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Biomedical subjects

D Miller

Publications and source records attributed to D Miller.

At least 325 records · Page 18Linked to original sources
PubMed1994

Positive and negative symptoms of schizophrenia: past, present, and future.

The "group of schizophrenias," normally referred to with a single nominative, is phenomenologically heterogeneous. Its symptoms represent multiple psychological domains, including perception, inferential thinking, language, attention, social interaction, emotion expression, and volition. Studies of psychopathology have simplified this complex array in several ways; one has been a subdivision into positive and negative symptoms. Reports by our group and others suggest that the symptoms of schizophrenia fall into three natural dimensions: positive symptoms subdivided into psychotic and disorganized dimensions, while a third negative dimension also emerges. Since these dimensions have impressive consistency across studies, future work must examine their relationship to clinically relevant concepts such as prognosis or etiology and examine four different aspects: longitudinal course, neural mechanisms, relationship to treatment, and interrelationships in other pathological conditions.

Brain↗
PubMed1994

Canine, human, and rat plasma insulin responses to galanin administration: species response differences.

Previous studies demonstrated that porcine galanin is a potent inhibitor of insulin secretion in many species but fails to alter human insulin secretion. To resolve whether this discrepancy was due to the use of a heterologous peptide or to a true species response difference, we studied the effect of a synthetic replicate of human galanin on glucose-stimulated insulin secretion in rats, dogs, and humans. On administration into rats, human and rat galanin significantly inhibited glucose-induced insulin responses to a similar degree. Similarly, porcine and human galanin significantly elevated canine plasma glucose and inhibited canine plasma insulin responses. In contrast, plasma glucose and insulin responses to glucose administration in humans were unaltered by the addition of human galanin at or above the maximum effective dose employed in dogs. Possible effects of galanin administration were seen on human glucagon and pancreatic polypeptide responses to glucose at the highest dose of human galanin infused. We conclude that galanin probably does not play a major role in modulating human beta-cell function.

Adult↗
PubMed1994

CYP19 (aromatase cytochrome P450) gene expression in human malignant endometrial tumors.

C19 steroids are converted to estrogens in a number of human tissues by the aromatase enzyme complex, which consists of aromatase cytochrome P450 (P450arom; product of the CYP19 gene) and NADPH-cytochrome P450 reductase. Aromatase activity has been previously demonstrated in endometrial tumors. In the present study, we investigated CYP19 gene expression and its regulation in endometrial tumor samples (n = 9). Using a specific method of competitive polymerase chain reaction after reverse transcription, varying levels of P450arom transcripts were detected in all endometrial adenocarcinomas (n = 8) and one mixed Müllerian tumor studied. No correlations were observed between P450arom transcript levels and histological type of the tumor, grade, myometrial invasion, stage of the disease, or patient age. We have recently demonstrated that the tissue-specific regulation of CYP19 gene transcription is in part the consequence of alternative promoter use. The use of each promoter gives rise to a P450arom transcript with a unique untranslated 5'-end. We analyzed the untranslated first exons in 5'-terminals of P450arom transcripts in endometrial adenocarcinomas using a specific reverse transcription-polymerase chain reaction/Southern hybridization method we recently developed. Our findings indicated the gonadal-type (promoter II) and one of the adipose stromal cell-type (I.3) promoters were primarily used for P450arom expression in adenocarcinomas. On the other hand, distribution of transcripts specific for I.3, I.4 (another adipose-type promoter), and promoter II in one mixed Müllerian tumor was uniform. Placental promoter (I.1)-specific P450arom transcripts were not detected in endometrial tumors. As P450arom transcripts were detected in all endometrial malignancies studied, whereas they were not demonstrable in the disease-free endometrium, activation or failure of inhibition of aromatase expression in these tumors may serve to promote neoplastic proliferation.

Adenocarcinoma↗
PubMed1994

Growth curve for Propionibacterium acnes.

We established growth curves for Propionibacterium acnes isolates recovered from eyes with chronic postoperative endophthalmitis. The growth curve plotted the average of the duplicate bacterial concentration against time. The generation time for P. acnes calculated from the growth curves was approximately 5.1 hours. The growth of P. acnes is slower than other anaerobic bacteria. This may account for its delayed appearance in culture of ocular specimens. It may also explain treatment failure if the concentration of an antibiotic injected into the vitreous does not remain at an effective level during the critical replicative phase of the organism.

