Biomedical subjects

D Lewis

Publications and source records attributed to D Lewis.

At least 145 records · Page 8Linked to original sources

PubMed1995

Breast lymphoma. A clinical and pathological review and 10-year treatment results.

Sixteen patients presenting with lymphoma involving the breast are described. Seven fulfilled the criteria for primary breast lymphoma, while the other 9 had evidence (sometimes only detected after extensive staging procedures) of concurrent lymphomatous involvement outside the breast. Histological diagnoses of the so-called primary breast lymphomas included 1 case of Hodgkin's disease and 6 of non-Hodgkin's lymphoma (including 2 with T-cell phenotypes). The patients with so-called secondary breast involvement included 8 with non-Hodgkin's lymphoma and 1 with a plasmacytoma of the breast with concomitant myelomatous involvement of bone marrow. Among the non-Hodgkin's lymphomas involving the breast the whole range of histological subtypes from low-grade to high-grade lesions were seen. There was no subtype of lymphoma with a specific predilection for breast involvement. Expression of oestrogen receptor protein as determined by immunocytochemical investigation using specific monoclonal antibodies was uniformly negative in lymphoid cells of 11 patients studied. Most of the patients in this series were treated by chemotherapy with uniformly good local control of lymphomatous involvement of the breast and an outcome similar to that of lymphomas presenting at other body sites. It is concluded that the approach to lymphomas of the breast should be similar to that of the equivalent types presenting elsewhere.

Adult↗

PubMed1995

Multiple birth concordance of street drug assays of meconium analysis.

To determine the prevalence of maternal drug usage in a mid-size midwestern city (population 250,000), we analyzed 1,175 consecutive meconium samples from the neonatal intensive care unit from March 1991 through December 1993. We focused on meconium assays from multiple births as a quality control method. Meconium specimens were analyzed using fluorescence polarization immunoassay (FPIA-Abbott Diagnostics) with confirmation done by gas chromatography/mass spectrometry (GC/MS). Cutoff concentrations of 5 ng/g were utilized for all analytes. A total of 151 samples (12.9%) tested positive. Cocaine-exposed neonates had the highest positive rate (63 or 5.4%), followed by marijuana (52 cases or 4.4%), cocaethylene (12 cases or 1%), and amphetamine (1 case or 0.1%). Nine patients (0.8%) had multiple drugs present. There were a total of 23 sets of multiple births (21 twins, 2 triplets); 20 sets of multiple births (42 patients) had concordance with all births testing negative. Three sets of twins had concordance in testing positive, with 1 twin testing positive for cocaine while the other twin tested positive for cocaine and marijuana. No absolute discordance of twins assays were noted. The rate of maternal drug use through measurement of meconium is about 12.95% in this mid-sized midwestern city. Twin studies provide an excellent method for verifying fetal drug exposure. The use of sets of multiple births provides a unique internal quality control mechanism in determining fetal drug exposure.

Female↗

PubMed1995

Suspecting the obvious in rheumatology.

In rheumatological medicine taking an accurate history is essential. So too is the skill of observing a clinical sign, recognising its significance and then following through with an appropriate line of questioning. This article highlights some of the rheumatological signs that may be observed by a seemingly casual head to toe scan of a patient.

Humans↗

PubMed1995

Relative repellency of woodsmoke and topical applications of plant products against mosquitoes.

The repellent action of various plant products was evaluated against anopheline and culicine mosquitoes in a rural village in the Wosera area, Papua New Guinea. A 5 x 5 Latin square design was used. Wood from four home-grown plant species was burned outdoors in the first experiment, and mosquitoes attracted to human bait were collected from 1800 to 2400 hours. In the second experiment, bruised leaves from another four plant species were rubbed on to the legs of human baits followed by mosquito collections. Woodsmoke and topical applications reduced biting of human volunteers by 79% and 51%, respectively. This low-technology control method may be included in the range of options for householders in order to reduce mosquito nuisance and improve their standard of health.

