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Biomedical subjects

K Harrison

Publications and source records attributed to K Harrison.

At least 37 records · Page 2Linked to original sources
PubMed1995

Medical eligibility, comprehension of the consent process, and retention of injection drug users recruited for an HIV vaccine trial.

Injection drug users (IDUs) at high risk for human immunodeficiency virus (HIV) infection are being identified as a population for HIV vaccine trials. We studied willingness of drug users to enroll and their comprehension of consent procedures in the context of a Phase II trial at one site. Of 175 people screened for enrollment and whose data sets were complete, 119 (68%) were IDUs. Of the 71 who were eligible, 39 (55%) were IDUs. Exclusion of IDUs was usually for medical reasons. Using a 17-item true/false test, comprehension of the informed consent procedure was high (median score, 16 of 17 for IDUs and non-IDUs); only three subjects (all of whom were IDUs) were excluded from enrollment due to lack of comprehension. Follow-up rates were similar for IDUs and non-IDUs. These data suggest that recruitment of IDUs into HIV vaccine trials is feasible, that IDUs can comprehend and complete the informed consent procedures, and that they return for follow-up visits.

AIDS Vaccines↗
PubMed1995

Maternal uniparental disomy of chromosome 2 in a baby with trisomy 2 mosaicism in amniotic fluid culture.

We describe the first case of a baby with maternal uniparental disomy of chromosome 2. Growth failure, hypothyroidism, and hyaline membrane disease were present at birth, and the first year of life was complicated by bronchopulmonary dysplasia. At age 14 months, motor and intellectual development were normal, but growth remained below the 10th centile. The baby was investigated for uniparental disomy because trisomy 2 mosaicism had been detected in a second trimester amniocentesis. This is the first reported case in which amniotic fluid chromosome mosaicism has been associated with uniparental disomy. Implications for prenatal diagnosis are considered.

Amniocentesis↗
PubMed1995

Clinical trial of fermented maize-based oral rehydration solution in the management of acute diarrhoea in children.

In an effort to identify appropriate fluids available in the home for oral rehydration therapy in Ghana, a study was designed to investigate the efficacy of fermented maize gruel, a popular Ghanaian traditional food, in the management of acute diarrhoea. Altogether 108 children aged between 4 and 27 months presenting with acute diarrhoea at the Princess Marie Louise Children's Hospital in Accra, with mild to moderately severe dehydration, were randomly assigned to treatment with either WHO/UNICEF oral rehydration solution (ORS) or fermented and unfermented maize solutions. About 35 children were admitted to each of the three treatment groups. Treatment with the rehydration fluid was maintained for 24 h. Efficacy of the various treatments, assessed in terms of fluid intake, stool output, stool frequency, weight gain and duration of diarrhoea, showed no significant variation among the three groups. The results indicate that the maize solutions were as effective as WHO/UNICEF ORS for oral rehydration therapy. However, the fermented maize was more readily accepted by the children than the unfermented solution. Because fermented maize gruel is widely consumed, inexpensive, readily available, and culturally acceptable to most communities in Ghana, it may be recommended as an appropriate home-available fluid for the management of acute diarrhoea in children at the community level.

Acute Disease↗
PubMed1995

Germinal transpositions of the maize element Dissociation from T-DNA loci in tomato.

We have analyzed the pattern of germinal transpositions of artificial Dissociation (Ds) transposons in tomato. T-DNA constructs carrying Ds were transformed into tomato, and the elements were trans-activated by crossing to lines transformed with a stabilized Activator (sAc) that expressed the transposase gene. The sAc T-DNA carried a GUS gene to monitor its segregation. The Ds elements were inserted in a marker gene so that excision from the T-DNA could be monitored. The Ds elements also carried a genetic marker that was intended to be used for reinsertion selection of the elements after excision. Unfortunately, this gene was irreversibly inactivated on crossing to sAc. Germinal excision frequencies of Ds averaged 15-40%, but there was large variation between and within plants. Southern hybridization analysis of stable transposed Ds elements indicated that although unique transpositions predominate, early transposition events can lead to large clonal sectors in the germline of developing plants and to sibling offspring carrying the same transposition event. Multiple germinal transpositions from three different loci were examined for uniqueness, and 15 different transpositions were identified from each of three T-DNA loci that carried a single independent Ds. These were mapped relative to the donor T-DNA loci, and for each locus 70-80% of the transposed elements were closely linked to the donor site.

