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Autopsy findings after coronary rotational atherectomy.

We describe the findings at autopsy in a patient who underwent Rotablator atherectomy of the right coronary artery. During the procedure, the artery became occluded. Despite attempts to reopen the vessel with balloon angioplasty and emergency coronary artery bypass grafting, the patient developed irreversible cardiac failure and expired 2 days after the Rotablator procedure. At autopsy, the right coronary artery was found to be occluded by thrombus. No evidence of dissection or perforation of the vessel wall was seen. Small intramyocardial arteries and arterioles, downstream from the treated vessel, were embolized by pulverized atheroma.

Angioplasty, Balloon, Coronary↗

[Gas-chromatographic determination of residual monomer in polymethylmethacrylate dental materials].

A gas-chromatographic method for fast and quantitative determination of residual monomer (methylmethacrylate, MMA) in the polymethylmethacrylate mixture obtained by mixing polymerized powder and monomer from two different manufacturers (Biocryl and Mayor) was established. The material was prepared in two different ways: by the so-called classic and by current procedures. Pulverized material was extracted by methanol and the content of free methylmethacrylate in the extract measured using a flame ionization detector on a 1.5 m, 6/3 mm glass column with a DC-200 filling (10%) on a Chromosorb WHP, 100/120 mesh and at constant temperature of 170 degrees C. For Biocryl, mean values x = 2.147 g/100 g of ground specimen (SD, 0.111) obtained by the "classic" procedure, and x = 2.199 g/100 g of ground specimen (SD, 0.166) for polymerisate obtained in a Presstherm device, respectively, were obtained. For Mayor, mean values x = 1.544 g/100 g of ground specimen (SD, 0.222) of the polymer obtained by the "classic" procedure, and x = 1.205 g/100 g of ground specimen (SD, 0.317) for polymerisate obtained in a Presstherm device, respectively, were recorded. The lower limit of MMA detection under chromatographic conditions was 0.01 mg.

Chromatography, Gas↗

[Methods for evaluating Aedes aegypti populations and insecticide treatment in a town of Trinidad, West Indies].

A. aegypti populations in four neighborhoods of Flanigan Town, Trinidad, were evaluated for 32 weeks by means of egg-laying traps, capture with human bait, and larva searches. The egg-laying traps were more effective for evaluating the mosquito population (P less than 0.001) than capture with human bait or larva searches. During weeks 12 to 15, treatments were applied using different combinations of insecticides and spraying strategies: focal and perifocal (FPFS), house (HS), and ultra-low volume (ULVS). In the FPFS approach, all drinking-water containers were sprayed with temephos at a concentration of 1 mg/l, and areas around artificial containers were treated with fenthion at 40%. The HS was done on all surfaces of interior walls using fenthion (emulsifiable concentrate) at 55% in a proportion of 1.6 g/m2. The ULVS, done from trucks two days a week (Monday and Friday) from 1600 to 1900 in the afternoon, used technical grade malathion at 95% pulverized at a rate of 0.13 l/min. Reduction of the A. aegypti population was 62% in the area treated with FPFS and ULVS; 93% in the area that received FPFS and HS; 84% in area C, which was treated with FPFS, HS, and ULVS; and 77% in the index area, where only FPFS was applied. The results suggest that HS may be more effective than ULVS in reducing the A. aegypti population. The problems of hidden breeding sites are discussed, as is the role of gravid mosquitoes in the reinfestation of treated areas.

Aedes↗

Flow cytometric analysis of the mechanism of methylmercury cytotoxicity.

