Ischemic stroke subtype is associated with outcome in thrombolyzed patients.

OBJECTIVES: The impact of ischemic stroke subtype on clinical outcome in patients treated with intravenous tissue-type plasminogen activator (IV-tPA) is sparsely examined. We studied the association between stroke subtype and clinical outcome in magnetic resonance imaging (MRI)-evaluated patients treated with IV-tPA. MATERIAL AND METHODS: We conducted a single-center retrospective analysis of MRI-selected stroke patients treated with IV-tPA between 2004 and 2010. The Trial of ORG 10172 in Acute Stroke Treatment criteria were used to establish the stroke subtype by 3 months. The outcomes of interest were a 3-month modified Rankin Scale score of 0-1 (favorable outcome), and early neurological improvement defined as complete remission of neurological deficit or improvement of ≥4 on the National Institute of Health Stroke Scale at 24 h. The outcomes among stroke subtypes were compared with multivariable logistic regression. RESULTS: Among 557 patients, 202 (36%) had large vessel disease (LVD), 153 (27%) cardioembolic stroke (CE), 109 (20%) small vessel disease, and 93 (17%) were of other or undetermined etiology. Early neurological improvement was present in 313 (56.4%) patients, and 361 (64.8%) patients achieved a favorable outcome. Early neurological improvement and favorable outcome were more likely in CE patients compared with LVD patients (odds ratio (OR), 2.1 (95% confidence interval, 1.4-3.3), and 2.0 (95% confidence interval, 1.2-3.3), respectively). CONCLUSIONS: Cardioembolic stroke patients were more likely to achieve early neurological improvement and favorable outcome compared with LVD stroke following MRI-based IV-tPA treatment. This finding may reflect a difference in the effect of IV-tPA among stroke subtypes.

Subnormal energy expenditure: a putative causal factor in the weight gain induced by treatment of hyperthyroidism.

AIMS: To examine the causes of weight gain occurring as an adverse effect of treatment of hyperthyroidism. METHODS: We measured 24-h energy expenditure (EE), body composition and spontaneous physical activity (SPA) in eight patients before and 1 year after treatment of hyperthyroidism was initiated, and eight controls. RESULTS: One year after initiation of treatment thyrotropin was normalized, thyroid hormones had fallen to the lower end of the reference range and fat mass had increased by 3.5 kg (p < 0.001). Twenty-four hour EE adjusted for fat-free mass (FFM) was 15% higher in hyperthyroid patients before treatment than in controls (p = 0.003), and treatment decreased 24-h EE by 1.9 MJ/day (p = 0.001). After treatment, 24-h EE, adjusted for FFM, was similar to the controls. Multiple regression analyses showed that the suppressed EE could partly be attributed to an iatrogenic suppression of thyroid hormones, resulting in lower sleeping EE. Twenty-four hour SPA was normal in the hyperthyroid state, but decreased after treatment by 21% (p = 0.045), to a level not significantly different, but still below that of the controls. CONCLUSIONS: The study suggests that weight gain during treatment of hyperthyroidism might be due to subnormal levels of EE and SPA caused by a suppression of the thyroid hormone to a level in the lower end of the normal range.

Effect of short-term high dietary calcium intake on 24-h energy expenditure, fat oxidation, and fecal fat excretion.

BACKGROUND: Observational studies have shown an inverse association between dietary calcium intake and body weight, and a causal relation is likely. However, the underlying mechanisms are not understood. OBJECTIVE: We examined whether high and low calcium intakes from mainly low-fat dairy products, in diets high or normal in protein content, have effects on 24-h energy expenditure (EE) and substrate oxidation, fecal energy and fat excretion, and concentrations of substrates and hormones involved in energy metabolism and appetite. DESIGN: In all, 10 subjects participated in a randomized crossover study of three isocaloric 1-week diets with: low calcium and normal protein (LC/NP: 500 mg calcium, 15% of energy (E%) from protein), high calcium and normal protein (HC/NP: 1800 mg calcium, 15E% protein), and high calcium and high protein (HC/HP: 1800 mg calcium, 23E% protein). RESULTS: The calcium intake had no effect on 24-h EE or fat oxidation, but fecal fat excretion increased approximately 2.5-fold during the HC/NP diet compared with the LC/NP and the HC/HP diets (14.2 vs 6.0 and 5.9 g/day; P < 0.05). The HC/NP diet also increased fecal energy excretion as compared with the LC/NP and the HC/HP diets (1045 vs 684 and 668 kJ/day; P < 0.05). There were no effects on blood cholesterol, free fatty acids, triacylglycerol, insulin, leptin, or thyroid hormones. CONCLUSIONS: A short-term increase in dietary calcium intake, together with a normal protein intake, increased fecal fat and energy excretion by approximately 350 kJ/day. This observation may contribute to explain why a high-calcium diet produces weight loss, and it suggests that an interaction with dietary protein level may be important.

