SEARCH · PubMed Health

Results for “Lithium Compounds”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources

PubMed2002

Transformation of yeast by lithium acetate/single-stranded carrier DNA/polyethylene glycol method.

In this chapter we have provided instructions for transforming yeast by a number of variations of the LiAc/SS-DNA/PEG method for a number of different applications. The rapid transformation protocol is used when small numbers of transformants are required. The high efficiency transformation protocol is used to generate large numbers of transformants or to deliver DNA constructs or oligonucleotides into the yeast cell. The large-scale transformation protocol is primarily applicable to the analysis of complex plasmid DNA libraries, such as those required for the yeast two-hybrid system. The microtiter plate versions of the rapid and high efficiency transformation protocols can be applied to high-throughput screening technologies.

DNA, Single-Stranded↗

PubMed2003

A new adhesive technology for all-ceramics.

OBJECTIVES: Evaluation of a new surface treatment method to obtain a good bond strength between a luting composite and several ceramics. METHODS: Specimen preparation and test procedure were done according to ISO 10477 Amendment 1. The surfaces of Empress II, InCeram-Alumina, InCeram-Zirconia and Frialit (ZrO2) were ground under water-cooling with 400 grit grinding paper, afterwards polished with 800 grit and air-dried. Each ceramic material investigated was divided into three groups of 10 specimens each. Group 1 was flame-treated with the PyrosilPen for 2.5 s, group 2 for 5 s and group 3 for 10 s/cm(2). After the flame treatment, a methacryl silane was applied followed by a luting composite. Prior to measuring shear bond strength, the specimens were thermocycled 5,000 times in a water-bath between +5 and +55 degrees C. Furthermore, SEM- and Fourier-transform infrared spectrophotometer (FT-IR)-investigations were done. As a control, Empress II etched and silaned was used. RESULTS: Shear bond strength measurements indicated that the optimal treatment time was 5 s/cm(2). Regarding this time the following bond strength values between the luting composite and the various ceramics were obtained: Empress II 23 (5)MPa, InCeram-Alumina 23 (5)MPa, InCeram-Zirconia 13 (8)MPa, and Frialit 16 (6)MPa. The control achieved 27 (6)MPa. On all surfaces of the flamed specimens Si could be detected by FT-IR.Significance. The PyrosilPen-Technology is an easy and effective method for surface-treating silicate, aluminum oxide and zirconium oxide ceramics to obtain good bonding to luting composites.

Aluminum Oxide↗

PubMed2003

Weibull analysis and flexural strength of hot-pressed core and veneered ceramic structures.

OBJECTIVE: To test the hypothesis that the Weibull moduli of single- and multilayer ceramics are controlled primarily by the structural reliability of the core ceramic.Methods. Seven groups of 20 bar specimens (25 x 4 x 1.2 mm) were made from the following materials: (1) IPS Empress--a hot-pressed (HP) leucite-based core ceramic; (2) IPS Empress2--a HP lithia-based core ceramic; (3 and 7) Evision--a HP lithia-based core ceramic (ES); (4) IPS Empress2 body--a glass veneer; (5) ES (1.1 mm thick) plus a glaze layer (0.1 mm); and (6) ES (0.8 mm thick) plus veneer (0.3 mm) and glaze (0.1 mm). Each specimen was subjected to four-point flexure loading at a cross-head speed of 0.5 mm/min while immersed in distilled water at 37 degrees C, except for Group 7 that was tested in a dry environment. Failure loads were recorded and the fracture surfaces were examined using SEM. ANOVA and Duncan's multiple range test were used for statistical analysis. RESULTS: No significant differences were found between the mean flexural strength values of Groups 2, 3, 5, and 6 or between Groups 1 and 4 (p>0.05). However, significant differences were found for dry (Group 7) and wet (Groups 1-6) conditions. Glazing had no significant effect on the flexural strength or Weibull modulus. The strength and Weibull modulus of the ES ceramic were similar to those of Groups 5 and 6. SIGNIFICANCE: The structural reliability of veneered core ceramic is controlled primarily by that of the core ceramic.

Aluminum Silicates↗

PubMed2003

Failure analysis of resin composite bonded to ceramic.

