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Biomedical subjects

K Harrison

Publications and source records attributed to K Harrison.

At least 91 records · Page 5Linked to original sources
PubMed1993

The application of a rapid D-dimer test in suspected pulmonary embolus.

A prospective, consecutive series of plasma D-dimer (D-D) using a rapid, sensitive, and semiquantitative latex agglutination test from 169 patients clinically suspected of having acute pulmonary embolus (PE) was performed to determine its clinical utility in acute PE. All patients had ventilation/perfusion (V/Q) scans and 20 patients (12%) subsequently had pulmonary arteriography (PAG). The 20 patients who subsequently had PAG were used to establish the predictive value(s). In 10 patients with normal D-D results, none had PE according to PAG. In 10 patients with abnormal D-D results, seven showed PE by PAG and three did not show PE by PAG. The sensitivity, specificity, positive predictive values, and negative predictive values of the plasma D-D tests for acute PE based on PAG were 1.00, 0.77, 0.70, and 1.00, respectively. In nine patients with indeterminate V/Q scans who had PAG, four had PE and the D-D result was abnormal. Five of these patients did not have PE and the D-D result was abnormal in three and normal in two. Seventeen patients had high-probability V/Q scans, all of whom had abnormal D-D results. Only one had PAG that showed PE in this group. A normal D-D result using a rapid latex agglutination method can effectively exclude the diagnosis of acute PE. The negative predictive value of the rapid latex agglutination method is as good as the more cumbersome enzyme-linked immunosorbent assay methods. An abnormal result is nonspecific and is not useful in the diagnosis of acute PE. While some "false positives" did occur, there were no false-negative results. The best use of the D-D test is in the examination of the patient with indeterminate V/Q studies. We conclude that the D-D test can rapidly provide information in determining whether a patient needs further angiographic studies.

Blood Coagulation Tests↗
PubMed1992

Pain perception in self-injurious patients with borderline personality disorder.

Pain ratings during the cold pressor test were significantly lower in female inpatients with borderline personality disorder who report that they do not experience pain during self-injury (BPD-NP group, n = 11), compared with similar patients who report that they do experience pain during self-injury (BPD-P group, n = 11), and normal female subjects (n = 6). Pain ratings were not significantly different in the BPD-P and normal control groups. Self-report ratings of depression, anger, anxiety, and confusion were significantly lower, and ratings of vigor significantly higher following the cold pressor test in the BPD-NP group, but not in the BPD-P group. Only anxiety was significantly lower in the normal control group following the cold pressor test. The implications and limitations of these preliminary findings are discussed.

Adolescent↗
PubMed1992

Factors affecting the separation and loading capacity of proteins in preparative gradient elution high-performance liquid chromatography.

The optimum conditions for the purification of proteins by gradient elution in reversed-phase liquid chromatography were studied, with emphasis on the column length. Because of the strong dependence of the retention of proteins on the mobile phase composition, very short columns can be used successfully to perform analytical separations. A similar conclusion is extended to preparative separations. Columns with different lengths and diameters were used. The dependence of the loading capacity for touching band separation on the column length, diameter and volume was studied, in addition to the regeneration time between successive runs, the starting mobile phase composition and the necessary column efficiency.

Animals↗
PubMed1992

Effective vectors for transformation, expression of heterologous genes, and assaying transposon excision in transgenic plants.

Progress in plant molecular biology has depended heavily on the availability of effective vectors for plant cell transformation and heterologous expression. In this paper we describe the structures of a wide array of plasmids which have proved extremely effective in (a) plant transformation, (b) expression of heterologous genes and (c) assaying the activity of transposons in transgenic plants. Constructs that confer resistance to kanamycin, hygromycin, streptomycin, spectinomycin and phosphinotricin, or that confer beta-glucuronidase (GUS) gene expression are presented. Binary vector constructs that carry polylinkers of the pUC and Bluescript types are also described. Plasmids that permit the expression of any heterologous reading frame from either nopaline synthase (nos) or octopine synthase (ocs) promoters, as well as the cauliflower mosaic virus 35S promoter, using either the nopaline synthase or octopine synthase 3' polyadenylation sequences, are presented. These constructs permit a choice of orientation of the resulting transgene of interest, relative to the orientation of the selection marker gene. Most of the plasmids described here are publicly available.

Amino Acid Oxidoreductases↗
PubMed1992

Reduced erythrocyte and leukocyte magnesium is associated with cyclosporin treatment and hypertension in renal transplant patients.

