Photoemission Orbital Tomography Using a Robust Sparse PhaseLift.

Photoemission orbital tomography (POT) from photoelectron momentum maps (PMMs) is a powerful technique that visualizes the shape of the molecular orbitals (MOs) of molecular films. For further utilization of POT, a simple and low-cost method of POT is highly required. Here, we propose a new POT method based on the PhaseLift algorithm (PhaseLift POT). This method utilizes a lifting procedure to convert the PMM, which is a second-order polynomial of MO coefficients, into a first-order polynomial of the lifted MO coefficients and further relaxes the equality constraint for a given PMM. We also established a method to improve the accuracy of phase retrieval from the noisy PMM data by using sparsity for MO coefficients (sparse PhaseLift POT). These methods make it possible to reconstruct the three-dimensional MOs, including phases of the wave function, directly from a single experimental PMM. This method can also precisely determine the adsorption-induced molecular deformations with an accuracy of 0.05 [Å]. Furthermore, the robust sparse PhaseLift POT is robust against unavoidable noise in the experimental PMMs due to the relaxation of the matching condition for a given PMM. Therefore, this will be an innovative tool for POT, especially for analyzing the dynamics of the molecules during the chemical reaction and excitation processes.

In-vitro fertilisation-embryo-transfer complicates the antenatal diagnosis of placenta accreta spectrum using MRI: a retrospective analysis.

AIM: To evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) for the antenatal diagnosis of placenta accreta spectrum (PAS). MATERIALS AND METHODS: Data from 95 patients with placenta previa or low-lying placenta who underwent MRI at Osaka University Hospital for the antenatal diagnosis of PAS between January 2013 and December 2018 were reviewed retrospectively. The antenatal MRI signs suggesting PAS were assessed. Patients were divided into two groups depending on whether they were diagnosed with PAS. Factors that affected PAS diagnosis were identified using multivariate analysis. RESULTS: The diagnostic accuracy of MRI for detecting PAS was as follows: 71.4% sensitivity, 96.4% specificity, and area under the curve (AUC) of 0.839 (95% confidence interval [CI]: 0.73-0.91). The diagnostic accuracy was lower in patients with in-vitro fertilisation with embryo transfer (IVF-ET): 22.2% sensitivity, 93.3% specificity, and AUC=0.578 (95% CI: 0.417-0.724). On multivariate analysis, only IVF-ET showed a significant association with false-positive or -negative MRI diagnosis of PAS (adjusted odds ratio: 26.5; 95% CI: 2.42-289.4; p=0.007). CONCLUSION: IVF-ET affects the antenatal diagnosis of PAS using MRI.

Short interpregnancy interval after B-Lynch uterine compression suture: a case report.

PURPOSE: The influence of the B-Lynch suture technique on subsequent fertility and pregnancy outcomes is not clear. In the present report, the authors describe the case of a very short interpregnancy interval following the successful placement of a B-lynch suture and discuss the associated problems. MATERIALS AND METHODS: A 33-year-old-woman underwent cesarean section after undergoing artificial induction of labor and subsequent atonic postpartum hemorrhage. Placement of a B-Lynch brace suture successfully stopped the bleeding and preserved the uterus. The patient became unexpectedly pregnant only four months later, making the present case the shortest reported interpregnancy interval after a surgery involving the B-Lynch suture. CONCLUSION: In the present case, fertility was not affected, and obstetric complications (abortion, fetal growth restriction, preterm delivery, and placenta previa) were not observed. Adhesions between the abdominal wall and the surface of the uterus along the previous B-Lynch suture line were observed and irregular, large blood vessels were observed on the surface of the uterus. Further reports are expected to determine the influence of the B-Lynch brace suture technique on the subsequent pregnancy.

Cesarean delivery via a transverse uterine fundal incision for the successful management of a low-lying placenta and aplastic anemia.

