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Biomedical subjects

M Young

Publications and source records attributed to M Young.

At least 235 records · Page 13Linked to original sources
PubMed1991

The role of light and sound technologies in the detection of vasa praevia.

Velamentous vessels across the internal os are rare (1 in 5000) but the high perinatal mortality (50-70%) has not improved with traditional methods of detection. In late pregnancy, Low Intrauterine Transcervical Endoscopy (LITE) can aid detection. Using LITE, such vessels have been 'seen' in 3 of 5000 patients examined; one case was detected fortuitously in 2500 patients examined during 1965-70, and two were detected in a special subgroup from 2500 patients examined during 1971-89 in which LITE was performed prior to labour with the express aim of excluding vasa praevia. Detection occurred before labour and in the absence of antepartum haemorrhage. In all three cases, the cervix was not dilated beyond 1 cm and a single velamentous vessel was found. The absence of labour and haemorrhage probably contributed to a zero perinatal mortality. Recently, ultrasound has been used in the detection of vasa praevia. Combination of abdominal real-time ultrasonography with LITE has permitted comparison of the efficacy of these two techniques; two of the patients with vas praevium were ultrasound negative but LITE positive. The risk of vasa praevia should be considered (a) when ultrasonography has shown a bilobed or succenturiate placenta, a low-lying placenta where the cord has a battledore insertion, a migrating placenta, or a suspicion of velamentous vessel traversing the internal os, (b) when there is a multiple or IVF pregnancy, or (c) when there is intrapartum bleeding or an irregularity in fetal heart rate. Inexperienced practitioners using LITE risk the rupture of a vas praevium. However, efficiently performed for those patients at increased risk of fetal hypoxia, or to detect meconium pollution of the amniotic sac or prior to amniotomy, LITE may fortuitously reveal a vas praevium and thereby enable action that prevents iatrogenic or spontaneous rupture.

Amnion↗
PubMed1991

Genes concerned with synthesis of poly(glycerol phosphate), the essential teichoic acid in Bacillus subtilis strain 168, are organized in two divergent transcription units.

Insertional mutagenesis has revealed that a 22 kbp segment from the hisA region of the Bacillus subtilis 168 chromosome (310 degrees on the genetic map) contains at least six independent transcription units, all apparently devoted to production of cell envelope components. Genes concerned with synthesis of poly(glycerol phosphate), poly(groP), an essential cell wall polymer in B. subtilis 168, are organized in two divergently transcribed operons denoted tagABC and tagDEF. Nucleotide sequence analysis indicates that three of these six genes encode extremely basic polypeptides. The deduced products of the tagABC operon may be involved in poly(groP) assembly and export, whereas those of the tagDEF operon, which are very hydrophilic, are more likely to be implicated in poly(groP) precursor biosynthesis. The first gene of the tagDEF operon encodes glycerol-3-phosphate cytidylyltransferase (Pooley et al., 1991, Journal of General Microbiology 137, 921-928) and its deduced product has significant homology with cholinephosphate cytidylyltransferase from yeast. There is also substantial homology between the deduced products of tagB in the tagABC operon and tagF in the tagDEF operon.

Amino Acid Sequence↗
PubMed1991

Effects of a take-home drug prevention program on drug-related communication and beliefs of parents and children.

Five hundred and eleven fourth, fifth, and sixth grade students and their parents from six schools in northwest Arkansas participated in this study. Students were blocked on school and grade level, then assigned randomly by class to either the intervention Keep A Clear Mind (KACM) program or a waiting list control. KACM students received four weekly correspondence lessons designed to be completed at home with a parent. KACM students reported significantly less perceived peer use of alcohol, tobacco, and marijuana, as well as significantly less peer pressure susceptibility to experiment with cigarettes. Mothers in the KACM program reported significantly more recent and frequent communication with their children about refusing drugs, and significantly greater discussions with their children regarding how to resist peer pressure to use alcohol, tobacco, and marijuana. Intervention program fathers reported significantly more communication with their children concerning how to resist peer pressure to drink alcohol and use tobacco, and significantly greater motivation to help their children avoid drug use. No significant differences were found between groups on student intentions to use drugs. These data suggest a print medium that emphasizes parent-child activities holds promise for accessing families and enhancing drug prevention communication.

Adult↗
PubMed1991

Be a winner: Arkansas' approach to involving law enforcement officers in drug education.

