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J Collins

Publications and source records attributed to J Collins.

At least 199 records · Page 11Linked to original sources
PubMed1995

Task difficulty and cognitive deficits in schizophrenia.

Investigators of schizophrenic cognition often produce 2 or more tasks of differing difficulty levels by manipulating a variable that affects the accuracy of both normal and schizophrenic individuals; the investigators find that the variable also affects the difference between the groups in accuracy and conclude that the variable taps a schizophrenic differential deficit. An alternative hypothesis is that task differences in true-score variance artifactually produce the finding. For free-response tasks, group differences tend to be larger when difficulty is near 50%. The authors illustrate a new method of controlling this artifact by selecting items for hard and easy tasks on opposite sides of 50% difficulty and equidistant from it. Using this design with an anagram task, they found that schizophrenic and normal individuals differ no more on hard anagrams than on easy ones, and they propose the design for testing hypotheses concerning schizophrenic deficit on tasks that differ in difficulty.

Cognition Disorders↗
PubMed1995

Cloning a balanced translocation associated with DiGeorge syndrome and identification of a disrupted candidate gene.

DiGeorge syndrome (DGS), a developmental defect, is characterized by cardiac defects and aplasia or hypoplasia of the thymus and parathyroid glands. DGS has been associated with visible chromosomal abnormalities and microdeletions of 22q11, but only one balanced translocation--ADU/VDU t(2;22)(q14;q11.21). We now report the cloning of this translocation, the identification of a gene disrupted by the rearrangement and the analysis of other transcripts in its vicinity. Transcripts were identified by direct screening of cDNA libraries, exon amplification, cDNA selection and genomic sequence analysis using GRAIL. Disruption of a gene in 22q11.2 by the breakpoint and haploinsufficiency of this locus in deleted DGS patients make it a strong candidate for the major features associated with this disorder.

Amino Acid Sequence↗
PubMed1995

Integration of physical, breakpoint and genetic maps of chromosome 22. Localization of 587 yeast artificial chromosomes with 238 mapped markers.

Detailed physical maps of the human genome are important resources for the identification and isolation of disease genes and for studying the structure and function of the genome. We used data from STS content mapping of YACs and natural and induced chromosomal breakpoints to anchor contigs of overlapping yeast artificial chromosome (YAC) clones spanning extensive regions of human chromosome 22. The STSs were assigned to specific regions (bins) on the chromosome using cell lines from a somatic hybrid mapping panel defining a maximum of 25 intervals. YAC libraries were screened by PCR amplification of hierarchical pools of yeast DNA with 238 markers, and a total of 587 YAC clones were identified. These YACs were assembled into contigs based upon their shared STS content using a simulated annealing algorithm. Fifteen contigs, containing between 2 and 74 STSs were assembled, and ordered along the chromosome based upon the cytogenetic breakpoint, meiotic and PFG maps. Additional singleton YACs were assigned to unique chromosomal bins. These ordered YAC contigs will be useful for identifying disease genes and chromosomal breakpoints by positional cloning and will provide the foundation for higher resolution physical maps for large scale sequencing of the chromosome.

Chromosome Mapping↗
PubMed1995

Routine tests during follow-up of patients after primary treatment for operable breast cancer. International (Ludwig) Breast Cancer Study Group (IBCSG)

BACKGROUND: Follow-up tests for patients after diagnosis and primary treatment of breast cancer are routinely performed. However, the usefulness of these follow-up parameters remains unclear. We determined the yield of a variety of blood tests used to detect the presence of overt metastatic disease. METHODS: 4105 patients enrolled in International (Ludwig) Breast Cancer Study Group (IBCSG) randomized clinical trials from 1978 to 1985 were analyzed for abnormal or equivocal findings in six routine blood tests obtained every 3 months for the first two years, every six months for years 3-5 and yearly thereafter. The relationship of test results to the occurrence of overt metastatic disease was evaluated. The relapses were categorized as follows in order to estimate the yield of the different tests for relevant sites of metastases: any breast cancer relapse, bone +/- other; liver +/- other. RESULTS: Alkaline phosphatase alone was abnormal in a high proportion of patients with either bone metastases, liver metastases, or both. SGOT and gamma-GT were also sensitive for patients with liver metastases. Bilirubin, serum calcium, and serum creatinine were relatively insensitive indicators of relapse. Abnormal test results were reported sometime during a patient's disease-free period for 3% to 6% of patients, depending on the test. CONCLUSIONS: Alkaline phosphatase was the most effective blood test to distinguish patients with relapse from those without relapse. It is inexpensive and its yield is relatively high for predicting liver and bone metastases. The routine use of the other tests analyzed to detect metastases was not justified.

