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D C Watson

Publications and source records attributed to D C Watson.

At least 19 recordsLinked to original sources
PubMed2001

Personality disorder in university students: a multitrait-multimethod matrix study.

The present study examined the prevalence of personality disorders (PDs) in a sample of first-year university students. The three self-report measures used to assess personality disorders were the (a) Coolidge Axis II Inventory (CATI); (b) Millon Clinical Multiaxial Inventory-II (MCMI-II); and (c) Minnesota Multiphasic Personality Inventory-Personality Disorder Scale (MMPI-PD). The prevalence of PD was estimated by including the number of participants above the cut-off scores selected for each of the three PD instruments. The results indicate prevalence in the range of 0% to 16% for the males, and approximately 1% to 26% for the females. These findings generally confirm the prevalence range of 5% to 15% reported in other investigations of nonpatient samples. With few exceptions, the three tests are generally consistent in their estimates of PD prevalence of all the 11 personality disorders. The multitrait-multimethod matrix reveals that the disorders are generally positively correlated with each other on all the three tests, suggesting considerable construct overlap. Specifically, passive-aggressive and schizotypal disorders produce the most convergent correlations. On the MMPI-PD, however, schizoid is a relatively more discriminant disorder.

Adolescent↗
PubMed1999

Post-translational processing of two alpha-amylase inhibitors and an arcelin from the common bean, Phaseolus vulgaris.

Mass spectrometric methods were used to investigate the proteolytic processing and glycopeptide structures of three seed defensive proteins from Phaseolus vulgaris. The proteins were the alpha-amylase inhibitors alphaAI-1 and alphaAI-2 and arcelin-5, all of which are related to the seed lectins, PHA-E and PHA-L. The mass data showed that the proteolytic cleavage required for activation of the amylase inhibitors is followed by loss of the terminal Asn residue in alphaAI-1, and in all three proteins, seven or more residues were clipped from the C-termini, in the manner of the seed lectins. In most instances, individual glycoforms could be assigned at each Asn site, due to the unique masses of the plant glycopeptides. It was found that alphaAI-1 and alphaAI-2 differed significantly in their glycosylation patterns, despite their high sequence homology. These data complement the previous X-ray studies of the alpha1-amylase inhibitor and arcelin, where many of the C-terminal residues and glycopeptide residues could not be observed.

Amino Acid Sequence↗
PubMed1999

Left ventricular outflow tract obstruction after partial atrioventricular septal defect repair.

BACKGROUND: Narrowing of the left ventricular outflow tract has been associated with partial atrioventricular septal defect (PAVSD) in about 3% of patients. Because of the predisposing anatomy, hemodynamically significant obstruction in the subaortic area may appear after repair of ostium primum atrial septal defects. METHODS: From 1984 to 1998, 40 patients underwent surgical correction of PAVSD by patch closure. The mean age at the initial repair was 5.8 years (range 3 months to 22 years). RESULTS: Nine patients had 12 subsequent operations for hemodynamically significant subaortic obstruction. The mean age at PAVSD repair was 17 months (3 to 42 months) (p < 0.001 compared with others). Follow-up work-up was obtained due to symptoms in 5 patients and an abnormal echocardiogram in 4 asymptomatic patients. Subaortic stenosis developed at a mean of 5 years (range 4 months to 10 years), and 6 or more years in 4 patients. The mean age at subaortic stenosis repair was 6 years (range 2 to 12 years). Nine patients underwent subaortic fibromuscular resection. Of these, 4 developed recurrent stenosis and 2 have undergone additional operations. CONCLUSIONS: Left ventricular outflow tract obstruction after PAVSD repair may be more frequent than reported. Because of the progressive nature of the process, echocardiography should be utilized liberally on patients to uncover subclinical stenosis. Long-term follow-up is essential for diagnosis due to delayed appearance and lack of reliable clinical signs.

Adolescent↗
PubMed1999

Molecular basis for the lack of mimicry of Brucella polysaccharide antigens by Ab2gamma antibodies.

