Differences in Tissue Oxygenation, Perfusion and Optical Properties in Brain Areas Affected by Stroke: A Time-Resolved NIRS Study.

Near infrared spectroscopy (NIRS) has been applied to measurements of cerebral blood oxygenation (CBO) in normal subjects and patients with various brain disorders including cerebrovascular diseases. However, it is not known whether NIRS allow us to measure CBO correctly in patients with abnormal cortices where optical characteristics such as optical pathlength (OP) may differ from those in normal cortex. In the present study, employing a time-resolved NIRS (TNIRS), we compared baseline hemoglobin (Hb) concentrations and OPs between normal and abnormal cortices in chronic stroke patients. We studied five patients with chronic cerebral infarction (two males, three females, age 59.0 ± 24.2 years) who were admitted to the University Hospital of Fukushima Prefectural Medical University. Employing TNIRS (TRS-20, Hamamatsu Photonics), we measured baseline Hb concentrations and OPs (760, 800, 830 nm) at various positions on the head. We observed that deoxy-Hb concentrations were significantly lower on the affected side (p < 0.01), and the tissue oxygen saturation was significantly higher than that on the affected side (p < 0.01), suggesting that oxygen consumption was reduced on the affected side. In addition, the OPs (760, 800 nm) were significantly longer on the affected side (p < 0.05); these changes might be caused by a possible increase of cerebrospinal fluid layer associated with brain tissue degeneration by ischemia. The present results suggest that NIRS should be performed on patients with abnormal cerebral cortices, giving special consideration to the possible difference in optical characteristics between normal and abnormal brain tissues.

Ectopic cardiovascular fat in middle-aged men: effects of race/ethnicity, overall and central adiposity. The ERA JUMP study.

BACKGROUND/OBJECTIVES: Higher volumes of ectopic cardiovascular fat (ECF) are associated with greater risk of coronary heart disease (CHD). Identifying factors that are associated with ECF volumes may lead to new preventive efforts to reduce risk of CHD. Significant racial/ethnic differences exist for overall and central adiposity measures, which are known to be associated with ECF volumes. Whether racial/ethnic differences also exist for ECF volumes and their associations with these adiposity measures remain unclear. SUBJECTS/METHODS: Body mass index (BMI), computerized tomography-measured ECF volumes (epicardial, pericardial and their summation) and visceral adipose tissue (VAT) were examined in a community-based sample of 1199 middle-aged men (24.2% Caucasians, 7.0% African-Americans, 23.6% Japanese-Americans, 22.0% Japanese, 23.2% Koreans). RESULTS: Significant racial/ethnic differences existed in ECF volumes and their relationships with BMI and VAT. ECF volumes were the highest among Japanese-Americans and the lowest among African-Americans. The associations of BMI and VAT with ECF differed by racial/ethnic groups. Compared with Caucasians, for each 1-unit increase in BMI, African-Americans had lower, whereas Koreans had higher increases in ECF volumes (P-values<0.05 for both). Meanwhile, compared with Caucasians, for each 1-unit increase in log-transformed VAT, African-Americans, Japanese-Americans and Japanese had similar increases, whereas Koreans had a lower increase in ECF volumes (P-value<0.05). CONCLUSIONS: Racial/ethnic groups differed in their propensity to accumulate ECF at increasing level of overall and central adiposity. Future studies should evaluate whether reducing central adiposity or overall weight will decrease ECF volumes more in certain racial/ethnic groups. Evaluating these questions might help in designing race-specific prevention strategy of CHD risk associated with higher ECF.

Impact of tumor growth rate during preceding treatment on tumor response to nivolumab or irinotecan in advanced gastric cancer.