Flow cytometric analysis of murine erythroleukemic cells (MELC) exposed in vitro to 2.5 to 7.5 mumol/l (micromolar) methylmercury (MeHg) reveals a dose-dependent decrease in the rate of DNA synthesis (rate of passage through the S phase of the cell cycle), manifested as the accumulation of most of the cells in the S phase, and a modest accumulation of cells in the G2/M phase of the cycle. Light microscopy reveals a progressive increase in chromosomal damage (condensation, pulverization). At or above 10 mumol/l MeHg, progression through all the phases of the cell cycle is blocked and mitotic cells are arrested irreversibly in anaphase, with most exhibiting arrangement of chromosomes in a wreathlike ring formation. Also the cells exhibit both nuclear propidium iodide (PI) fluorescence (indicative of loss of viability) and concurrent cytoplasmic carboxyfluorescein (CF) fluorescence (viable cells exhibit CF fluorescence and exclude PI). In addition, there is a dose-dependent increase in cellular refractive index (90 degrees light scatter), an apparent decrease in cell volume (axial light loss), and progressive resistance to detergent (NP-40)-mediated cytolysis. Resistance to detergent-mediated cytolysis is indicative of fixation (protein denaturation, cross-linking, and so on) of the plasma membrane/cytoplasm complex. Our findings indicate that DNA synthesis is the primary target of MeHg cytotoxicity and that apparent targets and degree of cytotoxicity are a complex function of dose.

Animals↗

Rate of ATP synthesis in the perfused rat liver by 31P cryo-NMR.

ATP concentrations in the perfused rat liver during normoxic perfusion, transient ischemia, and recovery from transient ischemia were measured using the modified 31P cryo-NMR method (Chance, B., Nakase, Y., Bond, M., Leigh, J. S., Jr., and McDonald, G. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 4925-4929). Transient ischemia was induced in the perfused livers of starved rats, and multiple freeze-trapped tissue samples were taken from each liver at short intervals (15-30 s) during ischemia or following reperfusion. The freeze-trapped tissue was pulverized together with an antifreezing agent and high energy metabolites were measured by 31P NMR at 243 K after thawing. By using the cryo-NMR technique, a biochemical time resolution of 2 s could be achieved. Absolute metabolite concentrations were calculated by comparing the peak areas with internal standards mixed into the samples. Good time resolution and reliable concentration measurements provided by the cryo-NMR method enable us to estimate the ATP synthesis rate in the perfused liver during reperfusion following transient ischemia. The rate of ATP synthesis in the normoxic perfusion was 1.95 mumol/min/g wet weight; the maximal ATP synthesis rate during the recovery phase from ischemia was 5.75 mumol/min/g wet weight.

Adenosine Triphosphate↗

[Other techniques of arterial recanalization].

During the last few years several new instruments have been added to the armentarium of endovascular procedures. They are aimed at destroying atheromatous plaques and recalibrating the arteries. The plaque destruction techniques include atherectomy which may be directional (as with Simpson's Atherocath) and applicable only to very proximal vascular segments, or rotational, pulverizing the plaques with a bur. In this category are the flexible Auth's rotablator and Stack's transluminal extraction catheter (TEC) where planning is combined with extraction. To traverse complete occlusions, Kaltenbach's rotating guide increases the success rate, but its use must always be completed by conventional angioplasty. Vascular recalibration can be achieved by stents or heating balloons. Numerous types of stent are now available. The best known are the Medivent stent which is self-expansive and stents with expanding balloons, such as the Palmaz Schatz stent or the radio-opaque Wiktor stent made of tantalum. These stents require an important anticoagulant therapy. These technique have widened the limits of angioplasty by tackling stenoses that have long been regarded as inaccessible. They have also made it possible to treat a number of acute occlusions. On the other hand, none of them has yet proved effective in the prevention of restenosis.

Arterial Occlusive Diseases↗

[Measuring carbon monoxide content in muscles].

A method ist described to determine the CO-content in the tissue of muscles. The prepared tissue is pulverized in a swinging mill at the temperature of liquid nitrogen. Parts of the powder are weighed into headspace vessels. Carbon monoxide ist ejected by a formerly described method and measured gaschromatographically. The Fe-content is determined after an acid disintegration by AAS. Acute intoxications lead to higher CO-contents in heart than in periphere muscles. Chronic exposure to carbon monoxide does not produce these differences.

Adolescent↗

Functional properties of the Kensey arterial recanalization catheter. In vitro investigations.

