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At least 811 records · Page 45Linked to original sources
PubMed1980

In vivo nitrosation of morpholine in mice by inhaled NO2.

Groups of 3-5 mice were gavaged with aqueous solutions of 2 mg morpholine and immediately exposed to 2-50 ppm levels of NO2 in inhalation chambers for periods of up to 3 hours. After exposure, mice were frozen and pulverized in liquid nitrogen, and aliquots of frozen powder (congruent to 8 g) were extracted with cold 35% aqueous methanol and methylene chloride. Concentrated methylene chloride solutions were analyzed for N-nitrosomorpholine (NMOR), using gas chromatography with a Thermal Energy analyzer detector. NMOR levels in controls (exposed to NO2 alone, or dosed with morpholine without subsequent NO2 exposure) were less than 5 ng/mouse. NMOR yields in test mice were time-dependent with respect to duration of NO2 exposure and dose-dependent with respect to NO2 levels. These preliminary studies demonstrate the in vivo nitrosating potential of nitrogen oxides.

Animals↗
PubMed1981

Gravimetric determination of ethoxylated mono- and diglycerides in bread.

A gravimetric method is described for the quantitative determination of ethoxylated mono-and diglycerides (EMGs) in bread at levels as low 0.42% (dry sample). The air-dried pulverized samples are Soxhlet-extracted 22 h with an azeotropic mixture of n-propanol-water. The contents are evaporated to dryness, and then treated with 5% HCl in methanol to trans-esterify the fatty acids present which are then removed by petroleum ether extraction. The EMGs are subsequently precipitated from aqueous solution with phosphomolybdic acid in the presence of barium ions. The precipitate is weighed and compared with known amounts of standard carried through the same procedure.

Bread↗
PubMed1981

Long-term association of N-(phosphonacetyl)-L-aspartate with bone.

By means of enzymatic and autoradiographic techniques, it has been demonstrated that, 24 hr after a single dose of the antitumor amino acid N-phosphonacetyl-L-aspartic acid (PALA), (400 mg/kg i.p.; 1.15 mmol/kg) to C57BL x DBA/2 F1 mice, the agent accumulates in bone to a concentration of approximately 400 microM; this is 3000 times greater than the Ki of PALA for its target enzyme, aspartate carbamoyltransferase. However, disproportionately low inhibition of enzyme activity was demonstrated in homogenates of bone from these recipients, suggesting that the drug was sequestered from its target in this tissue. Autoradiography of sections of femoral shafts from mice treated with 14C-labeled drug demonstrated that autoradiogram density due to [14C]PALA equivalents was confined to the bony matrix, with no label above background resolvable in bone marrow. Following in vivo administration of PALA (400 mg/kg i.p.), the half-life of the drug in the bone was approximately 23 days. In vitro, with equilibrium dialysis at pH 7.4, it was demonstrated that: (a) normal pulverized and decalcified bone bound PALA with capacities of 3.5 nmol/mg and 0.1 nmol/mg bone, respectively, at a PALA concentration of 5 mM; (b) binding of PALA to normal bone reached saturation at a concentration of 200 mM; and (c) PALA functions as a solubilizer of bone at concentrations above this. Since administration of PALA was shown to produce long-lasting inhibition of aspartate carbamoyltransferase in liver and tumor and since its ultimate half-life in the plasma of mice, following a single 400-mg/kg administration of the drug, is 8 days, it is suggested that bone serves as a reservoir from which PALA is released at a slow rate into plasma and other tissues.

Animals↗
PubMed1994

Extracorporeal shock wave lithotripsy (ESWL) for biliary stones: a nationwide survey in Japan.

