Hyperglycemia-related FAS gene and hsa-let-7b-5p as markers of poor outcomes for ischaemic stroke.

BACKGROUND AND PURPOSE: Hyperglycemia in acute stroke leads to poor neurological outcomes. The role of microRNA (miRNA) in hyperglycemia-associated genes can provide new avenues for stroke prognostic applications. We aimed to identify novel genes and their regulated miRNAs that are associated with hyperglycemia-induced unfavorable stroke outcomes and further validated in the plasma exosome. Moreover, we intended to evaluate the prognostic ability of miRNA-messenger RNA (mRNA) biomarkers in addition to using traditional risk factors. METHODS: After the integration analysis of small RNA sequencing and mRNA polymerase chain reaction array, two mRNAs and six miRNAs were selected for validation in middle cerebral artery occlusion animal models and ischaemic stroke patients. Receiver operator characteristic analysis was used to determine the performance of mRNA and miRNA expression. RESULTS: The increased Fas expression was associated with hyperglycemia after acute stroke onset in animal and human studies. In addition, Fas gene level was significantly higher in patients with an unfavorable outcome when compared with patients with a favorable outcome. The expression of Fas and miRNA hsa-let-7b-5p in addition to traditional risk factors could increase the discrimination and predictive ability for poor prognosis. The higher exosomal Fas was further observed among patients with an unfavorable outcome, suggesting Fas signal transporting through exosome in the circulation system. CONCLUSIONS: Combined analyses of Fas and has-let-7b-5p expression in addition to traditional risk factors are favorable prognostic biomarkers for predicting poor neurological outcomes at 3 months after stroke onset in ischaemic stroke patients. Additional studies are required to address the precise role of the apoptosis pathway in unfavorable hyperglycemia-induced stroke outcomes.

Evidence for enhanced distal tubule sodium reabsorption in chronic salt-depleted dogs.

In order to assess the renal tubular site(s) at which sodium reabsorption is enhanced in chronic sodium-depletion, seven normal dogs, six salt-depleted dogs, and three normal dogs receiving aldosterone were studied during a steady-state water diuresis under Pentothal anesthesia and during progressive hypotonic saline diuresis. For both maintenance of the water diuresis and progressive hypotonic saline diuresis 0.45% NaCl was used. During the steady state water diuresis delivery of sodium to the diluting segment of the nephron as approximated by solute-free water clearance + sodium clearance/glomerular filtration rate (CH2O + CNa/GFR) was significantly lower in salt-depleted dogs compared to normal dogs with or without aldosterone. During progressive hypotonic saline infusion fractional free water excretion (CH2O/GFR) was similar in all three groups as CH2O + CNa/GFR increased up to 12-14 ml/min-100 ml GFR. Thereafter, CH2O/GFR continued to rise in virtually a straight line in salt-depleted dogs but leveled off in normal dogs with or without aldosterone. These data demonstrate that enhanced sodium reabsorption in the diluting segment of the nephron is an important determinant of the renal sodium retention in chronic extracellular volume contraction in dogs in addition to confirming the presence of increased proximal tubule sodium reabsorption in these animals.

Effects of acetazolamide on proximal tubule C1, Na, and HCO3 transport in normal and acidotic dogs during distal blockade.

