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Biomedical subjects

R Patel

Publications and source records attributed to R Patel.

At least 451 records · Page 25Linked to original sources
PubMedDate not supplied

The measurement of prion protein in bovine brain tissue using differential extraction and DELFIA as a diagnostic test for BSE.

A simple diagnostic test for the detection of bovine spongiform encephalopathy (BSE), based on a commercially available time-resolved fluorescence immunoassay (DELFIA) for the measurement of the normal and disease-associated isoforms of prion protein (PrP), is described. The isoforms are sequentially extracted from homogenized bovine brain tissue using two concentrations of guanidine hydrochloride. This procedure initially extracts a soluble isoform and subsequently a less soluble disease-associated aggregated isoform. Following quantification of the two fractions, the percentage of the insoluble prion becomes a measurable parameter, independent of protein concentration, clearly identifying normal from infected animals displaying clinical signs of BSE. The mean percentages of insoluble PrP in brain tissue from 60 BSE-confirmed-positive cattle and 100 cattle that had never been exposed to the disease were 52.6% (SD = 22.8) and 3.9% (SD = 1.5), respectively. The assay is sensitive, with a detection limit of less than 50 pg PrP, and is robust and precise (CVs < 10%) over the appropriate working range.

Animals↗
PubMedDate not supplied

Total airway obstruction with neck extension: airway management of a patient with pharyngeal tumor.

Airway obstruction with the induction of anesthesia in children is common. Normally, neck extension with jaw thrust improves the airway. Flexion typically completes the obstruction. With the presence of a pharyngeal tumor, these relationships may not be the same. We present a case of complete airway obstruction with neck extension in the presence of a nasopharyngeal tumor. Flexion rather than extension of the neck relieved this airway obstruction. We highly recommend radiologic studies with neck extension and flexion in such cases.

Airway Obstruction↗
PubMedDate not supplied

Electrophysiologic and proarrhythmic effects of intravenous inotropic agents.

Intravenous inotropic agents promote increased myocardial contractility via elevation of myocyte calcium concentrations, a mechanism that is also known to promote the development of cardiac arrhythmias. The purpose of this article is to review the electrophysiologic effects and relative potential for proarrhythmia associated with dobutamine, dopamine, and the phosphodiesterase inhibitors amrinone and milrinone. Dobutamine increases sinoatrial node automaticity and decreases atrial and atrioventricular (AV) node refractoriness and AV nodal conduction time. The drug also decreases ventricular refractoriness in both healthy and ischemic myocardium. Dobutamine has been shown to increase heart rate in a dose-related fashion in animals and in humans. In humans, dobutamine has been reported to induce ventricular ectopic activity (VEA) in 3% to 15% of patients, although VEAs are often asymptomatic, requiring no intervention. Ventricular tachycardia (VT) associated with dobutamine appears to occur rarely. Patients with underlying arrhythmias or heart failure or those receiving excessive doses of dobutamine are at greatest risk for proarrhythmia. Dopamine increases automaticity in Purkinje fibers and has a biphasic effect on action potential duration. Dopamine has been reported to induce atrial or ventricular arrhythmias in animals. In humans, dopamine may be associated with dose-related sinus tachycardia but has also been reported to cause VEA, which is usually asymptomatic. Dopamine-associated VT appears to occur rarely. Dopamine produces greater elevations in heart rate or frequency of ventricular premature beats at a given value of cardiac index than does dobutamine. The phosphodiesterase inhibitors amrinone and milrinone increase conduction through the AV node and decrease atrial refractoriness. Intravenous administration of these drugs may result in sinus tachycardia in some patients and has been reported to cause VEA, which is often asymptomatic, in up to 17% of patients. VT has also been reported in association with short-term use of intravenous phosphodiesterase inhibitors. In summary, intravenous inotropic agents may be associated with proarrhythmic effects in some patients. The primary arrhythmias reported are sinus tachycardia and VEA, although other supraventricular or ventricular arrhythmias have been reported less commonly. However, clinically significant proarrhythmic effects associated with these agents appear to occur rarely, and, at conventional doses, intravenous inotropic agents are relatively safe with respect to proarrhythmic effects.

Adolescent↗
PubMedDate not supplied

Medication management in primary and secondary schools.

