Search PubMed⌕ Search

Biomedical subjects

M A Taylor

Publications and source records attributed to M A Taylor.

At least 91 records · Page 5Linked to original sources
PubMed1995

Correction of bone marrow nucleated cell counts for the presence of fat particles.

Although the use of bone marrow transplantation has increased greatly in recent years, the quality control procedures used in bone marrow processing laboratories remain less than ideal. Accurate marrow total nucleated cell (TNC) counts are essential for effective monitoring of bone marrow collection and processing. Aspirated marrow is variably contaminated by fat particles, resulting in overestimation of marrow TNC by automated analyzers. A recently-marketed hematological analyzer (Cobas-Helios; Roche Diagnostic Systems, Branchburg, NJ) offers the potential to correct marrow TNC counts for fat particles using available software. The authors investigated the accuracy of corrected TNC counts on 21 marrow samples, using a visual chamber count as the reference method. The correction methods studied were software correction, using the Cobas-Helios differential system, and replacement of the sample plasma with saline. Uncorrected automated marrow TNC counts (mean, 28.4 x 10(9)/L) were significantly higher than the visual reference counts (mean, 23.1 x 10(9)/L). Neither the mean corrected automated count (24.3 x 10(9)/L) nor the mean saline replaced count (24.6 x 10(9)/L) differed significantly from the mean visual reference count. For both the corrected automated and saline replaced counts, 20 of the 21 data points (95%) fell within a 95% confidence interval computed for the reference method. The authors conclude that both the corrected automated method, using the Cobas-Helios, and the saline replacement method are acceptable alternatives to the visual chamber count.

Adult↗
PubMed1995

Recombinant pro-regions from papain and papaya proteinase IV-are selective high affinity inhibitors of the mature papaya enzymes.

Proteolytic enzymes require the presence of their pro-regions for correct folding. Of the four proteolytic enzymes from Carica papaya, papain and papaya proteinase IV (PPIV) have 68% sequence identity. We find that their pro-regions are even more similar, exhibiting 73.6% identity. cDNAs encoding the pro-regions of these two proteinases have been expressed in Escherichia coli independently from their mature enzymes. The recombinant pro-regions of papain and PPIV have been shown to be high affinity inhibitors of all four of the mature native papaya cysteine proteinases. Their inhibition constants are in the range 10(-6) - 10(-9) M. PPIV was inhibited two to three orders of magnitude less effectively than papain, chymopapain and caricain. The pro-region of PPIV, however, inhibited its own mature enzyme more effectively than did the pro-region of papain. Alignment of the sequences of the four papaya enzymes shows that there is a highly variable section towards the C-terminal of the pro-region. This region may therefore confer selectivity to the pro-regions for the individual proteolytic enzymes.

Amino Acid Sequence↗
PubMed1995

Sinister psychotics. Left-handedness in schizophrenia and affective disorder.

The notion persists that psychotics, particularly schizophrenics, are less right-handed than the general population, and that this deviation is pathophysiologically important in some patients. We assessed handedness and psychopathology in 163 DSM-III schizophrenics, 103 affectives, and 112 normal subjects. Although schizophrenics were less right-handed than normal subjects, this difference was primarily due to more mixed handedness among schizoaffectives. Relationships between handedness and specific psychopathology were uninformative, and we conclude that handedness may not be an important consideration in the study of psychosis.

Adult↗
PubMed1995

Formal thought disorder in schizophrenia. Linguistic, attentional, and intellectual correlates.

Formal thought disorder (i.e., abnormal utterances and communication problems) is a prominent feature of schizophrenia. To investigate the hypothesis that formal thought disorder in schizophrenics represents a disturbance of language functioning, we compared 21 thought-disordered and 16 non-thought-disordered schizophrenics on the Porch Index of Communicative Ability. The thought-disordered schizophrenics were significantly more impaired. We also examined nonlinguistic factors potentially impacting language performance in schizophrenics (e.g., disturbed attention, intellect, and/or thought content). Reduced attention was the best predictor of language performance in the thought-disordered group, whereas low intellect and reduced attention were predictive of language dysfunction in the non-thought-disordered group. Disturbed thought content was not predictive of language impairment in either group. These findings provide partial support for the idea that formal thought disorder in schizophrenics represents defective language functioning.

Attention↗
PubMed1995

Decline of U.S. medical student career choice of psychiatry and what to do about it.