BACKGROUND: Nivolumab (NIVO) and irinotecan (IRI) are standard treatments for refractory advanced gastric cancer (AGC); however, it is unclear which drug should be administered first or in which cases. The tumor growth rate (TGR) during preceding treatment is reported to be associated with tumor response in metastatic colorectal cancer patients treated with regorafenib or trifluridine/tipiracil, suggesting that TGR may be useful for drug selection. Therefore, we evaluated the association between TGR during preceding treatment and the tumor response to NIVO or IRI. PATIENTS AND METHODS: We retrospectively evaluated consecutive AGC patients treated with NIVO or IRI and divided them into slow-growing (Slow) and rapid-growing (Rapid) groups according to TGR and the presence or absence of new lesions (NL+/NL-, respectively) during preceding treatment (Slow group: NL- with low TGR <0.30%/day; Rapid group: NL+ or high TGR ≥0.30%/day). RESULTS: A total of 117 patients (Rapid/Slow groups, 72/45; NIVO/IRI groups, 32/85) were eligible. All baseline characteristics except peritoneal metastases were similar between patients treated with NIVO and IRI in the Rapid and Slow groups. The response rate was significantly higher in patients treated with NIVO compared with IRI [31%/3%; odds ratio (OR), 13.8; P = 0.01; adjusted OR, 52; P = 0.002] in the Slow group, but there was no difference between patients treated with NIVO and IRI (5%/8%; OR, 0.68; P = 0.73; adjusted OR, 0.94; P = 0.96) in the Rapid group. Disease control rate, progression-free survival, and overall survival were consistent with these results. CONCLUSIONS: Our findings suggest that NIVO treatment is a more favorable option for patients with slow-growing tumors, and NIVO and IRI are similarly recommended for patients with rapid-growing tumors in refractory AGC. TGR and NL emergence during preceding treatment may be helpful for drug selection and warrant further investigation.

MAC-CCD system: a novel lymphocyte microwell-array chip system equipped with CCD scanner to generate human monoclonal antibodies against influenza virus.

We previously developed a lymphocyte microwell-array system, which effectively detects antigen-specific B-cells by monitoring intracellular Ca(2+) mobilization at the single-cell level with a fluorescent Ca(2+) indicator, fluo-4. However, it is difficult for the system to perform time-lapse monitoring. Here, we developed a novel method, a lymphocyte microwell-array chip system equipped with a charge-coupled device (CCD) time-lapse scanner (MAC-CCD system), for monitoring intracellular Ca(2+) mobilization. The MAC-CCD system is able to monitor intracellular Ca(2+) mobilization of more than 15,000-20,000 individual live B-cells every 10 s. In addition, we adopted a correlation method in a MAC-CCD system, which enabled us to detect B-cells with a frequency of as few as 0.046%. Furthermore, we succeeded in obtaining six influenza nucleoprotein-specific human monoclonal antibodies from the peripheral blood of influenza-vaccinated volunteers. These results demonstrate that the MAC-CCD system with a correlation method could detect very rare antigen-specific B-cells.

Spatiotemporal dynamics of inositol 1,4,5-trisphosphate that underlies complex Ca2+ mobilization patterns.

Inositol 1,4,5-trisphosphate (IP3) is a second messenger that elicits complex spatiotemporal patterns of calcium ion (Ca2+) mobilization and has essential roles in the regulation of many cellular functions. In Madin-Darby canine kidney epithelial cells, green fluorescent protein-tagged pleckstrin homology domain translocated from the plasma membrane to the cytoplasm in response to increased concentration of IP3. The detection of translocation enabled monitoring of IP3 concentration changes within single cells and revealed spatiotemporal dynamics in the concentration of IP3 synchronous with Ca2+ oscillations and intracellular and intercellular IP3 waves that accompanied Ca2+ waves. Such changes in IP3 concentration may be fundamental to Ca2+ signaling.

Surgery for infective endocarditis: determinate factors in the outcome.