The properties of the Kensey catheter (Cordis Corp., Miami Lakes, FL), a new rotational device for recanalization of arterial occlusions, were studied in vitro. There was no effective centering of the catheter tip in the vessel and no measurable dilatation of the vessel lumen during rotation of the catheter tip. Flow studies confirmed recirculation and repeated exposure of particles at the catheter tip. The vortex induced by the rotating cam disappeared in stenotic segments. The maximum size of the pulverized specimen material was 20 microns for the normal arterial wall, 90 microns for the calcified and atheromatous plaque, and 900 microns for the fresh venous thrombus. For plaque material, an additional reduction of large particles to 30 microns was seen with a decrease in force and an increase in rotation speed. The size of thrombus particles decreased with an increase of rotation speed and the duration of treatment.

Arterial Occlusive Diseases↗

[Exploration on baking conditions for Atractylodes macrocephala Kloidz in qiweibaizhusan bags].

This paper is concerned with a comprehensive study on the conditions required for baking pieces and grains of Atractylodes macrocephala Kloidz. through the determination of the relative content of atractylone and moisture content in the rhizome. Optimum roasting temperature and time before pulverizing have been determined, thus providing reliable basis for devising the suitable technological process.

Drugs, Chinese Herbal↗

Polymethylmethacrylate-induced release of bone-resorbing factors.

A pseudomembranous structure that has the histological characteristics of a foreign-body-like reaction invariably develops at the bone-cement interface in the proximity of resorption of bone around aseptically loosened cemented prostheses. This study was an attempt to implicate polymethylmethacrylate in this resorptive process. Unfractionated peripheral-blood mononuclear cells (consisting of lymphocytes and monocytes) and surface-adherent cells (monocyte-enriched) were prepared from control subjects who did and did not have clinical evidence of osteoarthrosis and from patients who had osteoarthrosis and were having a revision for failure of a cemented hip or knee implant. Cells were cultured for varying periods in the presence and absence of nonpolymerized methacrylate (one to two-micrometer spherules), pulverized polymerized material, or culture chambers that were pre-coated with polymerized cement. Conditioned media that were derived from both methacrylate-stimulated cell populations were shown to contain specific bone-resorbing mediators (interleukin-1, tumor necrosis factor, or prostaglandin E2) and to directly affect bone resorption in 45Ca-labeled murine limb-bone assays.

Animals↗

Determination of the optimum solvent system for extraction of minoxidil from a tablet dosage form.

Several pharmaceutical solvent systems commonly employed by the pharmacist during the extemporaneous dispensing of minoxidil topical solution using Loniten tablets were evaluated. These included ethanol, propylene glycol, water and a commercially available liquid, Vehicle/N. A total of twenty-five (10 mg) Loniten tablets were pulverized in a wedgewood mortar for five minutes. The tablet powder was then dissolved in the experimental solvent system and stirred thoroughly for ten minutes. The liquid dispersion was filtered using the vacuum filter method and the powder residue was then washed twice to obtain a fixed volume of the filtrate. The concentration of minoxidil in each solvent system was determined spectrophotometrically at the wavelength range of 280 to 282 nm depending upon the solvent. The amount of minoxidil extracted in each sample was calculated using the previously constructed standard curve in the respective solvent system. From the data obtained, it was concluded that Vehicle/N is the optimum solvent for such use, and the drug recovery was about 99%. Whereas, the mixture of methanol/propylene glycol/water at a volume ratio of 6:2:2 was observed to be the second best with a drug recovery of 97%. The addition of sodium lauryl sulfate had no effect in enhancing the solubility of drug when used in a solvent with poor recovery profile of drug. Also, the presence of excipients of the tablet dosage form did not interfere with the extraction process of minoxidil.

Minoxidil↗

[Serum and tissue silver levels after burns treated with silver compounds].