Administration, Cutaneous↗

PubMed1994

Discontinuing antiepileptic drugs in children with epilepsy. A comparison of a six-week and a nine-month taper period.

BACKGROUND: The optimal regimen for discontinuing antiepileptic medications in children with epilepsy is unknown. METHODS: We randomly assigned 149 children to either a six-week or a nine-month period of drug tapering, after which therapy was discontinued. Each group was composed of patients who had been seizure-free for either two or four years before drug tapering was begun. Most patients were receiving one antiepileptic drug; none were taking more than two. The children were evaluated periodically during and after the taper period. Sixteen patients were lost to follow-up before the beginning of the taper period. Proportional-hazards regression analysis was used to assess the risk of seizure recurrence among the remaining 133 patients. RESULTS: Seizures recurred in 53 patients (40 percent). The mean duration of follow-up was 39 months (range, 11 to 105) for the patients who did not have a recurrence of seizures. Neither the length of the taper period (six weeks vs. nine months, P = 0.38) nor the length of time the patients were free of seizures before the taper period was begun (two years vs. four years, P = 0.20) significantly influenced the risk of seizure recurrence. The presence of mental retardation (relative risk, 3.1, 95 percent confidence interval, 1.5 to 6.2) or spikes in the electroencephalogram at the time of tapering (relative risk, 1.9, 95 percent confidence interval, 1.0 to 3.4) increased the risk of seizure recurrence. CONCLUSIONS: The risk of seizure recurrence during drug tapering and after the discontinuation of antiepileptic drug therapy in children with epilepsy is not different whether the medications are tapered over a six-week or a nine-month period.

Adolescent↗

PubMed1994

An evaluation of cervical screening in general practice.

OBJECTIVES: To identify the technical practices of general practitioners (GPs) in relation to Papanicolaou (Pap) smear screening, and the differences in screening practices between male and female practitioners; to determine the cellular content of smears taken; and to correlate screening practices and demographic variables with smear results. DESIGN: During February-May 1992, a sample of Melbourne GPs filled in a questionnaire concerning their screening practices, and the results were correlated retrospectively with results of Pap smears taken in March and October 1991. SETTING: Melbourne metropolitan general practice. PARTICIPANTS: One hundred and seventy-nine GPs (72% participation rate among eligible practitioners) from a sample obtained from the register of the Medical Board of Victoria. RESULTS: Female doctors took significantly more smears than male doctors. An opportunistic approach to cervical screening was most commonly practised, with the patient being asked to ring for her results and the practice staff only contacted her if the result was abnormal. Only 43% of doctors indicated the use of a specific reminder system when rescreening was due. Endocervical cells were present in 79% of smears. The presence of endocervical cells was found to be related to the year of a doctor's graduation (with both very recent and older graduates [pre-1960s] having lower endocervical cell rates), and to be positively correlated with more postgraduate training. CONCLUSIONS: Our study suggests that further education and training in cervical screening is needed for some GPs, in particular, male doctors, graduates of less than four or greater than 20 years, and those without postgraduate training.

Adult↗

PubMed1994

Comparison of UV absorption and electrospray mass spectrometry for the high-performance liquid chromatographic determination of domoic acid in shellfish and biological samples.

Domoic acid, a neurotoxic amino acid produced by the marine diatom Nitchia pungens multiseries, was determined in samples of anchovies, razor clams, mussels, crab, rat serum, urine and feces by HPLC with UV absorption and electrospray (ESI) mass spectrometric (MS) detection. Shellfish samples were extracted with methanol-water followed by clean-up of the extracts with solid-phase extraction cartridges (strong anion or strong cation exchange). An aliquot of the fraction containing the domoic acid was analysed by HPLC. HPLC column size, mobile phase composition and flow-rate were selected so that essentially the same conditions could be used for both HPLC-UV and HPLC-ESI-MS with selected ion monitoring (SIM) determinations. These included the use of acetonitrile-water-formic acid as the mobile phase, at a flow-rate of 0.2 ml/min (split 13:1 for HPLC-ESI-MS-SIM, 10 microliters/min to the mass spectrometer). The results indicated that extracts found positive by the HPLC-UV method could be readily confirmed directly by HPLC-ESI-MS-SIM without additional sample treatment down to levels of 0.1 micrograms/g of domoic acid. This study demonstrates the use of HPLC-ESI-MS-SIM for the routine confirmation of domoic acid in a wide variety of samples.

