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Biomedical subjects

K Allen

Publications and source records attributed to K Allen.

At least 73 records · Page 4Linked to original sources
PubMed1996

Protein kinase C alpha, beta immunoreactivity in baker's yeast, lobster and wheat germ.

The immunoreactivity of PKC alpha (protein kinase C alpha) and PKC beta in wheat germ, lobster tail muscle and three strains of yeast was analysed by Western blotting with mouse anti-PKC active fragments. The potency of the immunoreactivity of PKC alpha activity was much greater than that of PKC beta. The occurrence of multiple bands may be due to PKC self-interactions and/or the interactions between PKC and other molecules. The evolutionary conservation of PKC alpha and PKC beta implies that these PKC isoenzymes may play important roles in Ca2+/lipid-dependent signal transduction and cell growth in these eukaryotes.

Animals↗
PubMed1995

Timing of weight gain and breast cancer risk.

BACKGROUND: Obesity and body-fat distribution have been associated with the incidence of breast and endometrial cancers. It may be critical to determine if the timing of weight gain during periods of hormonal change, such as menarche, pregnancy, or menopause, has different biologic effects, especially secondary to differences in the localization of body fat during these periods. The objective of the current study was to determine if excess weight in any particular decade of life or the timing of weight gain was more significant relative to breast cancer risk. METHODS: Anthropometric, medical, and hormonal histories were obtained from 218 consecutively recruited, newly diagnosed patients with breast cancer admitted to the H. Lee Moffitt Cancer Center and Research Institute (Tampa, FL) and 436 control subjects, matched in a two to one ratio for age and menopausal status. RESULTS: A weight gain of 15 pounds or more was observed for 63.8% of the patients compared with 49.3% control subjects (P = 0.0006) from age 30 to current age. Similarly, more than 48% of cases gained more than 15 pounds from ages 16 to 30 compared with 37% (P = 0.01) of the control population. Although weight gain from age 16 to adulthood was significantly higher in patients with breast cancer at each decade when compared with control subjects, a significant and independent association between weight at age 30 (P < 0.0001) and risk of breast cancer was noted. CONCLUSION: Women who progressively gain weight from puberty to adulthood, and specifically in the third decade of life, should be considered at a higher risk for developing breast cancer.

Adult↗
PubMed1995

Molecular characterization of an apical early endosomal glycoprotein from developing rat intestinal epithelial cells.

The apical endosomal compartment is thought to be involved in the sorting and selective transport of receptors and ligands across polarized epithelia. To learn about the protein components of this compartment, we have isolated and sequenced a cDNA that encodes a glycoprotein that is located in the apical endosomal tubules of developing rat intestinal epithelial cells. The deduced amino acid sequence predicts a protein of 1216 amino acids with a molecular mass of 133,769 Da. The deduced amino acid sequence together with amino-terminal amino acid sequencing indicate that there is a cleaved 21-amino acid signal sequence at the NH2-terminal portion of the molecule. There is a single hydrophobic region near the carboxyl terminus that has the characteristics of a membrane-spanning domain and a 36-amino acid cytoplasmic tail. We have found that the major form of this protein in intestinal epithelial cells has a molecular mass of 55-60 kDa, which is significantly smaller than the size predicted from the cDNA sequence, suggesting that the protein is synthesized as a large precursor and processed to the smaller form. The smaller form remains associated with the membrane, however, possibly through noncovalent association with the transmembrane portion of the molecule or with another membrane protein. The extracytoplasmic domain is cysteine-rich, with three cysteine-rich repeats that are similar to cysteine repeats present in several receptor proteins. However, there is no other significant similarity to other proteins in the GenBank. The cytoplasmic tail contains a possible internalization motif and several consensus motifs for serine/threonine kinases. Northern blot analysis suggests a single abundant message, and Southern blot analysis is consistent with a single gene and the absence of pseudogenes for this unique endosomal protein.

Amino Acid Sequence↗
PubMed1995

Epidural spinal cord stimulation in the management of spasms in spinal cord injury: a prospective study.

Forty-eight spinal cord injury victims were implanted with an epidural spinal cord stimulation system to treat spasms that had not satisfactorily responded to medical therapy. All the patients were at least 6 months after the injury. The protocol included assessment by independent examiners preoperatively and at 3, 6, 12 and 24 months after the implant. Pre- and postoperative data collection included the frequency and severity of the spasms. Combining the frequency and intensity scores into a 'severity' score provided a more accurate clinical picture. No patient observed neurological deterioration following the surgical procedure or the neurostimulation treatment. A statistically significant reduction in the severity of the spasms was observed in the follow-up evaluations, with results that progressively increased in time. It is appears that spinal cord stimulation is an effective and safe alternative in the management of spasms in spinal cord injury victims. Its exact role in relation to intrathecal baclofen infusion and ablative procedures remains to be defined.

