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Biomedical subjects

J Smith

Publications and source records attributed to J Smith.

At least 199 records · Page 11Linked to original sources
PubMed2000

Parasite control methods used by horse owners: factors predisposing to the development of anthelmintic resistance in nematodes.

One hundred and fifty horse owners, primarily private owners and riding schools, replied to a questionnaire concerning the practices they used to control parasites. Twenty-seven had experienced a parasite problem. Faecal samples from 188 horses selected at random showed that worm control practices were generally successful; however, many owners were not following recommendations for slowing the development of resistant parasites. In 1996, 86 per cent of the owners were using either three or two classes of anthelmintic a year, and they used a median of six doses with a range from one to 11. Approximately half the owners, more commonly owners of up to five horses, picked up their horses' faeces at least once a week, but these owners also used more doses of anthelmintic a year than owners who did not pick up faeces. One-third of the owners manually removed Gasterophilus species eggs from the horses' hairs, but 94 per cent of them also used ivermectin. Many owners treated specifically for Anoplocephala species, cyathostome larvae and Gasterophilus species, and these owners were the most likely to use three classes of anthelmintic a year. One-hundred-and-seven owners replied to a second questionnaire asking for information about the factors that influenced their anthelmintic control practices. Many owners, particularly private owners, were not influenced by the cost of the anthelmintic. For the timing and frequency of treatment, and the choice of drug, owners were most influenced by advertisements, magazine articles and veterinary surgeons. In two magazines aimed at horse owners, the brands of drugs most frequently advertised were the brands most commonly used by the owners, and articles in the magazines recommended the use of three classes of drug per year. These results are discussed in relation to their influence on the development of anthelmintic-resistant nematodes.

Animal Husbandry↗
PubMed2000

Cryosolvents useful for protein and enzyme studies below -100 degrees C.

For the study of protein structure, dynamics, and function, at very low temperatures it is desirable to use cryosolvents that resist phase separation and crystallisation. We have examined these properties in a variety of cryosolvents. Using visual and X-ray diffraction criteria, methanol:ethanediol (70%:10%), methanol:glycerol (70%:10%), acetone:methoxy-ethanol:ethanediol (35%:35%:10%), dimethylformamide:ethanediol (70%:10%), dimethylformamide (80%), methoxyethanol (80%), and methoxyethanol:ethanediol (70%:10%) were all found to be free of phase-changes down to at least -160 degrees C. The least viscous of these, methanol:ethanediol (70%:10%), was miscible down to -125 degrees C and showed no exo or endothermic transitions when examined using DSC. It is therefore potentially particularly suitable for very low temperature cryoenzymology.

Cryoprotective Agents↗
PubMed2000

Effectiveness on oral health of a long-term health education programme for mothers with young children.

AIM: To determine the effect of dental health education (DHE) on caries incidence in infants, through regular home visits by trained DH Educators over a period of 3 years. METHOD: A randomly selected cohort of 228 children born between 1st January and 30th September 1995, in a low socioeconomic/high caries suburb of Leeds (UK) were divided into the following groups: A) DHE focused on diet; B) DHE focused on oral hygiene instruction (OHI) using fluoride toothpaste; and C) DHE by a combined diet and OHI message. DHE was given using an interview and counselling for at least 15 minutes at home every 3 months for the first 2 years and twice a year in the third year of the study. A fourth group D was given diet and OHI, at home, once a year only. All children and mothers were examined for caries and oral hygiene. A fifth group E (control) received no DHE and were never visited but examined at 3 years of age only. RESULTS: In the groups of children visited regularly only two developed caries and three had gingivitis (all in group A). In group E, however, 33% of children had caries and nine (16%) had gingivitis. The differences in caries levels and caries risk factors between study and control groups were statistically significant (P < 0.001). Mothers of the study groups also showed an improvement in their own levels of gingivitis, debris and calculus scores by the second and third examinations (P < 0.001). CONCLUSION: Regular home visits to mothers with infants, commencing at or soon after the time of the eruption of the first deciduous teeth, was shown to be effective in preventing the occurrence of nursing caries.

Bottle Feeding↗
PubMed2000

Prediction of adverse outcomes in children with sickle cell disease.

BACKGROUND: The ability to identify infants with sickle cell anemia who are likely to have severe complications later in life would permit accurate prognostication and tailoring of therapy to match disease-related risks and facilitate planning of clinical trials. We attempted to define the features of such babies by following the clinical course of 392 children with sickle cell disease from infancy to about the age of 10 years. METHODS: We analyzed the records of 392 infants who received the diagnosis of homozygous sickle cell anemia or sickle cell-Beta(0)-thalassemia before the age of six months and for whom comprehensive clinical and laboratory data were recorded prospectively; data were available for a mean (+/-SD) of 10.0+/-4.8 years. Results obtained before the age of two years were evaluated to determine whether they predicted the outcome later in life. RESULTS: Of the 392 infants in the cohort, 70 (18 percent) subsequently had an adverse outcome, defined as death (18 patients [26 percent]), stroke (25 [36 percent]) frequent pain (17 [24 percent]), or recurrent acute chest syndrome (10 [14 percent]). Using multivariate analysis, we found three statistically significant predictors of an adverse outcome: an episode of dactylitis before the age of one year (relative risk of an adverse outcome, 2.55; 95 percent confidence interval, 1.39 to 4.67), a hemoglobin level of less than 7 g per deciliter (relative risk, 2.47; 95 percent confidence interval, 1.14 to 5.33), and leukocytosis in the absence of infection (relative risk, 1.80; 95 percent confidence interval, 1.05 to 3.09). CONCLUSIONS: Three easily identifiable manifestations of sickle cell disease that may appear in the first two years of life (dactylitis, severe anemia, and leukocytosis) can help to predict the possibility of severe sickle cell disease later in life.