Plasma, urine, erythrocyte and leukocyte magnesium were measured in normotensive and hypertensive renal transplant patients who were being treated with either azathioprine or cyclosporin. These were compared with essential hypertensive patients and normal subjects. Erythrocyte and leukocyte magnesium were reduced in renal transplant patients in independent association (ANOVA) with both cyclosporin treatment (P = 0.03, P = 0.016 respectively) and hypertension (P less than 0.001 for both). Therefore, hypertensive transplant patients on cyclosporin had the lowest magnesium content of both erythrocytes (1.22 +/- 0.09 mmol/l cells) and leukocytes (2.68 +/- 0.2 nmol/10(6) cells) compared to normal subjects (1.96 +/- 0.17 and 4.11 +/- 0.58 respectively) whereas normotensive transplant patients on azathioprine had normal values (2.12 +/- 0.16 and 5.13 +/- 1.0 respectively). Plasma magnesium was also reduced with cyclosporin treatment. Urine magnesium was not significantly different between any of the groups. Therefore, magnesium depletion may have a role in hypertension in renal transplant patients. Since cyclosporin treatment is also associated with magnesium depletion, this could explain the increased occurrence of hypertension in these patients.

Adult↗
PubMed1992

Promoter fusions to the Activator transposase gene cause distinct patterns of Dissociation excision in tobacco cotyledons.

To explore the effects of altering the level of Activator (Ac) transposase (TPase) expression, a series of plasmids was constructed in which heterologous promoters were fused to the TPase gene. Promoters for the cauliflower mosaic virus (CaMV) 35S transcript and the octopine synthase (ocs) and nopaline synthase (nos) genes were tested. These fusions, and constructs expressing TPase from the wild-type Ac promoter, were introduced into tobacco, and their activity was monitored by crossing to a line carrying Dissociation (Ds) in a streptomycin phosphotransferase gene (Ds::SPT). The SPT marker provides a record of somatic excisions of Ds that occur during embryo development. The patterns of somatic variegation that resulted from transactivation by each fusion were distinct and strikingly different from the pattern triggered by the wild-type Ac constructs. Unlike wild-type Ac, which caused transposition throughout embryo development, each fusion gave rise to sectors of discrete size. Sectors triggered by the CaMV 35S fusion were largest, ocs sectors were intermediate, and nos were smallest. These patterns appear to indicate differential timing of the activation of these promoters during embryogeny. Measurement of transcript abundance for each transformant indicated that the CaMV 35S-transformed plants accumulated approximately 1000-fold more TPase mRNA than plants containing wild-type Ac, whereas ocs- and nos-transformed lines accumulated about 100-fold and 20-fold higher levels, respectively. Measurements of germinal excision frequencies driven by the chimeric TPase fusions, however, indicated that increasing transcription does not necessarily result in an increase in germinal excision. These measurements showed that the ocs and nos fusions have very low rates of germinal excision. Only the CaMV 35S fusion transformants were found to have higher rates than the Ac constructs, although significant pod-to-pod variation was observed. Gel blot analysis of DNA from progeny carrying germinal excision events resulting from the CaMV 35S fusion showed that excision is associated with reinsertion and that siblings sometimes carry the same transposition events. These findings suggest that in tobacco there is no direct proportionality between TPase expression and Ac-Ds transposition activity. This possibility has important implications for understanding the regulation of Ac transposition and for designing efficient gene tagging systems.

Base Sequence↗
PubMed1992

Painful sensory symptoms in neuroleptic-induced extrapyramidal syndromes.

OBJECTIVE: The authors tested the hypothesis that neuroleptic-induced extrapyramidal syndromes are associated with painful sensations objectively conforming to the characteristics of primary sensory symptoms as reported in idiopathic and postencephalitic parkinsonism. METHOD: The frequency of subjective painful sensory symptoms and their relation to neuroleptic-induced extrapyramidal syndromes were examined in a consecutive series of 107 psychiatric patients newly admitted to acute care units at a teaching hospital. Patients without illnesses or conditions likely to be associated with pain were included in the study if they had a diagnosis other than organic mental syndromes and were receiving psychotropic medications as prescribed by their treating physicians. Structured interviews with a modified version of the McGill Pain Questionnaire to assess sensory complaints and neurological examinations for neuroleptic-induced extrapyramidal syndromes (parkinsonism and akathisia) were conducted independently by two raters blind to each other's findings and patients' medication status. RESULTS: Fourteen (23%) of 60 patients receiving neuroleptics reported experiences of spontaneous pain subjectively attributed to pharmacological treatment, compared with only one (2%) of 47 patients receiving psychotropic medications other than neuroleptics. There was no difference between these two groups in subjective complaints of paresthesia (8% versus 9%). Twelve (55%) of the 22 patients with neuroleptic-induced extrapyramidal syndromes reported pain, compared with only two (5%) of the 38 patients who received neuroleptics but did not experience extrapyramidal syndromes. CONCLUSIONS: Although consonant with the study hypothesis, these results should be regarded as preliminary and interpreted conservatively in the light of the methodological limitations of the study.