To assess the current status of extracorporeal shock wave lithotripsy (ESWL) for the treatment of gall-stones in Japan, we conducted a nationwide survey by sending a questionnaire to 251 institutions using this therapy. Replies were obtained from 50 institutions. The use of ESWL was investigated over the period from its introduction up to October 1992. ESWL was performed on 2,760 of 10,058 patients with gallstones (27.4%). The stones were completely pulverized in 1,021 of these 2,760 patients (37.0%). Complete disappearance was limited to single gallstones less than 20 mm in maximum diameter. A comparison in the number of ESWL sessions revealed no significant difference between the patients with and without a good response. Choledocholithiasis was resolved completely in 44.0% of 157 patients who underwent ESWL for this condition and intrahepatic stones were cured in 18.7% of 32 patients. Therefore, ESWL may be a useful form of conservative therapy for biliary calculi.

Cholelithiasis↗
PubMed1995

[Preparation of a levodopa/carbidopa solution in ascorbic acid (citridopa) and chromatographic and electrochemical assessment of its stability over 24 hours].

Levodopa/inhibitor improves motor function in parkinsonian patients. In its usual tablet form, however, its efficacy is reduced after several years, partially due to absorption deficiencies and changes in plasma kinetics; thus, other therapeutic strategies to provide a stable, easy to prepare formula are being sought. One such approach could be to dissolve L-dopa/carbidopa in ascorbic acid. This report describes the preparation method and demonstrates the stability of the sample using High pressure liquid cromatography (HPLC) with electrochemical detection. Regardless of the number of tablets the patient takes, the concentration of L-dopa/carbidopa/ascorbic acid remains constant (1/0.25/2 mg/ml). Thus, a patient taking 5 tablets of Sinemet Plus a day, would pulverize them in a glass, ceramic or marble mortar and add them to a measuring cup containing a 1 gram tablet of vitamin C (Redoxon) dissolved in 500 cc of cold water. This would be shaken or stirred until the Sinemet powder had dissolved. A few particles remaining in suspension after this process would be of no concern. The liquid would be stored in the refrigerator in an opaque or aluminum foil-covered glass bottle or, if possible, in several small dose-size vials. Using a measuring cup, a test tube and a syringe, the correct volume can be drawn out of the bottle and shaken well before drinking. The solution would be taken at regular intervals throughout the day (which vary from one patient to another) to maintain stable plasma L-dopa levels.

Ascorbic Acid↗
PubMed1994

Hair analysis for buprenorphine and its dealkylated metabolite by RIA and confirmation by LC/ECD.

Hair samples were obtained from 14 subjects admitted 2 or 3 months previously to a detoxification center. All reported an history of intravenous heroin abuse. After decontamination by two dichloromethane washes, about 50 mg hair were pulverized in a ball mill and incubated at 56 degrees C overnight in 1 mL 0.1 HCl. After neutralization, buprenorphine analyzed by RIA was in the range of 0.01 to 0.47 ng/mg. To confirm buprenorphine, liquid chromatography was used. After neutralization, drugs were extracted with toluene at pH 8.5 during a 3-step extraction procedure. A portion of the reconstituted residue was injected into a Lichrosorb CN column, with a mobile phase of phosphate buffer (pH 4.0)-acetonitrile-1-heptane sulfonic acid-butylamine (85:17:2:0.01, v/v). Detection was achieved by coulometry, and the potential of the electrodes was 0.15 and 0.50 V, respectively. Linear calibration curves were obtained from 0.02 to 2.0 ng/mg with a correlation coefficient r > 0.99 for both drugs. The detection limit for the major metabolite was about 0.01 ng/mg and 0.02 ng/mg for buprenorphine, using a 50 mg hair sample. Recovery (at 0.2 ng/mg) was 54 and 62% for norbuprenorphine and buprenorphine, respectively. Drugs concentrations in hair were in the range 0.02-0.59 and not detected--0.15 ng/mg for buprenorphine and norbuprenorphine, respectively. Results suggest that a dose-response relationship exists between the concentration of buprenorphine in hair and the administered dose.

Adult↗
PubMed1994

Effect of size and shape of the allogeneic bone grafts in bridging experimental ulnar gap in rabbits.