This study was performed in order to investigate serum and tissue silver levels in burns which were used 10 percent silver nitrate as a topical agent. We formed four groups of animals and pulverized 10 percent silver nitrate solution to the first group (GI) that included ten rabbits of which backs were burned by boiling water and silver sulphadiazine cream to second group (GII) with nine rabbits. We carried out 10 percent silver nitrate solution to the first control group (GIII) and silver sulphadiazine cream to the second control group (GIV) each of which had seven animals with unburned skin. We obtained blood samples from every animal before and after application of topical agent on the 1st, 3rd, 7th, 15th, 21st and 28th. We determined serum and tissue silver levels by atomic absorption spectrophotometer in kidney and liver of the animals which were sacrificed on the 28th day. In first and second groups we found that serum silver values reached on 3rd day to the maximum level and then the values decreased gradually. We also determined that diminution of the serum silver levels were prominent following on 15th day. It was shown that there was no silver in the serum on 28th day except four animals. The silver deposition in the liver was much more than in the kidney. Between these two groups there was significant difference neither in the serum on the same days nor the tissue silver levels. According to these data it was concluded that serum and tissue silver levels with 10 percent silver nitrate used in burns produced no difference from that of 1 percent silver sulphadiazine cream.

Administration, Topical↗

[Radiographic study of bone resorption at the proximal end of the femur after total hip replacements].

Radiography following cemented total hip replacement (THR) often revealed progressive bone resorption at the proximal end of the femur. The purpose of this study is to clarify the relation between this bone resorption and loosening of the acetabular component. The radiographic analysis was done using radiographs of two hundred and ninety-nine Müller type THR for osteoarthritis with minimum five years follow-up at regular intervals. The bone resorption at the proximal end of the femur appeared frequently in cases of loosened acetabular component. As acetabular loosening progressed, the bone resorption increased accordingly. Further study revealed that incidences of loosened acetabular component were statistically higher in cases of progressive bone resorption than in cases of non-progressive, 5.2 years after operation. This study indicates that progressive bone resorption might be a histological reaction caused by debris of pulverized bone cement generated by loosening acetabular component. The degree to which bone resorption progresses, therefore, directly reflects the amount of loosening of the acetabular component and should be a indicator for surgery to reconstruct loosened acetabular component.

Acetabulum↗

[Study of talc for pharmaceutical use. Trials of pharmacopoeias].

A study has been carried out on the possible pharmaceutical use of spanish talcs following the normalized assays of the main european pharmacopoeia and other quantitative methods. Only the talc nr3, not processed, meets all the assays of pharmacopoeia. The samples 2 and 4 (crushed) exceed the highest tolerated content in chlorides. The talc 1 (also crushed) only meets the loss on drying. The measures of some of these assays by using quantitative methods lead to more correct results and even sometimes in opposition with those obtained by pharmacopoeia methods. The particle size estimated by shifting and sedimentation shows that the crushed talcs are silty, whereas the only talc not processed is sandy. Considering the medium sizes estimated by scanning microscopy, it can be said that the pulverization of the talcs 1, 2 and 4 is characteristic of a micronization.

Particle Size↗

Concentration uniformity of extemporaneously prepared ranitidine suspension.

The concentration uniformity of an extemporaneously prepared ranitidine suspension was studied. To prepare the ranitidine suspension, 36 150-mg tablets were pulverized and suspended in 180 mL of distilled water. This mixture was diluted with simple syrup to a total volume of 360 mL, resulting in a final ranitidine concentration of 150 mg/10 mL. Samples from each of three bottles that had been filled with 60 mL of the suspension were assayed for ranitidine content by high-performance liquid chromatography. The sedimentation of suspended ranitidine tablet particles was studied by visual observation of the setting process in 10-mL samples from the same batch. The overall mean concentrations (in milligrams per milliliter) of ranitidine were 14.53, 15.25, 13.92, 12.67, and 12.72 at 0, 3, 7, 14, and 21 days, respectively. Compared with baseline, the difference in the ranitidine concentration was not significant over days 0-7. The ranitidine concentration was significantly reduced during the following time intervals: days 0-14, days 0-21, and days 7-21. In the settling experiments, the mean time (+/- S.D.) for sediment to first appear on the test tube bottom was 14.67 +/- 5.35 seconds. Approximately 40-50% (mean level = 3.2 mm) of the total sedimentation level (mean level = 7.3 mm) was observed one minute after shaking. The uniformity of ranitidine suspensions compounded according to procedures described in this report possibly could be improved with sonication. The ranitidine suspension should be well shaken, the dosage should be measured immediately after shaking, and the suspension should be used within seven days of compounding.