Animals↗

PubMed1994

A splice junction mutation in a new myopathic variant of phosphoglycerate kinase deficiency (PGK North Carolina).

We report on a 12-year-old boy with the myopathic form of phosphoglycerate kinase (PGK) deficiency, and unique kinetic and physical characteristics of the mutant enzyme (PGK North Carolina). A G-to-T substitution at the 5' end of intron 4 was identified in the PGK gene of this patient. The mutation destroys the consensus sequence GT at the 5' splice junction of the intron. Activation of a cryptic splice site within intron 4 causes the insertion into the transcript of a 30-bp fragment at the 5' end of intron 4. This insertion results in ten additional amino acids within the "nose" of the PGK molecule, but does not generate a frameshift or a premature stop codon.

Base Sequence↗

PubMed1994

Genomic diversity of small round structured viruses in the United Kingdom.

Fifty-two faecal specimens collected in the United Kingdom between 1986 and 1992, which contained small round structured virus (SRSV) particles, were tested by reverse transcriptase polymerase chain reaction assays using two primer pairs derived from sequences of Snow Mountain Agent and Norwalk virus. There was poor correlation between results obtained with each primer pair. Twenty specimens (38%) gave positive bands with SM51/31 primers and 18 (34%) were positive with SM52/32 primers, with a total of 30 specimens (57.7%) giving amplification products of the expected size with one or both primer pairs. Genomic variation was investigated by sequencing a 266 bp region of the RNA polymerase gene from nine strains which had been antigenically typed by solid phase immune electron microscopy (SPIEM). RNA sequence identities ranged from 53 to 99%. Three genomic groups were suggested by phylogenic analysis, the first of which contained Norwalk virus, Southampton virus, and strains typed by SPIEM as SRSV UK2. The second contained Snow Mountain agent and strains typed as either SRSV UK3 or UK4. The third contained strains typed as SRSV UK1 and strains untypeable by SPIEM. Some correlation was demonstrated when antigen typing by SPIEM and phylogenic grouping based on sequence data were compared.

Adult↗

PubMed1994

Malignant lymphoma with primary cardiac manifestations: a case report.

This case report describes a 29-year-old black patient presenting with right heart failure secondary to massive lymphomatous cardiac involvement. Additional sites of involvement included mesenteric lymph nodes and the small bowel. Malignant lymphoma with primary cardiac manifestations is very rare and follows an aggressive course. The importance of early diagnosis and commencement of immediate therapy is emphasized.

Adult↗

PubMed1994

Impact of nutritional rehabilitation on gastroesophageal reflux in neurologically impaired children.

The impact of nutritional rehabilitation on gastroesophageal reflux (GER) in 10 malnourished neurologically impaired children (NIC) was studied (mean age, 9.1 +/- 3.1 years). None of the children had an antireflux procedure (ARP), and all were fed exclusively through a percutaneous endoscopic gastrostomy (PEG). Malnutrition was defined as triceps skin fold thickness (TSF) below the fifth percentile for age and sex. GER was established using standard criteria for a 24-hour pH probe study. All children were treated with an H2 antagonist and a prokinetic agent, along with aggressive nutritional rehabilitation. When TSF was > or = 50th percentile, medications were stopped, and the 24-hour pH probe study was repeated. The mean weight gain was 8.8 +/- 3.7 kg over 8.4 +/- 2.3 months. The 24-hour pH probe study showed marked improvement after nutritional rehabilitation in six of 10 children. These children remained asymptomatic throughout long-term follow-up, without the use of medications. Two children had abnormal pH probe results and worsening clinical symptoms when taken off medications after nutritional rehabilitation. They were reexamined after reinstituting the prokinetic drug; results of the pH probe study were normal, and there was no clinical symptomatology. The patients were then given long-term medication. Two children (one with erosive esophagitis and one with persistent symptoms) underwent ARP. We conclude that despite accompanying GER, successful nutritional rehabilitation can be achieved in malnourished NIC, using PEG feeding and antireflux medication. Although some NIC with GER may need an ARP or long-term medication, in most malnourished NIC nutritional rehabilitation is associated with resolution of GER.