PURPOSE: To present a case report on the successful management of a low-lying placenta and aplastic anemia. Aplastic anemia is a rare but serious disorder that is often characterized by severe pancytopenia. Because of the rarity of aplastic anemia, a pregnancy complicated by it is rarely encountered by obstetricians. Moreover, placenta previa (low-lying placenta) complicated by aplastic anemia has not been previously reported. MATERIALS AND METHODS: The authors present the first reported case of placenta previa with aplastic anemia in a patient who had undergone a previous cesarean delivery. RESULTS: They successfully managed this case by making a transverse uterine fundal incision during an elective cesarean delivery. This incision minimized blood loss and enabled good visualization of the source of bleeding in the lower uterine segment. Bleeding was stemmed by suturing the source of bleeding. CONCLUSION: The authors propose that this procedure should be considered for patients with low platelet counts and abnormal placentation.

Interleukin-21 can efficiently restore impaired antibody-dependent cell-mediated cytotoxicity in patients with oesophageal squamous cell carcinoma.

BACKGROUND: We previously reported that Trastuzumab- and Cetuximab-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) in cancer patients was impaired in comparison with that in healthy donors because of NK-cell dysfunction. In this study, we evaluated whether IL-21 could improve the impairment of ADCC in patients with oesophageal squamous cell carcinoma (ESCC), as IL-21 was reported to have the ability to activate NK cells. METHODS: We examined Trastuzumab- and Cetuximab-mediated ADCC of peripheral blood mononuclear cells (PBMCs) or of enriched NK cells derived from ESCC patients (n=20) and healthy donors (n=16) in the presence of IL-21. We further analysed ADCC-related molecules (perforin, granzyme-B, and CD247) on NK cells in response to IL-21. RESULTS: Trastuzumab- and Cetuximab-mediated ADCC of PBMCs or of enriched NK cells was enhanced by the addition of IL-21 in a dose-dependent manner and the levels of ADCC enhanced by IL-21 in patients were high enough in comparison with those in healthy donors, paralleling the upregulation of CD247 on NK cells. CONCLUSION: IL-21 could efficiently restore impaired ADCC in ESCC patients with the upregulation of CD247 molecules.

Inverse correlation of HER2 with MHC class I expression on oesophageal squamous cell carcinoma.

BACKGROUND: As HER2 is expressed in 30% of oesophageal squamous cell carcinomas (ESCCs), T-cell-based immunotherapy and monoclonal antibodies targeted against HER2 are attractive, novel approaches for ESCCs. However, it was shown that there is an inverse correlation between HER2 and MHC class I expression on tumours. Thus, the correlation between HER2 and MHC class I expressions on ESCC was evaluated. METHODS: Expressions of MHC class I and HER2 in ESCC tissues (n=80) and cell lines were assessed by immunohistochemistry, fluorescence in situ hybridisation (FISH), and flow cytometry. We investigated whether HER2 downregulation with small interfering RNA (siRNA) in ESCC cell lines could upregulate the expression of MHC class I and the antigen presentation machinery components, and could increase their sensitivity for tumour antigen-specific CTLs. RESULTS: There was an inverse correlation between HER2 and MHC class I expressions in both tumour tissues and cell lines. Downregulation of HER2 with siRNA resulted in the upregulation of MHC class I expression, leading to increased CTL recognition by tumour antigen-specific CTLs. CONCLUSION: HER2-overexpressing ESCC tumour cells showed a reduced sensitivity for CTLs through the downregulation of MHC class I.

Oxidative stress-induced S100B protein from placenta and amnion affects soluble Endoglin release from endothelial cells.

