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K O'Connor

Publications and source records attributed to K O'Connor.

At least 73 records · Page 4Linked to original sources
PubMed1991

Gallstone imaging: getting the most out of the oral cholecystogram.

The introduction of "nonoperative" treatment alternatives to elective cholecystectomy (extracorporeal shock wave lithotripsy, contact dissolution of stones, and improved oral bile salts solvents) has reinstated the oral cholecystogram as an important diagnostic test providing structural and functional information on the status of the gallbladder. The basic principles involved in the proper performance and interpretation of the oral cholecystogram are reviewed from the perspective of the clinician who orders the test and makes management decisions based on its results.

Cholecystography↗
PubMed1991

Factors in the diagnostic delays of small bowel malignancy.

The overall survival from primary malignancies of the small intestine has not changed over more than four decades. This generally is ascribed to delays in establishing the diagnosis and the advanced stage of the disease when treatment is begun. There has been no critical analysis of these delays. To answer these questions, we reviewed the records of all patients diagnosed with small bowel malignancy from 1967 to 1988 at the Methodist Hospital of Indiana. The onset and duration of symptoms, first medical consultation, time of performance of diagnostic procedures and surgery were verified in 77 patients with histologically confirmed small bowel malignancies. The longest delay occurs from the time medical help is sought to the time the diagnosis is made, not from the onset of symptoms to the first medical consultation. The small bowel should always be considered as a source of unexplained, persistent subtle abdominal symptoms.

Adult↗
PubMed1991

The role of the physician in the late diagnosis of primary malignant tumors of the small intestine.

Survival from primary malignancies of the small intestine has not improved during the last four decades. One reason for this is the advanced stage of disease at the time of surgery. In order to determine why diagnosis is made late, we reviewed the records of all patients with small bowel malignancy diagnosed between 1967 and 1988. The time from the onset of symptoms to the first medical contact and the time from medical contact until diagnosis were evaluated in 77 patients. The average delay in diagnosis attributable 1) to the patient failing to report symptoms was less than 2 months, 2) to the physician not ordering the appropriate diagnostic test was 8.2 months, and 3) to the radiologist failing to make the diagnosis was 12 months. Thus, the major delay in diagnosis was after medical help was sought and not from the onset of symptoms to first medical consultation. Physicians must increase their sensitivity to the subtle but persistent symptoms that necessitate a small bowel evaluation.

Adenocarcinoma↗
PubMed1990

New family of high-resolution ion exchangers for protein and nucleic acid purifications from laboratory to process scales.

A new family of polymer-based ion exchangers was tested for the purification of acidic and basic proteins on both the analytical and preparative scales. Protein-Pak HR series packings are available as strong cation (SP) and weak anion (DEAE) exchangers, allowing the development of a purification method regardless of the isoelectric point of protein. Three particle sizes, 8, 15 and 40 microns, are offered in scalable Advanced Purification (AP) glass columns or as bulk packings. The lower back pressures of the 15- and 40-microns packings compared to that of the 8-microns material allow rapid throughput of large volumes without exceeding the pressure limitations of the resin or the column. The capacity of the AP1 (100 mm x 10 mm) glass columns, containing these ion-exchange packings, is comparable to other ion-exchange columns. The resolution of mouse serum, plasmids, and a standard protein mixture was demonstrated and compared with the results obtained with other resin-based ion exchangers of similar particle size. Proteins were purified without significant loss of biological activity or mass.

Alkanesulfonates↗
PubMed1990

Molecular analysis of immunosuppression induced by virus replication in lymphocytes.

The relationship between immunosuppression and oncogenesis can be determined by studying the molecular interactions between tumor-inducing viruses and lymphocytes. We approached this study by using a unique system of two genetically related Leporipoxviruses, malignant fibroma virus (MV), and Shope fibroma virus (SFV). MV induces a syndrome of a highly lethal, disseminated myxosarcoma, severe immune suppression, and replicates in lymphocytes both in vivo and in vitro. In contrast, SFV causes a benign fibromyxosarcoma without immune dysfunction and cannot replicate in lymphocytes. Earlier studies demonstrated that transfer of a 10.8-kb Bam HI piece of MV (fragment "C") to SFV resulted in the ability of SFV to replicate in lymphocytes and suppress immune function. These results suggested that lymphocytotropic replication and immune suppression was located on the left side of fragment C. We extended these studies by generating families of recombinants between MV and SFV by using subfragments of fragment C. The resulting recombinant viruses were analyzed for their ability to replicate in lymphocytes, suppress immune function, and produce tumors. Those recombinants expressing MV-like characteristics were mapped by endonuclease digestion. This study demonstrates that recombinants containing a 3.6-kb Nde I subfragment, as well as those containing an overlapping 1.9-kb Hinc II subfragment, were capable of replicating in lymphocytes, suppressing immune functions, and inducing disseminated tumors in rabbits. Our study has therefore identified a portion of MV DNA sufficient to transfer the unique pathogenicity of MV to SFV, and suggests that control of immune suppression and tumor dissemination may not necessarily be mediated by the same viral genes.