AIM: The appropriate operative procedures for treatment of infective endocarditis (IE) are still controversial. The authors reviewed their own operative results focusing on preoperative risk factors, intraoperative findings and operative procedures. METHODS: The authors reviewed the cases of 40 adult patients who had undergone surgery since 1999. The mean age of patients was 58 years ranging from 31 to 78 including 30 males and 10 females. Thirty-three patients had native valve endocarditis (NVE) and the remaining seven patients had prosthetic valve endocarditis (PVE). Diseased lesions were located in the mitral valve (MV) in 21 patients, aortic valve in 15 and mitral plus aortic valves in four. Twenty-eight patients (70%) were operated on during the active phase of IE. Streptococcus, Staphylococcus and Enterococcus species were predominant in the bacterial examination. RESULTS: Active vegetation was observed in 26 (65%) patients. Perforation of valve leaflets was observed in 11 (28%) cases. Changes of native MV leaflet were mild in 8 (40%) out of 20, which seemed to be reparable, while, changes of the native aortic valve leaflet were moderate to severe in 13 (87%) out of 15 patients. Valvular annuls were involved in the infection in 17 (43%) patients. Of the 33 NVE patients, prosthetic valve replacement was performed in 29 patients including 19 mitral and 15 aortic valves. MV plasty was performed in 4 patients. In seven PVE patients, prosthetic MV replacement was performed twice. In the aortic group, three patients underwent aortic root translocation, The Ross procedure and standard root replacement were performed respectively. Four patients died after surgery including one NVE case and three PVE cases. Three PVE patients who underwent aortic root translocation or the Ross procedure survived. The hospital mortality of NVE and PVE surgery was 3% and 43% (P<0.01), respectively. By univariant analysis, there were no significant correlations between operative results and preoperative factors such as bacteria, infective phase, cardiac failure, renal failure, sepsis or brain morbidity. The only significant factor on hospital mortality was PVE. Three patients died of non-cardiac diseases during the follow-up period. CONCLUSION: Operative results of NVE were good after complete resection of infective sites including valve annulus. Both valve replacement and plasty were available for NVE patients. In PVE, new strategies are indispensable and aortic root translocation or the Ross procedure should be a treatment of choice.

Site-specific Chemotherapy Based on Predicted Primary Site by Pathological Profile for Carcinoma of Unknown Primary Site.

AIMS: Although platinum-based combination chemotherapies are commonly used for unfavourable subsets of cancer of unknown primary (CUP), the prognosis remains poor. Several studies have suggested that gene expression profiling or immunohistochemistry was useful for the prediction of primary sites in CUP, and site-specific therapy based on predicted primary sites might improve overall outcomes. In Japan, to identify primary sites, immunohistochemical tests were commonly used for CUP in clinical practice. However, it is unclear whether site-specific therapy based on predicted primary sites by pathological examination contributes survival benefit for unfavourable CUP subsets. PATIENTS AND METHODS: In this study, 122 patients with unfavourable subsets of CUP were retrospectively reviewed. Ninety patients assigned to cohort A after July 2012 had received chemotherapy according to predicted primary sites; 32 patients assigned to cohort B before June 2012 had received platinum-based empiric chemotherapy. RESULTS: In cohort A, 56 patients (62.2%) with predicted primary sites by pathological examination received site-specific therapy; 34 patients (37.8%) with unpredictable primary sites received platinum-based empiric chemotherapy, the same as cohort B. The median overall survival was 20.3 months in patients with predictable primary sites in cohort A and 10.7 months in those of cohort B, with a significant difference between these cohorts (P = 0.03, adjusted hazard ratio = 0.57, 95% confidence interval 0.34-0.94). CONCLUSION: Site-specific therapy based on predicted primary sites by pathological examination could improve prognosis in patients with an unfavourable subset of CUP.

Dietary vitamin D is essential for normal insulin secretion from the perfused rat pancreas.