OBJECTIVE: To use fractographic principles to classify the mode of failure of resin composite bonded to ceramic specimens after microtensile testing. METHODS: A leucite-based ceramic (IPS Empress)-E1) and a lithia disilicate-based ceramic (IPS Empress2)-E2) were selected for the study. Fifteen blocks of E1 and E2 were polished through 1 microm alumina abrasive. The following ceramic surface treatments were applied to three blocks of each ceramic: (1) 9.5% hydrofluoric acid (HF) for 2 min; (2) 4% acidulated phosphate fluoride (APF) for 2 min; (3) Silane coating (S); (4) HF+S; (5) APF+S. An adhesive resin and a resin composite were applied to all treated surfaces and light cured. Twenty bar specimens for each group were prepared from the composite-ceramic blocks and stored in 37 degrees C distilled water for 30 days before loading to failure under tension in an Instron testing machine. Fracture surfaces were examined using scanning electron microscopy and X-ray dot mapping. Statistical analysis was performed using one-way ANOVA, Duncan's multiple range test, and Weibull analyses. RESULTS: Similar surface treatments were associated with significantly different bond strengths and modes of failures for E1 and E2. All fractures occurred within the adhesion zone. The microstructural difference between etched E1 and E2 ceramics was a major controlling factor on adhesion. SIGNIFICANCE: The quality of the bond should not be assessed based on bond strength data alone. Mode of failure and fractographic analyses should provide important information leading to predictions of clinical performance limits.

Acid Etching, Dental↗

PubMed2003

Scratch hardness and chipping of dental ceramics under different environments.

OBJECTIVE: The goal of this program was to identify promising environments that could efficiently minimize machining-induced damage of dental materials. METHODS: Single point abrasion (SPA) scratch testing was used on five materials to determine the scratch hardness and amount of edge chipping as functions of chemical environment, including air, water, saline and glycerol solutions. Limited testing was also done under additional environments expected to promote chemomachining effects via crack growth promotion or debris removal. A conical diamond indenter and a conventional tungsten carbide machining tool were used in the scratch tests. One-way ANOVA analysis was used to determine statistical differences among the variables. RESULTS: There was a consistent trend across materials that the water and saline yielded the lowest values of scratch hardness, air the next lowest, and the tests performed in glycerol yielded the highest hardness values. The measured hardness values using the conical diamond tool in the glycerol environments were about twice the hardness values measured under water and saline solutions. Environmental effects on chipping were minimal, but a linear relationship between load and per cent chipping was determined for the WC tool within the 10-50 N test range. The choice of scratch tool strongly affected scratch hardness and chipping tendency. SIGNIFICANCE: The chemical environment had an effect on machining characteristics, but the effects were more dependent on tool interactions rather than material specific properties. As a result, it may not be possible to utilize a particular single environment to substantially improve the damage response of dental materials to machining operations. Improvements in damage resistance can be environmentally obtained, but only for shallow cuts (finishing operations).

Air↗

PubMed1997

Chemical durability of Dicor and lithia-based glass-ceramics.

OBJECTIVES: The aim of this study was to analyze the effect of a nucleation agent (P2O5) and a colorant/nucleation agent (AgNO3) on the chemical durability of Li2O-Al2O3-CaO-SiO2(LACS) glass-ceramics in 4% HAc solution, deionized-distilled water, and in pH buffer solutions of pH 1, pH 9, and pH 11. METHODS: Glass powder [27.8 mol% Li2O, 2.5% Al2O3, 5.9% CaO, and 63.8% SiO2(LACS)] was melted, poured into a cylindrical graphite mold (16 mm diameter), cooled, cut into 2.2 mm thick disks, polished through 1200 grit SiC, nucleated at 510 degrees C for 3 h, and crystallized at 650 degrees C for 6 h. Dynamic corrosion tests of LACS glass-ceramic, LACS glass-ceramic containing 1.0 mol% P2O5 (LACSP), LACS glass-ceramic containing 0.78 mmol% AgNO3(LACSAg), and Dicor control specimens were performed in a shaker-bath unit at 80 degrees C at a shaker speed of 30 cycles/min for periods of up to 15 d. Differences in mean weight loss and ionic concentration were analyzed for statistical significance (p = 0.05) using ANOVA and the Tukey's Studentized Range Test. RESULTS: The mean weight loss over 15 d in 4% HAc increased in the following order: LACS (0.21 +/- 0.02 mg/cm2), LACSAg (0.25 +/- 0.05 mg/ cm2), and Dicor (0.27 +/- 0.05 mg/cm2). The differences in mean values were not statistically significant (p > 0.05). The amounts of Li+ leached in 32 mL of pH1 and pH11 buffer solutions were 3.1 +/- 0.3 microgram/cm2/mL and 243 +/- 49.0 micrograms/cm2/mL, respectively, for the LACS group, and 3.0 +/- 0.6 microgram/cm2/mL and 166 +/- 28.0 micrograms/cm2/mL for the LACSAg group. The differences in mean values are not statistically significant (p > 0.05). The high chemical durability in acidic environments of LACS glass-ceramics without P2O5 and their decreased durability at pH values of 9 and above were confirmed by SEM observations of the exposed surfaces. SIGNIFICANCE: The weight loss for the three glass-ceramic systems was highest in pH 11 buffer solution, which represents an unlikely in vivo environment. From a toxicological viewpoint, the maximum amount of Li+ released from 28 fully dissolved crowns of LACS glass-ceramic at a temperature of 80 degrees C (which is greater than any temperature experienced in the oral cavity) is approximately 1.2 mg; this amount appears to be below the daily limit of 2 mg allowable from food sources.