Animals↗
PubMed1990

Evaluation of melanoma/skin cancer screening in Massachusetts. Preliminary results.

Although screening for melanoma/skin cancer is theoretically of value, few data are available to evaluate its effectiveness or the value of a visual exam by a dermatologist as a cancer screening tool. From the 2560 persons screened for melanoma/skin cancer in Massachusetts in 1986 and 1987, the authors followed the positive screenees to determine their final diagnosis. The authors obtained information on 85% of these persons, and found nine malignant melanomas, 91 non-melanoma skin cancers, 39 dysplastic nevi, and three congenital nevi. The sensitivity of the visual exam by a dermatologist was 89% to 97% and the predictive value positive was 35% to 75% for skin cancer. The authors conclude that the yield of screening is equivalent to that of other major cancer screening efforts and that the sensitivity and predictive value of the visual examination by the dermatologist is appropriate for a cancer screening tool.

Carcinoma in Situ↗
PubMed1990

Towards a process paradigm in psychophysiology.

This article discusses a theory and method for classifying psychophysiological phenomena as processes prior to considering them as experimental responses. The initial aim then is to construe experimental units as continuous subject-centered processes whose beginning and end depends on the individuals' actions. Boundaries of such processes are systematically defined by first identifying the process as a dimension. Activities are then classified relative to this dimension. Process units are specified by considering two classes of activity which form opposite ends of the dimension of process. The two classes are equivalent in all respects save along the one dimension. These two classes are termed 'pro'- and 'null'-equivalence and are the process methods version of familiar H1 and H0 of hypothetico-deductive procedures. Proportional presence or absence of a parameter value during pro- and null-equivalence of a process is the basis for inferring that a particular measure does or does not typify the process. Actual parameter values of a measure can then form credible limits by which to classify other processes as equivalent or not. These limits can indicate for example whether two experimental effects are dealing with the same or a different process. There are some difficulties in applying this process method, but the general conclusion is that classifying psychophysiological responses at the outset in terms of process clarifies technical and inferential issues in experimentation.

Behavior↗
PubMed1990

Effects of coping style and relaxation on cancer chemotherapy side effects and emotional responses.

This study was designed to determine (a) the relationship of coping style to cancer chemotherapy side effects and (b) whether coping style moderated the impact of a relaxation intervention on anxiety, depression, and nausea associated with chemotherapy. Forty-eight cancer patients were assigned randomly to receive either progressive muscle relaxation training before chemotherapy (experimental group) or standard care (control group). Spearman correlations indicated that a "blunting" or distraction-oriented coping style was associated with less anticipatory anxiety, less depression, and less nausea during and after chemotherapy. Spearman correlations also indicated that a "monitoring" or information-gathering coping style was associated with more anticipatory anxiety, and more nausea before and during chemotherapy. Although there was a significant effect of the relaxation intervention on posttreatment nausea, there were no other between-group differences. The results did suggest, however, that relaxation was effective in reducing anticipatory anxiety among "blunters," but not "monitors," perhaps because relaxation is a distraction strategy and therefore is consistent with a blunting coping style. The effects of coping and relaxation on pretreatment anxiety may have important implications, because anxiety is a key factor in classic conditioning models of anticipatory nausea and vomiting.

Adaptation, Psychological↗
PubMed1989

Dizziness and perceptual style.

This study tested the hypothesis that patients suffering from non-organic ('psychogenic') dizziness would score higher on Witkins' frame dependence test than a group of dizzy patients with peripheral organic damage. A computerized version of the portable rod and frame test was administered to a group of 10 chronic ENT patients with peripheral vestibular disease, 10 ENT patients with no detectable organic problems and 10 non-dizzy controls. Contrary to the hypothesis, the psychogenic group had less frame-dependent error than the peripheral group and less (though not significantly so) than the normal group. Four of the psychogenic group had very low frame dependence scores. The experience of dizziness may not be necessarily related to anxiety proneness and may be a function of an inhibitory autonomous perceptual style as well as one overly dependent on external cues.

Adult↗
PubMed1989

Smoking reduction based on a situational model of craving.

Eight smokers participated in a smoking-cessation program involving controlled situational reduction and behavioral substitution. Six completed the treatment, and over-all reduction was significant. Reduction was maintained at 12-month follow-up. Ratings of positive images of smoking also changed posttreatment.