We have reported previously that arginine-induced insulin secretion was impaired in the vitamin D-deficient rat pancreas, and that it was improved by dietary vitamin D repletion (Norman, A. W., B. J. Frankel, A. M. Heldt, and G. M. Grodsky, 1980, Science [Wash. DC]. 209:823-825). In this study, we evaluate in the perfused rat pancreas system whether the effects of vitamin D and its metabolites on insulin secretion are direct in action on the pancreas and limited to the secretagogue arginine, or whether they are secondary to the hypocalcemia or reduced caloric and calcium intake associated with vitamin D deficiency. In an experiment where vitamin D-replete (+D) rats were pair-fed to D-deficient (-D) rats fed ad lib., the secretion of insulin in response to arginine infusion in the +D perfused rat pancreas was threefold higher than in the -D control. In a second experiment, the serum calcium level was elevated from the characteristic hypocalcemic level of -D rats (4.9 +/- 0.1 mg/dl) to a normal calcemic level (10.0 +/- 0.3 mg/dl) by feeding the rats a -D diet with dietary calcium levels ranging from 0.4 to 4%. In these -D rats, the pancreatic perfusion study with the secretagogue arginine showed a similar blunted insulin secretion response in all groups in spite of the significant differences of serum calcium levels. In a third experiment, insulin secretion in response to the separate administration of arginine (10 mM), glucose (16.9 mM), and tolbutamide (0.37 mM) was found to be significantly higher in pair-fed, normocalcemic +D rats than in -D rats with normal calcium levels. These results indicate that vitamin D or its metabolites are essential for normal insulin secretion and that the dietary intake of calcium and the resulting serum calcium levels play a lesser role than vitamin D availability in mediating insulin secretion.

Demonstration that the vitamin D metabolite 1,25(OH)2-vitamin D3 and not 24R,25(OH)2-vitamin D3 is essential for normal insulin secretion in the perfused rat pancreas.

It has previously been shown that vitamin D deficiency impairs arginine-induced insulin secretion from the isolated, perfused rat pancreas (Science 1980; 209:823-25). Since vitamin D is known to be metabolized to 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) and 24R,25-dihydroxyvitamin D3 (24,25[OH]2D3), it is essential to clarify which vitamin D metabolite has the important role of enhancing insulin secretion. In this report, a comparison is made of the relative efficacy of 3-wk repletion with vitamin D3 (980 pmol/day), 1,25(OH)2D3 (39 pmol/day or 195 pmol/day), and 24,25(OH)2D3 (650 pmol/day) on arginine-induced insulin secretion from the isolated, perfused rat pancreas; in this experiment, the daily caloric intake of the animals receiving vitamin D or its metabolites was controlled by pair feeding to the caloric intake of the vitamin D-deficient rats. 1,25(OH)2D3 repletion was found to completely restore insulin secretion to the levels seen in vitamin D3-replete, pair-fed controls in both the first and second phases, while 24R,25(OH)2D3 only partially improved insulin secretion, and then only in the first phase. Changes of both serum calcium levels and dietary caloric intake after vitamin D metabolite administration are concluded to play a lesser role on the enhancement of insulin secretion, since, in a separate experiment, vitamin D-deficient rats with normal serum calcium levels did not show recovery of insulin secretion equivalent to the vitamin D-replete animals under conditions of dietary pair feeding. These results suggest that 1,25(OH)2D3 but not 24,25(OH)2D3 plays an essential role in the normal insulin secretion irrespective of the dietary caloric intake and prevailing serum calcium levels.

Synthetic gastric inhibitory polypeptide. Stimulatory effect on insulin and glucagon secretion in the rat.

Effect of synthetic gastric inhibitory polypeptide (GIP) on insulin and glucagon secretion was stuied in vivo and in vitro in the rat. Intravenous administration of 1 microng./kg. GIP along with 0.625 gm./kg. glucose caused a more prominent rise of plasma insulin than did 0.625 gm./kg. glucose alone. The suppression of plasma glucagon levels induced by glucose was attenuated partially but not significantly by the concomitant administration of GIP. GIP (1 microng./kg. i.v.) alone raised both plasma insulin and glucago levels. In in-vitro experiments with isolated pancreatic islets, GIP significantly augmented insulin release induced by either 8.3 mM or 16.7 mM glucose, whereas the augmentation of glucagon release was observed at 3.3 mM, 8.3 MM, and 16.7 mM glucose concentrations. Three peptides, consisting of 1-28, 22-43, and 15-43 amino acids of GIP, failed to potentiate insulin and glucagon secretion. These results suggest that synthetic GIP has a stimulating effect on insulin and glucagon secretion.

Somatostatin release from the isolated, perfused diabetic rat pancreas: inverse relationship between pancreatic somatostatin and insulin.

