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PubMed1975

Bronchofiberscopy.

Probably no other diagnostic interpretive technique has revolutionized pulmonary medical practice in so short a time as flexible bronchofiberscopy. This state of the art review deals with flexible bronchofiberscopy, as well as comparisons to rigid bronchoscopic techniques. Historic development, specifications, indications, contraindications, sterilization of the instrument, and complications of these methods are discussed. Accessory procedures to bronchofiberscopy including biopsy, brushing, lavage, foreign body extraction, selective bacterial cultures, and research applications are considered. Finally, recommendations are made as to the training of a physician who performs bronchofiberscopy.

Anesthesia, Local↗
PubMed1996

Bonding to intact dentin.

It has been reported that the presence of a smear layer on dentinal substrates can compromise bonding. Typically, smear layers are removed by acidic agents that selectively extract calcium salts from dentin surfaces to leave a collagen-rich substrate. Acid-conditioned dentin (i.e., demineralized) is then primed and an adhesive agent applied. In the present study, we removed smear layers by "polishing" dentin specimens with a hydroxyapatite paste and ultrasonication. Bonding procedures were carried out by means of an aqueous solution of 20% 2-methacryloyloxyethyl phenyl phosphoric acid (phenyl-P) and 30% 2-hydroxyethyl methacrylate, referred to as 2OP-30H, a "self-etching primer". The 20P-30H solution was applied to "intact" dentin (i.e., non-demineralized) for either 30 or 60 s. Control samples received no application (O s) of the self-etching primer. Mean tensile bond strengths (10 MPa) were similar in both the 30-second- and 60-second-primed groups. The widths of formed hybrid layers varied from 0.3 +/- 0.2 micron at O s application (control) to 2.1 +/- 0.3 micron for the 30-second group and 4.1 +/- 0.2 micron for the 60-second group. SEM and TEM observations revealed that the 20P-30H self-etching primer created diffusion channels into "intact" calcium-rich dentin which permitted monomer to infiltrate dentin substrates. Hybrid layers identified under microscopic examination demonstrated resistance to both HCI and NaOCI treatments, suggesting that the hybrid layer was not defective, and that bonding was stable.

Acid Etching, Dental↗
PubMedDate not supplied

ADHD: a psychological response to an evolving concept. (Report of a Working Party of the British Psychological Society).

The British Psychological Society is the only national organization of psychologists within the United Kingdom representing all aspects of psychology and all subspecialisms within psychology. It is both a learned scientific society and a professional association. To address the concept of attention-deficit/hyperactivity disorder (ADHD), the Professional Affairs Board of the Society convened a Working Party, consisting of individuals nominated by subsystems of the Society because of their recognized professional and academic expertise. They covered a range of specialisms, including educational, clinical, criminological, neurological, and cognitive psychology. A report by the Working Party was published in September 1996. It had two main aims: first, to outline the research that was relevant to current understanding of the notion of ADHD from an historical, psychological, and biological perspective, and, second, to consider implications for practice in the light of the information obtained. The focus was predominantly on children, although it was recognized that problems could persist into adulthood. The intention was to write a report for professionals that also would be accessible to a wider audience. This article is a highly abridged version of the report. It omits the references to research reviews and research studies contained in the full account. Selected extracts are included in order to justify the conclusions and the recommendations that are made and to inform a North American audience of developments in the United Kingdom.

Adult↗
PubMedDate not supplied

Pharmacokinetics of intraperitoneal gemcitabine in a rat model.

