Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “shell”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,711 records · Page 95Linked to original sources

[The heavy metal content in the soft tissues and shells of specimens of 3 varieties of the Azov and Black Sea mussel Mytilus galloprovincialis].

In representatives of 15 micropopulations of the Black Sea mussels related to three varieties of Mytilus galloprovincialis var. dilatata, var. acrocyrta, var. frecviens the content of iron, zinc, lead, copper and cadmium in the soft tissues and shells has been determined with the use of atomic adsorption spectrophotometry. It has been found that of importance is the content of industrial wastes in the habitat of the micropopulation examined rather than its attribution to some or other variety. In representatives of all the varieties the accumulation of metals in soft tissues was higher than that is shells. By their concentration in tissues the metals examined can be aligned in the following row in decreasing order: iron, zinc, lead, copper and cadmium.

Animals↗

[Radiological reasoning and its computer-based simulation. Reasons to use computer-based diagnostic systems developed on shells].

Research on the medical applications of artificial intelligence has increased the knowledge of logical and methodological principles of clinical reasoning. Thus, computer-based diagnostic systems are developed on the basis of progress in this field, because thorough knowledge is necessary to obtain efficient simulation. This work was aimed at analyzing the structure of medical and radiological reasoning and at discussing the modalities to simulate it with computer-based diagnostic systems. The diagnostic process includes two steps: data collection and data interpretation; radiological reasoning involves the following 5 steps: procedural, executive, observative, interpretative and communicative. Each of them needs a different approach to simulation, considering, in its development, the different characteristics of each kind of reasoning. The expert system shells on the market are necessary tools to develop expert systems, but they cannot cover the whole of processes taking place during radiological work. Therefore, a particular, radiology-aimed shell should be developed to help the radiologist.

Artificial Intelligence↗

"Auctoritas" psychiatric expert system shell.

We present a short description of a complex psychiatric computer expert system, including functions that help the physicians and the hospital staff in the administrative, diagnostic, therapeutic, statistical, and scientific work. There are separate data-storing, health insurance-supporting, or simple advisory programs, but we can not avail a system--in our country--that provides us with all these functions together. Hence the aim of our program is to produce a universal computer system that makes the patients' long distance follow-up possible. Our diagnostic expert system shell, which is appropriate for using the symptoms and criteria scheme of the internationally accepted diagnostic systems such as DSM and ICD, helps to archive homogeneous, up-to-date psychiatric nosology; this is essential for the correct diagnostic, statistical, and scientific work. Let us introduce our expert system. It consists of four parts: administration, diagnostic decision support system, activities concerning treatment, and statistics. The part called "Administration" contains all data about actual and emitted in-patients and out-patients, including their particulars and data necessary for health insurance (duration of treatment, diagnosis); here we find and edit medical documents. The most important part of the "Auctoritas" system is the "Diagnostic decision support system." In practice, expert systems use decision trees with yes-no logic, fuzzy logic, and pattern matching on the basis of the method of deduction; and backward chaining or forward chaining on the basis of the direction of deduction. Our system uses the methods of fuzzy logic and backward chaining. In other medical disciplines, good results are achieved by applying the pattern matching method; to make validity and verification researches, however, these systems are inappropriate. The diagnoses relying on the up-to-date psychiatric diagnostic systems--DSM-IV and ICD-X--are based on classical logic and can be correctly validated and verified. Hence we have chosen the fuzzy logic, which is the up-to-date extension of classical logic and influences the validity and verification researches, for the construction of our system. The diagnostic part is a shell that can be filled up optionally with knowledge bases of the DSM-IV, ICD-X, or other diagnostic systems and has the following structure. The diagnostic course is biphased as we can differ symptoms and criteria (duration of the illness, aethyological factors). We managed to extend the traditional applications using yes-no logic with three factors that make the system more sensitive and flexible. These are the scaling, sorting by importance of symptoms, and reliability-validity results. The "scaling" means that the physician scales the input symptoms by severity; this influences the statistical probability of the possible diagnoses. "Sorting by importance" is gauging certain symptoms by importance in a syndrome. Finally the third point, "reliability-validity results," means taking account of the latest validity values of a certain disorder of the used diagnostic system--according to the latest validity researches--and the diagnostical reliability of our expert system. The "Activity concerning treatment" is a practical part of our program that contents the examination and therapy scheduling and monitoring results. Under the point of "Statistics," we can prepare all data of the patients in various ways. In summary, the "Auctoritas" computer system is a global database managing the newly-developed advisory system; it is appropriate for managing a complete hospital network system for the continuing individual long-distance observation of patients. It collects all the necessary information of one patient in one file. The long-term benefit is that it can compile and process large amounts of information about the patients and help physicians come to scientific conclusions for research and publications.