The changes in pancreatic somatostatin content and release were studied in streptozotocin (STZ)-diabetic rats. Male Wistar rats were treated with a graded dose of STZ (group I, 0; II, 25; III, 50; IV, 75 mg/kg), which produced various grades of diabetic rats four weeks later. The pancreatic somatostatin content increased in proportion to the dose of STZ (I, 189 +/- 31; II, 222 +/- 20, III, 343 +/- 4; IV, 515 +/- 36 ng/g wet wt), while graded reductions of insulin content were observed. Significant increases in glucagon content were found only in groups III and IV. Pancreatic somatostatin release increased during arginine infusion (19.2 mM) dose dependently, (I, 543 +/- 36; II, 946 +/- 64; III, 1229 +/- 55; IV, 2186 +/- 150 pg/15 min), and it correlated with the graded decreases of insulin release. The glucagon release induced by arginine, however, did not change significantly. These results indicate that pancreatic somatostatin content and release increased in STZ-diabetic rats in proportion to the degree of insulin deficiency.

Reversal of the enhanced somatostatin release from the isolated, perfused diabetic rat pancreas after the amelioration of diabetes by whole pancreas transplantation.

To investigate the pancreatic endocrine function in streptozotocin-diabetic rats before and after the whole pancreas was transplanted, pancreatic insulin, glucagon, and somatostatin content and release were measured. Highly inbred Lewis male rats were divided into the following three groups: normal control rats; streptozotocin-induced-diabetic rats; and streptozotocin-diabetic rats transplanted with whole pancreas. Studies in vivo revealed normalization of elevated blood glucose and marked improvement of the impaired arginine-induced plasma insulin release by the transplantation of a healthy pancreas into the diabetic rats. Neither basal nor arginine-induced plasma glucagon levels in the diabetic rats were significantly different from the normal group, but significantly higher plasma glucagon levels were found in the transplanted rats. Studies in vitro using the isolated perfused rat pancreas revealed a significant increase of somatostatin release from the diabetic pancreas, with a marked reduction of insulin release and almost normal glucagon release. In the transplanted rats, on the other hand, arginine-induced somatostatin release from the host pancreas was reduced to normal without a significant change in insulin or glucagon release. In addition, the endocrine function of the graft remained normal in the transplanted rats. Pancreatic somatostatin release, thus, appears to be effected by changes in circulating insulin, since pancreatic transplantation effectively corrects the circulating insulin level.

Theophylline: potentiation of arginine-induced somatostatin release from the isolated rat pancreas.

Somatostatin's release from the isolated rat pancreas was studied using a perfusion technique. Arginine at a concentration of 19 mM produced a biphasic increase in somatostatin release from the perfused rat pancreas. Both first and second phases of somatostatin's increase are significantly higher in the presence of 1 mM theophylline than in the absence of the drug. These results indicate the possible inclusion of the adenylate cyclase--cyclic AMP system in the regulatory mechanism of rat pancreatic somatostatin secretion.

Reversal of increased gastric somatostatin in streptozotocin-diabetic rats by whole pancreas transplantation.

Changes in both the content and the release of gastric somatostatin after amelioration of streptozotocin (SZ)-induced diabetes by whole pancreas transplantation were investigated in the present study. Highly inbred male Lewis rats were divided into three groups: normal, control rats; SZ-induced diabetic rats; and SZ-diabetic rats after whole pancreas transplantation. Fundic as well as antral somatostatin content in the streptozotocin-diabetic rats was significantly increased compared with the controls. Whole pancreas transplantation in SZ-diabetic rats markedly lowered the increased somatostatin content both in the fundus and the antrum. On the other hand, the exaggerated somatostatin release induced by glucagon from the isolated, perfused stomach observed in the SZ-diabetic rats was reduced to the level of normal rats by whole pancreatic transplantation. From these results, it is concluded that the hyperfunction of gastric D-cells in the SZ-diabetic rats is reversed by transplantation of whole pancreas.

Tolbutamide stimulates gastric somatostatin release from isolated perfused rat stomach.