Anemia↗
PubMed2000

The role of competing demands in the treatment provided primary care patients with major depression.

OBJECTIVE: To examine whether competing demands explain the appearance of inadequate primary care depression treatment observed at a single visit. DESIGN: A cross-sectional patient survey. PARTICIPANTS AND SETTING: Two hundred forty patients with 5 or more symptoms of depression seeing 12 physicians in 6 primary care practices, representing 77.4% of the depressed patients identified through 2-stage screening of more than 11,000 primary care attenders. MAIN OUTCOME MEASURES: In patients with elevated depressive symptoms, discussing depression as a possible diagnosis in untreated patients, and changing depression management in treated patients. RESULTS: Physicians and patients discussed depression in 46 (47.9%) of 96 untreated patients; physicians changed depression treatment recommendations in 87 (60.4%) of 144 treated patients with current symptoms. Chronic physical comorbidity decreased the odds that physicians and untreated patients discussed depression as a possible diagnosis (odds ratio = 0.66, P = .01). New problems decreased the odds that treatment recommendations would be changed in treated patients who remained depressed (odds ratio = 0.39, P = .05). Physicians and untreated patients were more likely to discuss depression as a possible diagnosis if patients reported antidepressant medication was acceptable (odds ratio = 4.57, P = .01) and less likely to discuss depression if patients reported specialty care counseling was acceptable (odds ratio = 0.33, P = .05). CONCLUSIONS: The attention depression gets during a given medical visit is less associated with the severity of the patient's depressive symptoms than with the number or recency of other problems the patient has. If competing demands provide ongoing barriers to depression treatment, interventions will be needed to assure that patients with chronic physical problems receive high-quality mental health care in the primary care setting.

Antidepressive Agents↗
PubMed2000

Mass spectral fragmentation pathways in cyclic difluoramino and nitro compounds

The recently synthesized compounds 4, 4-bis(difluoramino)-1-nitropiperidine (I), 1,4,4-trinitropiperidine (II), 1,1,4,4-tetranitrocyclohexane (III), 1,1,4, 4-tetrakis(difluoramino)cyclohexane (IV) and 3,3,7, 7-tetrakis(difluora-mino)octahydro-1,5-dinitro-1,5-diazocine (HNFX, V) are being considered as potential energetic materials. The mass spectra of these compounds were studied using electron ionization (EI) mass spectrometry. A collision-induced dissociation (CID) study of the major EI peaks was carried out using a Finnigan TSQ 700 tandem mass spectrometer. The mass fragmentation pathways are constructed and discussed. The decomposition of HNFX (V), under EI, appeared to parallel the thermal decomposition of nitramines where N-NO(2) cleavage is often the first step. However, the two nitramines with a six-membered ring structure (I and II) underwent initial loss of a geminal substituent; loss of a nitramine nitro group was the secondary step. The two cyclohexane structures (III and IV) showed similar initial fragmentation pathways, featuring successive losses of nitro or difluoramino groups. Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗
PubMed2000

In vitro bleeding time test can diagnose thrombotic thrombocytopenia purpura and can possibly monitor therapeutic plasma apheresis.

Thrombotic thrombocytopenia purpura (TTP) is perplexing, mainly because of its difficult diagnosis and dramatic clinical presentations, high mortality rates, and the effectiveness of empirical plasma infusions and plasma exchanges. Scientific evidence supports the hypothesis that TTP results from platelet hyperagglutination. To support this, a new in vitro bleeding time (Platelet-Stattrade mark) test was used. Eleven patients had a mean in vitro bleeding time of 7.3 +/- 2.1 seconds prior to plasma exchange and eight patients had a mean of 13.6 +/- 4.7 seconds after the plasma exchange procedure. Normal controls were 14 +/- 2 seconds. The test was used to monitor plasma exchanges in two patients. At the time the platelet count and LDH returned to normal, the Platelet-Stattrade mark remained shortened. The two patients relapsed and required continued plasma exchanges until Platelet-Stattrade mark corrected to normal. These results suggest that plasma exchanges may be effectively monitored by Platelet-Stattrade mark rather than the traditional parameters, i.e., LDH. Therefore, the Platelet-Stattrade mark test may be a useful test to diagnose TTP and monitor therapy in this disease.