Decision Making, Computer-Assisted↗

[Cooling shell in renal transplantation. Thermometric evaluation of a prototype].

We have developed a cooling system for renal transplants designed to eliminate the second period of warm ischaemia corresponding to the vascular anastomosis phase of renal transplantation. This is an autonomous and independent system which forms a shell around the transplant. Following application of the system, cooling is achieved by refrigeration of a Multitherm sponge contained in the wall of the shell. The thermometric characteristics of a prototype were evaluated in vitro and in vivo in pigs. This system allows the kidney to be preserved at a temperature of less than 10 degrees C for 1 hour without inducing any risk of lesions of the renal surface. Human applications should be developed in the near future.

Anastomosis, Surgical↗

[Preliminary survey on the traditional Chinese drug: shell of abalone or sea-ear].

According to an on-site survey of the commercial medicinal materials in China, it is demonstrated that the shells of abalone or sea-ear consist of nine types. Their original animals are Haliotios diversicolor, H. discus hannai, H. ovina, H. asinia, H. ruber, H. laevigata, H. semistrata, H. midae and H. cracherodii. Three of these types namely, H. semistrata, H. midae and H. cracherodii are not included in the Chinese Pharmacopeia. Furthermore, most of the shells of abalone or sea-ear presently on market are Haliotios ruber and H. discus hannai.

Animals↗

[Metabolism and utilization of calcium derived from hydrolysed oyster shell in rats].

Experimental rats modeled on calcium deficiency were fed with calcium derived from hydrolysed oyster shell, calcium carbonate and calcium chloride respectively, equivalent to 45 mg a day, for four weeks to study their bioavailability. Calcium contents in the blood, urine, feces and bone of rats were determined with atomic absorption spectrometry and EDTA complex titration, and their bone density was measured with densitometry. Results showed proportions of calcium absorption and retention were 67.3% +/- 16.7% and 64.6% +/- 17.5%, respectively, in rats fed with calcium from hydrolysed oyster, and their femur calcium content and bone density (BMC/BW) 131.2 +/- 1.48 mg/g and 0.318 +/- 0.034 g/cm2, respectively, significantly higher than those in the rats fed with calcium carbonate. There were no significant difference in blood calcium contents, weight gains and feed intake between those three groups of rats. It suggests that calcium derived from hydrolysed oyster shell may be absorbed and utilized more easily than calcium carbonate.

Animals↗

Determination of aflatoxin B1 in pistachio kernels and shells.

A method was developed for accurate measurement of aflatoxin B1 in the edible portion of pistachio nuts. Twenty-nine samples of kernels with and without their shells were slurried with a Mega Ultra Turrax. A subsample of the homogenate was extracted with water-methanol, defatted with petroleum ether, purified with a silica solid-phase extraction column, and redissolved in methanol. After separation on an octadecyl column and postcolumn reaction with on-line electrochemically generated bromine, the aflatoxin B1 derivative was detected fluorometrically. The shells contained less than 1% of the aflatoxin B1 found in the edible kernel, and they accounted for 41.7-46.8% of the weight of the whole pistachio. These observations indicate it is possible to analyze an entire sample, up to 25 kg, as a whole and still be able to judge whether it meets the legal tolerance limit of 5 micrograms aflatoxin B1/kg edible part, as set by the Dutch Food Act.

Aflatoxin B1↗

[Isolation and amplification of DNA from tortoise and turtle shells].

DNA was extracted from tortoise and turtle shells, two Chiense crude drugs which have been preserved for at least nine years. The cytochrome b sequence was amplified from the extracts using the polymerase chain reaction. Treatments with detergent and ultraviolet light were employed to destroy possible extraneous contamination. A control extract was set in parallel with the extracts of the specimens in order to detect contamination in solutions and reagents. The results show that significant amounts of genetic information can survive in the shells and may have important implications for their identification.

Animals↗

The effect of disulfiram on egg shell formation in adult Trichuris muris.

