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M A Taylor

Publications and source records attributed to M A Taylor.

At least 109 records · Page 6Linked to original sources
PubMed1994

Development and validation of a Multiple Ability Self-Report Questionnaire.

We present results from three studies on the development and validation of the Multiple Ability Self-Report Questionnaire (MASQ), a self-report measure comprising items from five cognitive domains; language, visuo-perceptual, verbal memory, visual memory, and attention. In Study 1, we determined the content relevance of the questionnaire items. In Study 2, we assessed the basic psychometric properties (i.e., internal consistency and test-retest reliability) of the MASQ in 118 individuals without neurologic or psychiatric disorder, aged 25 to 88 years. In Study 3 we provide validity data for the MASQ by comparing the ratings of normals to people with unilateral temporal-lobe epilepsy, and examining the relationship of self-report to objective test performance. The potential use of the MASQ to study the neurologic and psychological correlates of accuracy and unawareness in self-appraisal across different cognitive domains and various clinical groups is discussed.

Adult↗
PubMed1994

An unequivocal example of cysteine proteinase activity affected by multiple electrostatic interactions.

The role of electrostatic interactions between the ionizable Asp158 and the active site thiolate-imidazolium ion pair of some cysteine proteinases has been the subject of controversy for some time. This study reports the expression of wild type procaricain and Asp158Glu, Asp158Asn and Asp158Ala mutants from Escherichia coli. Purification of autocatalytically matured enzymes yielded sufficient fully active material for pH (kcat/Km) profiles to be obtained. Use of both uncharged and charged substrates allowed the effects of different reactive enzyme species to be separated from the complications of electrostatic effects between enzyme and substrate. At least three ionizations are detectable in the acid limb of wild type caricain and the Glu and Asn mutants. Only two pKa values, however, are detectable in the acid limb using the Ala mutant. Comparison of pH activity profiles shows that whilst an ionizable residue at position 158 is not essential for the formation of the thiolate-imidazolium ion pair, it does form a substantial part of the electrostatic field responsible for increased catalytic competence. Changing the position of this ionizable group in any way reduces activity. Complete removal of the charged group reduces catalytic competence even further. This work indicates that hydronations distant to the active site are contributing to the electrostatic effects leading to multiple active ionization states of the enzyme.

Amino Acid Sequence↗
PubMed1994

The problem of missing clinical data for research in psychopathology: some solution guidelines.

There are no guidelines to help psychiatric researchers statistically adjust for missing data. We discuss the problems resulting from missing values, and illustrate some of them with examples from our work. Using structured instruments, we obtained clinical information from 241 patients. Some instrument items were not rated, and these did not occur randomly: hallucinations and delusions were most frequently unrated, especially in chronic schizophrenics, and patients with high scores for other psychopathology. Systematically assigning an intermediate value between present and absent to nonrated items was a satisfactory solution, unaffected by nonrandom missing values. This simple solution was equivalent to a complicated one (vectoring) in discriminating patients. When relationships between variables are linear, we recommend the intermediate value method as a practical solution to missing values. We stress that missing values do not mean missing information, and the most common response to missing values (dropping subjects) is least informative.

Data Collection↗
PubMed1994

Patterns of speech disorders in schizophrenia and mania.

Formal thought disorder (FTD), defined as abnormal speech, has been associated with schizophrenia and likened to fluent aphasia. Whether FTD differentiates subtypes of schizophrenics and discriminates schizophrenics from other patients is unclear. We studied this issue by analyzing ratings of FTD of 170 schizophrenics and 62 manics. Eighty percent of emotionally blunted schizophrenics had FTD compared with 6.5% of manics. Factor analysis revealed verbiage disturbance and disorganized speech factors (44% of the variance). We assessed the discriminating ability of these factors, and compared these results to those from factors derived from Andreasen's positive/negative FTD construct, and to factors derived from speech and language diagnostic criteria for schizophrenia and mania in the proposed DSM-IV. Overall classifications were similar (91%, 91%, and 88%, respectively). We also found that FTD was related to emotional blunting, but not to other psychopathology.

Adolescent↗
PubMed1994

Personality and self-report of cognitive functioning.

We examined the relationship of trait personality dimensions (negative affectivity and positive affectivity) on self-report of cognitive functioning. Ninety-six subjects who were screened to be without evidence of psychiatric or neurologic disorder, and who had previously completed the Tellegen Differential Personality Questionnaire (mean interval = 2 years) were sent a self-report questionnaire of cognitive functioning (MASQ). As predicted, negative affectivity (NA) was more strongly related to self-appraisal of cognitive functioning than was positive affectivity (PA); subjects with higher NA scores acknowledged more cognitive difficulties. Negative affectivity was also a stronger predictor of cognitive self-report than was self-report of current sad mood state. The implications of these findings for the examination of self-appraisal and accuracy of self-report are discussed.

Journal Article↗
PubMed1994

Review article: coccidiosis of domestic ruminants.

Coccidiosis in ruminants results from complex interactions between hosts and parasites with many external factors influencing the severity of disease. The study of ruminant coccidiosis is still very much in its infancy despite the advances made in recent years in determining life cycles, pathogenesis, epidemiology and control. Many of the life cycles of the species, considered to be of lesser importance, have still to be elucidated and controversy still exists concerning the pathogenicity of some of these species. Outbreaks of coccidiosis occur with ever increasing frequency yet few drugs exist for prevention. Only limited investigations have been undertaken on immunological methods of control. This paper seeks to review the current knowledge on the biology and control of the coccidial species affecting cattle, sheep and goats.