Breast Neoplasms↗
PubMed1995

Highly effective protease inhibitors from variants of human pancreatic secretory trypsin inhibitor (hPSTI): an assessment of 3-D structure-based protein design.

The results of a protein design project are used to compare different predictive strategies with respect to protein-protein interactions. We have been able to generate variants of human pancreatic secretory trypsin inhibitor (hPSTI) optimized with respect to the affinity and specificity for human leukocyte elastase relative to trypsin and chymotrypsin, and in particular chymotrypsin. The extremely strong and specific human leukocyte elastase inhibitors were thus developed in three rounds of mutagenesis and two rounds of 3-D modelling; only 24 variants in total were synthesized, although variations at seven different amino acid positions were involved (i.e. from 20(7) possible variants). An excellent elastase inhibitor could be designed with the minimum of two amino acid exchanges. The value of structural modelling and actual structure determination is discussed in the light of the experimental results of the designed protein variants and the results of tertiary structure determinations of the free variant and the inhibitor-protease complex. Particular reference is given to the strategy to be followed in protein design projects in general and to the development of protease inhibitors in particular.

Amino Acid Sequence↗
PubMed1995

Transtelephonic monitoring and transmission of stored arrhythmia detection and therapy data from an implantable cardioverter defibrillator.

A new transtelephonic monitoring device designed for use with implantable cardioverter defibrillators (ICDs) was evaluated. It is capable of interrogating ICDs and transmitting the following data via telephone: programmed parameters (e.g., ventricular tachycardia [VT] and ventricular fibrillation [VF] detection, therapies), number of VT and VF episodes, identification of successful therapies, the 20 cycle lengths preceding the last episode detected, the 10 cycle lengths after the last delivered therapy, battery voltage, and real-time transmission of the patient's rhythm. Eighteen patients (mean age 64 +/- 17 years; 15 males) were implanted with an ICD and epicardial lead system. The patients who did not live near the primary hospital were provided with this transmitter and instructed to transmit monthly and whenever presyncope, syncope, or a shock were experienced. Five hundred ten episodes of spontaneous arrhythmia (495 VT, 15 VF) were detected in 14 of 18 patients in a 24-month period and the success of each therapy (antitachycardia pacing, cardioversion 0.4-34 J, defibrillation 34 J) was analyzed. The number of therapies delivered and their success (%) in terminating the arrhythmia were: 380 ramp/86%, 116 burst/84%, 119 cardioversion/57%, and 15 defibrillations/100%. Sixty-three (42%) of the 152 transmissions indicated an arrhythmia. Twenty-five (16%) of the 152 were transmitted because of symptoms. Sixteen (9.7%) of 165 VT episodes could not be terminated by the full set of programmed VT therapies. Analysis of the pre- and post-episode intervals along with the patient's transmitted rhythm indicated that sinus tachycardia or atrial fibrillation were likely responsible for these episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Fibrillation↗
PubMed1995

Indium-111-white blood cell detection of postradiation vesicocutaneous fistulas.

We present a case of urinary bladder fistulization which occurred approximately 25 yr after successful radiation therapy for uterine carcinoma. The extensive fistulas were detected with 111In-oxine-labeled white blood cell scintigraphy and were confirmed with a fistulogram, computed tomography and surgery. Scintigraphy was valuable for both initial detection as well as staging the extent of inflammation for subsequent diagnostic studies and surgical resection.

Cutaneous Fistula↗
PubMed1995

Update on implantable cardioverter defibrillators: knowing the differences in devices and their impact on patient care.

Sudden cardiac death, a common cause of cardiac mortality, can be treated with either pharmacologic therapy or implantation of an implantable cardioverter defibrillator. Tremendous technologic advances have changed implantable cardioverter defibrillator therapy from shock-only therapy to multiprogrammable, tiered-therapy devices with backup pacing. Methods of implantation have changed from open chest to non-thoracotomy procedures. To provide optimal patient care, the critical care nurse is challenged to be knowledgeable about the different devices. In this article, the authors examine the commonalities and differences in device function in the seven currently available implantable cardioverter defibrillators and their impact on patient care.

Critical Care↗
PubMed1995

Molecular definition of the 22q11 deletions in velo-cardio-facial syndrome.

