURPOSE

To document the findings of optical coherence tomography in eyes with tractional macular elevation associated with proliferative diabetic retinopathy, paying special attention to differentiating between tractional retinal detachment and retinoschisis.

DESIGN

Observational case series.

METHODS

We retrospectively reviewed images of optical coherence tomography obtained from 17 consecutive eyes (17 patients) with proliferative diabetic retinopathy without vitreous opacity and showing tractional macular elevation with or without foveal involvement.

RESULTS

Tractional retinal detachment and retinoschisis could be differentiated in the cross-sectional images of optical coherence tomography. Retinoschisis with or without associated retinal detachment was observed in 16 of 17 eyes (94%), whereas retinal detachment was observed in only six of 17 eyes (35%). Five eyes showed both findings of retinal detachment and retinoschisis.

CONCLUSIONS

Optical coherence tomography is useful for distinguishing tractional retinoschisis from retinal detachment in eyes with proliferative diabetic retinopathy and macular elevation. Tractional retinoschisis with or without retinal detachment is the most frequent pattern of tractional macular elevation in eyes with proliferative diabetic retinopathy.

Caveolar and intercellular channels provide major transport pathways of macromolecules across vascular endothelial cells

Serum macromolecules are transported through the vascular endothelial layer to the interstitium via the caveolae and interendothelial clefts, but the nature of the permeability of these structures is unknown, and the manner of caveola-vesicle transport is controversial. We have developed a method of detecting macromolecular channels using an in situ HRP perfusion into arteries previously perfused with aldehyde and random conventional sectioning for electron microscopy. Using unbiased morphometry, 4.75% of the abluminal caveolae and 15.13% of the intercellular clefts were the tracer-positive in rat aortic endothelium. In rat aortas treated with N-ethylmaleimide, all caveolae and most free vesicles in the cytoplasm except those around the Golgi area were HRP-positive in the endothelial cells; 1.48% of abluminal caveolae were structurally recognized as caveolar channels through the endothelial layer in a plane of single section. The length density of the abluminal caveolae was decreased to about 80% to the physiological control level whereas the larger invaginations were more frequently observed. Moreover 96.17% of the intercellular clefts were HRP-positive. We suggest that a flexible channel-system functions extensively as a macromolecular transport pathway in the arterial endothelium in vivo because the tracer-labeled abluminal caveolae and intercellular clefts should be opened to the luminal surfaces methodologically. We therefore propose that caveolar channels, rather than transcytosis, provide a mechanism of caveola-vesicle transport in the endothelial cells, because free vesicles involved in transcytosis were few in number.

[Evaluation of immunochromatography method for rapid detection of influenza A and B viruses]

We have evaluated a new rapid detection kit for influenza A and B viruses, known as the QuickVue Influenza test (Quidel Coporation, USA); which is based on immunochromatography using virus isolates and clinical specimens. Twelve strains of influenza A and B were tested for evaluate the reactivity and detection limits of this test. The QuickVue Influenza test showed a positive result for all twelve strains of influenza virus and a negative result for fourteen different kinds of other respiratory viruses. The detection limits for six strains were 5 to 30 pfu/ml for a cell culture, 1.0 x 10(3) to 6.0 x 10(4) pfu/ml for 1st PCR, 1 to 50 pfu/ml for nested PCR, 3.0 x 10(5) to 6.0 x 10(5) pfu/ml for the QuickVue Influenza test, 1.5 x 10(5) to 1.0 x 10(6) pfu/ml for the Directigen Flu A, and 7.5 x 10(5) to 5.0 x 10(6) pfu/ml for the FLU OIA. Furthermore, the QuickVue Influenza test were clinically evaluated using 92 throat swab specimens collected from patients with influenza-like illnesses. By cell culture, influenza viruses were detected in 49 of the 92 specimens (AH1N1: 20, AH3N2: 7, B: 22); the titers of the influenza viruses were between 2.5 pfu/ml and 7.0 x 10(5) pfu/ml. Compared to cell culture, the QuickVue Influenza test showed a sensitivity of 75.5%, a specificity of 93.0%, a positive predictive value of 92.5%, a negative predictive value of 76.9%, and an efficiency value of 83.7%. On the other hand, influenza viruses were detected in 54 of the 92 specimens (AH1N1: 19, AH 3N2: 10, B: 25) by RT-PCR. Compared to RT-PCR, the QuickVue Influenza test showed a sensitivity of 72.2%, a specificity of 97.4%, a positive predictive value of 97.5%, a negative predictive value of 71.2%, and an efficiency value of 82.6%. Overall, only one throat swab specimen produced a false positive result using the QuickVue Influenza test; thus, this test appears to have a high specificity. We conclude that the QuickVue Influenza test is a simple one-step test with a sensitivity and specificity equivalent to those of other conventional diagnostic kits. The test is useful and suitable for the diagnosis of influenza and for identifying influenza patients requiring antiviral therapy.