Adult↗
PubMed1992

Renal artery stenosis: prevalence and associated risk factors in patients undergoing routine cardiac catheterization.

The purposes of this study were to determine the prevalence of angiographically significant renal artery stenosis in a patient population referred for diagnostic cardiac catheterization and to develop a model that predicts the highest-risk subset of patients who have significant renal artery narrowing. A prospective validation cohort study was undertaken in a referral-based university hospital. After left ventriculography, abdominal aortography was performed to screen for the presence of renal artery disease. A convenience sample of 1,302 of 1,651 consecutive patients undergoing diagnostic cardiac catheterization were enrolled in the study. Of the 1,302 abdominal aortograms performed, 1,235 (95%) were deemed of adequate quality for the evaluation of renal artery anatomy. Renal artery disease was identified in 30% of the patients. Insignificant renal artery stenosis was found in 187 (15%) and significant (greater than or equal to 50% diameter narrowing) stenosis was found in 188 (15%). Significant unilateral disease was present in 11%, and bilateral disease was present in 4%. By univariable and multivariable logistic regression analysis, the association of both clinically and catheterization-derived variables with renal artery disease was assessed. Multivariable predictors included age, severity of coronary artery disease, congestive heart failure, female gender, and peripheral vascular disease. Hypertension was not an associated variable. These data reveal the previously undetected high prevalence of renal artery disease in patients undergoing cardiac catheterization and provide clinical and angiographic features that assist in predicting its presence.

Aged↗
PubMed1991

The predictive value of idiopathic failure to fertilize on the first in vitro fertilization attempt.

OBJECTIVE: To investigate the subsequent performance of patients with idiopathic fertilization failure on the first in vitro fertilization (IVF) cycle. DESIGN: A retrospective study of 2,322 consecutive patients undergoing their initial IVF cycle. SETTING: Advanced infertility treatment in an IVF/general infertility clinic. PATIENTS: In 5 years, 94 couples with unexplained failed oocyte fertilization had 270 cycles of treatment. Each couple's performance was tracked through subsequent cycles of treatment. INTERVENTIONS: In vitro fertilization with husband and donor sperm. MAIN OUTCOME MEASURE(S): Investigated retrospectively after 5 years of data collection. RESULTS: Sixty-five couples of the original 94 had a second IVF attempt. Fifty of these successfully fertilized oocytes with husband's sperm and 4 with donor sperm. Nineteen of the 65 couples who continued treatment achieved a pregnancy, and only one couple had continuing fertilization failure. CONCLUSIONS: The prognosis in the study group was surprisingly favorable despite the initial failed IVF treatment cycle.

Adult↗
PubMed1991

In vitro susceptibility of Brucella melitensis to antibiotics.

The in vitro susceptibilities of 86 recent clinical isolates of Brucella melitensis to minocycline, streptomycin, co-trimoxazole, rifampin, and six fluoroquinolones were determined. Minocycline exhibited the lowest MIC and was followed by rifampin and streptomycin. Among the quinolones, WIN 57273 and ciprofloxacin were the most active agents. No antibiotic combination of these agents exhibited synergy against 15 selected isolates. In killing rate experiments, streptomycin exhibited the most rapid kill (less than 12 h), while a complete kill with minocycline, rifampin, and ciprofloxacin was delayed up to 48 h. The combinations of streptomycin with each of minocycline, rifampin, or ciprofloxacin exhibited the fastest kills (within 2 h), while with the other combinations, a complete kill was delayed up to 96 h. These results demonstrate the discrepancy between the results of various in vitro methods in evaluating the antibiotic susceptibility of B. melitensis.

Anti-Bacterial Agents↗
PubMed1991

Effects of Bordetella pertussis infection on human respiratory epithelium in vivo and in vitro.

