Biomedical subjects

C E Willis

Publications and source records attributed to C E Willis.

18 recordsLinked to original sources

PubMed1996

Staphylococcus aureus and sore nipples.

OBJECTIVE: To correlate clinical symptoms and signs of sore nipples with the presence of Staphylococcus aureus and to determine the probability of mothers having S aureus-infected nipples when these local symptoms and signs are found. DESIGN: Two cohorts of consecutive patients were enrolled regardless of presenting complaint. A questionnaire was administered to determine the presence and severity of sore nipples. Objective findings on breast examination were documented. A nipple swab was taken for culture and sensitivity. SETTING: Breastfeeding clinic serving patients referred by family physicians, pediatricians, and community health nurses. PATIENTS: A sample of 227 breastfeeding mothers was collected in two cohorts. MAIN OUTCOME MEASURES: Answers to questions about sore nipples, objective findings from physical examination, and results from nipple swabs. RESULTS: Most subjects (51%) had sore nipples, and 45% of subjects had objective findings on examination; 23% of subjects had a positive nipple swab culture; 15% grew S aureus on culture. The risk of having S aureus colonization was 4.8 times greater if nipple pain was moderate or severe rather than mild. A break in nipple integument associated with cracks, fissures, ulcers, or pus gave a 35% chance of having S aureus colonization, five times greater than when the integument was intact. CONCLUSIONS: The study showed that mothers with infants younger than 1 month who complained of moderate to severe nipple pain and who had cracks, fissures, ulcers, or exudates had a 64% chance of having positive skin cultures and a 54% chance of having S aureus colonization.

Adolescent↗

PubMed1996

Casualties of the sun.

A retrospective review was carried out of all sunburn related attendances, during the periods 1/6/94-31/8/94 and 1/6/95-31/8/95, at the four A&E departments and at one of the general practices within the Northern Health and Social Services Board area. Four hundred and thirty patients had attended. The modal age group was 16-30 years. More males presented than females. Within the sexes more males presented in the under 16 years and over 30 years age group, while females were more common in the 16-30 years age group. There was documentation of blisters in 30% of patients. Those with blisters were more likely to be under 16 years and male. In females the most and least commonly affected areas correlated with the most and least commonly affected areas for cutaneous malignant melanoma. In these days of limited resources it is important to use epidemiological data such as this in order to contribute to the development of health promotion programmes and campaigns.

Adolescent↗

PubMed1995

Infant insufficient milk syndrome associated with maternal postpartum hemorrhage.

Insufficient milk syndrome is defined as failure to thrive in infants due to insufficient daily breastmilk intake. This discussion examines a possible association between insufficient milk syndrome and maternal postpartum hemorrhage. Ten consecutive cases of insufficient milk syndrome associated with maternal postpartum hemorrhage were identified. The mothers presented between 3 and 35 days postpartum. Maternal postpartum blood loss ranged from 500-1500 ml in eight cases (mean: 963 ml); in two cases, blood loss was noted as 400++ and 200++, respectively. Six mothers experienced a drop of hemoglobin by > 30g/L; two had a drop in blood pressure > 30mmHg for > 20 minutes. All infants were failing to thrive. Five infants suffered hypernatremic dehydration with serum sodium levels ranging from 148-166mmol/L. Breastmilk electrolytes were measured in six cases, and elevated sodium levels, ranging from 21-100mmol/L, in five cases. These data serve to heighten awareness of insufficient milk syndrome as a potential consequence of postpartum hemorrhage. Early postpartum review of all breastfeeding mothers and infants is strongly encouraged.

Adult↗

PubMed1991

Preliminary assessment of computed tomography and satellite teleradiology from Operation Desert Storm.

Computed tomography at military transportable hospitals was used for the first time during the recent Operation Desert Storm in the Saudi Arabian desert. Scan quality was excellent and the scans proved clinically important in patient management. A teleradiology link via satellite to the U.S. mainland was also successfully employed. The objectives of the teleradiology link were to validate the concept distant interpretation of images obtained on the battlefield and to provide specialty radiology consultation. This technology shows great promise for future applications, both for combat casualty care and for civilian disaster medical support operations.

Hospitals, Military↗

PubMed1988

An equation for DNA electrophoretic mobility in agarose gels.

Assignment of molecular weight to DNA fragments on the basis of electrophoretic mobility in agarose gels is complicated by nonlinearity of the relationship between mobility and molecular weight. Graphical methods that linearize sigmoidal curves provide a simplified description of the mobility function when applied to normalized mobility data. This description is valid over a wide range of molecular weights. Linear duplex molecules of lengths ranging from 118 to 169,200 base pairs were electrophoresed at voltage gradients of 1 to 6 V/cm through horizontal slab gels ranging from 0.2 to 1.6% agarose. A logit transformation of the mobility graphed versus the logarithm of molecular weight, analogous to a Hill plot of enzyme kinetics, is a straight line. Changes in the voltage gradient or gel composition alter the position but not the slope or linearity of the data plotted by this method. The logistic representation is compared with the conventional graph of log molecular weight versus mobility, with the graph of molecular weight versus reciprocal mobility, and with Probit analysis of the mobility function. Parameters were determined for one equation that accurately describes DNA mobility as a function of the three tested variables. Curves are presented that are useful in predicting fragment length, migration, resolution, and gel performance.

DNA, Viral↗

PubMed1984

The role of calcium in the regulation of prostacyclin synthesis by porcine aortic endothelial cells.