OBJECTIVE: In 1994, only 3.2% of U.S. medical school graduates chose psychiatry, the lowest proportion since 1929. Success in recruiting such graduates is necessary to maintain adequate numbers of psychiatrists. The authors' goal was to gain an understanding of the determinants of specialty selection to ensure adequate recruitment. METHOD: They reviewed all recruitment-related English-language publications since 1959: 173 papers, 17 reports, and 10 books. RESULTS: They found that recruitment has been cyclical, with success from 1940 to 1969 and from 1985 to 1988, decline from 1970 to 1984 and from 1989 to 1994, and a possible small upswing in 1995. The 1940-1969 success began with 1) public recognition of a dramatic shortage of psychiatrists to serve in the military and treat casualties and 2) the fervor of the community mental health movement, which promised to prevent mental illness; massive resources were provided for psychiatry during this period. The declines were associated with 1) the failure of the community mental health movement to fulfill its promise, 2) psychiatry's becoming more biologically oriented and medically conventional, and 3) the effects of managed care and increased competition for patients. The psychiatry departments that have high recruitment rates are in public-supported schools, particularly in the South, or give considerable priority and resources for medical student psychiatric education. CONCLUSIONS: A study of the psychiatric workforce is needed to ascertain whether there is a surplus or a shortage of psychiatrists. Regardless, to ensure adequate recruitment, medical institutions and departments of psychiatry must commit resources for student education in psychiatry.

Attitude↗
PubMed1994

Is evidence for homoeopathy reproducible?

We tested, under independent conditions, the reproducibility of evidence from two previous trials that homoeopathy differs from placebo. The test model was again homoeopathic immunotherapy. 28 patients with allergic asthma, most of them sensitive to house-dust mite, were randomly allocated to receive either oral homoeopathic immunotherapy to their principal allergen or identical placebo. The test treatments were given as a complement to their unaltered conventional care. A daily visual analogue scale of overall symptom intensity was the outcome measure. A difference in visual analogue score in favour of homoeopathic immunotherapy appeared within one week of starting treatment and persisted for up to 8 weeks (p = 0.003). There were similar trends in respiratory function and bronchial reactivity tests. A meta-analysis of all three trials strengthened the evidence that homoeopathy does more than placebo (p = 0.0004). Is the reproducibility of evidence in favour of homoeopathy proof of its activity or proof of the clinical trial's capacity to produce false-positive results?

Adult↗
PubMed1994

Combined modality treatment using BID radiation for locally advanced non-small cell lung carcinoma.

BACKGROUND: From February 1988 to August 1991, 82 patients were treated on Phase II trial of split-course multimodality treatment for locally advanced, non-small cell lung cancer (NSCLC). METHODS: Treatment consisted of twice-daily radiation (150 cGy/fraction) delivered with concomitant infusional cisplatin, etoposide, and fluorouracil for 1 week every third week. Patients were classified before initial treatment as either potentially resectable (eligible for surgery [ES]) or ineligible for surgery (IES). The ES group consisted of 38 Stage IIIA and 7 Stage IIIB patients. The IES group had 5 patients staged as IIIA and 32 staged as IIIB. Most patients were staged clinically. ES patients received three cycles of treatment (39 Gy) before resection. IES patients received four cycles (60 Gy) delivered with curative intent. RESULTS: Thirty-nine of 45 ES patients underwent resection. The pathologic response rate was 27%. Three-year actuarial local control was 86% for 41 evaluable ES patients. Three-year actuarial survival for the whole ES group was 39%, with a median follow-up for living patients of 32 months. The IES group faired less well, with an 18% 3-year actuarial survival. Treatment was well tolerated with a median weight loss of one-half pound, mild or moderate pneumonitis in 5%, mild esophagitis in 15%, and severe nausea and/or vomiting in 10% of patients. Treatment-related mortality was 5%. CONCLUSIONS: Patients treated with conventional radiation alone for Stage III NSCLC are rarely cured. This well tolerated Phase II study demonstrated encouraging results for such patients. Both local control and survival appeared promising, especially in patients rendered resectable after combined-modality treatment.

Adult↗
PubMed1994

Intracerebral hemorrhage complicating urokinase infusion into an occluded aortocoronary bypass graft.

Selective infusion of urokinase into occluded coronary bypass vein grafts is effective in restoring patency. We report the occurrence of intracerebral hemorrhage complicating an intra-graft urokinase infusion protocol. The patient had known cerebral vascular structural pathology without recent clinical complications. Caution with the use of thrombolysis in this setting is suggested.

Cerebral Hemorrhage↗
PubMed1994

Characterisation of the cDNA clones of two beta-tubulin genes and their expression in the potato plant (Solanum tuberosum L.).

The cDNA clones of two potato beta-tubulin genes were isolated from a tuberising stolon tip library. Analysis of 20 positive clones showed that they represented one or another of two different but very similar beta-tubulin genes, designated TUBST1 and TUBST2. The expression pattern of beta-tubulin genes in the potato plant was investigated by RNA blot analysis and by RT-PCR. Southern analysis of potato genomic DNA with coding and non-coding beta-tubulin probes revealed that there are multiple beta-tubulin genes in the potato genome and that there is likely to be considerable divergence in the 3' non-coding sequences. Phylogenetic analysis of plant beta-tubulin genes is described.