Bleeding Time↗
PubMed2000

Cell-type-specific and regulatable transgenesis in the adult brain: adenovirus-encoded combined transcriptional targeting and inducible transgene expression.

To achieve transient transgenesis within specific areas or cell populations in the adult central nervous system (CNS), we have developed a dual adenoviral vector system encoding for cell-type-specific and regulatable transcription units. To achieve combined cell-type-specific transcriptional targeting and inducible expression, we have engineered the expression of the tetracycline-dependent transcriptional elements (1) to be under the transcriptional control of either the astrocyte-specific, glial fibrillary acidic protein (GFAP) (2) or the neuronal specific enolase (NSE) promoter (3) within a dual adenoviral vector system. Cell-type specificity, inducibility, and levels of transgene expression were characterized in vitro in cell lines, and primary neocortical cultures and in the central nervous system (CNS) in vivo, and compared to a powerful pancellular beta-actin/CMV promoter. We demonstrate that the GFAP promoter is able to restrict tetracycline-dependent transgene expression to glial cells in cell lines, primary cultures, and in the CNS in vivo. However, although the NSE promoter did not show neuronal restricted transgene expression in vitro, it did so in the CNS in vivo. Our dual viral system also has provided evidence that an excess of transactivator is needed to achieve maximal transgene expression. Administration of doxycycline completely abrogated transgene expression both in vitro and in vivo. Consequently, our strategy demonstrates that combined cell-type specificity and simultaneous regulation of transgene expression can be obtained in the brain using adenoviral vectors.

Adenoviridae↗
PubMed2000

Large employers' selection criteria in purchasing behavioral health benefits.

To determine the criteria other than cost large employers use in selecting and monitoring behavioral health benefits, this study interviewed 31 of 44 (70.4%) randomly selected corporations employing at least 5,000 workers. While more than 60% of employers considered administrative efficiency and provider access to be very influential in their selection of behavioral health benefits, only 12.9% (95% confidence interval 0.7%-25.1%) considered clinical outcomes. Employers who considered clinical outcomes in their purchasing decision reported significantly greater satisfaction with the quality and cost of their behavioral health benefits. Following selection, 38.7% of corporations used employee complaints to monitor quality problems in their behavioral health benefits; 3.2% used clinical outcomes. If society expects employers to purchase behavioral health care on the basis of quality as well as cost, more employers need better indicators of quality.

Adult↗
PubMed2000

A trans-cultural comparison of four psychiatric case-finding instruments in a Welsh community.

BACKGROUND: Case-finding instruments have been developed for different purposes and in different cultural settings. Four instruments designed to detect psychiatric morbidity in community-based populations were studied in order to compare the performance of instruments from differing sources in a common setting. METHODS: The study was undertaken in a Welsh primary care setting. The Revised Clinical Interview Schedule (CIS-R) was used to define caseness. The instruments studied were the General Health Questionnaire (GHQ), the Mental Health Index (MHI), the Self Reporting Questionnaire (SRQ), and the Shona Symptom Questionnaire (SSQ). Performance was assessed by standard test indices, kappa values, and receiver operating curve analysis. The content of the four instruments was also compared. RESULTS: Sixty-nine adults completed the study. The prevalence of CIS-R caseness in this sample was 45%. No significant differences in case-recognition were found and all instruments had misclassification rates of 10% or less. The instruments showed wide variation in content. Half the items were unique to a single instrument and only three items (sleep, unhappiness and decision making) were shared by three instruments. The most frequent symptom within the total sample, and among cases, was the Zimbabwean concept of 'thinking too much'. CONCLUSIONS: Etic instruments (SRQ and SSQ) performed as well as emic ones (GHQ and MHI) in this setting, despite the wide variation in instrument structure.

Adult↗
PubMed2000

Analysis of HPC1, HPCX, and PCaP in Icelandic hereditary prostate cancer.

Putative prostate cancer susceptibility loci have recently been identified by genetic linkage analysis on chromosomes 1q24-25 (HPC1). 1q44.243 (PCaP), and Xq27-28 (HPCX). In order to estimate the genetic linkage in Icelandic prostate cancer families, we genotyped 241 samples from 87 families with eleven markers in the HPC1 region, six markers at PCaP, and eight at HPCX. Concurrently, we assessed allelic imbalance at the HPC1 and PCaP loci in selected tumors from the patients. For each of the candidate regions, the combined parametric and non-parametric LOD scores were strongly negative. Evidence for linkage allowing for genetic heterogeneity was also insignificant for all the regions. The results were negative irrespective of whether calculations were performed for the whole material or for a selected set of early age at onset families. The prevalence of allelic imbalance was relatively low in both the HPC1 (0%-9%) and PCaP (5%-20%) regions and was not elevated in tumors from positively linked families. Our studies indicate that the putative cancer susceptibility genes at chromosomes 1q24-25, 1q44.2-43, and Xq27-28 are unlikely to contribute significantly to hereditary prostate cancer in Iceland and that selective loss of the HPC1 and PCaP loci is a relatively rare somatic event in prostate cancers.

Alleles↗