Aluminum Silicates↗

PubMed2002

Bipolar disorder.

Bipolar, or manic-depressive, disorder is a frequent, severe, mostly recurrent mood disorder associated with great morbidity. The lifetime prevalence of bipolar disorder is 1.3 to 1.6%. The mortality rate of the disease is two to three times higher than that of the general population. About 10-20% of individuals with bipolar disorder take their own life, and nearly one third of patients admit to at least one suicide attempt. The clinical manifestations of the disease are exceptionally diverse. They range from mild hypomania or mild depression to severe forms of mania or depression accompanied by profound psychosis. Bipolar disorder is equally prevalent across sexes, with the exception of rapid cycling, a severe and difficult to treat variant of the disorder, which arises mostly in women. Because of the high risk of recurrence and suicide, long-term prophylactic pharmacological treatment is indicated. Lithium salts are the first choice long-term preventive treatment for bipolar disorder. They also possess well documented antisuicidal effects. Second choice prophylactic treatments are carbamazepine and valproate, although evidence of their effectiveness is weaker.

Anticonvulsants↗

PubMedDate not supplied

An example of abnormal glow curves identification in personnel thermoluminescent dosimetry.

The personal Dosimetry Service Seibersdorf analyses monthly a large number of thermoluminescent dosimeters (TLD). The dosimeters consist of LiF chips, and the readout is carried out with an automated Harshaw 8800 reader system. In some cases, the luminescent glow curves of the routine analysis do not have the expected form as a result of external chemical contamination, hardware problems, poor heat transfer, etc. It is therefore necessary to investigate the reasons for the irregularity of these curves. An algorithm for the investigation of the routine curves was developed. It is based on the fact that the shape of an abnormal glow curve differs from the shape of a normal one. An interesting type of abnormal glow curves in the routine service was found. Some dosimeters of a certain client, a steel industry, exhibit glow curves with an atypical shape and very high signals. In those dosimeters, a possible chemical contamination in the form of a powder was discovered, which interferes with the dosimetric signal. A quantitative analysis of that powder was made by means of inductively coupled plasma emission spectroscopy (ICP-OES) after microwave dissolution. Elements like aluminium, barium, calcium and others were found. Such elements are used in different combinations as thermoluminescent materials.

Algorithms↗

PubMed1999

Effect of electrolyte and solvent composition on capillary electrophoretic separation of some pharmaceuticals in non-aqueous media.

Non-aqueous capillary electrophoresis was used to study the separation selectivity of positively charged drug substances and negatively charged diuretics. Study was made of the effects of organic solvent composition and the background electrolyte on the separation. The separation selectivity could be altered considerably by varying the methanol/acetonitrile composition. In addition, the migration order and the resolution of the pharmaceuticals could be altered merely by changing the electrolyte cation or the anion. The electrolytes tested were alkali metal acetates, ammonium acetate, ammonium chloride and ammonium bromide. As with aqueous background electrolyte solutions, the electroosmotic flow was decreased with increasing size of the alkali metal cation of the electrolyte in methanol/acetonitrile 50:50 (v/v).

Acetates↗

PubMed2003

Lithium, anticonvulsants and suicidal behavior in bipolar disorder.