Troglitazone stimulates basolateral rheogenic Na+/HCO3- cotransport activity in rabbit proximal straight tubules

Thiazolidinedione derivatives, new insulin-sensitizing antidiabetic agents, are expected to have potential clinical use. Since these drugs cause edema in a variable proportion of patients, we examined whether troglitazone (Tro) has direct action on Na+ transport of rabbit proximal straight tubule perfused in vitro. For this purpose, we measured basolateral membrane voltage (V(B)) by conventional microelectrode techniques and intracellular pH (pH(i)) by microscopic fluorescence spectrophotometry with a pH-sensitive fluorescent dye, 2', 7'-bis-2-carboxyethyl-5-carboxyfluorescein. Tro at 50 microM in the bath significantly depolarized both transepithelial voltage and V(B). To examine whether the basolateral rheogenic Na+/HCO3- cotransport activity is affected by Tro, we observed V(B) deflection upon abrupt 10-fold decrease in bath HCO3- in the absence and presence of Tro. The apparent transference number of HCO3- (tHCO3), as calculated from the V(B) deflection, was significantly greater in the presence of Tro (50 microM) than that seen in its absence. Tro caused cell acidification and increased the intracellular acidification rates (dpH(i)/dt) upon abrupt 10-fold decreases in bath HCO3- and Na+ concentrations. The stimulatory effects of Tro on tHCO3 and dpH(i)/dt were dose dependent between 5 and 50 miccroM, but they were unaffected at 0.5 microM. From these results, we conclude that Tro acts on the proximal straight tubule and stimulates the basolateral rheogenic Na+/HCO3- cotransport activity. The stimulatory action of Tro may partly account for edema formation.

Superconductivity of ternary silicide with the AlB(2)-type structure Sr(Ga(0.37),Si(0.63))(2)

A ternary silicide Sr(Ga(0.37),Si(0.63))(2) was synthesized by a floating zone method. Electron diffraction and powder x-ray diffraction measurements indicate that the silicide has the AlB(2)-type structure with the lattice constants of a = 4.1427(6) A and c = 4.7998(9) A, where Si and Ga atoms are arranged in a chemically disordered honeycomb lattice and Sr atoms are inercalated between them. The silicide is isostructural with the high-temperature superconductor MgB(2) reported recently. Electrical resistivity and dc magnetization measurements revealed that it is a type-II superconductor with onset temperature of 3.5 K.

Arterial and venous Thrombelastograph variables differ during cardiac surgery

The Thrombelastograph (TEG; Haemoscope Corp., Skokie, IL) coagulation analyzer is an effective point-of-care monitor for routine clinical practice and clinical research. Prior investigators have used either arterial or venous samples of blood for TEG measurements. We conducted this prospective cohort study to determine potential differences in TEG variables between arterial and venous blood samples. Arterial and venous samples were drawn from 40 cardiac surgical patients, yielding 134 pairs for comparison. Twenty-nine comparisons (control) were between arterial and arterial samples and were not significantly different. For the arterial and venous comparisons (n = 105), mean (+/-sd) arterial and venous values were the following: reaction time, 10 +/- 2 mm vs 13 +/- 4 mm, P = 0.004; maximum amplitude, 59 +/- 9 mm vs 49 +/- 12 mm, P < 0.001; alpha angle, 61 +/- 10 degrees vs 51 +/- 14 degrees, P < 0.001; K, 5 +/- 2 mm vs 8 +/- 4 mm, P = 0.007; and lysis, 2.5 +/- 1.7 vs 2.5 +/- 2.0 (not significant), arterial versus venous, respectively. Arterial blood samples demonstrated TEG values reflecting stronger (larger maximum amplitude) and faster (shorter reaction time and K value, wider alpha angle) clot formation. The results suggest that users of TEG coagulation analyzers should be consistent with the site of blood sampling given the potential differences obtained.

IMPLICATIONS

Thrombelastograph (TEG) values obtained from venous blood samples differ from values obtained from arterial blood samples. When the TEG coagulation analyzer is used for clinical purposes, it is important to be consistent in the blood collection site.

"Avian-type" renal medullary tubule organization causes immaturity of urine-concentrating ability in neonates

BACKGROUND

While neonatal kidneys are not powerful in concentrating urine, they already dilute urine as efficiently as adult kidneys. To elucidate the basis for this paradoxical immaturity in urine-concentrating ability, we investigated the function of Henle's loop and collecting ducts (IMCDs) in the inner medulla of neonatal rat kidneys.

METHODS

Analyses of individual renal tubules in the inner medulla of neonatal and adult rat kidneys were performed by measuring mRNA expression of membrane transporters, transepithelial voltages, and isotopic water and ion fluxes. Immunofluorescent identification of the rCCC2 and rCLC-K1 using polyclonal antibodies was also performed in neonatal and adult kidney slices.

RESULTS

On day 1, the transepithelial voltages (V(Ts)) in the thin ascending limbs (tALs) and IMCDs were 14.6 +/- 1.1 mV (N = 27) and -42.7 +/- 6.1 mV (N = 14), respectively. The V(Ts) in the thin descending limbs (tDLs) were zero on day 1. The V(Ts) in the tALs were strongly inhibited by luminal bumetanide or basolateral ouabain, suggesting the presence of a NaCl reabsorption mechanism similar to that in the thick ascending limb (TAL). The diffusional voltage (V(D)) of the tAL due to transepithelial NaCl gradient was almost insensitive to a chloride channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB). The V(Ts) in the IMCDs were strongly inhibited by luminal amiloride. On day 1, both the tDL and tAL were impermeable to water, indicating the water impermeability of the entire loop. Diffusional water permeability (P(dw)) and urea permeabilities (P(urea)) in the IMCDs indicated virtual impermeability to water and urea on day 1. Stimulation by vasopressin (1 nmol/L) revealed that only P(dw) was sensitive to vasopressin by day 14. A partial isoosmolar replacement of luminal urea by NaCl evoked negligible water flux across the neonatal IMCDs, indicating the absence of urea-dependent volume flux in the neonatal IMCD. These transport characteristics in each neonatal tubule are similar to those in quail kidneys. Identification of mRNAs and immunofluorescent studies for specific transporters, including rAQP-1, rCCC2, rCLC-K1, rENaC beta subunit, rAQP-2, and rUT-A1, supported these findings.