It has been suggested that the establishment of a tubular fluid to plasma chloride gradient in the late proximal tubule by the reabsorption of bicarbonate (and other anions) in the early proximal tubule is responsible for a significant part of sodium chloride and water reabsorption in the proximal tubule. In the present study the effects of acetazolamide on proximal tubule water and electrolyte excretion were examined in 6 normal dogs and 10 chronic ammonium chloride-loaded dogs during distal blockade produced by ethacrynic acid and chlorothiazide administration. During distal blockade control urine/plasma osmolality and urine/plasma sodium were close to unity in all experiments. Urine/plasma chloride and urine/plasma bicarbonate were 1.21+/-0.02 and 0.75+/-0.07 in normal and 1.24+/-0.01 and 0.04+/-0.01 in acidotic dogs, respectively. After the administration of acetazolamide (20 mg/kg i.v.), there was a significant increase in urine flow, absolute and fractional excretion of sodium, bicarbonate, and chloride in all animals. Associated with these effects, urine/plasma osmolality and urine/plasma sodium remained unchanged but urine/plasma chloride decreased significantly to 1.15+/-0.01 in normal and to 1.19+/-0.01 in acidotic dogs. In acidotic dogs there was a significant correlation between the increase in bicarbonate, sodium, or chloride excretion after acetazolamide and the plasma bicarbonate level (range 6.8-12.5 meq/liter). These data demonstrate a significant effect of acetazolamide on bicarbonate, sodium, and chloride reabsorption in the proximal tubule even in the face of severe acidosis. Moreover, the data suggest that the decrease in chloride reabsorption (and accompanying sodium) after acetazolamide is related to the decrease in bicarbonate reabsorption and the associated decrease in the transtubular chloride gradient.

Inhibition of c-Jun DNA binding by mitogen-activated protein kinase.

Here we demonstrate that partially purified Xenopus p42 mitogen-activated protein (MAP) kinase phosphorylates bacterially expressed human c-Jun at a single site, serine 243. Several lines of evidence argue that this phosphorylation is due to p42 MAP kinase itself rather than some contaminating species. Phosphorylation of serine 243 markedly decreases the binding of c-Jun to oligonucleotides containing the 12-O-tetradecanoylphorbol-13-acetate response element. These findings suggest that MAP kinase may play a role in the down-regulation of c-Jun or in the cycle of transcriptional initiation and elongation.

Upregulation of CYP17A1 by Sp1-mediated DNA demethylation confers temozolomide resistance through DHEA-mediated protection in glioma.

Steroidogenesis-mediated production of neurosteroids is important for brain homeostasis. Cytochrome P450 17A1 (CYP17A1), which converts pregnenolone to dehydroepiandrosterone (DHEA) in endocrine organs and the brain, is required for prostate cancer progression and acquired chemotherapeutic resistance. However, whether CYP17A1-mediated DHEA synthesis is involved in brain tumor malignancy, especially in glioma, the most prevalent brain tumor, is unknown. To investigate the role of CYP17A1 in glioma, we determined that CYP17A1 expression is significantly increased in gliomas, which secrete more DHEA than normal astrocytes. We found that as gliomas became more malignant, both CYP17A1 and DHEA were significantly upregulated in temozolomide (TMZ)-resistant cells and highly invasive cells. In particular, the increase of CYP17A1 was caused by Sp1-mediated DNA demethylation, whereby Sp1 competed with DNMT3a for binding to the CYP17A1 promoter in TMZ-resistant glioma cells. CYP17A1 was required for the development of glioma cell invasiveness and resistance to TMZ-induced cytotoxicity. In addition, DHEA markedly attenuated TMZ-induced DNA damage and apoptosis. Together, our results suggest that components of the Sp1-CYP17A1-DHEA axis, which promotes the development of TMZ resistance, may serve as potential biomarkers and therapeutic targets in recurrent glioma.

Infusion intravenous pyelography and renal function. Effects in patients with chronic renal insufficiency.

Acute renal failure (ARF) following infusion intravenous pyelography (IVP) has been reported in patients with chronic renal insufficiency, particularly diabetics. Renal function was evaluated before and after infusion IVP in 40 patients with chronic renal insufficiency. In 11 of 12 (92%) diabetics and 17 of 28 (61%) nondiabetics, a 25% or greater increase in serum creatinine values and/or decrease in creatinine clearance was noted after IVP despite adequate hydration in all patients. The maximum decrease in kidney function occurred within three days and usually returned to or near pre-IVP levels in seven to ten days. At least 70% of the patients had hypertension and/or evidence of vascular disease. The data suggest that preexisting vascular disease in the kidney, possibly associated with the known vasoconstricting effects of contrast media, may be an important factor in the ARF following infusion IVP.