The crystal structure of the complex of an anti-Id Fab with an Fab specific for a Brucella polysaccharide antigen has previously been reported (Evans et al., 1994, J. Mol. Biol. 241, 691-705). To complement this study, the binding characteristics and immunological properties of this Ab2 and two others raised with a second anti-Brucella antibody were investigated, including quantitative kinetic measurements by surface plasmon resonance. The affinities of the Fabs from the Ab2s for the Ab1s were three orders of magnitude greater than those estimated for the antigen, but the Ab2s failed to induce antigen-binding Ab3s, that is, they were of the Ab2gamma type. The avidities of the Ab1s for antigen were however within one order of magnitude of their avidities for Ab2. Tests of 16 other anti-Brucella polysaccharide antibodies showed that the two idiotopes were not present in them, and in confirmation of the lack of a dominant idiotope, N-terminal sequencing of their H and L chains showed a wide variety of V genes were employed in the immune response to the Brucella polysaccharides. The failure of the Ab2 to induce antigen-reactive Ab3 thus appears to be due to neither intrinsic affinity nor idiotope frequency, but arises instead from structural reasons, for example, the incomplete penetration of the Ab2 into the binding-site cleft of the Ab1. The surface topography of polysaccharide antigens and their binding-sites thus appears to be especially difficult for Ab2s to mimic and will restrict their routine use as surrogates for T-cell independent polysaccharide antigens.

Amino Acid Sequence↗
PubMed1999

The threshold for air leak: stapled versus sutured human bronchi, and experimental study.

BACKGROUND: Little is known about the integrity of staple-closure of the bronchus and its tolerance to normal mechanical stresses (cough, sneezing, etc.) in the immediate early post-operative period. There are few studies which tested the mechanical strength of stapled bronchial closure compared with manually closed bronchi using the threshold for fluid leak across the bronchial suture line which differs from air. MATERIAL AND METHODS: Intact cadaveric tracheobronchial tree (n = 40) were selected, age range from 55 to 70, of which 60% were males. They were divided into two groups: group A, 20 left bronchi were closed with RLV 30 Ethicon 4.8 mm bronchial stapler; group B, 20 were closed with 4 0 Prolene simple interrupted sutures. All specimens were intubated with endotracheal tube and submerged under water before testing the immediate air leak with the standard 40 mm Hg inflation pressure. Inflation pressure was increased until air leak was detected. The stapled closures were resected and subjected to radiological examination. RESULTS: No air leak was detected in any bronchus at 40 mmHg regardless of the closure technique. The median leakage pressure was significantly higher in the hand sutured bronchi compared to the stapled group (200 vs. 105 mmHg, respectively) and 50% (n = 10) leaked from multiple sites in the stapled group compared with leakage from one site only in group B, this difference was statistically significant P < 0.001. The radiological appearance of the staples maintained the B configuration, recommended by the manufacturer as a sign of sound application. CONCLUSION: Hand sutured bronchi tolerated higher inflation pressure compared with the stapled ones before leaking air. Air leak at high pressure occurs in the presence of intact staples.

Aged↗
PubMed1999

Efficacy of and adherence to highly active antiretroviral therapy in children infected with human immunodeficiency virus type 1.

BACKGROUND: Clinical trials in adults have demonstrated the efficacy of highly active antiretroviral therapy (HAART) to suppress replication of HIV-1 to nondetectable levels, but lower success rates have been observed in practice. We sought to determine the efficacy of HAART in our population of HIV-1-infected children and to identify determinants of efficacy, especially the role of adherence to prescribed antiretrovirals. METHODS: The viral load and CD4+ T cell responses of 72 children with perinatally acquired HIV-1 treated with HAART including a protease inhibitor for at least 90 days were examined retrospectively in relation to adherence, as measured by pharmacy records for the first 180 days of HAART. RESULTS: Patients were defined as adherent if > or =75% of protease inhibitors and > or =75% of all antiretroviral prescriptions were filled. Of the 42 patients (58%) who were adherent, nondetectable viral loads were achieved and maintained in 22 (52%). A Kaplan-Meier plot showed a drop-off in patients maintaining a nondetectable viral load after 200 days. Higher initial viral load was the only pretreatment factor that identified adherent patients at risk for treatment failure. Only 3 (10%) nonadherent patients maintained a viral load of <400 copies/ml. The adherent group had a prompt and sustained increase in CD4+ T cell counts. CONCLUSIONS: HAART can achieve control of viral replication in HIV-1-infected children who adhere to therapy. However, treatment failure is likely unless there is a high level of adherence. Nonadherence to therapy is common and might be the major impediment to successful treatment of children infected with HIV-1.

Anti-HIV Agents↗
PubMed1999

Predicting personality disorder traits with the Defense Style Questionnaire in a normal sample.

This research examined the efficacy of the 40-item Defense Style Questionnaire (DSQ-40), measuring mature, neurotic and immature defense styles, to predict DSM-III-R personality disorders. The Coolidge Axis II Inventory, the Millon Clinical Multiaxial Inventory-II, and the MMPI personality disorder scales were used to measure 11 personality disorders in a nonclinical sample. The results show that most personality disorders are positively associated with the highly maladaptive immature defense style, and negatively associated with the mature defense style. Multiple regression analyses reveal that the combined variance accounted for by the defense styles range from 12% to 42% on the CATI, 3% to 42% on the MCMI-II, and 2% to 32% on the MMPI-PD. However, specific personality disorders cannot be predicted with the defense styles on any measure.