CONCLUSION

We hypothesize that the renal medullary tubule organization of neonatal rats shares a tremendous similarity with avian renal medulla. The qualitative changes in the organization of medullary tubules may be primarily responsible for the immature urine-concentrating ability in mammalian neonates.

Targeting platelet aggregation: CD39 gene transfer augments nucleoside triphosphate diphosphohydrolase activity in injured rabbit arteries

BACKGROUND

CD39, the major endothelial nucleoside triphosphate diphosphohydrolase (NTPDase), plays an important role in local thromboregulation. We hypothesized that balloon injury (BI) leads to an acute reduction in arterial NTPDase activity that could be restored by a targeted gene delivery strategy.

METHODS

Recombinant adenoviral vectors containing human CD39 (Ad-CD39) or beta-galactosidase (Ad-LacZ) were used. Endothelial (ECs) and smooth muscle cells (SMCs) were infected in vitro and NTPDase activity measured. New Zealand white rabbits (N = 28) underwent bilateral iliofemoral artery balloon injury, followed by incubation with Ad-CD39, Ad-LacZ, or vehicle. Explanted vessels were analyzed for NTPDase activity and localization of CD39 expression by immunohistochemistry. Deposition of fluorescent-labeled platelets was studied 3 days after injury and vector treatment.

RESULTS

In vitro, Ad-CD39 infection resulted in a greater than 40-fold increase in adenosine diphosphatase activity in ECs and a 3-fold increase in SMCs. In vivo, CD39 transgene expression localized to the luminal aspect of Ad-CD39--treated vessels. BI resulted in an acute reduction in vessel wall NTPDase activity (P <.05). Ad-CD39 augmented NTPDase activity when compared with vehicle or Ad-LacZ (P <.05). Platelet deposition on the injured arterial surface was modest and not different between Ad-CD39-- and Ad-LacZ--treated vessels.

CONCLUSIONS

BI decreases native NTPDase activity, which can be augmented by adenovirus-mediated gene transfer of CD39. Further studies are required to determine whether targeted delivery of CD39 could convey thromboprotective properties to an injured vessel.

Inactivity and muscle: effect of resistance training during bed rest on muscle size in the lower limb

The present study aimed to investigate the effect of dynamic leg press training on the physiological cross-sectional areas (PCSAs) of human lower limb muscles during 20 days of 6 degrees head-down tilt bed rest. Five healthy men comprised the resistance training group (BR-Tr) and data from two previous studies were used to derive a 10-man control group (BR-Cont). The BR-Tr performed two sessions (morning and afternoon session) of dynamic leg press action including knee extension and plantar flexion daily for the bed rest period: (1) three sets of 10 repetitions at 90% of maximum load and (2) 40% of maximum load to exhaustion. The PCSAs of the knee extensor (KE), knee flexor (KF), plantar flexor (PF), and dorsiflexor muscle groups were estimated using serial axial magnetic resonance (MR) images of the right-thigh and leg. After the bed rest period, the BR-Tr showed a significant increase in the PCSA of the KE. Although PCSA of the KF in two groups significantly decreased after bed rest, percentage of change in PCSA of the biceps femoris (long head) and semitendinosus muscles in the BR-Tr, which occupied approximately 70% of the KF, was significantly higher than those in the BR-Cont. Both the BR-Tr and BR-Cont groups showed significant decreases in the PCSA of PF with similar magnitude of 11.6% (P < 0.001) and 11.9% (P < 0.001), respectively. These results suggest that dynamic leg press training during bed rest can prevent deteriorating of the KE and a part of KF, but not the calf muscles.

Calcitriol controls the epithelial calcium channel in kidney

The recently cloned epithelial Ca2+ channel (ECaC), which is expressed primarily in 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3))-responsive Ca2+ -transporting epithelia, is postulated to constitute the rate-limiting step in active Ca2+ reabsorption. In the present study, the effect of 1,25(OH)(2)D(3) was investigated on ECaC mRNA and protein levels in kidneys of rats that were raised on a vitamin D-depleting diet. This diet decreased the serum 1,25(OH)(2)D(3) concentration significantly, which was accompanied by a marked drop in serum Ca2+ level. Both 1,25(OH)(2)D(3) and Ca2+ levels were normalized within 48 h after 1,25(OH)(2)D(3) administration. In 1,25(OH)(2)D(3)-deficient rats, ECaC mRNA and protein levels of the kidney cortex were significantly decreased compared with the repleted animals, suggesting that 1,25(OH)(2)D(3) exerts its stimulatory effect on Ca2+ reabsorption via increased ECaC expression. In agreement with this observation, the elucidated human ECaC promoter contains several consensus vitamin D-responsive elements. ECaC was restricted to the apical membrane of the distal part of the distal convoluted and the connecting tubule. This conclusion was based on only minor overlap with the localization of the thiazide-sensitive NaCl co-transporter and complete co-localization with the 1,25(OH)(2)D(3)-dependent Ca2+ binding protein, calbindin-D(28K). In conclusion, ECaC, present in the distal part of the nephron, is an important target for 1,25(OH)(2)D(3)-mediated Ca2+ reabsorption.