Adolescent↗

PubMed1994

Maternal cocaine use without evidence of fetal exposure.

We report a case of lack of fetal exposure to cocaine and benzoylecgonine as evidenced by meconium and hair analysis, but exposure to nicotine and its metabolite cotinine, after extensive maternal use of cocaine and nicotine. These data suggest that the mode of maternal use of cocaine and individual differences in placental handling of the drug may protect some fetuses, and highlight the need to address interpatient variability.

Adult↗

PubMed1994

Pharmacokinetics and tissue distribution of recombinant human transforming growth factor beta 1 after topical and intravenous administration in male rats.

Recombinant human transforming growth factor beta (rhTGF-beta 1) enhances the healing process after topical application to various animal wound models. A detailed pharmacokinetic and tissue distribution study was performed to support the clinical development of rhTGF-beta 1 for wound healing indications. Rats received radioiodinated or unlabeled rhTGF-beta 1 as an intravenous (iv) bolus or as a topical formulation applied to a full thickness wound. Plasma concentrations of TGF-beta 1 were estimated from TCA-precipitable radioactivity or were measured by ELISA. Following iv administration, the initial half-life was rapid (< 11 min), regardless of whether radiolabeled or unlabeled rhTGF-beta 1 was used. The terminal half-life was long (163 min) when the test material was radioiodinated and administered as a trace dose and relatively short (< or = 61 min) when given at high doses and assayed by ELISA. Analysis of plasma radioactivity by SDS-PAGE revealed a time-dependent clearance of the 25-kDa parent molecule without a significant appearance of lower molecular weight radiolabeled metabolites. The majority of the radioactivity was associated with highly perfused organs, known iodide elimination pathways, and the thyroid at 1 and 8 hr after iv injection. After topical administration of a high dose (0.8 mg/kg), no immunoreactive TGF-beta 1 was detectable in plasma samples taken over a 48-hr period. However, trace amounts (< or = 0.05 ng/mL) of acid-precipitable radioactivity were detected in plasma after topical application of [125I]rhTGF-beta 1 (1 microgram/kg, 126 microCi/kg).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗

PubMed1994

The use of untreated bednets and malaria infection, morbidity and immunity.

The effect of bednet use was investigated, without undertaking a specific intervention, in four cross-sectional community-based surveys in 10 villages of a highly endemic area of Papua New Guinea. Over half (55%) of the villagers interviewed reported that they had used a bednet on the previous night. In general and after adjustment for age, village and housing characteristics, bednet users, particularly children, had lower parasite prevalences and spleen rates and less enlarged spleens than non-users. However, users were similar to non-users in terms of fever reported for the previous week, axillary temperature, parasite density and haemoglobin level. The prevalence of antibody to the ring erythrocyte surface antigen and the major merozoite surface antigen 2 was lower in users than non-users. The association with malariometric indices and immune responses remained significant when bednet users were compared with non-users in houses without bednets. Thus, untreated bednets do not reduce malaria transmission sufficiently to decrease morbidity. They might paradoxically increase the risk of clinical malaria by lowering the development of humoral immunity.

Adolescent↗

PubMed1994

The comparative analgesic efficacy of transcutaneous electrical nerve stimulation and a non-steroidal anti-inflammatory drug for painful osteoarthritis.