Oxidative stress with elevated intracellular Ca(2+) concentration as well as endothelial dysfunction is a component of pre-eclampsia. Our aim was to investigate the oxidative stress-dependent expression of Endoglin and Ca(2+)-binding S100B protein from villous and amniotic tissue cultures, and to assess sEng expression from S100B protein-stimulated endothelial cells. We initially examined Endoglin and Hydroxy-nonenal-(HNE)-modified proteins in the placentas and amnion obtained from women with pre-eclampsia (n = 8), and healthy controls (n = 8) by immunohistochemistry. To examine oxidative stress and the S100B protein effect on sEng expression from endothelial cells, normal villous and amniotic tissue cultures were stimulated by 4-HNE, sodium fluoride and xanthine/xanthine oxidase, whereas human umbilical vein endothelial cell cultures were treated with S100B protein in a dose- and time-dependent manner at 37 degrees C in an environment of 95% air and 5% of CO(2). Culture supernatants were assessed using ELISA. Cell viability was determined using MTS assay. The concentrations of sEng and S100B protein were significantly increased in the villous and amniotic tissue culture supernatants under oxidative stress. S100B protein-stimulated endothelial cells released sEng into conditioned media with a significantly higher expression levels at a concentration of 200 pM-20 nM S100B by 2 h, whereas treated with 200 nM of S100B endothelial cells significantly expressed sEng by 12 h and stimulated the cell proliferation by the same period of time. Our findings show that oxidative stress affects sEng and S100B protein expression from villous and amniotic tissues, and picomolar and low nanomolar concentrations of S100B protein significantly up-regulate sEng release from endothelial cells leading to endothelial dysfunction.

CCL17 and CCL22 chemokines within tumor microenvironment are related to infiltration of regulatory T cells in esophageal squamous cell carcinoma.

It has been reported that an increased population of regulatory T cells (T-regs) is one of the reasons for impaired anti-tumor immunity. We investigated the frequency of Foxp3(+) T-regs in tumor-infiltrating lymphocytes (TILs) and peripheral blood lymphocytes (PBLs) of patients with esophageal squamous cell carcinoma (ESCC). Furthermore, in order to elucidate the mechanisms behind T-regs accumulation within tumors, we evaluated the relationship between CCL17 or CCL22 expression and the frequency of Foxp3(+) T-regs. CD4(+)CD25(+)Foxp3(+) T-regs as a percentage of CD4(+) cells were counted by flow cytometry. The frequency of CCL17(+) or CCL22(+) cells among CD14(+) cells in tumors was also evaluated by flow cytometry. Moreover, an in vitro migration assay using T-regs derived from ESCC was performed in the presence of CCL17 or CCL22. The frequency of Foxp3(+) T-regs in TILs was significantly higher than that in the normal esophageal mucosa (24.6 +/- 10.0 vs 7.1 +/- 5.9%, P < 0.01). The frequency of Foxp3(+) T-regs in PBLs of ESCC patients was significantly higher than that in normal healthy donors (7.0 +/- 4.2 vs 2.5 +/- 1.0%, P < 0.01). Furthermore, the frequency of CCL17(+) or CCL22(+) cells among CD14(+) cells within tumors was significantly higher than that of normal esophageal mucosa, and there was a significant correlation between the frequency of CCL17(+) or CCL22(+) cells and Foxp3(+) T-regs in TILs. In addition, the in vitro migration assay indicated that T-regs were significantly induced to migrate by CCL17 or CCL22. In conclusion, CCL17 and CCL22 within the tumor are related to the increased population of Foxp3(+) T-regs in ESCC.

NK cell dysfunction with down-regulated CD16 and up-regulated CD56 molecules in patients with esophageal squamous cell carcinoma.

NK cells can be divided into two subsets, CD56(dim) and CD56(bright) NK cells, based on their expression of CD56 and CD16. In the present study, we analyzed NK cell dysfunction in patients with esophageal squamous cell carcinoma (ESCC), with a particular focus on the expression of CD16 and CD56 molecules. Expression of CD16 and CD56, and the distribution of CD56(dim) or CD56(bright) NK cells gated on CD56(+)CD3(-) NK cells were compared between ESCC patients (n= 40) and healthy donors (n= 38). Purified NK cells were evaluated for Cetuximab-mediated antibody-dependent cellular cytotoxicity (ADCC) against epidermal growth factor receptor (EGFR)-expressing ESCC cell lines. Although there were no significant differences in the distribution of CD56(dim) and CD56(bright) NK cells between ESCC patients and healthy donors, down-regulated CD16 and up-regulated CD56 were significantly observed on NK cells of ESCC patients, paralleling the impairment of Cetuximab-mediated ADCC, in comparison with healthy donors. After patients received curative resections of ESCC, the down-regulated CD16 and up-regulated CD56 were significantly restored to the levels of healthy donors. Moreover, TGF-beta1 partially contributed to down-regulation of CD16 on NK cells. Down-regulated CD16 and up-regulated CD56 molecules on NK cells were observed in ESCC patients, resulting in NK cell dysfunction.