BACKGROUND: Gemcitabine (2'-2' difluorodeoxycytidine) has been shown to possess a broad spectrum of antitumor activity against various malignancies, particularly pancreatic carcinoma. For cancers occurring within the abdominal cavity, the advantage of intraperitoneal (i.p.) chemotherapy over intravenous (i.v.) chemotherapy is the high drug concentration that can be achieved locally. In addition, the cytotoxic effect of several anticancer agents can be enhanced by hyperthermia. Using a rat model, this study was designed to compare i.p. vs i.v. gemcitabine and to evaluate the effect of hyperthermia on i.p. gemcitabine. METHODS: In the first phase of this study, 18 Sprague Dawley rats were given a single dose of gemcitabine then randomized into three groups according to dose and route of delivery of chemotherapy (12.5 mg/kg--i.v., 12.5 mg/kg--i.p. or 125 mg/kg--i.p.). In a separate experiment (phase 2), 12 Sprague Dawley rats were given a continuous i.p. perfusion of gemcitabine (12.5 mg/kg in 150 mL total perfusate) and randomized into two groups according to the temperature of the peritoneal perfusate (normothermic or hyperthermic). During the course of both experiments, peritoneal fluid and blood were sampled using a standardized protocol. At the end of the procedure the rats were sacrificed and all urine was extracted. Selected tissue samples were taken from rats in the second phase of the study. The concentration of gemcitabine in all samples was determined by high performance liquid chromatography (HPLC). RESULTS: When gemcitabine was delivered at 12.5 mg/kg (phase 1) the area under the curve (AUC) was significantly higher with i.p. administration as compared to i.v. administration (P = 0.001). The AUC ratio (AUC peritoneal fluid/AUC plasma) was 12.5+/-3.2 for i.p. delivery as opposed to 0.2+/-0.2 for i.v. delivery (P = 0.0002). The AUC ratio for i.p. gemcitabine at 125 mg/kg was 26.8+/-5.8. Although there was no significant difference in drug concentrations between samples from the normothermic and hyperthermic groups, all tissue samples (except stomach) in the hyperthermic group exhibited increased gemcitabine concentrations. CONCLUSION: These experiments demonstrated that the exposure of peritoneal surfaces to gemcitabine is significantly increased with i.p. gemcitabine. Intraabdominal hyperthermia had no significant effect on the pharmacokinetics of i.p. gemcitabine but there was evidence of increased absorption of gemcitabine in most intraabdominal tissues. Due to the likelihood of a high incidence of microscopic residual disease after resection of a pancreatic carcinoma, clinical studies to evaluate i.p. hyperthermic gemcitabine may be indicated.

Animals↗
PubMed1987

Poly(ether) urethane reactivity with metal-ion in calcification and environmental stress cracking.

Since their introduction to the biomedical community in 1967, polyurethanes have been used in a number of biomedical applications. In chronic applications evidence is now available which suggests that polyurethanes may be subject to various cracking phenomena. Environmental stress cracking and calcification are two phenomena resulting in poly(ether)urethane cracking, which have been shown to be enhanced by ion complexation. Much evidence now exists which defines the ability of poly(ether)urethanes to selectively extract ions, especially calcium ion from solution. Metal ion binding appears to enhance environmental stress cracking and appears to be a first step in the process of calcification.

Biocompatible Materials↗
PubMedDate not supplied

Web-based three-dimensional Virtual Body Structures: W3D-VBS.

Major efforts are being made to improve the teaching of human anatomy to foster cognition of visuospatial relationships. The Visible Human Project of the National Library of Medicine makes it possible to create virtual reality-based applications for teaching anatomy. Integration of traditional cadaver and illustration-based methods with Internet-based simulations brings us closer to this goal. Web-based three-dimensional Virtual Body Structures (W3D-VBS) is a next-generation immersive anatomical training system for teaching human anatomy over the Internet. It uses Visible Human data to dynamically explore, select, extract, visualize, manipulate, and stereoscopically palpate realistic virtual body structures with a haptic device. Tracking user's progress through evaluation tools helps customize lesson plans. A self-guided "virtual tour" of the whole body allows investigation of labeled virtual dissections repetitively, at any time and place a user requires it.

Anatomy↗
PubMed2001

Diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography in the follow-up of papillary or follicular thyroid cancer.