Regulation of gamma-glutamyltransferase in cisplatin-resistant and -sensitive colon carcinoma cells after acute cisplatin and oxidative stress exposures.

Glutathione plays an important role in drug resistance of tumor cells and in their ability to resist oxidative stress. Improved salvage of glutathione can be obtained through increased activity of gamma-glutamyltransferase (GGT), which is of importance in the maintenance of cellular glutathione homeostasis. We investigated the regulation of GGT in 2 cisplatin-resistant and 1 cisplatin-sensitive colon carcinoma cell lines. Enzyme activity was induced in all 3 cell lines after acute exposure to cisplatin. The elevation was significantly higher in sensitive cells (3.3-fold) than in resistant (1.6- to 1.7-fold) cells. Exposure of cells to oxidative stress generated by menadione also resulted in enzyme induction but only in cisplatin-sensitive cells. Addition of anti-oxidants had different effects on the 2 inductions: N-acetylcysteine blocked the induction of both cisplatin and menadione, whereas catalase and glutathione-ester blocked only the menadione induction. Glutathione depletion alone was not sufficient to induce GGT in these cells. The data show that GGT is regulated by multiple mechanisms during anti-tumor drug treatment and oxidative stress and that reactive oxygen species were involved in the menadione, but not cisplatin, induction of the enzyme.

Heteroaryl analogues of AMPA. 2. Synthesis, absolute stereochemistry, photochemistry, and structure-activity relationships.

We have previously shown that (S)-2-amino-3-(3-hydroxy-5-phenyl-4-isoxazolyl)propionic acid [(S)-APPA, 2] is a weak agonist at (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptors, specifically activated by (S)-AMPA (1), whereas (S)-2-amino-3-[3-hydroxy-5-(2-pyridyl)-4-isoxazolyl]propionic acid [(S)-2-Py-AMPA, 5] and (RS)-2-amino-3-[3-hydroxy-5-(2-thiazolyl)-4-isoxazolyl]propionic acid (4) are potent AMPA agonists. On the other hand, (R)-APPA (3) and (R)-2-Py-AMPA (6) have been shown to be weak AMPA antagonists. We now report the synthesis of 2-Py-AMPA (7a) and the isomeric compounds 3-Py-AMPA (7b) and 4-Py-AMPA (7c) as well as the 7a analogues, (RS)-2-amino-3-[3-hydroxy-5-(6-methyl-2-pyridyl)-4-isoxazolyl]p ropion ic acid (7d) and (RS)-2-amino-3-[3-hydroxy-5-(2-quinolinyl)-4-isoxazolyl]propionic acid (7e). Furthermore, (RS)-2-amino-3-[3-hydroxy-5-(2-furyl)-4-isoxazolyl]propionic acid (2-Fu-AMPA, 7f) and its 5-bromo-2-furyl derivative (7g) were synthesized, and (S)-2-Fu-AMPA (8) and (R)-2-Fu-AMPA (9) were prepared by semipreparative chiral HPLC resolution of 7f. HPLC analyses and circular dichroism spectroscopy indicated the absolute stereochemistry of 8 and 9 to be S and R, respectively. This was confirmed by an X-ray crystallographic analysis of 9.HCl. In receptor binding (IC50 values) and rat cortical wedge electrophysiological (EC50 values) studies, 7c (IC50 = 5.5 +/- 0.6 microM; EC50 = 96 +/- 5 microM) was shown to be markedly weaker than 7a (IC50 = 0.57 +/- 0.16 microM; EC50 = 7.4 +/- 0.2 microM) as an AMPA agonist, whereas 7b,d,e were inactive. The very potent AMPA agonist effect of 7f (IC50 = 0.15 +/- 0.03 microM; EC50 = 1.7 +/- 0. 2 microM) was shown to reside exclusively in 8 (IC50 = 0.11 +/- 0.01 microM; EC50 = 0.71 +/- 0.11 microM), whereas 9 did not interact significantly with AMPA receptors, either as an agonist or as an antagonist. 8 was shown to be photochemically active and is a potential photoaffinity label for the recognition site of the AMPA receptors. Compound 7g turned out to be a very weak AMPA receptor agonist (IC50 = 12 +/- 0.7 microM; EC50 = 160 +/- 15 microM). None of these new compounds showed detectable effects at N-methyl-d-aspartic acid (NMDA) or kainic acid receptors in vitro. The present studies have emphasized that the presence of a heteroatom in the 2-position of the heteroaryl 5-substituent greatly facilitates AMPA receptor agonist activity.