Adolescent↗
PubMed1995

Metabolic activity in rat visual system during exposure to high and low intensities of patterned and diffuse light.

An examination of rat visual system activity, during exposure to either "pattern" (black and white stripes) or "diffuse" (eye covered by white mask) visual stimulation at high or low illumination intensities (1600 and 1 lux at cornea, respectively), was carried out using the 2-deoxyglucose (2-DG) autoradiographic technique. Pattern elevated 2-DG uptake in the dorsal and ventral lateral geniculate nuclei, in the lateral posterior nucleus, and in area 17, but was less effective at the high than at the low light intensity. Diffuse light also elevated 2-DC uptake in the thalamic nuclei but the increase was less impressive and the same at both intensities. Diffuse light at either high or low intensity had no effect on cortex. Like thalamus and cortex, pattern was a less effective stimulus for the colliculus at the high than at the low intensity, but, in contrast to thalamus and cortex, high intensity diffuse light suppressed 2-DG uptake in the colliculus to a level below that produced by darkness; low intensity diffuse light had no effect. These 2-DG findings are discussed in terms of how forebrain and midbrain divisions of the rat's rod-dominated visual system maintained their respective spatial processing and change-detecting functions over a considerable range of illumination intensity.

Animals↗
PubMed1995

Barriers to treatment for addicted African-American women.

This article describes barriers to treatment identified by a sample of substance-abusing/addicted women (mostly African-American). A self-administered questionnaire, the Allen Barriers to Treatment Instrument, was submitted to 97 substance-abusing/addicted women throughout the state of Illinois who were not in treatment. Results showed that the barriers most identified by these subjects included responsibility for child care, lack of insurance or money, and community issues.

Adolescent↗
PubMed1994

Effects of music on cardiovascular reactivity among surgeons.

OBJECTIVE: To determine the effects of surgeon-selected and experimenter-selected music on performance and autonomic responses of surgeons during a standard laboratory psychological stressor. DESIGN: Within-subjects laboratory experiment. SETTING: Hospital psychophysiology laboratory. PARTICIPANTS: A total of 50 male surgeons aged 31 to 61 years, who reported that they typically listen to music during surgery, volunteered for the study. MAIN OUTCOME MEASUREMENTS: Cardiac responses, hemodynamic measures, electrodermal autonomic responses, task speed, and accuracy. RESULTS: Autonomic reactivity for all physiological measures was significantly less in the surgeon-selected music condition than in the experimenter-selected music condition, which in turn was significantly less than in the no-music control condition. Likewise, speed and accuracy of task performance were significantly better in the surgeon-selected music condition than in the experimenter-selected music condition, which was also significantly better than the no-music control condition. CONCLUSION: Surgeon-selected music was associated with reduced autonomic reactivity and improved performance of a stressful nonsurgical laboratory task in study participants.

Adult↗
PubMed1994

Studies on the relationship between changes in radiographic bone height and probing attachment.

The aim of this investigation was to determine the relationship between loss of radiographic crestal bone height and probing attachment loss. As part of this aim, we are introducing a new method for determination of a threshold for significant probing attachment loss which takes into account the error contributed by alteration in tissue tone. 57 adults with established periodontitis were selected. Radiographs were taken using the Rinn alignment system. Crestal change was determined from bone height measurements on digitized images of pairs of radiographs using the "side-by-side" technique of analysis developed recently by us. Probing attachment loss was measured using the Florida electronic probe system. Radiographic and probing measurements were made at baseline and after 1 year. No treatment was given during this period. A direct and significant relationship was observed between radiographic bone loss and probing attachment loss on a site basis (p = 0.0001, r2 = 0.018) and between subject means (p = 0.0014, r2 = 0.16). Radiographic and probing attachment change at all categories of sites, dichotomously classified as to not changing or loosing indicated 13% of sites were loosing by measurement of radiographic change and 9.6% were loosing by measurement of attachment change. Concordance in radiographic and attachment level change was found in 82% of sites examined. The relative diagnostic import of change in probing attachment or change in radiographic bone height requires treatment outcome studies based on use of diagnostic information of the 2 measuring techniques used singly and in combination.

Adult↗
PubMed1994

Development of an instrument to identify barriers to treatment for addicted women, from their perspective.

This article reports the development of the Allen Barriers to Treatment Instrument, designed specifically for identifying barriers for women. An extensive search and review of the literature in the areas of barriers, access to care, and utilization of services was completed. Not only was a definition for "barriers" derived from this search, indicators for items used on the instrument were ascertained also. The article presents information on the rationale for developing the instrument the way it is and information on scoring.