Positron emission tomography with 18F-fluorodeoxyglucose is a relatively new nuclear imaging technique in oncology. We conducted a systematic review to determine the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography in patients suspected of recurrent papillary or follicular thyroid carcinoma. Two reviewers independently selected, extracted, and assessed data from relevant literature found in computerized databases and by reference tracking. Prospective and retrospective studies with 10 human subjects, or more, that evaluated the accuracy of ring positron emission tomography, using 18F-fluorodeoxyglucose in follicular and papillary thyroid cancer, were included. Studies on 18F-fluorodeoxyglucose imaging using gamma cameras, reviews, case reports, editorials, letters, and comments were excluded. The methodological quality was assessed by applying the criteria for diagnostic tests recommended by the Cochrane Methods Group on Screening and Diagnostic Tests. A rating system was used for qualitative analysis consisting of four levels of evidence (1 = highest level; 4 = lowest level). Fourteen studies met the inclusion criteria. All studies claimed a positive role for positron emission tomography but, at evidence levels 3 or 4, precluding quantitative analysis. Methodological problems included poor validity of reference tests and a lack of blinding of test performance and interpretation. The reviewed material was heterogeneous with respect to patient variation and validation methodology. The most consistent data were found on the ability of 18F-fluorodeoxyglucose positron emission tomography to provide an anatomical substrate in patients with elevated serum Tg and negative iodine-131 scans. In conclusion, the results seem to support the potential of 18F-fluorodeoxyglucose positron emission tomography to identify and localize foci of recurrent cancer in the latter patient subset. However, implementation of positron emission tomography in a routine diagnostic algorithm requires additional evidence.

Adenocarcinoma, Follicular↗
PubMed2004

KIN17 encodes an RNA-binding protein and is expressed during mouse spermatogenesis.

Genotoxic agents deform DNA structure thus eliciting a complex genetic response allowing recovery and cell survival. The Kin17 gene is up-regulated during this response. This gene encodes a conserved nuclear protein that shares a DNA-binding domain with the bacterial RecA protein. The KIN17 protein binds DNA and displays enhanced expression levels in proliferating cultured cells, suggesting a role in nuclear metabolism. We investigated this by studying the expression profile of KIN17 protein during mouse spermatogenesis. As expected, the expression level of Kin17 is higher in proliferating than in differentiated cells. KIN17 is selectively extracted from this tissue by detergents and a fraction was tightly associated with the nuclear matrix. Germinal cells ubiquitously express Kin17 and the protein is located mainly in the nucleus except in elongated spermatids where cytoplasmic staining is also observed. Sertoli and germ cells that are no longer mitotically active express KIN17, suggesting a general role in all testicular cell types. In adult testis a significant proportion of KIN17 co-purifies with polyadenylated RNA. KIN17 directly binds RNA, preferentially poly(G) and poly(U) homopolymers. These results together with the identification of KIN17 as a component of the human spliceosome indicate that this protein may participate in RNA processing.

Animals↗
PubMed1996

Calcium-dependent bidirectional power stroke of the dynein arms in sea urchin sperm axonemes.

Active sliding between doublet microtubules of sea urchin sperm axonemes that were demembranated with Triton X-100 in the presence or absence of calcium was induced with ATP and elastase at various concentrations of Ca2+ to examine the effects of Ca2+ on the direction of the power stroke of the dynein arms. Dark-field light microscopy of microtubule sliding revealed that the sliding from the axonemes demembranated with Triton and millimolar calcium and disintegrated with ATP and elastase showed various patterns of sliding disintegration, including loops of doublet microtubules formed near the head or the basal body. These loops were often thicker than the remaining axonemal bundle. In contrast, only thinner loops were found from the axonemes demembranated with Triton in the absence of calcium and disintegrated with ATP and elastase at high Ca2+ concentrations. Electron microscopic examination of the direction of microtubule sliding showed that the doublet microtubules in the axonemes demembranated in the presence of millimolar calcium moved toward the base of the axonemes by the dynein arms on the adjacent doublet microtubule as well as by their own dynein arms. Doublet microtubules in the axonemes demembranated in the absence of calcium moved toward the base of the axonemes only by their own dynein arms. Similar observations have been obtained from the axonemes from which the outer dynein arms were selectively extracted. From these observations, we can conclude that the dynein arms generate force in both directions and this feature of the dynein arms arises from at least the inner dynein arms.