Adolescent↗
PubMed1998

Gender, age, and cultural differences in the Defense Style Questionnaire-40.

The Defense Style Questionnaire-40 is a 40 item short form of the 88 item Defense Style Questionnaire. A cross-cultural comparison was made between a sample of 635 Canadian university students and an Australian sample of 388 subjects reported by Andrews, Singh, and Bond. Differences between the two samples were noted for several of the defense scales. These may be a reflection of differential socialization patterns in coping with stress for the two countries. Gender and age comparisons were made for the 20 defense scales. Some interesting differences were noted for gender on the suppression, pseudoaltruism, and isolation scales. The internal structure of defense styles was also found to have similarities and differences for males and females with the DSQ-40.

Adaptation, Psychological↗
PubMed1998

Comorbidity of DSM-IV personality disorders in a nonclinical sample.

The issue of comorbidity within the Axis II personality disorders was explored using a large sample of university students who were administered the Coolidge Axis II Inventory (CATI). Comorbidity patterns with this normal sample were compared with recent clinical data reported by several other researchers. The results confirm the high degree of comorbidity within Axis II and the similarity in the comorbidity patterns with clinical and nonclinical samples. With the CATI, a 30.4% comorbidity rate was obtained for Histrionic and Narcissistic Personality disorders (Pd). The paranoid, passive-aggressive and borderline personality disorder traits were comorbid with several other Pds. For Cluster A, there was low comorbidity except for Paranoid Pd and Schizotypal Pd. With Cluster B, the co-occurrence was moderate to strong. A moderate amount of interrelationship was obtained for the Cluster C Pds. The DSM-IV clusters were also strongly interrelated. An additional finding was the similarity between self-report and structured interview methodology in obtained personality disorder comorbidity.

Adolescent↗
PubMed1998

Impact of ultrafiltration on blood use for atrial septal defect closure in infants and children.

BACKGROUND: Infants and children undergoing open cardiac operations have a high incidence of blood product transfusion. Ultrafiltration has been shown to reverse hemodilution and improve myocardial function and hemodynamics after cardiopulmonary bypass (CPB). METHODS: The effect of ultrafiltration on the amount of blood transfusion and hospital charge in 39 consecutive patients who underwent elective atrial septal defect repair was examined. Patients in group I (n=26) had a conventional cardiopulmonary circuit prime with blood, whereas 13 patients had bloodless prime (group II). Ultrafiltration was used immediately after weaning from CPB in group II. The patients in group I received blood products after discontinuation of CPB to achieve a hematocrit of 30%. The amount of blood product used, hematocrit immediately after CPB and on arrival in intensive care unit, postoperative hemodynamics and saturations, total operating room charge, blood charge, hospital stay, and hospital charge were compared. RESULTS: Mean body weight (15.8 kg in group I versus 17.5 kg in group II) and preoperative hematocrit values (35.6% in group I versus 34.2% in group II) were similar. Mean hematocrit immediately after CPB was 22% and 14% in group I and II, respectively (p < 0.0001). The mean hematocrit upon arrival to the intensive care unit was 34% in group I and 22% in group II (p < 0.0001). The amount of blood product transfusion was 32 mL/kg in group I and 3 mL/kg in group II patients (p < 0.0001). The patients in group II had significantly less blood bank charges; however, operating room charges and total hospital charges were similar between the two groups. CONCLUSIONS: Elective atrial septal defect repair was performed with no blood product transfusion without increased morbidity or hospital stay. Ultrafiltration can be used to reverse hemodilution resulting from a bloodless CPB prime without an increase in hospital charge.

Blood↗
PubMed1998

Double patch closure of ventricular septal defect with increased pulmonary vascular resistance.

BACKGROUND: Closure of a large ventricular septal defect (VSD) in children with elevated pulmonary vascular resistance is associated with significant morbidity and mortality. Pulmonary hypertensive episodes continue to be a major cause of postoperative morbidity and mortality. We designed a fenestrated flap valve double VSD patch in an effort to decrease the morbidity and mortality associated with the closure of a large VSD with elevated pulmonary vascular resistance. METHODS: Eighteen children (mean age, 5.7 years) with a large VSD and elevated pulmonary vascular resistance (mean, 11.4 Wood units) underwent double patch VSD closure using moderately hypothermic cardiopulmonary bypass and cardioplegic arrest. The routine VSD patch was fenestrated (4 to 6 mm) and on the left ventricular side of the patch, a second, smaller patch was attached to the fenestration along its superior margin before closure of the VSD. RESULTS: All children survived operation and were weaned from inotropic and ventilator support within 48 hours postoperatively. Postoperative pulmonary artery pressures were significantly lower than preoperative values. One child died 9 months postoperatively. CONCLUSIONS: Closure of a large VSD in children with elevated pulmonary vascular resistance can be performed with low morbidity and mortality when a flap valve double VSD patch is used.