Partially decalcified allogeneic bone matrix was cut into the sizes and shapes of cylinders, bone strips and pulverized bone powder. Large osteoperiosteal gaps were created in rabbit's ulnae. A total of 14 gaps were filled with bone strips, 20 with powder, six with cylinders and two were left unbridged to serve as control. The healing of gap was assessed at intervals with a maximum follow up of 24 weeks. Clinically at 12 weeks the bone strips could not be moved separately from each other, the whole tubular bone had also united whereas gaps filled with bone powder did not diminish in size. Radiologically union occurred earlier (around 12 weeks) in bone strips as compared to cylinders (approx-18 weeks). With bone powder only a faint line of the remnants was visible. Gross examination findings of the grafted area were in concurrence with the clinical and radiological findings. Overall the gaps filled with bone strips had 100 per cent success with early osteo induction and remodelling as compared to long cylinders whereas gaps filled with bone powder had complete failure.

Animals↗
PubMed1994

p53 protein accumulation detected by five different antibodies: relationship to prognosis and heat shock protein 70 in breast cancer.

Nuclear accumulation of p53 protein is associated with a poorer clinical outcome in breast cancer patients. Heat shock protein 70 (hsp70) is a chaperone that binds to mutant p53 and consequently could regulate its accumulation or localization. The aims of this study were to determine if the prognostic significance of p53 accumulation was dependent on the type of antibody used for detection and whether hsp70 was associated with this accumulation. Node-negative breast tumors (n = 169) were examined by immunohistochemistry for nuclear p53, cytoplasmic or nuclear hsp70, and for p53 gene alteration by single-strand conformation polymorphism analysis. Frozen sections of pulverized breast tumors were stained with five p53 antibodies (240, 1801, 421, BP53-12, and CM1), a cocktail of both 240 and 1801, and the hsp70 antibody C92. Protein level was expressed as the sum of a proportion and intensity score (total 0, 2-8) with > or = 2 defined as positive staining. The cocktail 240/1801 gave the highest rate of positive staining (45%), followed by BP53-12 (35%), 1801 (27%), 240 (25%), CM1 (24%), and 421 (18%), with a high correlation between antibodies. Positive staining with each individual antibody or the cocktail was significantly associated with estrogen receptor and progesterone receptor negativity, age < 50, and high S-phase fraction. Only staining detected by the 240/1801 cocktail was associated with significantly worse overall survival; 85 versus 70% at 5 years for p53-negative compared to p53-positive tumors, respectively (P = 0.02). There was no association between nuclear or cytoplasmic hsp70 staining and accumulation of p53. Patients that were p53-negative/cytoplasmic hsp70-positive had a better overall survival than those that were p53-negative/cytoplasmic hsp70-negative. No other combination of p53 and hsp70 status could further define subsets of patients with a significantly different prognosis compared to p53 status alone. Tumors without a detectable p53 gene alteration by single-strand conformation polymorphism but with accumulated p53 protein did not have relatively increased levels of hsp70. We conclude that in node-negative breast cancer, the cocktail of two antibodies, 240/1801, resulted in the highest rate of positive staining and was most strongly associated with overall survival compared with either antibody alone or with the other individual antibodies. By immunohistochemistry, nuclear accumulation of p53 was not associated with cytoplasmic or nuclear hsp70 levels.

Adult↗
PubMed1993

[Safety conditions for working with stabilized chlorine dioxide used for disinfection].

Disinfectants called by producers stabilized chlorine dioxide (ClO2) are most often composed of sodium carbonate aqueous solution and ClO2. Stability is due to sodium chlorate which is produced under these conditions. Solutions of active ClO2 obtained through acidification of the preparation with citric acid and an appropriate water dilution are used in disinfection. Then, free ClO2 becomes an active disinfecting factor--a gas of strong irritative properties. During a disinfecting process the gas is liberated from the solution due to pulverization and dryness of disinfected objects. The study indicated that the safety of work with disinfectants requires mechanical ventilation of working premises. The transformation of stabile ClO2 into an active form should be induced by adding an appropriate volume of the stabilising preparation to citric acid solution. Such a procedure assures that a maximum of gaseous ClO2 will be retained in water.