Base Sequence↗
PubMed1995

Oral cavity and pharyngeal cancer among Department of Veterans Affairs hospital discharges.

OBJECTIVES: The purpose of this study is to determine the number of oral cavity and pharyngeal cancers among hospital discharges at Department of Veterans Affairs (VA) medical centers in one 12-month period. METHODS: A SAS file was created from the patient treatment file (PTF) with all discharges during fiscal 1990 having ICD-9-CM codes for oral cavity and pharyngeal cancer. Up to 10 discharge diagnoses from the most recent discharge summary were included in the data set. ICD-9-CM codes for alcohol dependence syndrome, drug dependence, and nondependent abuse of drugs also were included. ICD-9-CM codes for salivary and nasopharyngeal cancers were excluded. RESULTS: There were 3,733 unique individuals discharged with a diagnosis of oral cavity and pharyngeal cancer. The majority of cases (62%) were found in the oral cavity. The age distribution of oral cavity and pharyngeal cancer did not parallel the age distribution of veterans discharged during this year. Race and ethnicity of those discharged with the disease does not differ from that of all VA hospital discharges for 1990. CONCLUSIONS: VA data provide descriptive statistics of oral cavity and pharyngeal cancer among VA hospital discharges. VA data sets such as the PTF may offer the opportunity to examine hospital management issues, length of stay, and co-morbid diagnoses associated with oral cavity and pharyngeal cancer.

Adult↗
PubMed1994

Developmentally regulated cell death on expression of the fungal avirulence gene Avr9 in tomato seedlings carrying the disease-resistance gene Cf-9.

Plant defense responses are induced when the products of disease-resistance genes and pathogen avirulence genes interact. We report here the effects of expressing the Cladosporium fulvum avirulence Avr9 gene product in a tomato line containing the Cf-9 disease-resistance gene. A synthetic Avr9 gene was constructed to produce constitutive high-level expression of AVR9 peptide in the plant apoplast. Avr9 expression in Cf-9-containing tomato lines is lethal, but cell death is developmentally regulated, in that necrosis is not visible until 10 days after planting seed. Plant lines lacking Cf-9 and expressing Avr9 remain healthy. The synthetic Avr9 gene exhibited the same specificity of action as the authentic C. fulvum Avr9 gene. Our results have significant implications for strategies using the gene combination Avr9/Cf-9 to engineer plants with enhanced disease resistance.

Amino Acid Sequence↗
PubMed1994

Chloroplast targeting of spectinomycin adenyltransferase provides a cell-autonomous marker for monitoring transposon excision in tomato and tobacco.

Antibiotic resistance genes can act as either cell autonomous or non-cell autonomous genetic markers with which to monitor the excision of plant transposons. To convert spectinomycin resistance from a non-cell autonomous resistance to cell autonomous resistance, a transit peptide for chloroplast localization from a petunia ribulose bisphosphate carboxylase (rbcS) gene was fused in-frame to the aadA gene, which confers spectinomycin and streptomycin resistance. Constructs were generated in which the expression of this chimeric gene was prevented by the presence, in the 5' untranslated leader, of the maize transposons Activator (Ac) or Dissociation (Ds). When progeny of tobacco or tomato plants transformed with these constructs were germinated on spectinomycin-containing medium, germinally revertant and somatically variegated individuals could be distinguished.

Base Sequence↗
PubMed1994

Tetrasomy 12p (Pallister-Killian syndrome): ultrasound indicators and confirmation by interphase fish.

Tetrasomy 12p (Pallister-Killian syndrome) is a mosaic aneuploidy syndrome in which the isochromosome is present in amniocytes with a much greater percentage than fetal lymphocytes. Two new cases identified by prenatal diagnosis are reported. Indications for prenatal diagnosis were advanced maternal age and fetal anomalies. The most consistent reported prenatal ultrasound findings for tetrasomy 12p include polyhydramnios with short femurs and a diaphragmatic hernia. Recognition of congenital malformation patterns prenatally may allow appropriate selection of tissue for chromosome analysis. Molecular cytogenetic analysis using fluorescence in situ hybridization was used retrospectively to confirm the presence of the isochromosome 12p in various formalin-fixed fetal tissues. The levels of mosaicism detected in fetal and placental tissues were lower than those detected prenatally.