Adolescent↗
PubMed1998

The synthesis of sialylated oligosaccharides using a CMP-Neu5Ac synthetase/sialyltransferase fusion.

Large-scale enzymatic synthesis of oligosaccharides, which contain terminal N-acetyl-neuraminic acid residues requires large amounts of the sialyltransferase and the corresponding sugar-nucleotide synthetase, which is required for the synthesis of the sugar-nucleotide donor, CMP-Neu5Ac. Using genes cloned from Neisseria meningitidis, we constructed a fusion protein that has both CMP-Neu5Ac synthetase and alpha-2,3-sialyltransferase activities. The fusion protein was produced in high yields (over 1200 U/L, measured using an alpha-2,3-sialyltransferase assay) in Escherichia coli and functionally pure enzyme could be obtained using a simple protocol. In small-scale enzymatic syntheses, the fusion protein could sialylate various oligosaccharide acceptors (branched and linear) with N-acetyl-neuraminic acid as well as N-glycolyl- and N-propionyl-neuraminic acid in high conversion yield. The fusion protein was also used to produce alpha-2,3-sialyllactose at the 100 g scale using a sugar nucleotide cycle reaction, starting from lactose, sialic acid, phosphoenolpyruvate, and catalytic amounts of ATP and CMP.

Catalysis↗
PubMed1998

Role of paired basic residues in the expression of active recombinant galactosyltransferases from the bacterial pathogen Neisseria meningitidis.

The lgtB gene encoding a beta-1,4-galactosyltransferase gene and the lgtC gene encoding an alpha-1,4-galactosyltransferase from the bacterial pathogen Neisseria meningitidis were cloned into an expression vector and overexpressed in Escherichia coli. Both genes expressed very well, but problems with C-terminal proteolysis were encountered with both proteins. The lgtC protein was initially isolated from extracts of recombinant E.coli as a truncated species that retained enzymatic activity, and was subsequently shown by mass spectrometry to be 19 residues shorter than the expected protein. A specific set of engineered C-terminal deletions was constructed to investigate their effect on the expression of lgtC. As many as 28 residues could be deleted with little effect on activity, and with the concomitant improvement of the overall expression up to fivefold over the full length protein. The lgtB protein was also proteolysed in extracts of normal E.coli strains into enzymatically inactive fragments lacking 28 or 41 C-terminal residues. This degradation could be prevented by expression in an ompT protease deficient strain of E.coli. The full length lgtB protein was not stable in soluble protein extracts from all recombinant strains, however a stable enzyme preparation could be achieved with the membrane fraction from cells of the ompT deficient strain expressing lgtB. Specific deletions of lgtB were also constructed, and 15 residues could be removed without loss of enzyme activity and also with the concomitant improvement of the overall expression up to twofold over the full length protein. Longer deletions produced protein but activity could not be detected in these recombinant strains. Examination of the glycosyltransferase sequences from a wide range of bacteria showed their C-terminal segments of approximately 50 amino acids frequently contained paired basic residues. Engineering of these segments may therefore be required as a general practice to produce these enzymes for use in the large scale chemi-enzymatic synthesis of carbohydrate-based therapeutics.

Amino Acid Sequence↗
PubMed1997

Characterization of a recombinant Neisseria meningitidis alpha-2,3-sialyltransferase and its acceptor specificity.

The structure and specificity of the recombinant alpha-2,3-sialyltransferase from Neisseria meninigitidis are reported. This enzyme showed an unusual acceptor specificity in that it could use alpha-terminal and beta-terminal Gal residues as acceptors. In addition (beta1-->4)-linked and (beta1-->3)-linked terminal Gal served as acceptors. These properties distinguish the bacterial enzyme from the more widely investigated mammalian equivalents. The protein was expressed as a membrane-associated protein in Escherichia coli at a level of 750 U/l (approximately 250 mg/l). The protein could be extracted with buffers containing 0.2% Triton X-100 and purified to homogeneity using immobilized-metal-affinity chromatography. Electrospray-ionization mass spectrometry of peptides obtained by cleavage with cyanogen bromide and trypsin confirmed over 95% of the deduced amino acid sequence. When used for enzymatic synthesis in coupled reactions with recombinant CMP-Neu5Ac synthetase, the alpha-2,3-sialyltransferase could sialylate fluorescent derivatives of N-acetyllactosamine with N-acetylneuraminic acid, N-propionylneuraminic acid and N-glycoloylneuraminic acid.