This paper describes a project which is a joint venture of the Northwest Arkansas Police Institute and the Program in Health Sciences at the University of Arkansas. Funded by the U.S. Department of Education under the Drug Free Schools and Communities Act, the focus of the project has been the development of an innovative drug education program which brings uniformed law enforcement officers into the elementary school classroom. The officers lead an eight week instructional program at the fifth or sixth grade levels using our Be A Winner curriculum.

Arkansas↗
PubMed1990

Bioequivalence of two thorazine tablet formulations using radioimmunoassay and gas chromatographic-mass spectrometric methods.

Two analytical methods for the analysis of chlorpromazine (CPZ), a radioimmunoassay (RIA) and a GLC-MS method, were compared in a bioequivalence study of two CPZ tablet formulations (Thorazine: film coated and sugar coated). Thirty-six nonsmoking, healthy, male volunteers completed the study. Each subject ingested single doses (2 x 25 mg) of the test (T) and the reference (R) formulations in a two-way crossover design with a two-week drug-free interval between doses. Following each administration, plasma concentrations of CPZ were monitored over a period of 24 h by both RIA and GLC-MS methods. Plasma concentrations and pharmacokinetic parameters determined by either analytical method showed wide intersubject variation, with the GLC-MS data showing relatively higher magnitude of intersubject variation than the RIA data. In general, plasma concentrations measured by RIA were significantly different from those measured by GLC-MS (paired t tests: p less than 0.0001). As indicated by the regression analysis, concentrations determined by RIA were 1.3-1.4 times higher than those determined by GLC-MS. There were strong and significant correlations between the two methods for both T and R (r greater than 0.75: p less than 0.0001). Similar statistical relationships were found between the plasma concentrations of CPZ determined by the two methods at each sampling time and the bioequivalence parameters area under the plasma level versus time curves up to the last measurable concentration (AUCt0) and the maximum plasma concentration (Cmax).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Epidermolysis bullosa: evidence for linkage to genetic markers on chromosome 1 in a family with the autosomal dominant simplex form.

DNA from members of a three-generation pedigree of Irish origin, displaying an autosomal dominant simplex form of epidermolysis bullosa of the epidermolytic, simplex, or Koebner variety (EBS2), was analyzed for linkage with a set of markers derived from the long arm of chromosome 1. Two-point analysis revealed positive lod scores for five of these markers, AT3 (Z = 2.107, theta = 0), APOA2 (Z = 1.939, theta = 0.15), D1S66 (Z = 1.204, theta = 0), D1S13 (Z = 1.026, theta = 0.15), and D1S65 (Z = 0.329, theta = 0.15). Multilocus analysis, incorporating the markers D1S19, D1S16, D1S13, APOA2, D1S66, AT3, and D1S65, resulted in a lod score of 3 maximizing at AT3. These data strongly support previous tentative indications of linkage between EBS2 and genetic markers on the long arm of chromosome 1.

Base Sequence↗
PubMed1990

Effects of monocular occlusion on neural and motor response times for two-dimensional stimuli.

Previous studies have shown that there are advantages associated with the simultaneous use of both eyes to view two-dimensional stimuli. To investigate further this binocular advantage, three experiments were conducted using male and female names presented on a video display as stimuli. In the first experiment, simple reaction times (RT's) were found to increase by about 6% as a result of monocular occlusion. In the second experiment, visual evoked response (VER) and P300 implicit times were also found to increase as a result of occlusion. The third experiment confirmed these results and investigated the sensitivity of evoked potential techniques to changes in stimulus complexity. The three experiments demonstrate that monocular occlusion does have a significant effect on processing speed for two-dimensional visual stimuli. The major portion of this effect (62%) is manifest at the level of the visual cortex, and is not perceived by subjects as significantly increasing the mental workload associated with generating responses to these stimuli.

Adult↗
PubMed1990

Conjugative plasmid transfer from Escherichia coli to Clostridium acetobutylicum.

The conjugation mechanism of IncP plasmids may be employed to mobilize small non-conjugative plasmids from Escherichia coli to a wide range of different organisms. This strategy has been adapted for use with the Gram-positive anaerobe, Clostridium acetobutylicum NCIB 8052. Several shuttle vectors containing replicons from pAM beta 1 (Enterococcus faecalis), pCB101 (Clostridium butyricum) or pWV01 (Streptococcus cremoris), together with the cis-acting oriT region of RK2, have been constructed, and transferred to and established in this organism. One of the vectors apparently contains a hot spot for insertion of IS1. Conjugative mobilization of plasmids from E. coli will provide a useful alternative to electroporation for effecting gene transfer to this industrially important anaerobe.

Clostridium↗
PubMed1990

Single intrauterine fetal death in a suspected monozygotic twin pregnancy.