Animals↗
PubMed1997

Association of hnRNP S1 proteins C2 and D2 with vimentin intermediate filaments.

S1 proteins A-D are hnRNP proteins which were originally isolated from nuclei of various tissues, by selective extraction of pH 4.9 from the supernatants of nuclei mildly treated with DNase I or RNase A. In the present study, a hybridoma was isolated which produced a monoclonal antibody that reacted specifically with S1 proteins C2 and D2. When the antibody was used in indirect immunofluorescence staining of cultured cells, it stained, in addition to the nuclei, the cytoskeleton-like fibrous structures in the cytoplasm. We demonstrate that the cytoskeletal filaments are vimentin intermediate filaments. This is the first report on the hnRNP protein-association with cytoskeleton, and will help to clarify cytoplasmic mRNA localization as well as cytoplasmic distribution of hnRNP proteins.

Animals↗
PubMed2005

Quantitative determination method for trace amount of penicillin contaminants in commercially available drug product by HPLC coupled with tandem mass spectrometry.

A quantitative determination method for trace amount of penicillin contaminants in an active pharmaceutical ingredient (API) has been developed. Selective extraction of penicillin contaminants from the matrix containing API and specific separation among penicillin contaminants were achieved through an on-line column switching technique with gradient elution, followed by tandem mass spectrometric determination. Validation was conducted on the developed method in terms of specificity, linearity, accuracy, precision, and detection limit, and appeared reasonable. The detection limit was estimated as 0.03 ng/ml or lower of the concentration of penicillin contaminants in the preparation, corresponding to 4 parts par billion (ppb) against the API. This fulfilled the regulatory requirement by the authorities.

Amoxicillin↗
PubMed1995

Rapid and simple procedure for purifying PAS-4 glycoprotein from bovine milk fat globule membrane.

The isolation and partial characterization of PAS-4 glycoprotein (78 kDa) from bovine milk fat globule membrane (MFGM) is described. PAS-4 was selectively extracted with Triton X-114 nonionic detergent and then fractionated on DEAE-Sepharose at pH 7.5. The PAS-4 fraction that was not bound on DEAE-Sepharose gave a single band by SDS-PAGE. The recovery of PAS-4 was 57.4% from MFGM. An amino acid analysis found a high percentage of nonpolar residues. Approximately 7.2% of carbohydrate from PAS-4 was composed of mannose, galactose (Gal), N-acetylglucosamine, N-acetylgalactosamine (GalNAc), and sialic acid, most of the Gal and GalNAc in PAS-4 being released after mild alkaline hydrolysis. This indicated that PAS-4 contained both N- and O-linked sugar chains in concordance with the results of lectin affinity. PAS-4 had apparent isoelectric points of 7.45, 7.41, and 7.32, but these were shifted to pI 7.47 by a neuraminidase treatment. The apparent molecular weight of PAS-4 after deglycosylation with N-glycanase was approximately 57,000 by SDS-PAGE.

Animals↗
PubMedDate not supplied

Screening children for family violence: a review of the evidence for the US Preventive Services Task Force.

BACKGROUND: We wanted to evaluate the benefits and harms of screening children in primary health care settings for abuse and neglect resulting from family violence by examining the evidence on the performance of screening instruments and the effectiveness of interventions. METHODS: We searched for relevant studies in MEDLINE, PsycINFO, CINAHL, ERIC, Cochrane Controlled Trials Register, and reference lists. English language abstracts with original data about family violence against children focusing on screening and interventions initiated or based in health care settings were included. We extracted selected information about study design, patient populations and settings, methods of assessment or intervention, and outcome measures, and applied a set of criteria to evaluate study quality. RESULTS: All instruments designed to screen for child abuse and neglect were directed to parents, particularly pregnant women. These instruments had fairly high sensitivity but low specificity when administered in high-risk study populations and have not been widely tested in other populations. Randomized controlled trials of frequent nurse home visitation programs beginning during pregnancy that address behavioral and psychological factors indicated improved abuse measures and outcomes. No studies were identified about interventions in older children or harms associated with screening and intervention. CONCLUSIONS: No trials of the effectiveness of screening in a health care setting have been published. Clinician referrals to nurse home visitation during pregnancy and in early childhood may reduce abuse in selected populations. There are no studies about harms of screening and interventions.