Infusion intravenous pyelography and renal function. Effect of hypertonic mannitol in patients with chronic renal insufficiency.

In a previous prospective study, we reported that infusion intravenous pyelography (IVP) in 40 patients with chronic renal insufficiency resulted in acute renal failure (ARF) in 28 patients (70%). In an attempt to prevent this complication, we have evaluated the conditions of another group of 37 patients with chronic renal insufficiency treated in a similar manner except that each patient received 250 mL of 20% mannitol 60 minutes after infusion of the IVP dye (diatrizoate sodium, 300 mL of a 30% solution). These patients were similar to those in the previous study with regard to age, sex, renal function, and incidence of diabetes. Only eight (22%) of the 37 patients had ARF develop after infusion IVP in this study. This incidence was significantly lower compared with 70% in the previous study. We conclude that administration of hypertonic mannitol 60 minutes after administration of the radiographic contrast material is highly effective in preventing ARF after infusion IVP in patients with chronic renal insufficiency.

Growth hormone inhibits activation of phosphatidylinositol phospholipase C by insulin in ob/ob mouse adipose tissue.

The cellular mechanism(s) by which GH produces insulin resistance in peripheral tissues is poorly understood. Recent evidence suggests that insulin exerts certain of its intracellular actions by rapidly activating phosphatidylinositol-specific phospholipase C(s) (PI-PLC) in the plasma membranes of target cells. Therefore, the present study was conducted to determine whether insulin can activate PI-PLC in adipose tissue of the genetically obese (ob/ob) mouse, an animal that responds markedly to GH with enhanced peripheral insulin resistance. Also, experiments were performed to determine whether the activation of PI-PLC by insulin could be blocked by S-carboxymethylated human GH (RCM-hGH), a GH derivative possessing mainly diabetogenic activity. Isolated adipose segments were incubated for various periods with insulin (10 mU/ml), homogenized and centrifuged to obtain a 150,000 x g pellet, and the latter was assayed for the ability to produce [3H]inositol phosphate from phosphatidyl[3H]inositol. PI-PLC activity was significantly stimulated 5 min after exposure of the segments to insulin. By 10 min, the insulin effect was no longer apparent, and after 30 min, insulin reduced the activity of the enzyme. One hour after exposure to insulin, PI-PLC activity returned to the control level. When adipose segments of RCM-hGH-treated mice (200 micrograms/day for 3 days sc) were incubated for 5 min with insulin, the ability of insulin to activate PI-PLC was abolished. However, RCM-hGH did not alter basal PI-PLC, indicating that its action involves the mechanism by which the enzyme is activated by insulin. Also, studies utilizing acute RCM-hGH treatment showed that its inhibitory effect on insulin activation of PI-PLC occurs within the same time frame as the onset of enhanced insulin resistance in the adipose tissue. Thus, the ability of GH to inhibit the activation of PI-PLC by insulin in adipocytes may account, at least in part, for its ability to induce insulin resistance in these cells.

The stimulatory effect of insulin on diacylglycerol generation in adipocyte membranes from ob/ob mice is impaired by growth hormone.