Both bradykinin (EC50 = 8 ng/ml) and the ionophore A23187 (EC50 = 3 X 10(-7) M) potently stimulated arachidonate release and prostaglandin synthesis in porcine aortic endothelial cells. The response to each was completely dependent on extracellular Ca2+ (EC50 = 3 X 10(-7) M); no role for intracellular Ca2+ was noted. The rapid Ca2+ influx prompted by either activator was consistent with the time course for arachidonate release. Whereas the arachidonate released in response to bradykinin was transient, that released in response to A23187 was more prolonged, and paralleled a continued influx of Ca2+. Ca2+ entry elicited by bradykinin was mediated by channels which could not be blocked by verapamil. When Mn2+ was substituted for Ca2+, no stimulation of prostacyclin synthesis was seen in response to A23187; however, the bradykinin response was unaffected. The mechanism of these effects was studied using doses of bradykinin or A23187 which resulted in increases in Ca2+ influx and prostacyclin synthesis of similar magnitude for each agonist. Under these conditions, trifluoperazine blocked elevated prostacyclin synthesis (ID50 = 5-6 X 10(-6) M for each agonist). Trifluoperazine sulfoxide, however, was much less active. Pimozide inhibited bradykinin-stimulated prostacyclin synthesis at low doses (ID50 = 3 X 10(-6) M). Trifluoperazine was much less effective against high doses of A23187 (4 X 10(-6) M). These data suggest that arachidonate release and prostacyclin synthesis are dependent on influx of extracellular calcium and subsequent activation of a Ca2+-dependent phospholipase by a calmodulin-mediated mechanism.

Animals↗

PubMed1982

Effect of anthracycline analogues on the appearance of newly synthesized total RNA and messenger RNA in the cytoplasm of erythroleukemia cells.

Effects of the structural analogues, adriamycin (ADM), daunomycin (DNM), carminomycin (CMM), 4-demethoxydaunomycin (4D-DNM), pyrromycin (PYM), marcellomycin (MCM), and aclacinomycin (ACM) upon total cell RNA synthesis and the appearance of total RNA and poly(A)+-RNA in the cytoplasm of uninduced Friend erythroleukemia cells were investigated. The anthracyclines inhibited cellular RNA synthesis with IC50 values of 1-3 microM (ADM, DNM), 0.3-0.5 microM (CMM, 4D-DNM, PYM), and 0.06 microM (MCM, ACM). IC50 values for the appearance of total RNA in the cytoplasm were consistently 2-3 times lower than those for total cell RNA synthesis for each anthracycline. IC50 values for the inhibition of poly(A)+-RNA in the cytoplasm by ADM, DNM, and CMM were equivalent to those for total RNA synthesis. The values for MCM and ACM were 2-3 times higher than those for total RNA synthesis. The kinetic actions of drug-induced inhibition of poly(A)+-RNA appearance in the cytoplasm and inhibition of total RNA synthesis were equivalent for ADM, DNM and CMM, whereas the other anthracyclines showed different kinetics. These studies confirm the greater sensitivity of nucleolar RNA synthesis to Class II anthracyclines in erythroleukemia cells and suggest that inhibition of post-transcriptional events may occur in cells exposed to PYM, MCM, and ACM but at higher concentrations than are required for inhibition of RNA synthesis.

Animals↗

PubMed1979

High pressure liquid chromatography for simultaneous analysis of anticonvulsants: comparison with EMIT system.

We present a new high pressure liquid chromatography (HPLC) method for the simultaneous analysis of primidone, phenobarbital, phenytoin, and carbamazepine in serum. The chromatographic separation is carried out using an Altex model 110-A pump, a 250 times 4.6 mm column containing 5 mum Spherisorb ODS particles and a variable wavelength ultraviolet detector set at 197 nm. The mobile phase is a mixture of acetonitrile, distilled water, and 1.75 M phosphoric acid (27:72.8:0.2). The flow rate is 1.5 ml/min, and the analysis time is 17 min. A 200 mul aliquot of serum is buffered at pH 5 and extracted with dichloromethane. The extract is evaporated to dryness and dissolved in methanol for chromatographic analysis. Cyclopal is used as the internal standard and quantification is achieved using peak height ratios. This HPLC method is evaluated for precision and accuracy with reference to the EMIT system. The least-squares regression analysis of comparison data for the drugs shows a favorable correlation. Also, a paired t-test indicates no significant difference for the HPLC and EMIT values for primidone, phenobarbital, phenytoin, and carbamazepine. From this study we conclude that this HPLC method could be successfully used for the simultaneous therapeutic monitoring of the four anticonvulsants.

Anticonvulsants↗

PubMed1978

Enzymatic determination of plasma ammonia: evaluation of Sigma and BMC Kits.

We compared two kit methods for the enzymatic determination of plasma ammonia. The procedures involved measuring the decrease in absorbance at 340 nm resulting from the consumption of NADH in the Sigma kit, NADPH in the BMC kit. Both kits gave acceptable results for aqueous samples, but for plasma specimens values with the Sigma kit significantly exceeded those obtained with the BMC kit. In our hands, values with the BMC kit were more accurate and precise. On the basis of these results, we conclude that the BMC kit is the better choice.

Ammonia↗

PubMed1977

Malonaldehyde content of food.

Several types of commercially available food both cooked and uncooked were tested for the presence of the carcinogenic initiator and mutagen, malonaldehyde, which is a breakdown product of unsaturated fatty acids. The thiobarbituric acid derivative of malonaldehyde from meat extract was identified either by thin layer chromatography or by gas chromatography after silylation. Malonaldehyde was also identified directly by gas chromatography. Among the meats purchased from supermarkets, beef had the greatest amounts of malonaldehyde. Turkey and cooked chicken had high levels. Most cheeses had only small amounts of malonaldehyde. In contrast, many vegetables and fruits had either minute amounts or no malonaldehyde.

Animals↗

PubMed1974