The effect of disulfiram on egg shell morphology in the parasitic nematode Trichuris muris was studied in vitro and in vivo. Daily disulfiram treatment of mice infected with T. muris beginning 25 days after infection and continuing for 26 days resulted in the production of malformed eggs by adult female worms in all treated groups. In addition, significantly fewer adult worms were found at necropsy in mice treated with 5.0 or 7.5 mg/kg/day of disulfiram as compared with mice treated with 2.5 mg/kg/day or control mice. Adult worms collected from infected, untreated mice and placed in aerobic culture for 5 days in media containing 4 or 8 micrograms/ml of disulfiram released malformed eggs into the culture medium after 30 hr in culture. Oral inoculation of naive mice with malformed eggs did not result in T. muris infections in the mice. The results of these studies suggest that inhibition of phenol oxidase results in disruption of normal egg production by T. muris females and that the enzyme might be a useful target in the development of control strategies aimed at nematode parasites that rely on phenol oxidase for egg shell hardening.

Administration, Oral↗

Fabrication of an amalgam core using a customized acrylic resin shell.

This article describes a build-up technique that uses a customized acrylic resin shell for restoring endodontically treated molars that are involved in three-unit fixed partial denture design. The shell confines the amalgam without impinging on the periodontium to ensure a proper core foundation, an ideal tooth preparation, and a more predictable final restoration.

Acrylic Resins↗

Microbial utilization of the neurotoxin domoic acid: blue mussels (Mytilus edulis) and soft shell clams (Mya arenaria) as sources of the microorganisms.

The neurotoxin domoic acid is produced in quantity by the diatom Pseudo-nitzschia multiseries and is released to the environment directly and indirectly via food chains. Presumably there is a mechanism for the biodegradation and disposal of domoic acid and as bacteria are logical candidates for such an activity, a search for bacteria competent to carry out biodegradation of domoic acid was initiated. Extensive trials with a wide variety of bacteria isolated mainly from muds and waters taken from the marine environment showed that the ability to grow on or degrade domoic acid was rare; in fact, domoic acid was inhibitory to resting cells or growing cultures of most of these bacteria. In contrast, using enrichment techniques, it was possible to isolate from molluscan species that eliminate domoic acid readily, i.e., blue mussels (Mytilus edulis) and soft-shell clams (Mya arenaria), bacteria that exhibited growth with and biodegradation of domoic acid when supplemented with low concentrations of growth factors. The species that retain domoic acid for lengthy periods, such as sea scallops (Placopecten magellanicus) and red mussels (Modiolus modiolus), only occasionally yielded bacteria with this capability. The differences may be a result of the mechanisms used by the different shellfish in dealing with domoic acid, i.e., freely available in the blue mussels and soft-shell clams but likely sequestered in the digestive glands of sea scallops and red mussels and thus, largely unavailable for bacterial utilization. The results show that Mytilus edulis and Mya arenaria, almost uniquely, are prime and reliable sources of domoic acid utilizing bacteria. These findings suggest a strong possibility that autochthonous bacteria may be significant factors in the elimination of the neurotoxin in these two species of shellfish.

Animals↗

Salmonella in raw shell eggs in Northern Ireland: 1996-7.

The shells and contents of 2090 packs of six raw eggs from shops in Northern Ireland were examined for the presence of salmonella between April 1996 and October 1997. Nine isolates of salmonella were detected from separate packs of eggs (0.43%). One of the isolates was from egg contents (0.05%), where salmonella can proliferate to levels likely to cause human infection if the egg is inadequately cooked. Visible dirt and organic contamination were poor predictors of salmonella contamination since most contaminated eggs had apparently clean and uncracked shells. Contaminated eggs were more likely to have been sold from small shops than supermarkets. Sampling for uncommon pathogens is expensive, labour intensive, and yields many negative results. The small numbers of positive results make it particularly susceptible to variations between methods. It continues to be important to cook eggs thoroughly to eliminate the risk of salmonellosis since this survey suggests that over 10,000 boxes containing one or more contaminated eggs may be sold in Northern Ireland each year. Caterers should use pasteurised liquid egg. A system of branding to enable eggs to be traced to individual flocks would assist in the investigation of outbreaks.

Eggs↗

Variability associated with testing shelled corn for fumonisin.

Variances associated with sampling, sample preparation, and analytical steps of a test procedure that measures fumonisin in shelled corn were estimated. The variance associated with each step of the test procedure increases with fumonisin concentration. Functional relationships between variance and fumonisin concentration were estimated by regression analysis. For each variance component, functional relationships were independent of fumonisin type (total, B1, B2, and B3 fumonisins). At 2 ppm, coefficients of variation associated with sampling (1.1 kg sample), sample preparation (Romer mill and 25 g subsample), and analysis are 16.6, 9.1, and 9.7%, respectively. The coefficient of variation associated with the total fumonisin test procedure was 45% and is about the same order of magnitude as that for measuring aflatoxin in shelled corn with a similar test procedure.