Significance of fetal fibronectin and cytokine measurement in the cervicovaginal secretions of women at term in predicting term labor and post-term pregnancy

OBJECTIVE

To determine whether fetal fibronectin (FFN) or cytokine concentrations in cervicovaginal secretions can be used to predict term labor and post-term pregnancy.

STUDY DESIGN

FFN and cytokines were assayed in cervicovaginal mucus from 122 pregnant women at 29-35 weeks and weekly from week 36 to parturition.

RESULTS

FFN concentrations were elevated from about 3 weeks before parturition; a correlation was found between FFN levels and sampling-to-delivery intervals. Parturition was best predicted within 7 days of sampling when the FFN value was >or=50ng/ml between 36 and 41 gestational weeks. Interleukin-1beta (IL-1beta) concentrations were elevated from 3 to 4 weeks before parturition; a correlation was found between IL-1beta levels and sampling-to-delivery intervals. Parturition was best predicted within 7 days of sampling, with an IL-1beta cut-off value of >or=100pg/ml.

CONCLUSION

Term labor and post-term pregnancy can be predicted within 7 days of sampling, using FFN and IL-1beta concentrations in cervicovaginal secretions of pregnant women.

Optical coherence tomography of tractional macular elevations in eyes with proliferative diabetic retinopathy

PURPOSE

To document the findings of optical coherence tomography in eyes with tractional macular elevation associated with proliferative diabetic retinopathy, paying special attention to differentiating between tractional retinal detachment and retinoschisis.

DESIGN

Observational case series.

METHODS

We retrospectively reviewed images of optical coherence tomography obtained from 17 consecutive eyes (17 patients) with proliferative diabetic retinopathy without vitreous opacity and showing tractional macular elevation with or without foveal involvement.

RESULTS

Tractional retinal detachment and retinoschisis could be differentiated in the cross-sectional images of optical coherence tomography. Retinoschisis with or without associated retinal detachment was observed in 16 of 17 eyes (94%), whereas retinal detachment was observed in only six of 17 eyes (35%). Five eyes showed both findings of retinal detachment and retinoschisis.

CONCLUSIONS

Optical coherence tomography is useful for distinguishing tractional retinoschisis from retinal detachment in eyes with proliferative diabetic retinopathy and macular elevation. Tractional retinoschisis with or without retinal detachment is the most frequent pattern of tractional macular elevation in eyes with proliferative diabetic retinopathy.

A novel recombinant adeno-associated virus vaccine induces a long-term humoral immune response to human immunodeficiency virus

Recombinant adeno-associated virus (AAV) has attracted tremendous interest as a promising vector for gene delivery. In this study we have developed an HIV-1 vaccine, using an AAV vector expressing HIV-1 env, tat, and rev genes (AAV-HIV vector). A single injection of the AAV-HIV vector induced strong production of HIV-1-specific serum IgG and fecal secretory IgA antibodies as well as MHC class I-restricted CTL activity in BALB/c mice. The titer of HIV-1-specific serum IgG remained stable for 10 months. When AAV-HIV vector was coadministered with AAV-IL2 vector, the HIV-specific cell-mediated immunity (CMI) was significantly enhanced. Boosting with AAV-HIV vector strongly enhanced the humoral response. Furthermore, the mouse antisera neutralized an HIV-1 homologous strain, and BALB/c mice immunized via the intranasal route with an AAV vector expressing the influenza virus hemagglutinin (HA) gene showed protective immunity against homologous influenza virus challenge. These results demonstrate that AAV-HIV vector immunization may provide a novel and promising HIV vaccination strategy.

Protein kinase C and phosphatidylinositol 3-kinase independently contribute to P-glycoprotein-mediated drug secretion in the mouse proximal tubule

We have recently reported that the apical membrane of the proximal tubule S2 segment from wild-type mice (WT mice) has the capacity for P-glycoprotein- (P-gp-) mediated drug efflux, whereas mice in which both mdr1a and mdr1b genes are disrupted (KO mice) do not. To examine the intracellular regulatory mechanisms of drug-transporting P-gp activity, we isolated and perfused proximal tubule S2 segments from WT and KO mice, and measured luminal efflux of the intracellular fluorescence of rhodamine 123, a fluorescent substrate of P-gp. The decay half-time of the intracellular fluorescence (t1/2) was regarded as an index of the drug-transporting P-gp activity. In the WT mice, the t1/2 was 36+/-5 s (n=35) during the basal period, and was significantly increased to 440+/-45 s by the luminal addition of verapamil (an inhibitor of P-gp). The addition of phorbol 12-myristate 13-acetate (PMA) [a protein kinase C (PKC) activator] to the bath increased t1/2, but 4alpha-phorbol (the inactive form of PMA) did not. The PMA-induced increase in t1/2 was further increased by the luminal addition of verapamil, and was partially inhibited by co-treatment with staurosporine or H-7 (inhibitors of PKC). Pretreatment with wortmannin or LY294002 [inhibitors of phosphatidylinositol 3-kinase (PI 3-kinase)] added to the bath also increased t1/2. The wortmannin- and LY294002-induced increase in t1/2 was also further increased by the luminal addition of verapamil. The effects of PMA on t1/2 were additive after cotreatment with wortmannin or LY294002. In the KO mice, t1/2 was 440+/-25 s (n=18) during the basal period, and was no longer affected by the addition of verapamil, staurosporine, H-7, wortmannin, or LY294002. Based on the use of pharmacological agents, we conclude that in the proximal tubule from WT mice, P-gp-mediated drug secretion occurs independently via PKC- and PI 3-kinase-dependent processes, whereas it is not present in KO mice, independently of PKC- and PI 3-kinase.