Physiologically, the action of insulin on carbohydrate and lipid metabolism is opposed by several hormones, including glucocorticoids, glucagon, catecholamines, and pituitary GH. Perhaps least is known about the mechanism(s) involved in the antiinsulin action of GH. Since the generation of diacylglycerol (DAG) appears to be an early event in the insulin-signaling cascade, it was of interest to determine whether GH would interfere with this effect of insulin. Experiments were conducted to determine whether insulin would stimulate the generation of DAG in adipocytes of the obese (ob/ob) mouse, and whether this response could be blocked by the diabetogenic GH derivative S-carboxymethylated human GH (RCM-hGH). Isolated adipocytes of the ob/ob mouse were used for these studies, because unlike normal rodents, the ob/ob mouse responds predictably to the antiinsulin action of GH. Insulin produced a rapid biphasic increase in the amount of DAG in a crude membrane fraction of the adipocytes. The first peak in DAG mass occurred within 5 min of exposure of the cells to insulin, and the second peak occurred after 30 min. The first peak in DAG mass did not occur in adipocytes that had been incubated with pertussis toxin before exposure to insulin. Also, adipocytes isolated from ob/ob mice that had been treated with RCM-hGH failed to respond to insulin with an increase in DAG mass. RCM-hGH blocked both the first and second insulin-induced peaks in DAG mass within 6 h of its administration. This is the time at which ob/ob mouse adipocytes exhibit increased insulin resistance in response to RCM-hGH. Neither exposure to insulin nor treatment with RCM-hGH had any appreciable effect on the fatty acid composition of the DAG present in the adipocyte membranes. These findings are compatible with the idea that GH produces some defect in the insulin-signaling cascade that is proximal to the events that result in the generation of DAG in the adipocyte.

Tissue-specific regulation by vitamin D status of nuclear and mitochondrial gene expression in kidney and intestine.

Vitamin D is responsible, through the actions of its metabolite, 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3], for the generation of a wide array of biological responses, particularly in the intestine, kidney, and bone. 1 alpha,25-(OH)2D3 is known to interact with its nuclear receptor to mediate the regulation of gene transcription. Although many genes and gene products have been shown to be regulated by 1 alpha,25-(OH)2D3 (e.g. calbindin-D28K in the intestine and kidney; collagen, osteocalcin,and osteopontin in bone), their recognition has been largely the result of empirical testing. In this report we have used subtractive hybridization analysis of complementary DNA libraries prepared from messenger RNA (mRNA) isolated from the intestine and kidney of vitamin D-replete or vitamin D-deficient chicks to identify genes for novel proteins whose steady state mRNA levels are regulated by dietary vitamin D status. In the kidney we observed the down-regulated expression of at least seven mitochondrially encoded transcripts and the up-regulated expression of five nuclear encoded genes, two of which are metallothionein and the beta-subunit of aldolase. In the intestine, six mitochondrially encoded transcripts are up-regulated, and seven nuclear encoded transcripts were either up- or down-regulated. Thus, in addition to identifying new nuclear encoded genes whose mRNAs are regulated by vitamin D status, our approach has demonstrated the tissue-specific regulation of mitochondrial gene expression in the intestine and kidney.

The biosynthesis of cholesterol side-chain cleavage cytochrome P-450 in the rabbit corpus luteum depends upon estrogen.

To gain a better understanding of the luteotropic action of estrogen, we have investigated the effect of estrogen on the synthesis of the enzyme, cholesterol side-chain cleavage cytochrome P-450 (P-450scc) in the rabbit corpus luteum. Using an established protocol, rabbits were treated with estradiol, and the estradiol was then withdrawn on day 9 of pseudopregnancy, which caused an 88% fall in serum progesterone within 48 h. In other rabbits, estradiol was replaced at 48 h which stimulated a 6.6-fold increase in serum progesterone concentration within the next 24 h. Luteal tissues were incubated with [35S]methionine and homogenized, and a mitochondrial fraction lysate was obtained. Equal trichloroacetic acid-precipitable radioactivity was taken for immunoprecipitation using a well-characterized polyclonal antiserum against bovine adrenal P-450scc. The immunoisolated proteins were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and radioactivity was visualized by autofluorography. The results indicate that the rate of synthesis of P-450scc in 48 h-estradiol withdrawn animals was markedly reduced, and by 72 h of withdrawal was barely detectable. When estradiol was reintroduced, the synthesis of P-450scc was increased. Despite the prominent changes in P-450scc synthesis, immunoblotting revealed only a minimal (approximately 30%) decrease in relative P-450scc content by 72 h after estradiol withdrawal. Analyses of DNA and protein contents of luteal tissues revealed an increase in DNA per mg luteal tissue, a decline in total tissue protein/DNA ratio, but no change in mitochondrial fraction protein/DNA ratio after estrogen withdrawal. The results indicate that de novo synthesis of P-450scc in the corpus luteum is sensitive to estrogen; however, the estrogen-sensitive rate-limiting step(s) for steroidogenesis are at other sites in the steroid biosynthetic pathway.