BACKGROUND: Lithium has been found to be effective in reducing suicide rates during long term treatment of patients with bipolar disorders. Data on the efficacy of anticonvulsant mood stabilizers in reducing suicide risk are sparse. METHOD: Charts of 140 bipolar patients treated continuously for a minimum of 6 months during a 23-year period of private practice by the senior author were extracted from nearly 4000 patient records. Data extracted from the charts were incidence of completed suicide, number of suicide attempts, and number of hospitalizations for suicidal ideation or behavior per 100 patient-years of either 'on' or 'off' lithium or anticonvulsant mood stabilizer monotherapy. RESULTS: Only one completed suicide (during a period off of lithium) occurred in the patients studied. Incidence of non-lethal suicidal behavior was not different during treatment with lithium, compared with anticonvulsants. Being on a mood stabilizer significantly protected against suicidal behavior. The relative protective effect was more modest than in reports from other treatment settings. LIMITATIONS: This was a retrospective chart review study of naturalistically treated patients. CONCLUSIONS: Treatment of patients with bipolar disorder with either lithium or anticonvulsant mood stabilizers was associated with reduced risk of suicidal behavior. This study did not find evidence for a difference in the protective effect of the two types of mood stabilizing medications against non-lethal suicidal behavior in the naturalistic setting of private practice.

Adult↗

PubMed2003

[Pharmacological treatment of post-traumatic behavioural disorders].

OBJECTIVE: Literature review of the data concerning pharmacologic treatment of post-traumatic behavioural disorders. This review is limited to the treatment of agitation, excitation, mood lability, hostility and agressivity as defined by the NRS and excludes pharmacologic treatment of mental slowness, cognitive disorders and depression. METHODS: Medline interrogation using keywords Traumatic Brain Injury, Agitation, Agressivity, Behaviour, Pharmacology, Neuroleptics, Benzodiazepines, Carbamazepine, Valproate, Buspirone, SSRI, Propanolol, Methylphenidate and review of recent contents. The data finally includes 29 original studies. RESULTS: The overall level of evidence is quite low as the data mainly consist in open studies and case reports. These data and data from reviews or didactic articles suggest the efficiency of a variety of treatments. Mood-stabilizing antiepileptics, and specially carbamazepine constitute together with SSRI antidepressants the first choices. Some data suggest efficiency of buspirone, methylphenidate and atypic neuroleptics. Lithium requires close monitoring but is probably efficient. It is difficult to conclude concerning propanolol. CONCLUSION: The available data is in favour of the use of CBZ and SSRI antidepressants. Further studies are required. It is necessary to establish clear evidence of the efficiency of CBZ and assess the effects of methylphenidate, which is almost not prescribed in France.

Adrenergic beta-Antagonists↗

PubMed2002

Analysis of the neutron component at high altitude mountains using active and passive measurement devices.

The European Council directive 96/29/Euratom requires dosimetric precautions if the effective dose exceeds 1 mSv/a. On an average, this value is exceeded by aircrew members. Roughly half of the radiation exposure at flight altitudes is caused by cosmic ray-induced neutrons. Active (6LiI(Eu)-scintillator) and passive (TLDs) Bonner sphere spectrometers were used to determine the neutron energy spectra atop Mt. Sonnblick (3105 m) and Mt. Kitzsteinhorn (3029 m). Further measurements in a mixed radiation field at CERN as well as in a proton beam of 62 MeV at Paul Scherrer Institute, Switzerland, confirmed that not only neutrons but also charged particles contribute to the readings of active detectors, whereas TLD-600 and TLD-700 in pair allow the determination of the thermal neutron flux. Unfolding of the detector data obtained atop both mountains shows two relative maxima around 1 MeV and 85 MeV, which have to be considered for the assessment of the biologically relevant dose equivalent. By convoluting the spectra with appropriate conversion functions the neutron dose equivalent rate was determined to be 150 +/- 15 nSv/h. The total dose equivalent rate determined by the HTR-method was 210 +/- 15 nSv/h. The results are in good agreement with LET-spectrometer and Sievert counter measurements carried out simultaneously.

Aerospace Medicine↗

PubMed2002

Aminophylline aggravates long-term morphological and cognitive damages in status epilepticus in immature rats.

Here, we investigated whether aminophylline, an adenosine receptor antagonist used usually as a treatment for premature apnea, had synergistic effects on status epilepticus in the developing brain. On postnatal day 14 (P14), four groups of rats intraperitoneally received saline, aminophylline, lithium--pilocarpine (Li-PC), and Li-PC plus aminophylline, respectively. Subsequently, the Morris water maze task was performed at P80. The brains were then analyzed with cresyl violet stain for histological lesions and evaluated for mossy fiber sprouting with the Timm stain. No seizures were elicited in the saline-treated or aminophylline-treated rats. Both the Li-PC-treated and aminophylline plus Li-PC-treated rats exhibited seizures and there was no significant difference in mortality between the two groups. More interestingly, as in adulthood (P80), aminophylline aggravated the spatial deficits and histological damages seen in Li-PC-treated rats. In summary, this present study suggests that the use of adenosine receptor antagonists, such as aminophylline, exacerbates seizure-induced damage in the developing brain.