Learning proper nouns and common nouns without clues from syntax

Syntax has been noted to play an important role in word learning in English; it distinguishes the fundamental conceptual difference between individuals (coded as proper nouns), nonindividuals (coded as mass nouns), and classes of individuals (coded as count nouns). The Japanese language does not have grammatical markers flagging the distinctions between count nouns and mass nouns, between proper nouns and common nouns, or between singulars and plurals. How Japanese 2- and 4-year-olds assign meaning to novel nouns associated with familiar and unfamiliar animals and inanimate objects was studied in the research reported here. When a novel label was given to an unfamiliar object, children assumed it to be a name for a basic-level object category whether the referent was an animal or an inanimate object. If the named object already had an established name, and if the object was an inanimate object, the children mapped the noun to a subordinate category. When the named object was an animal, however, they tended to interpret the label as a proper name. These results demonstrated that in the absence of useful information from syntax, 2-year-old Japanese children are able to fast map a noun to its meaning by elegantly coordinating word-learning biases and other available sources of information.

Matrix metalloproteinases in human diabetic and nondiabetic vitreous

PURPOSE

To compare matrix metalloproteinase (MMP) activities in human vitreous samples from patients with diabetic retinopathy (DR) and other vitreoretinal diseases, and to investigate the factors influencing the MMP activities in human DR vitreous samples.

METHODS

Thirty-one diabetic and 17 nondiabetic vitreous samples (from nine patients with macular holes and eight patients with epiretinal membranes) were examined. Samples collected at the time of pars plana vitrectomy were subjected to substrate zymography to conduct a quantitative analysis of MMP activity. Immunoblotting against antihuman MMP-1, 2, and 9 was performed to identify MMP in vitreous samples. The effects of posterior vitreous detachment (PVD), vitreous hemorrhage, proliferative membrane, traction detachment, and cystoid macular edema on MMP activities were investigated.

RESULTS

All vitreous samples from both DR and non-DR patients showed a single band at the position of 72 kD, corresponding to MMP-2. Another band at 99 kD, corresponding to MMP-9, was detected significantly more often in DR samples than in non-DR samples: 45.2% and 0%, respectively (P = 0.0007). The number of samples showing a band from MMP-9 was significantly higher in partial PVD samples than in complete PVD samples: 66.7% and 15.4%, respectively (P = 0.001).

CONCLUSION

The results indicated that MMP-9 may be involved in DR and that partial PVD may be related to the MMP-9 activity in DR.

Impact of HIV type 1 protease, reverse transcriptase, cleavage site, and p6 mutations on the virological response to quadruple therapy with saquinavir, ritonavir, and two nucleoside analogs

Genotype alterations of HIV-1 protease, reverse transcriptase, cleavage sites p7/p1 and p1/p6, as well as p6(gag) and transframe protein p6* were studied in an observational cohort of 42 individuals who received antiretroviral therapy consisting of saquinavir, ritonavir, and two nucleoside analogs. In a multivariate logistic regression analysis, the prior protease inhibitor experience (odds ratio, 6.20; 95% CI, 1.22-31.38) and the presence of primary protease mutations (odds ratio, 9.99; 95% CI, 1.05-94.72) were independently associated with virological failure. Moreover, a trend was observed in that individuals with N-terminal amino acid insertions in the proline-rich motif of the p6(gag) protein were less likely to experience virological failure (OR, 0.17; 95% CI, 0.02-1.35; p = 0.09). In contrast, the presence of secondary protease, reverse transcriptase, or cleavage site mutations was not independently associated with treatment failure. However, mutations at cleavage site p7/p1 (p = 0.01) and C-terminal p6* mutations (p = 0.02) were both associated with primary protease mutations. In conclusion, the presence of primary protease mutations was the most important predictor of the subsequent virological response. Moreover, there is some evidence that insertions in the proline-rich area of the p6(gag) protein may affect the virological response. The relationship between mutations of cleavage sites or C-terminal p6* residues and protease mutations suggests that these alterations may serve a compensatory role, increasing viral fitness.

Identification of a new multigene four-transmembrane family (MS4A) related to CD20, HTm4 and beta subunit of the high-affinity IgE receptor

We report here the cloning of eight new cDNAs that encode a family of proteins related to the B-cell-specific antigen CD20, a hematopoietic-cell-specific protein HTm4, and high affinity IgE receptor beta chain (FcvarepsilonRIbeta). They include four clones from human, and another four clones from mouse. They share similar structure (four transmembrane domains) with amino acid identities of 25-40%. Therefore, they represent distinct genes and comprise a gene superfamily. This superfamily is now named membrane-spanning four-domains, subfamily A (the approved symbol is MS4A) to distinguish them from tetraspanins with similar structure. The highest homologies among these proteins are found in the transmembrane domains, especially in the first and second transmembrane domains, and conserved residues are also recognized in the inter-transmembrane domains. In northern blot, they were mostly expressed in lymphoid tissues: thymus and spleen. However, some were expressed in nonlymphoid tissues including brain, heart, kidney, liver, testis, lung, GI tracts, and pancreas. They may represent proteins functioning either directly as ligand-gated ion channels or as essential components of such channels. The identification of this relatively large gene family in various tissues will allow the further elucidation of physiological significance of this gene family, that is currently unclear.