Carbohydrate-deficient transferrin: marker of actual alcohol consumption or chronic alcohol misuse?

Carbohydrate-deficient transferrin (CDT) is a useful indicator of excessive alcohol consumption with higher sensitivity and specificity than other markers that are used. In the present study, CDT was analysed in 161 patients hospitalized in a surgical ward to evaluate whether history of drinking and chronic alcohol misuse are important determinants of CDT elevations. Fifty-one of the patients were diagnosed as alcohol-dependent and they all reported a long history of alcohol abuse. Several of these, as well as many of the non-dependent patients, reported a high, recent alcohol consumption (> or = 60 g/day for the previous 2 weeks). CDT performed better in detecting patients with alcohol dependency than in detecting patients with high alcohol consumption irrespective of dependency, showing higher sensitivity (47 vs 37%), likelihood ratio (4.7 vs 3.4), and a statistically significant difference in the receiver-operating characteristic curve areas (P = 0.04 in a two-tailed comparison test). In two subgroups, one with alcohol-dependent and one with non-dependent patients, consuming similar amounts of alcohol (range: 60-170 g/day), the sensitivity of CDT was 52 and 5%, respectively. We conclude that CDT is a better marker for patients with chronic alcohol misuse than as a marker for high actual alcohol consumption alone.

Analogues of carbacholine: synthesis and relationship between structure and affinity for muscarinic and nicotinic acetylcholine receptors.

A series of acyclic and heterocyclic analogues of carbacholine (1) was synthesized using N-methylcarbacholine (MCC, 2), N,N-dimethylcarbacholine (DMCC, 3), and the corresponding tertiary amine (4) as leads. Whereas nicotinic acetylcholine receptor affinity was determined using [3H]nicotine as the radioactive ligand, [3H]oxotremorine-M ([3H]Oxo-M) and [3H]quinuclidinyl benzilate ([3H]QNB), in some cases supplemented with [3H]pirenzepine ([3H]PZ), were used as radioligands for muscarinic acetyicholine receptors on rat brain membranes. On the basis of receptor binding data, nicotinic/muscarinic (N/M) selectivity factors were determined, and muscarinic receptor efficacy (M agonist index) and M1 selectivity (M2/M1 index) estimated. In most cases, quaternized analogues showed higher affinity than the corresponding tertiary amines for muscarinic and, in particular, nicotinic receptor sites. Among the new compounds, N,N-diethylcarbacholine (9e) (IC50 = 0.046 microM), (S)-1-methyl-2-(N,N- dimethyl-aminocarbonyloxymethyl)pyrrolidine (17k) (IC50 = 0.068 microM), and the corresponding quaternized analogue, 18k (IC50 = 0.018 microM) showed the highest nicotinic receptor affinity. The tertiary amine, 17k showed much higher nicotinic receptor affinity than the acyclic analogue, 4 (IC50 = 5.7 microM), and the N/M selectivity factor determined for 17k (150) is an order of magnitude lower than that of nicotine (1400). THe N/M selectivity factors for MCC (2) and DMCC (3), previously reported to be highly selective nicotinic receptor ligands, were shown to be 6.5 and 60, respectively, the latter value being comparable with that of 18k (89).