Carboxylic Acids↗

Estrogen enhancement of Ca-, Mg-, and Ca-Mg-stimulated adenosine triphosphatase activity in the chick shell gland.

The effect of 17 beta-estradiol (E2) on Ca-, Mg-, and Ca-Mg-ATPase activity was investigated in the shell gland of 6-week-old chicks. In the first study, each of 42 birds was implanted with three E2 (Compudose-200) pellets. An additional 6 sham-implanted birds served as controls for measurements of body weight and concentrations of E2 and Ca in plasma. The activities of Mg-, Ca-, and Ca-Mg-ATPase peaked coincident with maximum plasma E2 concentrations 8 days after implantation and then progressively declined in concert with the decline in plasma E2. By 29 days after implantation, the ATPase activities were similar to those measured in birds whose E2 pellets had been removed for 11 days. Concentrations of plasma E2 dropped from peak values of 1676 +/- 317 at Day 8 to 611 +/- 180 pg/ml at Day 29. When birds whose E2 pellets had been removed were reimplanted with three pellets per bird, plasma E2 again increased to 1637 +/- 227 pg/ml. ATPase activity in these reimplanted birds also was greater (P < 0.05) than activities measured in E2-removed or E2-maintained birds. In a second study the Ca-ATPase Km and Vmax were determined in E2-implanted chicks (three pellets per bird) and compared to E2-withdrawn chicks. Five days after reimplantation of chicks with E2, there was a significant increase in both Vmax (3.38 +/- 0.21 vs 2.37 +/- 0.28 micrograms Pi/mg protein/min; P < 0.05) and Km (0.31 +/- 0.02 vs 0.25 +/- 0.01 mM Ca; P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Ultrastructural and biochemical alterations in the livers from chick embryos maintained in shell-less culture.

Ultrastructural and biochemical studies were conducted on the livers from chick embryos maintained in shell-less culture up to stage 39 (Hamburger-Hamilton) and from control embryos developed in ovo up to the same stage. The ultrastructural characteristics of hepatic cells from the cultured embryos were similar to those found in the controls except that they contained many large lipid droplets and were almost devoid of lipoprotein granules normally associated with the Golgi complex and the smooth endoplasmic reticulum. These changes suggest the existence of alterations in the lipid metabolism. The livers from cultured embryos showed also a decreased incorporation of tritiated leucine into proteins, which indicates a reduced rate of protein synthesis. These results are consistent with previous reports showing that cultured embryos possess hypoproteinemia. Lactic dehydrogenase activity was similar and pyruvic kinase higher in the livers from cultured with respect to control embryos. This appears to indicate that both aerobic and anaerobic glycolysis were not depressed and that the changes observed in the rate of protein synthesis should not be attributed to hypoxia. "Fat-storing cells" similar to those described in mammals were found both in control and cultured embryos. They had not been previously described in the livers from chick embryos.

Animals↗

Crystal orientation in the shell of the domestic fowl: an electron diffraction study.

The eggshell of the domestic fowl has been studied by transmission electron microscopy and diffraction. Thin sections of shell were prepared by chemical and ion-beam thinning techniques. Each calcite column of the palisade layer consisted of crystallites of diameter 20 to 30 micrometer with some tendency for crystallite alignment within a single column. Evidence indicates that there was no significant preferred orientation in the palisade layer as a whole. Only in the surface layer was any preferred orientation detected, and here (1014) planes tended to lie parallel to the surface. The results are compared with previously published data, and calcite nucleation and growth are discussed.

Animals↗

A new biomaterial, hen egg shell membrane, to eliminate heavy metal ion from their dilute waste solution.

The egg shell membrane (ESM) is an intricate lattice network of stable and water-insoluble fibers with high surface area. ESM accumulates and eliminates various heavy metal ions from dilute aqueous solution with high affinity and in short contact time, depending on pH and characteristics of the individual ion. Under certain conditions, the level of precious ions, Au, Pt, and Pd accumulation approaches 55, 25, and 22% of dry wt of ESM, respectively. Also uranium uptake 30% of that of ESM. Experiments suggested that ESM is promising to use for the purpose of removal/recovery of metals and water pollution control.

Adsorption↗

Lysine-derived cross-links in the egg shell membrane.

Egg shell membrane protein contains significant quantities of the lysine-derived aldehyde, allysine, and its aldol condensation product. NaB3H4 reduction followed by alkaline hydrolysis of purified protein revealed that there were six residues/1000 of both allysine and the reduced aldol while only traces of desmosine and isodesmosine were detected. The amino acid composition of the membrane protein did not resemble that of mammalian elastin.

2-Aminoadipic Acid↗