Bordetella pertussis infection probably involves attachment to and destruction of ciliated epithelial cells, but most previous studies have used animal tissue. During an epidemic, nasal epithelial biopsy specimens of 15 children (aged 1 month to 3 1/2 years) with whooping cough were examined for ciliary beat frequency, percent ciliation of the epithelium, and ciliary and epithelial cell ultrastructure. In addition, the in vitro effects of filtrates from a 24-h broth culture and of tracheal cytotoxin derived from B. pertussis on human nasal tissue organ culture were measured. B. pertussis was cultured from nasal swabs from 12 children. The mean ciliary beat frequency of their nasal biopsy specimens, 11.3 Hz (range, 10.4 to 13.0 Hz) was similar to that found in biopsy specimens from 10 normal children (mean, 12.5 Hz; range, 11.8 to 13.5 Hz). The abnormalities of the epithelium observed in 14 of 15 patients were a reduction in the number of ciliated cells, an increase in the number of cells with sparse ciliation, an increase in the number of dead cells, and extrusion of cells from the epithelial surface. In vitro, neither culture filtrate nor tracheal cytotoxin had any acute effect on ciliary function, but culture filtrate and tracheal cytotoxin (1 and 5 microM, respectively) caused extrusion of cells from the epithelial surface of turbinate tissue, loss of ciliated cells, an increased frequency of sparsely ciliated cells, and toxic changes in some cells. These changes were dose dependent and progressive, and between 36 and 90 h ciliary beating ceased. The observations made with patient tissue confirm that B. pertussis infection damages ciliated epithelium, and the in vitro experiments suggest that tracheal cytotoxin may be responsible for the abnormalities observed in vivo.

Bacterial Adhesion↗
PubMed1990

A Neurospora crassa ribosomal protein gene, homologous to yeast CRY1, contains sequences potentially coordinating its transcription with rRNA genes.

We have isolated and sequenced a Neurospora crassa ribosomal protein gene (designated crp-2) strongly homologous to the rp59 gene (CRY1) of yeast and the S14 ribosomal protein gene of mammals. The inferred sequence of the crp-2 protein is more homologous (83%) to the mammalian S14 sequence than to the yeast rp59 sequence (69%). The gene has three intervening sequences (IVSs) two of which are offset 7 bp from the position of IVSs in the mammalian genes. None correspond to the position of the IVS in the yeast gene. Crp-2 was mapped by RFLP analysis to the right arm of linkage group III. The 5' region of the gene contains three copies of a sequence, the Ribo box, previously shown to be required for transcription of both 5S and 40S rRNA genes. We speculate that the Ribo box may coordinate ribosomal protein and rRNA gene transcription.

Amino Acid Sequence↗
PubMed1990

Multiple-sited (heterotopic) pregnancy after in vitro fertilization and gamete intrafallopian transfer.

Pregnancies occurring simultaneously in different body sites (heterotopic pregnancies) are a rare condition thought to occur in 1 of 30,000 spontaneous pregnancies. Individual cases may occur after in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT). In the past 4 1/2 years, our unit has performed 6,204 IVF/GIFT or pronuclear stage transfer cycles of treatment. Ten such pregnancies proven by surgical, ultrasound, and histological diagnosis have occurred. In the same period 640 IVF, 355 GIFT, and 6 pronuclear stage transfer clinical pregnancies were achieved. This suggests that the incidence of heterotopic pregnancy after assisted reproduction is closer to 1 of 100 pregnancies. Clinicians managing early complications of IVF, GIFT, and/or pronuclear stage transfer pregnancies should be aware of this relatively high incidence of concomitant intrauterine and extrauterine pregnancy.

Female↗
PubMed1990

Purification and characterization of D-2-haloacid dehalogenase from Pseudomonas putida strain AJ1/23.

A D-2-haloacid dehalogenase was isolated and purified to homogeneity from Pseudomonas putida strain AJ1/23. The enzyme catalysed the stereospecific dehalogenation of the D-isomer of 2-chloropropionate. Using a new ion-chromatograph assay, the enzyme was found to catalyse the dehalogenation of short-chain 2-halocarboxylic acids. Maximum enzyme activity occurred at pH 9.5 and 50 degrees C and the enzyme was insensitive to most -SH reagents. The enzyme has an Mr of about 135,000 and appears to be composed of four subunits of identical Mr.

Hydrocarbons, Chlorinated↗