Animals↗
PubMed1993

Giardiasis in lambs at pasture.

Faecal samples from a group of lambs at pasture were screened at weekly intervals for nine weeks for the presence of Giardia species using a modified zinc sulphate flotation method. Fifty-nine of 86 lambs (68.6 per cent) excreted giardia cysts on one or more occasions. They were first detected at approximately three weeks of age and the highest incidence of excretion of cysts occurred when the lambs reached a mean age of 37 days. The lambs had diarrhoea but it was attributed to the presence of Eimeria ovinoidalis.

Animals↗
PubMed1993

Nucleotide sequence and expression in Escherichia coli of cDNAs encoding papaya proteinase omega from Carica papaya.

We have cloned and sequenced two similar, but distinct, cDNAs from both fruit and leaf tissues of Carica papaya. The C-terminal portion of the predicted amino acid (aa) sequence of one of the clones has complete identity with the mature enzyme sequence of the cysteine proteinase papaya proteinase omega (Pp omega). The second clone contains ten individual bp changes compared with the first and encodes a protein with three single-aa substitutions, only one of which is located in the mature sequence, but most noticeably carries an additional 19-aa C-terminal extension. The clones encode pre-pro precursor isoforms of Pp omega. The former of these clones has been expressed in Escherichia coli using a T7 polymerase expression system to produce insoluble pro-enzyme which has been solubilized and refolded to yield auto-activable pro-Pp omega.

Amino Acid Sequence↗
PubMed1993

Factors effecting the thermostability of cysteine proteinases from Carica papaya.

Thermal denaturation of four Carica papaya cysteine proteinases (papain, chymopapain, papaya proteinases 3 and 4) was studied as a function of pH using high-sensitivity differential scanning calorimetry. The ratios of calorimetric enthalpy to Van't Hoff enthalpy suggest that, for all these proteins, denaturation occurs as a non two state process, via an intermediate structure. Differences in the thermal stabilities of the proteinases; chymopapain > papaya proteinase 3 > papain > papaya proteinase 4, were correlated to their amino acid sequence to explain the observations in terms of mobility and specific residue mutation. Three-dimensional structures of papain and papaya proteinase 3 were similarly used to illustrate the influence of atomic mobility on stability.

Calorimetry, Differential Scanning↗
PubMed1993

Elongational flow studies on type IV collagen: comparison with type I.

Elongation flow techniques have been used to investigate the birefringent response of monodisperse type IV collagen in dilute solution and the results compared with type I collagen. A four-roll mill apparatus was used to characterize the solutions at low strain rates, epsilon < or = 300 s-1. The birefringence is nonlocalized and rises gradually to a plateau value, in accordance with rigid-rod behavior. The gradients of the tangent to the curves at zero strain rate are estimated for types IV and I collagen. The concentrations of the solutions used were in the dilute to semidilute regimes. Using a value of 300 nm for the length of type I collagen, values of 364-408 nm were calculated for the length of the type IV collagen molecule, depending on the concentration regime chosen, which is consistent with biochemical predictions based on a rigid molecule. The results imply that the behavior of type IV collagen molecules in solution is similar to type I collagen, despite the presence of several sequence interruptions in the type IV helix.

Chemistry, Physical↗
PubMed1993

Pulmonary artery hemodynamic response to proximal balloon dilatation of a large dominant right coronary artery.

The human right ventricle has a relatively low tolerance to even short periods of ischemia. During angioplasty of the right coronary artery, pulmonary artery pressure typically rises due to an increase in right ventricular afterload caused by left ventricular dysfunction during ischemia. We have presented two cases of angioplasty in the early proximal portion of a large, highly dominant right coronary artery. Pulmonary artery and systemic pressure fell during balloon inflation probably secondary to acute severe right ventricular failure, though an interaction with left ventricular dysfunction cannot be excluded. These observations do emphasize the hemodynamic and combined ventricular consequences of proximal angioplasty in a large, dominant right coronary artery, particularly in the setting of preexisting left ventricular dysfunction.

Aged↗
PubMed1993

Are schizophrenia and affective disorder related? preliminary data from a family study.

OBJECTIVE: Most investigators presume that schizophrenia and affective disorder are separate diseases. Others have proposed alternatives to this Kraepelinian view. These alternatives were addressed by preliminary analyses of data from a family study of psychopathology. METHOD: The authors identified 1,895 first-degree relatives of 166 patients with DSM-III schizophrenia, 71 patients with affective disorder, and 85 medical comparison probands; 949 relatives were blindly diagnosed. RESULTS: The risks for schizophrenia and affective disorder (unipolar melancholia and bipolar disorder combined) were significantly higher in the relatives of the schizophrenic probands and the relatives of the probands with affective disorder than in the relatives of the comparison probands. The morbid risk for nonmelancholic depressions was not significantly higher. Among the relatives of the schizophrenic probands, the risk for affective disorder was highest among the relatives of the patients with "core" schizophrenia, who were younger at illness onset, had chronic illness, had severe emotional blunting, and showed few affective features. CONCLUSIONS: Despite limitations, these preliminary analyses, consistent with other studies, suggest some familial relationship between schizophrenia and severe forms of affective disorder.

Adult↗