Aging↗

PubMed2000

Assessment of large single-fraction, low-energy X-ray dose with radiochromic film.

PURPOSE: To investigate the accuracy of in vivo dosimetry using radiochromic film for large single-fraction, low-energy irradiations. METHODS AND MATERIALS: Gafchromic MD-55-2 radiochromic film and LiF thermoluminescent dosimeters (TLDs) were placed in vivo on 25 patients to ascertain their effectiveness for assessment of dose. All patients received 10 Gy single fractions at energies ranging from 100 kVp (half-value layer [HVL] = 3.5 mm Al) up to 250 kVp (HVL = 2.3 mm Cu). Effects of small air gaps were also investigated using LiF TLDs and radiochromic film. RESULTS: Radiochromic film adequately measured applied dose for 25 patients in vivo with a standard deviation of 5.5% from prescribed dose. LiF TLDs recorded a standard deviation of 4.1% from measured to applied dose. Small air gaps which can be created under the film or TLDs during in vivo dosimetry were shown to have a measurable but minimal effect on results for gaps less than 5 mm. CONCLUSIONS: Gafchromic film has adequately measured applied dose in vivo at low energy for large 10 Gy single-fraction irradiation.

Fluorides↗

PubMed2002

Extracorporeal therapies for acute intoxications.

Intoxications frequently perturb acid-base and electrolyte status, intravascular volume, and renal function. In selected cases, extracorporeal techniques effectively restore homeostasis and augment intoxicant removal. The use of 4-methylpyrazole, an inhibitor of alcohol dehydrogenase, is a new and effective treatment for patients exposed to toxic alcohols. In this section, practical approaches to commonly encountered intoxicants and the use of extracorporeal techniques are critically reviewed.

Alcohols↗

PubMed2006

[Medication and memory: interactions among the elderly].

Several different systems govern human memory, and different drugs may act specifically on one or more of them. The central nervous system in the elderly is particularly sensitive to drugs, and an iatrogenic cause must be sought for all recent and/or sudden alterations in memory functions. In the case of recent alterations in memory, all nonessential drugs, especially psychotropic agents; should be withdrawn or reduced. Elderly persons, especially those with dementia, are at risk because of the frequent and substantial effects of drugs on their memory: the benefit-risk ratio must be evaluated regularly and essential treatments maintained.

Adrenal Cortex Hormones↗

PubMed2006

[Non-corticosteroid drug-induced metabolic bone disease].

After osteoporotic fracture or low bone mineral density measurements, it is necessary to look for secondary causes of osteoporosis, such as drugs. Corticosteroids are the most common cause of drug-induced metabolic bone disease. Other drugs responsible for bone disease include: aromatase inhibitors, GnRH agonists, anticonvulsants, heparin, and L thyroxin at TSH-suppressive doses. Confirmation is required of data about neuroleptics and antivitamin K.

Aged↗

PubMed2002

Early life stress changes concentrations of neuropeptide Y and corticotropin-releasing hormone in adult rat brain. Lithium treatment modifies these changes.

Experiences of early life stress are more prevalent among depressed patients than healthy controls. Neuropeptide Y (NPY) was suggested to play a role in the pathophysiology of depression. Consequently, we investigated in adult rats the effects of maternal deprivation for 3 h/day during postnatal days (PND) 2-14 and of dietary lithium during PND 50-83 on brain levels of NPY-like immunoreactivity (LI). Brain levels of corticotropin-releasing hormone (CRH) and serum corticosterone were also measured. Maternal deprivation reduced NPY-LI levels in the hippocampus and the striatum but increased NPY-LI and CRH-LI levels in the hypothalamus. Lithium treatment counteracted the effect of maternal deprivation in the hippocampus and striatum by increasing NPY-LI levels. In the hypothalamus, lithium tended to decrease CRH-LI but further increased levels of NPY-LI; it also increased serum corticosterone levels. The results suggest that early life stress has long-term effects on brain NPY with implications for the development of depression/vulnerability to stress, and that one therapeutic mechanism of action of lithium is to increase brain NPY.

Animals↗