Thirty-six non-hospitalized subjects with chronic pain from OA of the knee participated in an evaluation of transcutaneous electrical nerve stimulation (TENS) and naproxen, an NSAID. All pre-experiment treatment was withdrawn. Each subject experienced in some order three 3-week treatment phases: NSAID plus placebo TENS; TENS plus placebo drug; and double placebo. A broad range of pain measures was used, including daily diary ratings, and four-times-per-day ratings entered into a small electronic data logger (the PIPER) worn by the subject. A substantial placebo response occurred across all conditions, which may have masked treatment differences. Broad comparisons across subjects, combining the four main measures of pain, found no significant differences among the three experimental treatments. Analysis of diary and PIPER data for individuals suggested that, in a small minority of subjects, the NSAID plus placebo TENS combination may be more effective than double placebo. The PIPER ratings seemed to tap aspects of the pain experience different from those captured by conventional measures, suggesting the value of very frequent pain assessments, such as those entered by a subject into the PIPER, in the study of chronic pain.

Adult↗

PubMed1994

Transposition of IS2 into the hemB gene of Escherichia coli K-12.

Genetic studies of the hemB gene in Escherichia coli have resulted in the recovery of both stable and unstable mutant strains. The stable strains have been shown to result from large deletions. This study demonstrates that unstable strains result from the insertion of transposable element IS2 primarily into the 5' region of the structural gene; the instability results from precise excision of the element, producing strains with both high and low frequencies of reversion. This first report of IS2 insertion into hemB suggests that this gene may be a preferred target for insertion of this transposable element.

Aldehyde Oxidoreductases↗

PubMed1994

Relationship between humoral response to Plasmodium falciparum merozoite surface antigen-2 and malaria morbidity in a highly endemic area of Papua New Guinea.

The prevalence and concentration of antibodies to merozoite surface antigen-2 (MSA-2) were measured in blood samples collected during a cross-sectional survey. Antibodies were measured by enzyme-linked immunosorbent assay using two recombinant proteins that closely approximated the full-length mature MSA-2 polypeptides expressed by the Plasmodium falciparum isolate FC27 and the cloned line 3D7 and that were representative of the dimorphic forms of MSA-2. Antibodies were also measured to a form of the 3D7 MSA-2 lacking the central repetitive sequences (d3D7). High antibody prevalence was observed to all three antigens: the overall prevalence of IgG to FC27, 3D7, and d3D7 was 91%, 90%, and 90%, respectively. The majority of individuals > or = 5 years of age had antibodies to both forms of MSA-2. The geometric mean antibody units increased with age with a plateau being reached by 15-20 years of age. There was a significant positive association of antibody prevalence with both the presence of the parasite and an enlarged spleen in children. This study provides the first evidence that antibodies against nonrepeat regions of MSA-2 are associated with fewer fever episodes and less anemia, both known to be indicators of malaria morbidity.

Adolescent↗

PubMed1994

Comparison of approximate and iterative methods to calculate the efficiency of haemodialysis as KT/V.

Dialysis dose is given by the index KT/V, where K is the dialyser urea clearance, T the duration of dialysis and V the notional urea distribution volume. KT/V may be calculated using the single pool model and an iterative calculation which requires a computer program. Three estimates of KT/V, each based on simple correction of the log ratio in (C0/C1), where C0, C1 denote the pre- and post-dialysis blood urea concentrations in mg/ml, were developed and compared with the values of KT/V given by iteration. The first estimate was given by adding two terms to the log ratio to account for the effect of ultrafiltration and urea generation while the second and third estimates were given by increasing the log ratio by 12.5% and 15% respectively. All estimates gave good agreement when compared with the iterative technique by Bland-Altman analysis for 27 patients on standard 4 hour dialysis treatment using 4 different dialysers (0.71 < KT/V < 1.62). The mean difference in all cases was less than 0.025 and the differences were not clinically significant. The use of these approximate formulae to estimate dialysis efficiency avoids the need for complex calculation or additional blood samples.

Adult↗