Child↗
PubMed1999

Biomass conversion to mixed alcohol fuels using the MixAlco process.

The MixAlco process is a patented technology that converts any biodegradable material (e.g., sorted municipal solid waste, sewage sludge, industrial biosludge, manure, agricultural residues, energy crops) into mixed alcohol fuels containing predominantly 2-propanol, but also higher alcohols up to 7-tridecanol. The feedstock is treated with lime to increase its digestibility. Then, it is fed to a fermentor in which a mixed culture of acid-forming microorganisms produces carboxylic acids. Calcium carbonate is added to the fermentor to neutralize the acids to their corresponding carboxylate salt. The dilute (approximately 3%) carboxylate salts are concentrated to 19% using an amine solvent that selectively extracts water. Drying is completed using multi-effect evaporators. Finally, the dry salts are thermally converted to ketones which subsequently are hydrogenated to alcohols. All the steps in the MixAlco process have been proven at the laboratory scale. A techno-economic model of the process indicates that with the tipping fees available in New York (126 dollars/dry tonne), mixed alcohol fuels may be sold for 0.04 dollars/L (0.16 dollars/gal) with a 60% return on investment (ROI). With the average tipping fee in the United States rates (63 dollars/dry tonne), mixed alcohol fuels may be sold for 0.18 dollars/L (0.69 dollars/gal) with a 15% ROI. In the case of sugarcane bagasse, which may be obtained for about 26 dollars/dry ton, mixed alcohol fuels may be sold for 0.29 dollars/L (1.09 dollars/gal) with a 15% ROI.

Journal Article↗
PubMed1985

[Development of two assay systems of desialylated hCG specific for O-serine or N-asparagine linked carbohydrate chain and their clinical application].

Two specific and sensitive assays have been developed for the measurement of as-hCG in this study. These assay systems are immunoradiometric assays which utilize peanut lectin, Arachis hypogaea (PNA) or caster bean lectin, Ricin communis agglutinin (RCA-I), to selectively extract as-hCG and then directly quantify with purified and radiolabeled antiserum against hCG beta COOH terminal peptide (beta-CTP). PNA is highly specific for the terminal carbohydrate linkage Gal beta-(1----3)-GalNAc which is only exposed in hCG when the O-serine linked oligosaccharide of its unique beta-CTP region are desialylated. RCA-I is also specific for the terminal carbohydrate beta-D-Galp., especially the linkage of Gal beta-(1----4)-GlcNAc, which is exposed in hCG when the N-asparagine linked oligosaccharide of its alpha and beta subunits are desialylated. The assays (PNA-R525 and RCA-I-R525) are capable of reliably and accurately measuring as little as 0.01 and 0.002 pmoles as-hCG/ml without interference from hCG, respectively (crossreactivity: 0.1% and 0.03%). The urine concentrates of a patient with choriocarcinoma and a normal pregnant woman were fractionated by Sephadex G-100 gel filtration and total hCG and as-hCG levels were measured. When the fractions were analysed by beta-CTP RIA, there were two peaks of immunoreactive hCG in the urine of a patient with choriocarcinoma. The bigger molecular fractions were hCG of native size, and 16% of which was desialylated. The smaller molecular fraction was beta-CTP, and practically all of that was desialylated. Whereas, beta-CTP could not be observed, and only 1.5% of hCG of native size was desialylated in the urine of a normal pregnant woman. Although the absolute levels of as-hCG in the urine specimens increased as total hCG increased, the proportion of as-hCG decreased as total hCG concentration increased. The proportion of as-hCG in urine specimens from choriocarcinoma patients was higher than specimens from patients with hydatidiform mole (including invasive mole) in both these lectin immunoradiometric assay (LIRMA) systems. Also, the proportion of as-hCG in urine specimens from molar patients was higher than those from normal pregnant women using PNA as extracting reagent. Whereas, when RCA-I was used, there was no significant difference between specimens from molar patients and those from normal pregnant women.(ABSTRACT TRUNCATED AT 400 WORDS)

Asialoglycoproteins↗
PubMed2001

The search for new antimalarial drugs from plants used to treat fever and malaria or plants ramdomly selected: a review.