Development of visual pattern discrimination in the fly depends on light experience.

Pattern discrimination by dewinged walking flies (Boettcherisca peregrina) was tested in behavioral experiments. After emergence, the flies were deprived of light or visual patterns. Deprivation impaired the normal development of visual pattern discrimination without impairing phototaxis. Flies kept in a lighted, white, unpatterned environment could not discriminate visual patterns, nor could flies kept in continuous darkness. These results indicate that there is considerable plasticity in the structure of the visual system of these flies.

Amniotic fluid 'sludge' detected in patients with subchorionic hematoma: a report of two cases.

Amniotic fluid 'sludge' is defined as the presence of dense aggregates of particulate matter in close proximity to the internal cervical os. It is of clinical significance in asymptomatic patients at high risk for spontaneous delivery, and in patients with preterm labor and intact membranes. Subchorionic hematoma is another ultrasound finding that is associated with a higher incidence of threatened miscarriage and preterm delivery. We report two cases of occurrence of amniotic fluid sludge in patients with previously detected large subchorionic hematoma. In the first case subchorionic hematoma and amniotic fluid sludge were detected by ultrasonography at 13 + 1 and 18 + 6 weeks' gestation, respectively, followed by preterm premature rupture of membranes, placental abruption and emergency Cesarean section. In the second case subchorionic hematoma and amniotic fluid sludge were detected by ultrasound at 11 + 3 and 15 + 5 weeks' gestation, respectively, followed by miscarriage with histological chorioamnionitis. The coincidence of subchorionic hematoma and amniotic fluid sludge in these cases points to a possible connection between these two significant ultrasound findings.

The human tumor-associated antigen RCAS1 in pregnancies complicated by pre-eclampsia.

The human tumor-associated antigen RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is considered to play a role in the escape of tumor cells from immune surveillance and, at the same time, participates in the inhibition of the maternal immune response during pregnancy. The aim of our study was to investigate the expression of tumor-associated RCAS1 protein in the placenta and amniotic membranes and to assess and compare its concentration in amniotic fluid, maternal and cord blood sera in pregnancies complicated by pre-eclampsia. Samples were obtained from women with pre-eclampsia (N=9), pre-eclampsia with IUGR (N=4), normotensive IUGR (N=7) and healthy term controls (N=25) after delivery. Placentas were studied by immunohistochemistry, Western blot analysis and real-time (RT)-PCR. For assessment of RCAS1 protein concentrations in biological fluids, ELISA was performed. RCAS1 mRNA expression in the placentas of pre-eclamptic patients was significantly lower than in controls (p<0.01). The maternal blood serum RCAS1 protein concentration in the pre-eclampsia cases was also significantly lower than in controls (p=0.0207). The other study groups did not differ significantly. This study reveals the possible role of the RCAS1 protein in the development of pre-eclampsia through an immunological pathway.

Hard x-ray photoemission study of Yb1-x Zr x B12: the effects of electron doping on the Kondo insulator YbB12.

We have carried out hard x-ray photoemission spectroscopy (HAXPES) of Yb1-x Zr x B12 ([Formula: see text]) to study the effects of electron doping on the Kondo insulator YbB12. The Yb valences of Yb1-x Zr x B12 at 300 K estimated from the Yb 3d HAXPES spectra decreased after substituting Yb with Zr from 2.93 for YbB12 to 2.83 for Yb0.125Zr0.875B12. A temperature dependent valence decrease was found upon cooling for all doping concentrations. We found peak shifts of the B 1s and Zr 3d5/2, and Yb3+ 4f spectra toward the deeper binding-energy with increasing Zr concentration, which indicates a shift of the Fermi level to the higher energy and that of the Yb 4f hole level close to the Fermi level, respectively, due to electron doping. These results qualitatively show the enhanced hybridization between the Yb 4f and conduction-band states with Zr substitution, consistent with magnetic susceptibility measurements.