Chemistry, Pharmaceutical↗

An osteosarcoma cell and matrix retained morphogen for normal bone formation.

Histophysiology, ultrastructure, chemical analyses of transplants and implants of Dunn and Ridgway mouse osteosarcomas demonstrate that tumorigenesis is a manifestation of deranged morphogenesis in developing mesenchymal cell populations. The end product of development is defective, incompletely calcified, disorganized bone without any inclusions of bone marrow tissue. When Dunn osteosarcoma is freeze-dried and then implanted, the tumor is resorbed and replaced by deposits of normal cartilage, bone, and bone marrow. Freeze-dried Ridgway osteosarcoma is replaced only by a fibrous connective tissue scar. Disaggregated Dunn tumor osteoblasts synthesize a trypsin-labile collagenase-resistant cell surface localized bone morphogen. Tumor matrix stroma, prepared by sequential chemical extraction of soluble non-collagenous proteins also contains significant quantities of the same bone morphogen. Tumor tissue pulverized to particle size as small as 44 micrometer3 transmitted bone morphogen more rapidly than intact tumor tissue. The total tumor cell and stroma mediated bone morphogen produces three times more normal bone than normal cortical bone matrix. Our working hypothesis is that a normal bone morphogenetic polypeptide (BMP) is synthesized by Dunn osteosarcoma cells and retained by the tumor matrix stroma. Neither the mechanism of transmission nor the mesenchymal cell receptor sites of BMP are known.

Alkaline Phosphatase↗

Isolation and characterization of retinal and choroidal biomatrix.

Retinal and choroidal biomatrices (extracellular materials) and lens capsule were isolated from bovine eyes. Water-insoluble biomatrices were collected by filtration after repeated ultrasonic disruption of the cells and treatment with EDTA. Light and electron microscopic examination showed that the isolated lens capsule, retinal and choroidal biomatrices were free of cellular components. These biomatrices were then solubilized after pulverization in liquid nitrogen and applied to SDS-polyacrylamide gel electrophoresis. Electrophoretic patterns of the biomatrices were quit different from one another, while immunoblotting demonstrated the presence of laminin as a common constituent.

Animals↗

Model for the formation of double minutes from prematurely condensed chromosomes of replicating micronuclei in drug-treated Chinese hamster ovary cells undergoing DNA amplification.

Double minutes (DM) have been associated with gene amplification in drug-resistant cells and tumor cells. However, the mechanisms by which DM are formed have not been elucidated. We present here a model to describe a possible mechanism of DM formation based on the observations made in two independent early drug-selected multidrug-resistant cell lines and from in vitro somatic cell fusion experiments between synchronized S- and M-phase cells. The multidrug-resistant cell lines contain both DM and amplified mdr (P-glycoprotein) gene. Cytogenetic analyses of cells at early stages of selection revealed the presence of a number of micronuclei in a subpopulation of these cells. These micronuclei were often asynchronous in their progression through the cell cycle. As a result, premature condensation of micronuclear chromatin was often observed in metaphase plates. The pulverized chromatin pattern seen in certain instances of S-phase prematurely condensed chromosomes displays a striking resemblance to DM structures. These DM-like structures are linked by replicating DNA as revealed by DNA labeling experiments. Somatic cell hybrids between S- and M-phase cells when grown in vitro demonstrated that S-phase prematurely condensed chromatin indeed gives rise to extra chromosomal structures in the successive cell generations. It is hypothesized that distinct DM-like structures may arise from the partially replicated and prematurely condensed S-phase chromosomes following their liberation as extra chromosomal entities after replication and/or recombination in the succeeding division cycle(s). The enrichment for DM containing specific genes in drug-resistant cells may result from the subsequent drug selections.

Animals↗