Chlorine↗
PubMed1993

[Laparoscopic cholecystectomy of large gallbladder calculi].

Laparoscopic cholecystectomy is more laborious in patients with large gallbladder stones in that they can only be removed safely after an enlargement of one incision or intraoperative lithotripsy. Preoperative extracorporeal shock-wave lithotripsy (ESWL) might theoretically solve this problem and facilitate the extraction of the gallbladder. Ten patients with minimum one stone > 20 mm of diameter received ESWL treatment within 24 h before operation. Complete pulverization of stones was achieved in only one patient. Additional mechanical fragmentation by forceps was necessary in 7 and an enlargement of the incision in 5 of 10 patients. Compared to 10 patients with corresponding stones and mechanical lithotripsy ESWL showed no advantage and cannot be recommended because of increase of costs.

Adult↗
PubMed1994

[Analysis of causes of incorrect use of dose aerosols].

Preparations administered by inhalation make relatively high demands on the skill and knowledge of the patient in handling this form of application, for the effectivity of the therapy is inseparably linked to its faultless application. The present article aims at analysing possible mistakes in handling and at finding the most effective way of avoiding them. Several groups of patients with different previous knowledge were analysed in respect of handling skill and the influence of training on an improvement of the same; the patients' self-assessment was analysed by questioning them. Most mistakes are committed by patients whose only information consists of the contents of the package circular. Written instructions alone cannot convey sufficient information especially on how to synchronize the release operations. Major mistakes are insufficient expiration before application in 85.6% of the patients and lack of synchronisation in 55.9%, while the lowest rate of errors in respect of handling was seen in patients who had undergone training and instruction. Training in application associated with demonstration and subsequent exercise reduces the error ratio to a tolerable level. Pulverizers free from propelling gas and preparations applied by means of a spacer are clearly superior to others in respect of a comparatively low error rate. 99.3% of all patients believe they are correctly following the instructions, but on going into the question more deeply it becomes apparent that 37.1% of them make incorrect statements. Hence, practical training in application should get top priority in the treatment of obstructive diseases of the airways. The individual steps of inhalation technique must be explained in detail and demonstrated by means of a placebo dosage aerosol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Partially purified reindeer (Rangifer tarandus) bone morphogenetic protein has a high bone-forming activity compared with some other artiodactyls.

Noncollagenous proteins, including bone morphogenetic protein (BMP), were extracted in 4 mol/l guanidinium hydrochloride (GuHCl) from the pulverized and HCl-demineralized matrix of reindeer, bovine, sheep and porcine bone. To remove water-soluble material, the GuHCl solution was dialyzed against water and water-insoluble material and redissolved in 4 mol/l GuHCl. Gelatin peptides were removed by extraction in 0.25 mol/l citrate buffer (pH 3.1). The yield consisted mostly of large complexes and protein molecules of molecular weight less than 35,000 daltons. Isoelectric focusing of the material showed three to four different protein molecules: three acidic and one neutral. Bone-forming activity was investigated by implanting 0.6-15.0 mg of partially purified protein preparation into the thigh muscles of BALB mice. Radiologically detectable formation of new bone required 0.6 mg of reindeer BMP, 2.5 mg of bovine BMP, 5.1 mg of sheep BMP, and 8.0 mg of porcine BMP. A rough estimate of the area of the deposits showed that reindeer BMP had the highest bone formation activity, and porcine had the lowest. The formation of new bone was confirmed histologically. It is suggested that the differences in osteogenic activity are due to quantitative differences in BMP constituents or in the degree of complex formation in the protein preparations. Also immune and other defense mechanisms may generate differences in osteogenic response.