Alcoholism↗
PubMed1994

Psychometric assessment of the Allen Barriers to Treatment Instrument.

The purpose of this study was to determine the psychometric properties of the Allen Barriers to Treatment Instrument (ABTI). Internal consistency reliability was assessed as well as five types of validity: face, content, criterion-related, convergent, and construct. A panel of experts was used to assess face and content validity of the ABTI; a two-group comparison method was used to evaluate criterion-related validity; qualitative analysis of responses to open-ended questions on the ABTI provided information about convergence; and item-to-total correlations of scores along with factor analysis was used to evaluate construct validity. Results showed strong evidence of the reliability and validity of the ABTI.

Adolescent↗
PubMed1994

cDNA sequence identity for the type I interferon receptor subunit from cell lines of widely differing responsiveness to interferon.

Melanoma cell lines exhibit strikingly different sensitivity to the antiproliferative effects of interferon. cDNAs encoding the Type I interferon receptor subunit were amplified by polymerase chain reaction, using as template RNA isolated from three melanoma cell lines displaying greater than 100 fold range in their sensitivity to the antiproliferative effects of IFN-beta. Comparison of the cDNA sequences obtained with the published cDNA sequence from the highly interferon-sensitive lymphoid cell line Daudi revealed only one base change that leads to a conservative amino acid substitution. It is concluded that the cellular differences in responsiveness to interferon, of the melanoma cell lines tested, do not arise from the expression of variants of the cloned Type I interferon receptor subunit.

Base Sequence↗
PubMed1993

The histopathology of infrainguinal vein graft stenoses.

The precise histopathological nature of vein graft stenoses is unclear. Some authors have suggested that these lesions are due to intimal hyperplasia and others have claimed that they are fibrous strictures. The aim of this study was to determine the histological nature of infrainguinal vein graft stenoses by examining sections of vein grafts that had developed stenoses and had been surgically revised. This was performed using a combined anti-smooth muscle actin/Millers elastin stain. The results show that vein graft stenoses are due to intimal hyperplasia whereby smooth muscle cells proliferate and cause thickening of the intimal layer.

Aged↗
PubMed1993

A novel device for the rapid in-clinic measurement of haemoglobin A1c.

In order to evaluate a novel technique for measuring haemoglobin A1c using a cassette-based immunoassay method we have undertaken a laboratory evaluation using 48 patient samples and a separate within-clinic prospective study of 59 diabetic patients. Individuals were recruited from general (48 patients), paediatric (19 patients), obstetric (24 patients), and general practice (15 patients) diabetic clinics. Agreement was evaluated between HbA1c results obtained using the new method (AMES DCA 2000) and an established laboratory assay (DIAMAT HPLC system). The mean differences between the two results (AMES DCA 2000-DIAMAT) (95% confidence intervals) were: laboratory -0.69% (-1.42 to 0.04%); paediatric clinic -0.93% (-1.93 to 0.07%); obstetric clinic -0.29% (-1.09 to 0.51%), and general practice clinic -0.77% (-1.3 to -0.24%). For the AMES DCA 2000, the coefficient of variation for HbA1c of 5.2% was 1.6% and for HbA1c of 13%, 2.4%. This instrument was used without difficulty by four different operators. Intra-assay coefficient of variation for each operator was < 3.4%. In 9/18 patients where a specific assessment of clinical utility was made, knowledge of the HbA1c result at the time of consultation lead to a change in treatment. Methodology of this type may be used successfully within a diabetic clinic setting in both primary care and hospital environments.

Adult↗
PubMed1993

The effectiveness of low dose slow release aspirin as an antiplatelet agent.

An open, randomized, parallel group study of three different aspirin preparations was carried out. The objective of this study was to compare their ability to inhibit the production of thromboxane A2 (measured as thromboxane B2 [TXB2]) from platelets. Three aspirin preparations were studied: Acetard 300 mg, Acetard 100 mg and Platet 100 mg. The study was conducted in 45 healthy adult volunteers and treatment continued once daily for 7 days. The results of the TXB2 assay show that the administration of all three treatment preparations produced a rapid drop in TXB2 levels of all volunteers. The baseline TXB2 level was reduced by 95% for all groups by day 3. Analysis by day showed a significant difference (P < 0.05) between treatments at day 1, with Acetard 100 mg having higher TXB2 levels than the other two groups. Analysis of changes from baseline showed a significant reduction (P < 0.05) in TXB2 levels at Days 1 to 14 for all three groups. Platelet aggregation also showed a significant reduction, being reduced to 10% of control at 7 days. It then reverted back to baseline by 28 days for all treatment groups. In conclusion, low dose aspirin is very effective as an antiplatelet agent and in a slow release form loses none of its patency.

Adult↗