Hormone dependency of chromosome aberrations induced by 7,12-dimethylbenz[a]anthracene in rat bone marrow cells: site-specific increase by erythropoietin.

The frequency of chromosome aberrations (CA) 6 hours after iv injection of 50 mg 7,12-dimethylbenz[a]anthracene (DMBA)/kg was studied in bone marrow cells of the noninbred Long-Evans rat under various hematopoietic conditions. The percentage of metaphase cells with CA was enhanced by anemia and suppressed by polycythemia. The low incidence of CA in polycythemic rats was reversed by 6 U of sheep erythropoietin (EP) injected at the time of DMBA treatment. The interchromosomal and intrachromosomal distribution of CA indicated that hematopoietic stimuli, more specifically EP, greatly enhanced DMBA-induced CA in specific chromosomal regions.

Chemical carcinogenesis in the rat: common mode of action of carcinogens at the chromosome level.

The chromosomal distribution of chromosome aberrations (CA) and sister chromatid exchanges (SCE) induced by various chemical carcinogens such as 7,12-dimethylbenz[a]anthracene, 7,8,12-trimethylbenz[a]anthracene, 1-butyl-1-nitrosourea, urethan, 4-nitroquinoline 1-oxide, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide, and the antineoplastic compound mitomycin C was studied with the use of noninbred Long-Evans male rat bone marrow cells in vivo and in vitro. The CA and SCE induced by these structurally different chemicals were distributed in a similar pattern among and along chromosomes when the chemicals were given a short time (6 hr) before the metaphase cells were harvested. The specific distribution pattern of chemically induced CA and SCE along chromosomes was attributed to the late DNA replication of the vulnerable chromosome regions. Conversely, X-ray-induced CA were distributed more randomly. Thus the different chemical carcinogens were shown to exert a similar genetic effect at the chromosome level.

Change in oligomeric structure of solubilized Na+/K(+)-ATPase induced by octaethylene glycol dodecyl ether, phosphatidylserine and ATP.

Membrane-bound Na+/K(+)-ATPase purified from dog kidney was solubilized with octaethylene glycol dodecyl ether (C12E8), and the resultant solubilized enzyme was chromatographed on a TSKgel G4000SWXL or G3000SWXL column equilibrated with elution buffers containing various ligands affecting oligomerization of the enzyme. Weight-averaged molecular weight (Mw) values for the main protein components eluted were estimated by low-angle laser light-scattering photometry. With increasing concentration of C12E8 included in the elution buffer from 0.1 to 5 mg/ml, the Mw decreased from 230,000 to 153,000, indicating that C12E8 induced dissociation of the enzyme. In contrast, the Mw of the protein component increased up to 1.44.10(6) as the concentration of phosphatidylserine (PS) added to the elution buffer containing a fixed concentration of 0.3 mg/ml C12E8 was increased to 120 micrograms/ml. The association and/or aggregation were reversible by removal of the PS by rechromatography. Addition of PS to the elution buffer also allowed the solubilized enzyme to exhibit ATPase activity comparable to that of the membrane-bound enzyme during passage through the column. This was also the case with phosphatidylglycerol (PG) and phosphatidylinositol, but not with phosphatidylcholine or phosphatidylethanolamine. The specific refractive index increment (dn/dcp) of the solubilized enzyme was increased by addition of exogenous PG or PS, strongly suggesting that the phospholipid became bound to the enzyme, and that it induced association of the enzyme. The association induced by PS was inhibited by ATP and ADP, but not AMP. The concentrations for half-maximal inhibition were 0.44 mM for ATP and 0.88 mM for ADP. The PS-induced associated enzyme isolated by chromatography in the presence of 120 micrograms/ml PS was dissociated by ATP with K0.5 of 0.16 mM. The dissociating effect of C12E8, ATP and ADP and the associating effect of PS on the solubilized enzyme are consistent with the reports that C12E8 mimics the effect of regulatory ATP at the low-affinity site on the conformational transition from E2 to E1, and that phospholipids are essential for the reverse transition from E1 to E2. The results can be explained by assuming that the enzyme takes the form of a loosely associated diprotomer in the E1 state and a tightly associated one in the E2 state.