Abnormalities, Multiple↗
PubMed1994

Analysis of the chromosomal distribution of transposon-carrying T-DNAs in tomato using the inverse polymerase chain reaction.

We are developing a system for isolating tomato genes by transposon mutagenesis. In maize and tobacco, the transposon Activator (Ac) transposes preferentially to genetically linked sites. To identify transposons linked to various target genes, we have determined the RFLP map locations of Ac- and Dissociation (Ds)-carrying T-DNAs in a number of transformants. T-DNA flanking sequences were isolated using the inverse polymerase chain reaction (IPCR) and located on the RFLP map of tomato. The authenticity of IPCR reaction products was tested by several criteria including nested primer amplification, DNA sequence analysis and PCR amplification of the corresponding insertion target sequences. We report the RFLP map locations of 37 transposon-carrying T-DNAs. We also report the map locations of nine transposed Ds elements. T-DNAs were identified on all chromosomes except chromosome 6. Our data revealed no apparent chromosomal preference for T-DNA integration events. Lines carrying transposons at known map locations have been established which should prove a useful resource for isolating tomato genes by transposon mutagenesis.

Base Sequence↗
PubMed1994

Astrocytoma with a unique telomere association.

Many primary pediatric brain tumors are characterized by nonrandom cytogenetic abnormalities involving specific structural rearrangements and loss or gain of specific chromosomes. We describe a low-grade cerebellar astrocytoma with telomeric association of chromosomes 18 and 21 in a 7-year old girl. The nonrandom telomeric association of these chromosomes represents a unique cytogenetic finding in this type of pediatric brain tumor.

Astrocytoma↗
PubMed1993

Effects of sentence form on the construction of mental plans from procedural discourse.

Memory for procedural discourse was examined in two experiments. In Experiment 1, memory was assessed using recall; in Experiment 2, a recognition test was used. In both experiments, the memorability of three types of action statements were compared: a transitive verb form, in which the action was described by a main clause; a verbal adjective form, in which the action was indicated by an adjective derived from a verb; and an implicit action form, in which the action was only implied. Information associated with transitive verbs and verbal adjectives was more likely to be recalled than information associated with implicit actions. Although a manipulation of prior knowledge affected overall recall performance, it did not interact with sentence form. In addition, recognition accuracy was affected by neither sentence form nor prior knowledge. To account for these results, it was proposed that transitive verbs and verbal adjectives generate a semantic representation that includes features of the action, whereas implicit actions do not. This difference in semantic representation leads to structural differences in a mental plan for the task. The obtained effects on recall reflect these differences in plan structure.

Adult↗
PubMed1993

A genetic analysis of DNA sequence requirements for Dissociation state I activity in tobacco.

Our objective was to test whether the double Ds structure correlated with Dissociation state I activity (i.e., high frequency of chromosome breakage and low frequency of reversion) in maize exhibited similar properties in tobacco. A genetic assay was established to test double Ds and related structures for their ability to cause loss of the linked marker genes streptomycin phosphotransferase and beta-glucuronidase in transgenic tobacco. An engineered double Ds element and a simple Ds element showed behavior consistent with that of state I and state II Ds elements, respectively, as described for maize. DNA structural rearrangements accompanied marker gene loss. Dissection of the double Ds structure showed that a left end and a right end of Ds in direct orientation were sufficient for the instability observed. This result suggested that left and right ends of Ds in direct orientation can participate in aberrant transposition events, consistent with two different models for double Ds-induced chromosome breakage proposed previously. Both models predict that the inversion of a half Ds element accompanies the aberrant transposition event. Such an inversion was detected by polymerase chain reaction experiments in tobacco and maize only when Activator activity was present in the genome.

Base Sequence↗
PubMed1993

Postoperative vomiting factors in IVF patients.

Postoperative vomiting patterns were documented in 504 patients having general anaesthesia for oocyte retrieval for in vitro fertilization or related procedures and compared with patient preoperative history and expectations, response to ovarian hyperstimulation, and details of the anaesthesia. The results showed that the likelihood of vomiting was related to peak plasma oestradiol level and the patient's expectation based on previous experience of anaesthesia.

Anesthesia, General↗