In vivo assessment of mutations in the phenylalanine hydroxylase gene by phenylalanine loading: characterization of seven common mutations.

UNLABELLED: Mutations in the gene encoding phenylalanine hydroxylase (PAH) cause persistent hyperphenylalaninaemia. To date, more than 200 point mutations and microdeletions have been characterized. Each mutation has a particular quantitative effect on enzyme activity and recessive expression of different mutant alleles results in a marked interindividual heterogeneity of metabolic and clinical phenotypes. In this paper we demonstrate how a simple clinical test can be used to evaluate the correlation between mutation genotype and phenylalanine metabolism. In hyperphenylalaninaemic patients with known PAH mutation genotype, we have investigated phenylalanine turnover in vivo by measuring the ability to eliminate a test dose of L-phenylalanine. All patients could be considered functionally hemizygous for one of their mutant alleles by carrying on the other allele a mutation that is known to completely abolish PAH activity and encode a peptide with no immunoreactivity. Seven mutations (R408W, IVS-12nt1, R261Q, G46S, Y414C, A104D, and D415N) were characterized by oral phenylalanine loading, each mutation being represented by at least three patients. The elimination profile determined for a 3-day period provides a measure to compare residual activity of the mutant proteins and to assign each mutation to a particular metabolic phenotype. The established relation between genotype and phenotype may enable prediction of the severity of the disease by genotype determination in the newborn period. This will aid in the management of hyperphenylalaninaemia and may improve prognosis. CONCLUSION: The possibility of predicting the residual enzyme activity by DNA analysis performed already in the newborn period allows the prompt implementation of a diet that is adjusted to the degree of PAH deficiency. This may improve management and prognosis of hyperphenylalaninaemia.

An occipito-temporal syndrome in adolescents with optimally controlled hyperphenylalaninaemia.

The study included 16 adolescents with optimally controlled hyperphenylalaninaemia (McKusick 26160), of whom six did not require treatment according to conventional criteria. All except the two patients with lowest median serum phenylalanine level throughout childhood (most values at 200-300 mumol/L) had white matter abnormalities detectable with magnetic resonance imaging. The lesions were particularly prominent in the watershed regions between the posterior and middle cerebral arteries. In most patients with moderate or severe hyperphenylalaninaemia frontal white matter lesions were present as well. Normal proton magnetic resonance spectra indicated that the lesions were stable. Occipital EEG abnormalities were frequent, and deficient performance on a pattern-recognition test was a characteristic neuropsychological finding. Serum phenylalanine levels at about 300 mumol/L or below throughout childhood and early adolescence may be required to avoid lesions. The present study demonstrates the limitations of even an optimally controlled dietary regimen in hyperphenylalaninaemia.

Cognitive development in offspring of untreated and preconceptionally treated maternal phenylketonuria.

A survey is given of literature reports on the effect of performance in offspring from 26 maternal PKU pregnancies treated prior to conception. The survey includes two women who were referred to us for genetic counselling because they had both given birth to microcephalic, mentally retarded children. The women were discovered to suffer from unrecognized maternal PKU with fasting phenylalanine concentration of 1.1-1.5 mmol/L. A strict diet was introduced prior to planned pregnancy and after some months on diet (phenylalanine concentrations less than 0.6 mmol/L) they became pregnant again. Serum phenylalanine levels were monitored weekly throughout pregnancy, and adjustments in the diet were made to keep serum phenylalanine concentration within the range of 0.18-0.42 mmol/L. The outcome of the pregnancies were healthy children who have developed normally. Their IQs are 105 and 119 at ten and four years of age, respectively and their head circumferences are normal. Our data show that the effect of preconceptional dietary treatment was children with a normal performance, contrary to their older siblings born following untreated pregnancies. These results are in agreement with the survey of ten years' promising experiences with preconceptional treatment in maternal PKU. The data may help to motivate young PKU women to accept planned pregnancies and to encourage them to return to the strict diet, which has prevented them from being retarded.