Velo-cardio-facial syndrome (VCFS) is a common genetic disorder among individuals with cleft palate and is associated with hemizygous deletions in human chromosome 22q11. Toward the molecular definition of the deletions, we constructed a physical map of 22q11 in the form of overlapping YACs. The physical map covers > 9 cM of genetic distance, estimated to span 5 Mb of DNA, and contains a total of 64 markers. Eleven highly polymorphic short tandem-repeat polymorphic (STRP) markers were placed on the physical map, and 10 of these were unambiguously ordered. The 11 polymorphic markers were used to type the DNA from a total of 61 VCFS patients and 49 unaffected relatives. Comparison of levels of heterozygosity of these markers in VCFS patients and their unaffected relatives revealed that four of these markers are commonly hemizygous among VCFS patients. To confirm these results and to define further the breakpoints in VCFS patients, 15 VCFS individuals and their unaffected parents were genotyped for the 11 STRP markers. Haplotypes generated from this study revealed that 82% of the patients have deletions that can be defined by the STRP markers. The results revealed that all patients who have a deletion share a common proximal breakpoint, while there are two distinct distal breakpoints. Markers D22S941 and D22S944 appear to be consistently hemizygous in patients with deletions. Both of these markers are located on a single nonchimeric YAC that is 400 kb long. The results also show that the parental origin of the deleted chromosome does not have any effect on the phenotypic manifestation.

Abnormalities, Multiple↗
PubMed1995

In situ effects of interferon on human glioma protein kinase C-alpha and -beta ultrastructural localization.

Transmission electron microscopy was used to determine how immunogold labeling of PKC-alpha or -beta is modulated by the antitumor drug IFN (HuIFN alpha-2b) in the cytoplasm, membrane structures, and nucleus of rapidly dividing and confluent human glioma U-373 cells. Results showed that except for nuclear localization, there were no specific cytoplasmic organelles that PKC-alpha or -beta translocated to following HuIFN alpha-2b treatment. Electron micrographs of PKC-beta in proliferating cells depicted 1.34-fold more PKC-beta in the nucleus than in the cytoplasm and a 1-min HuIFN alpha-2b (500 units/ml) treatment transiently increased PKC-beta immunoreactivity in the cytoplasm (1.95-fold) and nucleus (1.97-fold). In confluent cells, incubation with HuIFN alpha-2b for 2 min significantly decreased cytoplasmic PKC-beta immunoreactivity by 37%, and no change was observed in nuclear PKC-beta labeling. PKC-alpha labeling in proliferating cells showed similar immunoreactivity in both control cytoplasm and nucleus. Treatment of proliferating cells with HuIFN alpha-2b for 2 min decreased PKC-alpha in the cytoplasm (59%) and nucleus (44%). In confluent cells, cytoplasmic PKC-alpha labeling decreased 59% at 1 min, 61% at 2 min, and 76% at 10 min of HuIFN alpha-2b treatment. Nuclear PKC-alpha decreased by 65% at 1 min, 80% at 2 min, and 62% at 10 min after HuIFN alpha-2b treatment. Western blots of total PKC-alpha in proliferating and confluent cells and PKC-beta in confluent cells showed similar results. However, Western blots of total PKC-alpha and -beta in proliferating cells did not demonstrate any significant changes in either PKC-alpha or -beta immunoreactivity following 1-min HuIFN alpha-2b treatment. These results suggest that treatment of proliferating U-373 cells with HuIFN alpha-2b for 1 min unfolds and exposes PKC-beta antigenic sites (hinge region) and increases in situ PKC-beta immunogold labeling.

Amino Acid Sequence↗
PubMed1995

Integrated clinical database in a health maintenance organization.

This paper describes the development and implementation of the first phase of a comprehensive clinical information system in the Kaiser Permanente Northwest Region. This system integrates information from disparate departmental systems into a single clinical database. By using periodic batch downloads of patient data from departmental systems into the clinical database, rather than requiring real-time updates, we have been able to implement this system with relative ease and speed. It contains patient demographics, lab, outpatient pharmacy, radiology, pathology, dictated consults, admission histories and physicals, discharge summaries, and other dictated reports for over 380,000 Health Plan Members. The system is fast, intuitive, reliable, and user-friendly. In March 1994, there were approximately 1,600 active users. These individuals accounted for approximately 410,000 transactions in the month, with an average daily transaction volume of 11,450. Quantifiable cost-savings, in terms of decreased chart pulls and decreased phone calls for information, have offset the cost of development and implementation to some extent. Less quantifiable improvements in the quality of care and the associated cost-savings may eclipse the quantifiable benefits. This system lays the foundation for our clinical information system efforts.

Health Maintenance Organizations↗
PubMed1994

Present and future projects of the International Breast Cancer Study Group.

The International Breast Cancer Study Group (formerly the Ludwig Group) has conducted nine clinical trials since 1978 (see the Appendix for participants and authors). Biologic hypotheses related to the combined use of chemotherapy and endocrine therapy in women with operable breast cancer were tested. Questions of timing of chemotherapy with respect to tumor surgery and late introduction of chemotherapy were also evaluated. Ongoing and future trials continue in this tradition to investigate combinations of available endocrine therapies and cytotoxic agents.

Aged↗