Animals↗
PubMed1993

Comparative pharmacokinetic evaluation of compressed naproxen suppositories in humans.

Compressed naproxen (CAS 22204-53-1) suppositories (250 mg) were formulated by dispersing the drug in molten polyethylene glycol 4000 followed by congealing and pulverizing the mass into granules and then compressing into suppositories. Their pharmacokinetic performance was evaluated and compared with that of a standard naproxen tablet in 12 healthy human volunteers. There were no statistically significant (p > 0.05) differences in Cmax, tmax, t1/2, AUC and mean residence time (MRT) observed after oral and rectal administration of tablet and suppository, respectively. The relative rectal bioavailability of naproxen from the compressed suppositories was 96.7 +/- 2.6%. Pharmacokinetics of naproxen after oral and rectal administration was highly comparable.

Adult↗
PubMed1993

Extraction, evaluation, and amplification of DNA from decalcified and undecalcified United States Civil War bone.

Deoxyribonucleic acid (DNA) was extracted from documented skeletal specimens of U.S. Civil War soldiers to determine the need for decalcification prior to extraction. The polymerase chain reaction (PCR) was performed to determine if the calcification state had an effect on the ability to amplify the extracts and to determine how successful amplification would be with these aged specimens. Bone samples were pulverized to a fine powder and divided into two sets. One set of samples was decalcified and the other set left undecalcified. Both sets were extracted using an organic procedure. The results demonstrate that decalcification is not a necessary step in the extraction process and that the yield of DNA is generally two times greater when decalcification is omitted. Furthermore, the calcification state had no effect on the ability to perform the PCR. Although the extracted DNA was very degraded, a 410 base pair (bp) segment of the mitochondrial DNA (mtDNA) control region was amplified. These results suggest that DNA can be extracted and amplified from 125 year old bone without decalcification, which may assist in the identity of modern and historic forensic specimens.

Anthropology, Physical↗
PubMed1993

Stability of famotidine in an extemporaneously prepared oral liquid.

The stability of famotidine in an extemporaneously prepared oral liquid stored at 4 and 24 degrees C for 30 days was studied. Famotidine liquid was prepared by pulverizing and suspending 12 40-mg tablets in distilled water. This mixture was diluted with cherry syrup to a total volume of 60 mL, resulting in a famotidine concentration of 8 mg/mL. The liquid was divided into two 30-mL amber glass bottles and stored at 4 degrees C and at room temperature (24 degrees C). Samples from each of the two bottles were assayed for famotidine content by high-performance liquid chromatography. Each sample was assayed in duplicate at time 0 and on days 2, 5, 10, 15, 20, 25 and 30. The concentration of famotidine remained above 90% of original concentration for 20 days at 4 degrees C and for 15 days at room temperature. After 30 days, famotidine concentration was reduced by 15% and 24% at 4 degrees C and room temperature respectively. Famotidine liquid 8 mg/mL compounded extemporaneously from tablets was stable for 20 days at 4 degrees C and for 15 days at 24 degrees C.

Chromatography, High Pressure Liquid↗
PubMed1996

Comparative pharmacokinetic evaluation of compressed suppositories of diclofenac sodium in humans.

Diclofenac sodium (CAS 15307-79-6) suppositories were formulated using polyethylene glycol 4000 as the base by dispersing the drug in the molten base, congealing the mass, followed by pulverization, sieving and subsequent compression of the resultant granules. These suppositories were evaluated with respect to their pharmacokinetic behaviour in 12 healthy, male human volunteers. The results were compared with those obtained after oral administration of a commercial enteric coated tablet. Bioequivalence between rectal suppositories and commercial tablets was observed with respect to AUC0-infinity and Cmax. However, tmax differed significantly (p < 0.05) in case of rectal administration (0.625 +/- 0.065 h) compared to oral tablet (1.58 +/- 0.06 h). The relative rectal bioavailability was 107.19 +/- 3.2.

Administration, Oral↗