Acute non-Q wave cocaine-related myocardial infarction.

Since our initial report in 1984 of six patients with AMI temporally related to cocaine use, we have observed 19 additional patients in whom ischemic chest pain syndromes occurred shortly after intranasal or IV use of cocaine or after smoking the drug. Seventeen patients (89 percent) developed non-Q wave infarction and two had Q-wave infarction. One patient manifested angina with striking ST-segment elevation. None of the patients had diabetes or hypertension, and all but one were cigarette smokers. The serum cholesterol level was 162 +/- 7 mg/dl. Four of the five patients who consented to coronary angiographic studies displayed normal coronary arteries, and one showed proximal stenosis of the right coronary artery. The cold pressor test was performed in seven patients; none had angina or ECG changes induced by cold stimulation. We conclude that T-wave infarction is a common form of an acute cardiac event related to cocaine abuse, and its pathogenesis may involve that of the cocaine-induced coronary vasospasm.

The cellular and molecular regulation of 1,25(OH)2D3 production.

The synthesis of 1,25(OH)2D3 is a critical control point in the regulation of calcium metabolism, and possibly in the growth and differentiation of a number of cell types. This paper reviews our current understanding of the regulation of this process at the cellular and molecular levels, with the emphasis on the mechanisms of feedback control 1,25(OH)2D3 itself, control of parathyroid hormone, the roles of cyclic AMP dependent protein kinase and protein kinase C, and the interaction between the various intracellular regulators of 1,25(OH)2D3 production.

Sacral parasite conjoined twin.

BACKGROUND: A variant of conjoined twins is one in which one twin is incomplete. CASE: A female infant was born vaginally at 40 weeks' gestation to a healthy primipara. No important abnormalities were noted during prenatal examinations. The infant was fully developed in all external aspects except for a parasitic body conjoined with her sacrococcygeal region. Separated by operation 2 weeks after birth, the parasite contained lower limbs, adipose tissue, muscles, and a bowel sac. Over 4 years of observation, no abnormalities have been found since the operation. CONCLUSION: Obstetricians should be aware of the existence of a parasite twin during prenatal examinations and of the importance of the differential diagnosis of parasite and teratoma, a neoplasm with malignant potential.

Effects of chlorpromazine on ischemic rat kidney: a functional and ultrastructural study.

The effects of chlorpromazine, an agent with inhibitory effects of calcium influx, phospholipase activation, and Na-K-ATPase, on preserving renal function and proximal tubular ultrastructure were evaluated in renal ischemia. After right nephrectomy chlorpromazine (0.025 mg) or 1 ml of 0.9 per cent saline was selectively administered to the rat kidney immediately prior to a sixty-minute occlusion of the remaining renal artery. Pretreatment with chlorpromazine resulted in a significant attenuation in the rise in postischemic serum creatinine. Hypothermia of the kidney during ischemia provided an additional protective effect. Electron microscopic study of the proximal convoluted tubule demonstrated that the structural damage was less severe in chlorpromazine-treated rats and virtually complete preservation of a normal ultrastructure was observed when hypothermia was added.

The price elasticity of opium in Taiwan, 1914-1942.

Between 1895 and 1945, the Japanese colonial government virtually eliminated opium use in Taiwan by licensing and treating existing users, prohibiting sales to others, and raising the price. We evaluate these policies using a two-part model to describe the fraction of the population using opium and consumption among users, and the rational addiction model by Becker et al. (1991). We confirm that opium is addictive and find no evidence supporting the rational addiction hypothesis. Demand is price-elastic with estimated short- and long-run demand elasticities of -0.48 and -1.38. These results have implications for control of other addictive substances.