[Anesthesia for a patient with cardiac sarcoidosis]

Anesthesia for a 49-year-old man with cardiac sarcoidosis is reported. Preoperative cardiac examination showed left ventricular dysfunction (ejection fraction = 27%) and myocardial conduction defects. In addition, his previous history included atrial fibrillation and cerebral infarction. Transesophageal echocardiography showed thrombus in the left appendage. Anesthesia was induced with fentanyl and diazepam and maintained with fentanyl and isoflurane. Perioperative hemodynamic monitoring included direct arterial pressure, central venous and pulmonary artery pressure and continuous cardiac output. In addition, transesophageal echocardiography was useful for watching thrombus in the left appendage. His hemodynamic condition was stable and no neurological complication was noted after anesthesia.

[A case of multiple sclerosis with recurrent episodes of psychiatric symptoms]

We reported a 19-year-old woman with multiple sclerosis (MS) with recurrent episodes of psychiatric symptoms at the age of 10 and 19, as the first and 11th relapse, respectively. Her first episode of MS resembled acute encephalitis at the age of 9 and she relapsed 12 times. The psychiatric symptoms were not mood disorders but altered states of consciousness, such as the delirous state. She was treated with high doses of intravenous methylpredonisolone and her symptoms were almost resolved, but her anxiety neurosis remained. Her MRI showed demyelination in the white matter of the frontal lobe and the hippocampus, which suggested that psychiatric symptoms of MS would be related to the frontal lobe lesion.

Changes in muscle size, architecture, and neural activation after 20 days of bed rest with and without resistance exercise

Nine healthy men carried out head-down bed rest (BR) for 20 days. five subjects (TR) performed isometric, bilateral leg extension exercise every day, while the other four (NT) did not. Before and after BR, maximal isometric knee extension force was measured. Neural activation was assessed using a supramaximal twitch interpolated over voluntary contraction. From a series cross-sectional magnetic resonance imaging scans of the thigh, physiological cross-sectional areas (PCSA) of the quadriceps muscles were estimated (uncorrected PCSA, volume/estimated fibre length). Decrease in mean muscle force after BR was greater in NT [-10.9 (SD 6.9)%, P < 0.05] than in TR [0.5 (SD 7.9)%, not significant]. Neural activation did not differ between the two groups before BR, but after BR NT showed smaller activation levels. Pennation angles of the vastus lateralis muscle, determined by ultrasonography, showed no significant changes in either group. The PCSA decreased in NT by -7.8 (SD 0.8)% (P < 0.05) while in TR PCSA showed only an insignificant tendency to decrease [-3.8 (SD 3.8)%]. Changes in force were related more to changes in neural activation levels than to those in PCSA. The results suggest that reduction of muscle strength by BR is affected by a decreased ability to activate motor units, and that the exercise used in the present experiment is effective as a countermeasure.

P-glycoprotein-mediated drug secretion in mouse proximal tubule perfused in vitro

To examine the functional significance of drug-transporting P-glycoprotein (P-gp), studies were conducted in the isolated and perfused proximal tubule S2 segment from mice disrupting both mdr1a and mdr1b genes [mdr1a/1b(-)(-)] and their wild-type mice. Efflux of the intracellular fluorescence of rhodamine 123, a fluorescence substrate of P-gp, into the lumen was measured, and the decay half-time of the intracellular fluorescence (T(1/2)) as an index of the drug-transporting P-gp activity was regarded. In the wild-type mice, the T(1/2) was 34 +/- 4 s (n = 36) at the basal period and was increased to 434 +/- 41 s by the addition of luminal verapamil, a P-gp inhibitor. In the mdr1a/1b(-)(-) mice, the T(1/2) was 407 +/- 16 s (n = 10) at the basal period and was no longer affected by the luminal addition of verapamil. The digoxin content in the kidney after a repeated administration of the drug was markedly elevated in the mdr1a/1b(-)(-) mice. In conclusion, P-gp-mediated drug efflux capacity indeed exists in the apical membrane of proximal tubule cells from the wild-type mice, whereas it is absent in that of the mdr1a/1b(-)(-) mice.

Congenital giant aneurysm of the left atrial appendage mimicking pericardial absence case report

A 25-year-old man was found to have an abnormal cardiac contour on a chest radiograph, and was referred. Transesophageal echocardiography suggested herniation of the left atrial appendage (LAA) through a gap in the pericardium, and magnetic resonance imaging indicated congenital partial absence of the pericardium. Cardiac dysfunction was caused by compression from the enlarged left atrium and thrombi were thought to be present in the appendage, so surgery was performed. The intraoperative diagnosis was congenital LAA aneurysm. Although distinguishing between congenital LAA aneurysm and congenital absence of the pericardium is reported to be possible with magnetic resonance imaging, we were unable to so in this case.