Minimum enzyme unit for Na+/K+-ATPase is the alpha beta-protomer. Determination by low-angle laser light scattering photometry coupled with high-performance gel chromatography for substantially simultaneous measurement of ATPase activity and molecular weight.

The oligomeric state of canine renal NA+/K+ -ATPase solubilized by octaethylene glycol n-dodecyl ether (C12E8) was studied by means of low-angle laser light scattering photometry coupled with high-performance gel chromatography (HPGC). At around 0 degree C the solubilized enzyme was separated into the (alpha beta)2-diprotomeric and alpha beta-protomeric protein components with Mr values of 302,000 +/- 10,000 and 156,000 +/- 4,000, respectively, in approximately equal quantities. As the temperature of chromatography was increased toward 20 degrees C, the two protein components converged into a single major component. The Mr of this component depended on the monovalent cation included in the elution buffer, and was 255,000 or 300,000 in the presence of 0.1 M NaCl or 0.1 M KCl, respectively. A computer simulation technique showed that the solubilized enzyme was in a dissociation-association equilibrium of 2 protomers = diprotomer at 20 degrees C, and the difference in apparent Mr of the solubilized enzyme between the two species of monovalent cation was interpreted by an association constant (Ka) in the presence of 0.1 M KCl that was about 50-fold larger than in the presence of 0.1 M NaCl. In order to measure ATPase activity and Mr of the solubilized enzyme simultaneously, a TSKgel G3000SW column had been equilibrated and was eluted with an elution buffer containing 0.30 mg/ml C12E8 and 60 microgram/ml phosphatidylserine (bovine brain) as well as the ligands necessary for the enzyme to exhibit the activity at pH 7.0 and 20 degrees C. The solubilized enzyme was always eluted as a single protein component irrespective of the the amount of the protein applied to the column, ranging between 240 and 10 microgram. The Mr of the protein component, however, decreased from 214,000 and 158,000 with the decrease of the protein amount. The specific ATPase activity, however, remained constant at a level of 64 +/- 4% of that of the membrane-bound enzyme even in the range of protein concentration sufficiently low as to allow the enzyme to exist only in the protomeric form. Thus, the alpha beta-protomer is concluded to be the minimum functional unit for the ATPase activity. The value of Ka obtained from the concentration-dependent dissociation curve was 5 . 10(5) M-1 for the enzyme turning over, and 1.1 . 10(7) M-1 for the enzyme inhibited with ouabain. It was discussed, based on the values of Ka obtained, that the enzyme would exist as the diprotomer or the higher oligomer in the membrane.

Side-chain structure is critical for the transport of sterols from lysosomes to cytoplasm.

Macrophages take up and metabolize negatively charged liposomes containing free cholesterol efficiently, resulting in a massive accumulation of cholesteryl esters and triacylglycerols in their cytoplasm (Nishikawa, K., Arai, H. and Inoue, K. (1990) J. Biol. Chem. 265, 5226-5231). This system was used to assess the effects of structural variation of sterol on the intracellular transport and the metabolism of endocytosed sterols by the cells. Liposomes containing phytosterols with an extra one (campesterol) or two (beta-sitosterol, stigmasterol, fucosterol) carbons at the C-24 position of the cholesterol side-chain were endocytosed as efficiently as those containing cholesterol without exhibiting any apparent toxicity on the cells. Esterification of endocyotosed phytosterols was, however, extremely low; campesterol esterification was only 20% that of cholesterol and either beta-sitosterol or stigmasterol was not esterified appreciably. A morphological study showed that the endocytosed phytosterols were accumulated in the phagolysosomes of the cells. Blocking of esterification of endocytosed cholesterol by an acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor did not lead to cholesterol accumulation in the phagolysosomes. These data suggest that accumulation of endocytosed phytosterols in phagolysosomes is not a consequence of the inability of the cell to esterify sterols in the endoplasmic reticulum. In the light of these observations, we conclude that cultured macrophages can discriminate between sterols that differ only by a methyl or ethyl group at the C-24 position at their lysosomal compartment.