Hospital ownership and cost and quality of care: is there a dime's worth of difference?

Nonprofit organizations may predominate when output quality is difficult to monitor. Hospital care has this characteristic. This study compared program cost and quality of care for Medicare patients hospitalized following onset of four common conditions by hospital ownership. Payments on behalf of Medicare patients admitted to for-profit hospitals during the first 6 months following a health shock were higher than for those admitted to other hospitals. With quality measured in terms of survival, changes in functional and cognitive status, and living arrangements, we found no differences in outcomes by hospital ownership.

17Beta-estradiol inhibits oxidized low density lipoprotein-induced generation of reactive oxygen species in endothelial cells.

Increase of intracellular reactive oxygen species (ROS) has been proposed to cause endothelial injury, and oxidized LDL (oxLDL) actions are associated with an early increase of ROS. Estrogen protects vascular cells partly via its antioxidant effects and by preventing lipid peroxidation. However, whether it can inhibit oxLDL-induced stimulation of ROS generation in endothelial cells is unknown. We utilized the fluorescent dye (DCFH-DA) to measure ROS generation and compared the stimulant effect of tert-butylhydroperoxide (TBH) and oxLDL in human umbilical vein endothelial cells (HUVECs). We found that TBH, H2O2, and oxLDL rapidly stimulated ROS generation, and in a dose-dependent manner with TBH. A concentration of estrogen effective in preventing lipid peroxidation was employed either by pretreatment of cells 18 h prior to or by direct co-incubation (30 min) with HUVEC and oxLDL. Estrogen (54 microM) pretreatment significantly suppressed both TBH- and oxLDL- induced stimulation of ROS generation. Both 1 and 54 microM concentration of estrogen could directly inhibit oxLDL-induced ROS production in HUVECs. Thus, either 18 h pretreatment or 30 min co-incubation with estrogen reduced stimulated ROS generation, suggesting that both cellular and direct actions of estrogen may be involved.

Neuro-ophthalmic complications of raised intracranial pressure, hydrocephalus, and shunt malfunction.

1. Ophthalmic signs are important for the diagnosis and management of elevated intracranial pressure. 2. Visual loss, visual field loss, dorsal midbrain syndrome, and acute papilledema may occur well in advance of ventricular dilation. 3. For younger patients with hydrocephalus, amblyopia should be checked for, and the absence of papilledema does not ensure normal intracranial pressure. 4. Treatment should be delivered to control intracranial pressure and preserve vision in a timely fashion.

Contaminated site remedial investigation and feasibility removal of chlorinated volatile organic compounds from groundwater by activated carbon fiber adsorption.

Groundwater contaminated by dense, non-aqueous phase liquids (DNAPLs) such as chlorinated solvents has become a serious problem in some regions of Taiwan. The sources of these contaminants are due to industrial discharges. These chlorinated volatile organic compounds (VOCs) have been proven to be carcinogenic to humans. The groundwater is used for domestic drinking water supply in some cities of Taiwan and the severely contaminated groundwater has to be treated in order to meet the requirement of drinking water standards. This study covers two areas of work. In the first part, polluted groundwater samples were collected from the contaminated site and analytical results indicated measurable concentrations of 12 representative chlorinated VOCs in water samples. The primary VOCs detected included trichloroethene (TCE), tetrachloroethene (PCE), 1,1,2-trichloroethane (1,1,2-TCA), and 1,1-dichloroethene (1,1-DCE). Second, to remove VOCs groundwater was treated using adsorption on activated carbon fiber (ACF). This involved pumping groundwater through vessels containing ACF. Most VOCs, including TCE, PCE, 1,1,2-TCA, and DCE, were readily adsorbed onto ACF and are removed from the water stream. Our study showed that the technology was able to significantly reduce chlorinated VOCs concentrations in groundwater.