A calcium-activated cation current by an alternatively spliced form of Trp3 in the heart

To investigate a cDNA encoding cation current, we isolated an alternatively spliced form of a rat Trp3, designated Trp3sv. Trp3sv encodes 736 amino acids with a unique N terminus and six transmembrane segments. Expression of the cRNA in Xenopus oocytes was successfully performed. The cation selective current appeared after the addition of ionomycin or induced by prolonged depolarization but not by hyperpolarization. This induction was not observed by a treatment with thapsigargin, phorbol ester, or ATP. Na(+), K(+), tetraethylammonium, and divalent cations were permeable, while N-methylglucamine and chloride were nominally impermeable ions. The currents were not inhibited by flufenamate ruthenium red but nonspecifically by 2 mm Gd(3+). Northern as well as Western blot suggested lower levels of the expression observed in some organs, while reverse transcriptase-polymerase chain reaction suggested that it widely spread among various organs. Therefore, we may conclude that N-terminal spliced valiant of Trp3, Trp3sv, encodes a calcium-activated cation channel in various organs.

[Rethinking the Sapir-Whorf hypothesis: role of language in shaping thought]

Traditionally, the issue of the relationship between language and thought has been framed as the Sapir-Whorf hypothesis, in which crosslinguistic-crosscultural universality or diversity of thought has been the center of the debate. The long-lasting debate revolving around the hypothesis has not yielded a clear, satisfactory conclusion. This unsatisfactory result seems to be largely attributed to the fact that (a) the term "thought" has been so vaguely defined, and that (b) the interpretation of the Sapir-Whorf hypothesis itself has been quite diverse among researchers. In this paper, I argue that the question we should ask is not whether thought is universal or different across different language groups. Instead, we should ask more specific (and realistic) questions, taking it for granted that our thought is constrained by innate language-independent cognitive faculties but at the same time a large part of our thought is shaped by language. The questions we should ask are: in what cognitive domains (e.g., spatial cognition, ontological knowledge, categorization of natural objects etc.), at what specific level (e.g., perception, memory, knowledge representation, on-line information processing) and in what degree (a) our thought is influenced by the specific structure of the given language (or is immune to it) and (b) our thought is shaped by language learning (or constrained by language-independent innate cognitive structure). In order to reevaluate the Sapir-Whorf hypothesis in this new perspective, I reviewed literature mainly focusing on three distinctive cognitive domains: ontological knowledge with respect to individuation, categorization of natural objects, and spatial cognition.

Secoiridoid glycosides from the flower buds of Lonicera japonica

Two secoiridoid glycosides, loniceracetalides A and B, were isolated in very small amounts, together with 10 known iridoid glycosides, from the flower buds of Lonicera japonica. The structures of loniceracetalides A and B were determined by spectroscopic analysis.

[Sensitivity and specificity of rapid diagnosis kit detecting separately influenza A and B viruses]

Sensitivity and specificity of the Directigen Flu A + B kit, a rapid test for influenza virus A and B, were evaluated. This test detects influenza A and B viruses separately by EIA. Reactivity of the kit was tested using a total of 23 isolates: 13 isolates of human influenza virus A (H1N1, H3N2) and 10 isolates of human influenza virus B. All of the isolates were tested positive and no difference in reactivity was found in antigenic variables and subtypes. The kit was only reactive to influenza virus A and B, not reactive to other viruses. Typical influenza A and B strains were tested for detection limit. 7.8 x 10(3) pfu/ml was a detection limit for influenza virus A (H1N1: Beijing/262/95), 4.7 x 10(4) pfu/ml for influenza virus A (H3N2: Kitakyusyu/159/93), and 3.1 x 10(4) pfu/ml for influenza virus B (Guangdong/05/94). The Directigen Flu A + B kit was a easy-to-use, rapid detection device and the kit has sensitivity and specificity equivalent to other diagnostic devices, suggesting the kit are useful in medical institutions.

[Clinical evaluation of rapid diagnostic kit detecting separately influenza A and B viruses]

The Directigen Flu A + B kit, a rapid diagnostic device for influenza virus A and B was evaluated. The nasopharyngeal aspirates were obtained from 239 patients who visited our hospital, between January and March, 2000, presenting flu-like symptoms. Influenza virus AH1: 77 and AH3: 51 were isolated from 128 specimens and none from 111 specimens. Directigen Flu A + B showed 115 specimens positive and 106 specimens negative. The sensitivity and specificity of this kit were 89.8% (115/128) and 95.5% (106/111) compared with viral isolation. Agreement on positive and negative interpretations between Direction Flu A and this kit was 97.9% (234/239). In the evaluation of this kit for influenza B virus, 60 frozen nasopharyngeal aspirates collected from February to April, 1999 were used. The sensitivity and specificity of this kit were 88.9% (16/18) and 88.1% (37/42) compared with viral isolation. Agreement on positive and negative interpretations between FLU OIA and this kit was 91.7% (55/60). The Directigen A + B demonstrated sensitivity and specificity equivalent to the conventional kits in nasopharingeal aspirates. This kit can also differentiate influenza A and B viruses, a feature which is useful for treatment using anti-viral agents such as amantadine and neuraminidase inhibitor. To date, the kit is the most effective tool for the rapid diagnosis of influenza.