The antepartum death of a fetus in a twin pregnancy is associated with significant risk of mortality and morbidity in the surviving infant. A recent case of single intrauterine death in a suspected monozygotic twin pregnancy at a regional hospital prompted a study of similar cases in the hospital's recent experience and a review of the current literature. We report the successful conservative management of fetal death in a monozygotic twin pregnancy.

Adolescent↗
PubMed1990

Pap smear usage in New South Wales--impact of active promotion.

Less than 25 per cent of eligible Australian women have cervical ('Pap') smear tests in any year. Rates are particularly low (less than 8%) for women over 55 years, the group at highest risk of cervical cancer. A regional program, actively promoting Pap smears by widespread direct community intervention and attention to service needs, targeting women over 55 years and under 25 years, was conducted on the North Coast (population 132,000 women) immediately after a New South Wales State-wide media campaign in February 1988. The number of Pap smears done in the region increased 119 per cent for women over 55 years and 44 per cent for 15-24 year-olds during the promotion (63% overall) compared to New South Wales increases of 58 per cent for women over 55 years and 23 per cent for 15-24 year-olds (31% overall). Differences between the North Coast and New South Wales were statistically significant for all age groups in March and in April for women over 55 years. Differences between New South Wales and Australia (no active promotion) were significant for women over 55 years in March and April. Records from a sample of 152 women attending clinics during the campaign showed 63 per cent had not had a smear test for three or more years, 10 per cent never.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Use of integrational plasmid excision to identify cellular localization of gene expression during sporulation in Bacillus subtilis.

Sporulation in Bacillus subtilis is a simple developmental system involving the differentiation of two sister cells, the prespore and the mother cell. Many of the genes that regulate sporulation (spo genes) are thought to be expressed differentially. However, direct demonstration of differential gene expression, by fractionation of prespore and mother cell proteins, is possible only at a relatively late stage of development. H. De Lencastre and P. J. Piggot (J. Gen. Microbiol. 114:377-389, 1979) have described a genetic method for determining the cellular location of the requirement for spo gene expression. Here we describe a similar method based on the use of integrational plasmids that can insertionally inactivate any given spo gene. Loss of the integrated plasmid by homologous recombination leads to the restoration of spo gene function. If this occurs just before sporulation begins, the phenotypes of the progeny of heat-resistant spores should depend on whether the gene is required in the prespore or the mother cell. Thus, we show that for known prespore-specific genes, such as spoIIIG and spoVA, only phenotypically Spo+ progeny that have lost the integrated plasmid are produced. In contrast, for mother-cell-specific genes, such as spoIIIC and spoVJ, a substantial proportion of the progeny are asporogenous, having retained the integrated plasmid. On the basis of our results, the spoIID and spoIIIA genes, which are expressed soon after division, appear to be required only in the mother cell compartment.

Bacillus subtilis↗
PubMed1990

Cytotoxic activity of cobalamin in cultured malignant and nonmalignant cells.

The cytotoxic effect of cobalamin (vitamin B12) on the growth of malignant and nonmalignant cell lines in culture has been examined. Among the four cobalamins studied, 5'-deoxyadenosylcobalamin, an enzymatically active derivative, was an effective cytotoxic agent. The data indicated that adenosylcobalamin seemed to act selectively on fast-growing malignant cells. Methylcobalamin was also effective at elevated concentrations. Cyanocobalamin was not toxic to all cell lines studied. Hydroxocobalamin at very high concentrations was able to slightly decrease growth of certain cell lines. The results support the hypothesis that the cytotoxic effect of cobalamin was associated with the metabolic activities of this vitamin at the cellular level. Also, cobalamin may be a potential antitumor agent.

Animals↗
PubMed1990

Effect of dietary ascorbic acid on heat-induced eye lens protein damage in guinea pigs.

The effect of large intake of dietary ascorbic acid on heat-induced eye lens protein damage has been studied. Male guinea pigs of the Hartley strain were used. Ascorbic acid was administered to the experimental animals in the drinking water. The mean daily ascorbic acid intakes for the control and experimental animals were 10 and 366 mg/kg body weight, respectively. The ascorbic acid level in the lens of the experimental animals was significantly higher than in the controls, but no differences in the content of water-soluble lens proteins were observed. When a solution of water-soluble protein was incubated at 60 degrees C, insoluble aggregates were formed. The loss of water-soluble proteins from the lens of the experimental animals was significantly less than that of the controls. The results indicated that large quantities of dietary ascorbic acid were able to protect lens constituents against heat-induced damage.

Animals↗