The effect of tolbutamide on somatostatin release from the isolated perfused stomach was investigated in both normal and streptozotocin-diabetic rats. Tolbutamide (10, 100, and 1000 microgram/ml) evoked a significant and dose-dependent increase in gastric somatostatin release. The tolbutamide (100 microgram/ml)-induced gastric somatostatin secretion was not influenced by differences in glucose concentration (1.5, 5.5, and 16.5 mM) throughout the perfusion period. Tolbutamide (100 microgram/ml)-induced gastric somatostatin release in streptozotocin-diabetic rats was significantly higher than in normal rats. Thus, tolbutamide is a potent secretagogue for gastric somatostatin secretion, and this effect is more prominent in diabetic animals.

Concentration and secretion of gastric somatostatin in streptozotocin-diabetic rats.

Both the release and the content of gastric somatostatin were investigated in streptozotocin-diabetic rats. Fundic and antral somatostatin contents were both increased in streptozotocin-diabetic rats compared with control animals. Basal somatostatin levels in the perfusates of streptozotocin-treated animals were not significantly different from those of the control animals. However, the peak values of somatostatin release induced by 5 x 10(-9) M glucagon in the diabetic animals were significantly higher than those of the controls. These results lead us to conclude that a hyperfunctioning state of the gastric D-Cells exists in hypoinsulinemic diabetes.

Effects of insulin and pancreatic polypeptide on gastric somatostatin release.

Effects of arginine and such pancreatic hormones as insulin and pancreatic polypeptide on gastric somatostatin release from the isolated perfused rat stomach were studied. The stomach was isolated from a fasted rat by a modification of the method of Lefébvre and was perfused with 4.6% dextran Krebs-Ringer biocarbonate buffer containing 5.5 mM glucose. Both insulin and pancreatic polypeptide (10(-10), 10(-9), and 10(-8) M) caused a significant decrease in gastric somatostatin secretion. Insulin (10(-10) M), furthermore, inhibited the glucagon (5 x 10(-8) M)-induced somatostatin response. Arginine (10 and 19 mM) failed to elicit any significant change of somatostatin release. These results suggest that gastric somatostatin release is affected by pancreatic hormones.

Failre of suppress plasma glucagon concentrations by orally administered glucose in diabetic patients after treatment.

Plasma glucagon response to glucose in diabetic subjects was observed before and after treatment. In normal subjects, plasma glucagon concentrations decreased substantially after an oral glucose load. In all diabetic patients before treatment, plasma glucagon was not suppressed and rather tended to rise paradoxically despite pronounced hyperglycemia. In diabetics treated with sulfonylurea or insulin, basal plasma glucagon concentrations were significantly lower than those in patients who were not treated. However, plasma glucagon response to an oral glucose load was not normalized by successful treatment with sulfonylurea or insulin, in spite of improvement of glucose tolerance. These results suggest that the insensitivity of the A-cell to hyperglycemia exists after treatment, and this abnormal plasma glucagon response to glucose after treatment may be caused either by impaired response of endogenous insulin to glucose, which is sustained even after treatment, or by an intrinsic defect of the A-cell.

Somatostatin release from isolated perfused rat pancreas. Possible role of endogenous somatostatin on insulin release.

In order to elucidate the role of endogenous somatostatin in the control of insulin and glucagon secretion, glucagon- or insulin-induced somatostatin release from the isolated perfused rat pancreas was studied. Immunoreactive somatostatin was persistently released for 60 min in response to perfusion by 5.5 mM glucose at concentrations ranging between 10 and 15 pg/ml. The addition of glucagon (10(-8), 10(-7), and 10(-6) M) caused a dose-related increase of somatostatin release. In contrast, insulin release, especially its first phase, was suppressed when concentrations of glucagon were increased. The addition of insulin (10(-7) M and 10(-6) M) had no significant effect on somatostatin and glucagon release. These results raise the possibility that endogenous somatostatin and glucagon together regulate insulin secretion, suggesting a close interrelationship between insulin, glucagon, and somatostatin secretion within the islet.