Protective effect of phytic acid hydrolysis products on iron-induced lipid peroxidation of liposomal membranes

Beneficial effects of dietary phytic acid (myo-inositol hexaphosphate; IP6) have often been explained by its strong iron ion-chelating ability, which possibly suppresses iron ion-induced oxidative damage in the gastrointestinal tract. Because phytic acid is hydrolyzed during digestion, this work aimed to know whether its hydrolysis products (IP2, IP3, IP4, and IP5) could still prevent iron ion-induced lipid peroxidation. Studies using liposomal membranes demonstrated that hydrolysis products containing three or more phosphate groups are able to inhibit iron ion-induced lipid peroxidation although their effectiveness decreased with dephosphorylation. Similarly, they also prevented iron ion-induced decomposition of phosphatidylcholine hydroperoxide. These results demonstrate that intermediate products of phytic acid hydrolysis still possess iron ion-chelating ability, and thus they can probably prevent iron ion-induced lipid peroxidation in biological systems.

Application of Rh-catalyzed cyclization to the formation of a chiral quaternary carbon

Rh-Catalyzed cyclization was applied to the formation of a chiral quaternary carbon. It has become clear that the Rh-complex can discriminate between isopropenyl and 2-isopentenyl (or isopentyl) substituents, and the cyclization afforded 3,3,4-trisubstituted cyclopentanones with a chiral quaternary carbon in a stereoselective manner. The cyclization of 4-pentenals 6a, b by an achiral neutral Rh(PPh3)3Cl afforded 3,3,4-cis-trisubstituted cyclopentanones (+/-)-7a,b in 86-96%, and the cyclization by a cationic Rh[(R)-BINAP]CIO4 afforded 3,3,4-trans-trisubstituted cyclopentanones (-)-8a, b of 82-86% ee in 88-98% yields. The mechanism of stereoselection by Rh-complexes is also discussed.

Fluctuations of lamellar structure prior to a lamellar-->gyroid transition in a nonionic surfactant system

Fluctuations of lamellar structure prior to a lamellar-->gyroid transition in a nonionic surfactant-water system has been investigated by means of small-angle x-ray scattering (SAXS) and differential scanning calorimeter measurements. For large DeltaT (DeltaT=T-T(LG), where T is the temperature and T(LG) the lamellar-->gyroid transition temperature) in the lamellar phase, the SAXS profiles can be described by a Caille correlation function for undulating lamellar structure. Approaching the temperature to the T(LG), an excess diffuse scattering grows at the lower Q (Q is the magnitude of scattering vector) side of the first lamellar peak. Highly oriented lamellar samples revealed that the excess diffuse scattering arises from in-plane density fluctuations. We attribute this diffuse scattering to the perforation fluctuation layer (PFL) structure and we show that the PFL is an equilibrium structure. At T(LG), the PFL transformed to the gyroid phase through a transient ordered structure having a rhombohedral symmetry.

Metastatic cardiac papillary carcinoma originating from the thyroid in both ventricles with a mobile right ventricular pedunculated tumor

A 62-year-old man with a history of surgical therapy for papillary thyroid carcinoma was admitted because of chest pain, dyspnea on effort, pretibial edema, and slight fever. An electrocardiogram showed ST segment elevation in the precordial leads and low voltage in the limb leads. A large solid mass was demonstrated in both ventricles, with pericardial effusion, by echocardiography, thoracic computed tomography scan, transesophageal echocardiography, and angiography. A punch biopsy of the tumor revealed metastatic papillary carcinoma. During radiation therapy, the patient suddenly died of ventricular fibrillation. At autopsy, the tumor occupied almost the entire right ventricular cavity, expanding toward the main trunk of the pulmonary artery with a mobile peduncle and it had infiltrated the left ventricular wall through the interventricular septum. Microscopic examination confirmed metastatic papillary thyroid carcinoma. Only 2 other cases of cardiac metastases of papillary thyroid carcinoma have been reported and this case is the first report of metastases in both ventricles with a mobile right ventricular pedunculated tumor.

Effect of protamine on cation-selective permeability in hamster medullary thick ascending limb of Henle's loop

To estimate the contribution of the paracellular shunt pathway to cation-selective permeability in the hamster medullary thick ascending limb of Henle's loop, we observed the effect of protamine, a selective blocker of paracellular conductance, on salt-diffusion voltage (dVT) in the isolated nephron segment perfused in vitro. When 300 microg/ml protamine was added to the lumen, the lumen-positive dVT generated upon reduction of the lumen NaCl concentration was decreased from 5.1 +/- 0.9 to 0.8 +/- 0.8 mV and the calculated Na+/Cl- permeability ratio was decreased from 1.40 +/- 0.14 to 0.86 +/- 0.08. Although the effect of protamine persisted after removal of the agent from the lumen, addition of 30 U/ml heparin, which neutralizes protamine, returned the dVT toward the control level. This effect was almost the same when the orientation of the imposed NaCl gradient was reversed. Protamine exhibited a similar effect on dVT in the presence of ouabain added to the bath. Protamine was without effect from the bath. Protamine did not affect the basel VT perfused with the control solution. Increased VT by decreasing perfusion pressure was inhibited by adding protamine from the lumen. These observations suggest that the paracellular pathway contributes to the cation selectivity of the medullary thick ascending limb. The cation selectivity of the paracellular shunt pathway may mainly account for the changes in VT which are either dependent on the luminal flow rate or transmural NaCl concentration gradient, while it may not contribute to the basal level of VT.