Amino Acid Sequence↗
PubMed1994

Characterisation of the S-adenosylmethionine decarboxylase (SAMDC) gene of potato.

S-adenosylmethionine decarboxylase (SAMDC) is involved in the biosynthesis of the polyamines, spermidine and spermine. Recently, we reported the isolation of a putative cDNA clone of the SAMDC clone of potato (Plant Mol Biol 20; 641-651). In order to confirm that the potato genes does encode SAMDC, a complementation experiment with a yeast strain that possesses a null mutation in the SAMDC gene was performed. The yeast strain contains a deletion-insertion mutation in the SAMDC gene and has an absolute requirement for the addition of exogenous spermidine for growth. When the full-length potato cDNA was expressed in the mutant yeast strain there was no longer a requirement for exogenous spermidine. Immunoblotting experiments suggest that the potato SAMDC gene product has an apparent molecular mass of 39 kDa. Expression of the SAMDC gene was high in the young and actively dividing tissues and low in the mature and non-dividing tissues of both vegetative and reproductive organs. Additionally, isolation and characterisation of the corresponding genomic clone is reported. The gene has one intron in its 5'-untranslated sequence but otherwise the transcribed portion is identical to the cDNA clone.

Adenosylmethionine Decarboxylase↗
PubMed1994

Nonlinear dynamics of immunogenic tumors: parameter estimation and global bifurcation analysis.

We present a mathematical model of the cytotoxic T lymphocyte response to the growth of an immunogenic tumor. The model exhibits a number of phenomena that are seen in vivo, including immunostimulation of tumor growth, "sneaking through" of the tumor, and formation of a tumor "dormant state". The model is used to describe the kinetics of growth and regression of the B-lymphoma BCL1 in the spleen of mice. By comparing the model with experimental data, numerical estimates of parameters describing processes that cannot be measured in vivo are derived. Local and global bifurcations are calculated for realistic values of the parameters. For a large set of parameters we predict that the course of tumor growth and its clinical manifestation have a recurrent profile with a 3- to 4-month cycle, similar to patterns seen in certain leukemias.

Animals↗
PubMed1994

Microbial predation in coupled chemostats: a global study of two coupled nonlinear oscillators.

Predator-prey systems in continuously operated chemostats exhibit sustained oscillations over a wide range of operating conditions. When two such chemostats interact through flow exchange, the interplay of the oscillation frequencies gives rise to a wealth of dynamic behavior patterns. Using numerical bifurcation techniques, we perform a detailed computational study of these patterns and the transitions between them as the coupling strength and relative frequencies of the two chemostats vary. We concentrate on certain strong resonance phenomena between the two frequencies as well as their mutual extinction and provide a representative sampling of possible phase portraits for our model system. Our observations corroborate recent mathematical results and case studies of coupled nonlinear chemical oscillators in which regions of mutual extinction as well as the Arnol'd structure for two-parameter families of maps of the plane have been observed. We highlight certain unexpected features of the operating diagram discovered through our computational study and discuss their implication for the dynamic response of the chemostat system.

Animals↗
PubMed1994

Variations in oocyst output associated with Cryptosporidium baileyi infections in chickens.

Groups of birds, aged 2, 16 and 30 days, were experimentally infected with 400, 20,000 or 1,000,000 oocysts of Cryptosporidium baileyi. The faecal oocyst output for each group was determined by collection of faeces on Days 0, 5, 7 and 13-21 post-infection (p.i.). The duration of patency of infection, as determined by oocyst excretion, declined more rapidly in the older age groups but persisted longer in birds challenged with the lower oocyst numbers.

Age Factors↗
PubMed1994

Family study of schizophrenia and personality.

The purpose of this study was to determine whether the abnormal characteristics observed in relatives of schizophrenics represent variations in normal personality. Relatives (N = 340) of patients with schizophrenia, affective disorder, and medical or surgical conditions were personally interviewed about psychiatric symptoms and completed the Multidimensional Personality Questionnaire. Relatives who were themselves ill had elevated scores on some scales. Relatives of schizophrenics had normal scores on all personality scales, but relatives of affectively ill probands differed from other relatives on Well-Being and measures of Negative Emotionality. When schizophrenic probands were subtyped by symptoms, relatives of emotionally blunted schizophrenics were found to have slightly lower scores on Social Closeness than did relatives of controls. Overall, these results suggest that schizophrenia is unrelated to normal personality.

Adolescent↗