Adult↗
PubMed1987

cDNA cloning and complete primary structure of the alpha subunit of a leukocyte adhesion glycoprotein, p150,95.

The leukocyte adhesion receptors, p150,95, Mac-1 and LFA-1 are integral membrane glycoproteins which contain distinct alpha subunits of 180,000-150,000 Mr associated with identical beta subunits of 95,000 Mr in alpha beta complexes. p150,95 alpha subunit tryptic peptides were used to specify oligonucleotide probes and a cDNA clone of 4.7 kb containing the entire coding sequence was isolated from a size-selected myeloid cell cDNA library. The 4.7-kb cDNA clone encodes a signal sequence, an extracellular domain of 1081 amino acids containing 10 potential glycosylation sites, a transmembrane domain of 26 amino acids, and a C-terminal cytoplasmic tail of 29 residues. The extracellular domain contains three tandem homologous repeats of approximately 60 amino acids with putative divalent cation-binding sites, and four weaker repeats which lack such binding sites. The cDNA clone hybridizes with a mRNA of 4.7 kb which is induced during in vitro differentiation of myeloid cell lines. The p150,95 alpha subunit is homologous to the alpha subunits of receptors which recognize the RGD sequence in extracellular matrix components, as has previously been shown for the beta subunits, supporting the concept that receptors involved in both cell-cell and cell-matrix interactions belong to a single gene superfamily termed the integrins. Distinctive features of the p150,95 alpha subunit include an insertion of 126 residues N-terminal to the putative metal binding region and a deletion of the region in which the matrix receptors are proteolytically cleaved during processing.

Amino Acid Sequence↗
PubMed1987

Cloning of the beta subunit of the leukocyte adhesion proteins: homology to an extracellular matrix receptor defines a novel supergene family.

We have isolated cDNA clones encoding the beta subunit of the human LFA-1, Mac-1, and p150,95 family of leukocyte adhesion proteins. The deduced 769-amino-acid sequence defines a cysteine-rich polypeptide with the characteristic features of an integral membrane protein. Peptide sequence data, Northern blot analysis, and Southern blot analysis suggest that a single gene encodes the beta subunit of all three leukocyte adhesion proteins. There is 45% homology between the beta subunit sequence and band III of integrin, a chick fibronectin and laminin receptor. This homology defines a new supergene family of cellular adhesion proteins.

Amino Acid Sequence↗
PubMed1987

Relationship of anxiety level and recall of information to the interval between orientation and first patient care day.

Sophomore students' responses to two different intervals between orientation and first clinical day in medical/surgical nursing were examined. Variables studied were anxiety state and ability to recall information which had been presented. Prior to orientation all students were given the Spielberger STAI-S and STAI-T anxiety scales. At the beginning of the first laboratory session the students completed the STAI-S scale and a teacher-made quiz on information presented in orientation. Students in Group I (n = 51) had their first laboratory one week after orientation. Group II (n = 39) had their first laboratory the day following orientation. There was no significant difference between the two groups on cumulative grade point average, beginning STAI-T or STAI-S. Likewise, there was no significant difference between the scores made on the quiz. (The validity and reliability of the quiz were not determined.) There was a significant difference between the two groups on changes in state anxiety from orientation to the first laboratory. Group I (laboratory one week after orientation) was more anxious than Group II (laboratory one day after orientation) (p = 0.024). Both groups were significantly more anxious in the Spring than Fall quarter (p = 0.034). It was concluded that anxiety related to a new clinical experience might be lessened if the first clinical day closely followed orientation. It was also noted that students may be more anxious in the Spring than in the Fall of the year.

Anxiety↗
PubMed1986

Motor potentials and motor performance associated with introverted and extraverted smokers.

Motor potentials associated with a motor task and with the initiation of the smoking act were recorded from two groups of 5 introverted and 5 extraverted smokers during sham and real smoking sessions on two separate occasions. The aim was to test hypotheses derived by O'Connor from the motor model of smoking: firstly, that change in background motor set would alter the smoker's smoking pattern, and secondly, that smoking would principally affect extraverts' general motor preparation (as measured by motor potentials preceding a tapping task), whilst improving introverts' selective inhibition (as measured by performance on a tracking task requiring skillful co-ordination). Smoking did increase the motor readiness potential preceding tapping in extraverts. Smoking decreased involuntary rest pauses of introverts and their error on the tracking task. There were, however, no differences in puff parameters across motor conditions. But larger motor potentials preceding the smoking act in introverts indicated a greater involvement of introverts in the smoking act itself. The results offer limited support to the proposal of the motor model that motor demand regulates both the motivation to smoke and the effects of smoking.

Adult↗