Amino Acid Sequence↗
PubMed1996

Cloning of the lipooligosaccharide alpha-2,3-sialyltransferase from the bacterial pathogens Neisseria meningitidis and Neisseria gonorrhoeae.

The genes encoding the alpha-2,3-sialyltransferases involved in lipooligosaccharide biosynthesis from Neisseria meningitidis and Neisseria gonorrhoeae have been cloned and expressed in Escherichia coli. A high sensitivity enzyme assay using a synthetic fluorescent glycosyltransferase acceptor and capillary electrophoresis was used to screen a genomic library of N. meningitidis MC58 L3 in a "divide and conquer" strategy. The gene, denoted lst, was found on a 2. 0-kilobase fragment of DNA, and its sequence was determined and then used to design probes to amplify and subsequently clone the corresponding lst genes from N. meningitidis 406Y L3, N. meningitidis M982B L7, and N. gonorrhoeae F62. Functional sialyltransferase was produced from the genes derived from both L3 N. meningitidis strains and the N. gonorrhoeae F62. However, the N. meningitidis M982B L7 gene contained a frameshift mutation that renders it inactive. The expression of the lst gene was easily detected using the enzyme assay, and the protein expression could be detected when an immunodetection tag was added to the COOH-terminal end of the protein. Using the synthetic acceptor N-acetyllactosamine-aminophenyl-(6-(5-(fluorescein-carboxamido)-hexan oic acid amide), the alpha-2,3 specificity of the enzyme was confirmed by NMR examination of the reaction product. The enzyme could also use synthetic acceptors with lactose or galactose as the saccharide portion. This study is the first example of the cloning, expression, and examination of alpha-2,3-sialyltransferase activity from a bacterial source.

Amino Acid Sequence↗
PubMed1996

Suppression of the antibody response to a polymorphic peptide from the platelet alloantigen integrin beta3 with low molecular weight antigen arrays.

The allelic human platelet alloantigens PIA1/PIA2 are determined by a 33 Leu-Pro substitution in the second disulfide loop of the integrin beta3 subunit of the fibrinogen receptor, alphaIIb beta3 (GPIIb-IIIa). Alloantibodies to PIA1 cause neonatal alloimmune thrombocytopenia. We studied the suppression of specific Ab production to a disulfide-looped peptide spanning the polymorphic region of integrin beta3, 24AWCSDEALPLGSPRCD39 (LPL). Mice immunized with LPL coupled to OVA (LPL-OVA) produced Abs specific for LPL. When immunized animals were injected with low m.w. dextran heavily derivitized with LPL (Dex(low)LPL(high)), levels of Ab to LPL fell immediately and remained low 1 mo later. Both high affinity and total Abs were affected. Arrays with lower peptide density or a high m.w. backbone did not induce well sustained suppression. Abs to OVA were unaffected by the arrays. Naive mice given Dex(low)LPL(high) were tolerant to subsequent immunization with LPL-OVA. In transfer experiments, irradiated recipients of spleen cells or purified 8 cells from animals suppressed with Dex(low)LPL(high) did not respond to LPL-OVA. Spleen cells from suppressed animals did not suppress the response to LPL-OVA in recipients of immune B cells. These results demonstrate that peptide arrays, by a mechanism sensitive to molecular configuration, induce tolerance to peptide immunization and suppress an ongoing, high affinity Ab response. Peptide arrays induce the elimination or irreversible anergy of specific memory B cells and do not require a non-B spleen cell population to maintain suppression.

Amino Acid Sequence↗
PubMed1996

A normative study of the Coolidge Axis II Inventory.

The Coolidge Axis-II Inventory (CATI) is a 200-item self-report inventory that is designed to measure DSM-IV personality disorders (PD's). Norms with a sample of 1,790 Canadian college students are compared with a US sample of 573 college students and 36 elderly subjects. Comparisons for the 11 DSM-IV personality disorder scales are made with several age groups and with gender. Some interesting similarities and differences were observed. With the Canadian sample, a gender difference was found on the antisocial scale. Age differences were found for on several PD scales in that younger respondents (17-24 years) scored higher than the older ones (25-57 years). This information is likely to be helpful to clinicians in monitoring age related behavioral changes in personality disorder.

Adolescent↗