OBJECTIVE: To summarize present knowledge about medication management in primary and secondary schools; to place this knowledge in its drug use and organizational contexts; and to provide a foundation for studying the problem and developing policy- and practice-level interventions aimed at alleviating it. To offer recommendations for practitioners, policy makers, and health professions educators aimed at improving the situation. DATA SOURCES: MEDLINE database (1966-1998); International Pharmaceutical Abstracts database (1977-1998); complete Medscape full-text search; contents of the Journal of School Nursing and the Journal of School Health (1966-present). STUDY SELECTION: We reviewed 95% of all articles, books, and reports identified using the search terms elementary school, middle school, junior high school, high school, primary school, secondary school, school nurse, school health, and schoolchildren. DATA EXTRACTION: The literature on this topic includes background material describing the nature of the problem and its political and organizational context and implying its significance; summaries of regulations, guidelines, and recommendations regarding medication management in the schools; and empirical studies. Few articles address pharmacist involvement in medication management in schools. DATA SYNTHESIS: Although approaches to this important problem vary widely, a set of core medication management guidelines is identifiable. Formal research is sparse, but it shows that medication use is widespread in schools and carries significant therapeutic and safety consequences. CONCLUSION: Pharmacists and school nurses must cross professional borders if they wish to play a role in solving this important drug therapy problem. Pharmacists can provide therapeutic and contextual perspectives on the problem, while school nurses can implement solutions within the schools.

Child↗
PubMedDate not supplied

Double-stranded cyclic oligonucleotides with non-nucleotide bridges.

A series of double-stranded, cyclic oligodeoxynucleotides with non-nucleotide bridges have been synthesized, and their physicochemical properties and susceptibility to enzymes have been investigated. These bridged duplexes are of potential interest for their binding properties to transcription factors and other DNA-binding proteins. Triethylene glycol has been employed as the bridge to alter the lipophilicity of the duplex and avoid the potential for enzymatic cleavage. The synthetic route involved the synthesis of a 3'-phosphorylated, nicked double-stranded precursor with the final internucleotide bond being formed chemically using a water soluble carbodiimide. These bridged duplexes have high thermal dissociation temperatures, and the Tm for a triethylene-bridged 20 base pair duplex was higher than that for the corresponding pentathymidylate-bridged duplex. EcoR I endonuclease cleaved a ligated, bridged duplex at a slower rate than the corresponding unmodified duplex, whereas the unligated, bridged duplex was cleaved more rapidly. Sufficient amounts of the bridged octamer and dodecamer were prepared for proton NMR spectroscopic studies, and 2D COSY and NOESY spectra were obtained. The results indicate that the ligated duplex has a B-form conformation.

Base Sequence↗
PubMedDate not supplied

The DNA sequence and comparative analysis of human chromosome 20.

The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.

Animals↗
PubMedDate not supplied

Blood-taking practices and needle-stick injuries in house officers.

The blood-taking practices and prevalence of needle-stick injuries were recorded for 46 house officers working at the two largest teaching hospitals in Sheffield and 38 house officers working at three hospitals in London. Wearing gloves when performing venesection or inserting an intravenous cannula was generally perceived as making the procedure more difficult and no house officer in either centre wore gloves when performing routine venesection. Twenty-five (54.3%) of the house officers from Sheffield resheathed needles by hand, while a further 14 (28.3%) placed the sheath onto a work surface before attempting to manoeuvre the needle back into its sheath. Only 7 (17.4%) house officers denied resheathing needles after performing venesection. Twenty-seven (58.7%) admitted to having had a needle-stick injury within 3 months of commencing their first house officer post. Twenty-seven (71.1%) of the house officers from London resheathed needles, the remainder disposing of the needle by placing it straight into an appropriate container. Twenty-five (66%) admitted to having had a needle-stick injury the first 6 months of being a house officer. Training in the correct techniques of venesection with emphasis on either avoiding resheathing needles or resheathing safely is essential early in the medical student curriculum and needs regular repetition.

Accidents, Occupational↗
PubMedDate not supplied

Comparison of the influence of spermicidal and non-spermicidal contraception on bacterial vaginosis, candidal infection and inflammation of the vagina--a preliminary study.

This preliminary study compared the signs, symptoms and prevalence of bacterial vaginosis (BV) and candidal infections in women using spermicides, with those using other forms of contraception, to establish whether nonoxynol-9 had any therapeutic value against BV or gave rise to vaginal candidiasis and inflammation. Overall results showed that the prevalence of BV in non-spermicide users was 35/113 (31%) but was significantly less in spermicide users, 10/66 (15%), P < 0.05. Nonoxynol-9 was not associated with increased isolation of Candida albicans, which was found in 16/113 (14%) of non-spermicide users, and in 8/66 (12%) of those using spermicides, P > 0.1. Vaginal inflammation and discharge were significantly less in spermicide users, 19/66 (29%) than in the non-spermicide group, 50/113 (44%), P < 0.05. Nonoxynol-9 contraception was associated with a significantly reduced prevalence of BV, but not with increased candidiasis or vaginal inflammation.

Candidiasis, Vulvovaginal↗