In this review we discuss the ongoing situation of human malaria in the Brazilian Amazon, where it is endemic causing over 610,000 new acute cases yearly, a number which is on the increase. This is partly a result of drug resistant parasites and new antimalarial drugs are urgently needed. The approaches we have used in the search of new drugs during decades are now reviewed and include ethnopharmocology, plants randomly selected, extracts or isolated substances from plants shown to be active against the blood stage parasites in our previous studies. Emphasis is given on the medicinal plant Bidens pilosa, proven to be active against the parasite blood stages in tests using freshly prepared plant extracts. The anti-sporozoite activity of one plant used in the Brazilian endemic area to prevent malaria is also described, the so called "Indian beer" (Ampelozizyphus amazonicus, Rhamnaceae). Freshly prepared extracts from the roots of this plant were totally inactive against blood stage parasites, but active against sporozoites of Plasmodium gallinaceum or the primary exoerythrocytic stages reducing tissue parasitism in inoculated chickens. This result will be of practical importance if confirmed in mammalian malaria. Problems and perspectives in the search for antimalarial drugs are discussed as well as the toxicological and clinical trials to validate some of the active plants for public health use in Brazil.

Acute Disease↗
PubMed1978

The management of drug induced gingival hyperplasia in mentally retarded patients with hemophilia: a report of two cases.

Two cases of hemophilia in severely mentally retarded patients with drug-induced gingival hyperplasia are presented. The method of management in each case is described. A conservative approach is recommended in which tissue removals and only selected extractions are performed. It is also suggested that the sequela of dilantin hyperplasia be considered when dilantin is used in patients with hemophilia or severely mentally retarded patients whose oral hygiene may be difficult to maintain. If feasible, as in the first case reported, discontinuance of the drug should be considered. In case 2 the patient is presently being weaned from dilantin therapy. It should be understood that the authors are concerned with the immediate clinical management of drug-induced gingival hyperplasia in mentally-retarded patients with hemophilia. Although this method of management has proved successful in the hands of the authors, we do not have data to show that it is the best form of treatment for these patients.

Adult↗
PubMed1988

Abnormal lymphocyte profiles and leukotriene B4 status in a patient with Crohn's disease and severe periodontitis.

THIS CASE REPORT DESCRIBES clinical and laboratory findings for a 60-year-old woman with recently diagnosed Crohn's disease and severe generalized periodontitis. Comparison of dental radiographs taken in 1975, in 1983, and at the time of our evaluation in 1986 revealed dramatic progression of alveolar bone loss over that period. Standard laboratory blood tests did not reveal any remarkable significant leukocyte abnormalities, but flow cytometric analysis of lymphocytes revealed a paucity of B cells stained with anti-light chain antibodies, and an increased proportion of T lymphocytes which were dully-stained with anti-CD5 monoclonal antibody. B cell function as determined by in vitro proliferative responsiveness to anti-IgM antibody was only about 50% of that observed with cells from two healthy normal subjects. Serum leukotriene B4 (LTB4) was elevated to 150% of normal values, in spite of the fact that the patient was taking a systemic anti-inflammatory drug which is known to reduce LTB4 levels. The microbial flora was highly mixed and included several putative periodontopathic bacteria. Therapy consisted of oral hygiene instruction, scaling and root planing, mucoperiosteal-flap curettage, extracoronal splinting, and selective extraction of three teeth. The periodontal status improved markedly with therapy. Possible relationships between the patient's immunological status, her Crohn's disease, and the severe periodontal breakdown are discussed.

B-Lymphocytes↗