Interstitial muscle insulin and glucose levels in normal and insulin-resistant Zucker rats.

To study interstitial insulin and glucose concentrations, microdialysis was performed in the medial femoral muscles in normal SD rats as well as in insulin-resistant obese Zucker rats during a euglycemic insulin clamp. [14C]inulin was given (0.1 mCi/rat) as a constant subcutaneous infusion 24 h before the insulin clamp. Insulin infusion rates were 5-8 mU x kg(-1) x min(-1) (low rate) for 140 min and 10-20 mU x kg(-1) x min(-1) (high rate) for another 100 min. The relationship between insulin and [14C]inulin dialysate recoveries was evaluated in vivo and in vitro in plasma to calculate interstitial insulin concentration. Relative microdialysis recovery of interstitial insulin in vivo was 3.0 +/- 0.3% (mean +/- SE, n = 68). In normal SD rats, plasma and interstitial insulin concentrations were identical when plasma insulin was < or =250 mU/ml, whereas interstitial insulin was lower when plasma insulin was > or =350 mU/ml. Half-maximal glucose infusion rate was achieved in the presence of plasma and interstitial insulin concentrations of approximately 140 mU/ml, whereas maximal glucose disposal was seen at interstitial insulin concentrations of approximately 325 mU/ml, corresponding to approximately 500 mU/ml in plasma. In electrically stimulated and contracting (1 Hz) normal muscle with markedly increased blood flow, the dialysate insulin concentration was significantly higher at high rates, but not at low rates, of insulin infusion. In insulin-resistant obese Zucker rats, the interstitial insulin concentration was similar to that in plasma, even at pharmacological concentrations. The glucose infusion rate was significantly lower in the obese Zucker rats at both insulin infusion rates than in the lean animals. The glucose content in dialysates from skeletal muscle was equal in both obese and lean rats during the low insulin infusion rate. During the high insulin infusion rate, dialysate glucose concentrations decreased significantly in both groups but were significantly higher in the obese Zucker rats. The data suggest that transport of insulin and glucose diffusion across the capillary wall are rate limiting for insulin as well as for glucose metabolism in muscle in normal rats. This does not appear to be the case in the insulin-resistant obese Zucker rats, where the reduced insulin responsiveness in muscle is due to muscular cellular defects rather than an inhibited transcapillary delivery of insulin.

Early evolution of large micro-organisms with cytological complexity revealed by microanalyses of 3.4 Ga organic-walled microfossils.

The Strelley Pool Formation (SPF) is widely distributed in the East Pilbara Terrane (EPT) of the Pilbara Craton, Western Australia, and represents a Paleoarchean shallow-water to subaerial environment. It was deposited ~3.4 billion years ago and displays well-documented carbonate stromatolites. Diverse putative microfossils (SPF microfossils) were recently reported from several localities in the East Strelley, Panorama, Warralong, and Goldsworthy greenstone belts. Thus, the SPF provides unparalleled opportunities to gain insights into a shallow-water to subaerial ecosystem on the early Earth. Our new micro- to nanoscale ultrastructural and microchemical studies of the SPF microfossils show that large (20-70 µm) lenticular organic-walled flanged microfossils retain their structural integrity, morphology, and chain-like arrangements after acid (HF-HCl) extraction (palynology). Scanning and transmitted electron microscopy of extracted microfossils revealed that the central lenticular body is either alveolar or hollow, and the wall is continuous with the surrounding smooth to reticulated discoidal flange. These features demonstrate the evolution of large micro-organisms able to form an acid-resistant recalcitrant envelope or cell wall with complex morphology and to form colonial chains in the Paleoarchean era. This study provides evidence of the evolution of very early and remarkable biological innovations, well before the presumed late emergence of complex cells.