Cataract Extraction↗
PubMed1994

Pseudomonas aeruginosa corneal ulcer isolates distinguished using the arbitrarily primed PCR DNA fingerprinting method.

Infection of the eye by Pseudomonas aeruginosa can result in corneal inflammation (keratitis) and ulceration, and permanent decrease in vision if not successfully treated. We tested for diversity among P. aeruginosa strains from corneal ulcers by the sensitive and efficient 'RAPD' (for 'random amplified polymorphic DNA') fingerprinting method. This method uses single oligonucleotides of arbitrarily chosen sequence as primers in low-stringency PCR amplification, and results in strain-specific arrays of DNA fragments. Tests of 20 independent P. aeruginosa corneal ulcer isolates yielded 19 different arrays of products with each of three arbitrary primers, indicating that all but two of the strains differed from one another. Additional isolates from three patients (infected eye, contact lens or eye drops) yielded fragment patterns that were identical to those of the original isolate in each case. Thus, our results demonstrate considerable diversity among P. aeruginosa corneal ulcer isolates, and suggest that just one clone may predominate in typical infections.

Adult↗
PubMed1994

Memphis Business Group on Health: a model for health care reform and cost containment.

A market-driven, community-based, competitive health care model has effectively assisted Memphis employers to achieve their cost containment and health care reform objectives. Members of the Memphis Business Group on Health joined forces and successfully implemented a variety of programs and services that resulted in dramatic cost savings and reform of health care delivery systems. Programs included development of a purchasing alliance for negotiating contracts for hospital, medical, workers' compensation, psychiatric, and substance abuse care and other service and product options. Utilization management programs focused on appropriate consumption of resources and intensive management of critical cases. While increases in per employee costs averaged 14.7 percent per year for five years nationally, members of the Memphis Business Group on Health held their increases to an average of 6 percent per year.

Cost Control↗
PubMed1994

The Tec 6 vaporizer: why desflurane needs to be heated.

The Ohmeda Tec 6 was designed as an agent-specific vaporizer for desflurane. Its exterior framework offers some unique features. Aside from its unique filling port, broad calibration range, and additional light-emitting diodes (LEDs), its large size literally sets it apart from all other models. As distinctive as the exterior appears, its interior design is even more unconventional; that is, it is not a variable-bypass, flow-over system. There are no mixing chambers, baffles, or temperature-sensing bellows; a differential pressure transducer system takes their place. Many modifications were made primarily to accommodate the remarkably high vapor pressure of desflurane. This is especially true in regard to the sump heating unit. Although there are many options to accommodate a high vapor pressure, a heating unit serves the purpose best. A brief review of vaporization and fundamental thermodynamics will demonstrate why this is so.

Anesthetics, Inhalation↗
PubMed1994

Gastroepiploic and inferior epigastric arteries for coronary artery bypass. Early results and evolving applications.

BACKGROUND: Internal thoracic artery (ITA) conduits are known to provide long-term patency and increased patient survival with low morbidity after coronary artery bypass grafting (CABG). Excellent clinical results with the ITA have stimulated interest in additional arterial grafts. METHODS AND RESULTS: To review our experience and evaluate postoperative complications associated with these new conduits, from May 1985 to September 1993, we studied 290 patients who underwent CABG using additional arterial conduits. The right gastroepiploic artery (GEA) was used in 152 patients and the inferior epigastric artery (IEA) was used in 130 patients. Eight patients with both GEA and IEA grafts were excluded. Patient records were analyzed as to preoperative characteristics, angiographic findings, operative data, and postoperative complications. Statistical analysis was done using the Pearson chi 2 statistic and the t test. Ninety-eight percent of patients received one concomitant ITA graft, and the majority of patients in both groups had bilateral ITA grafts. The GEA group had a higher proportion of reoperations (GEA group, 54%; IEA group, 16%; P < .001), previous myocardial infarction (MI) (GEA group, 67%; IEA group, 50%; P = .004) and New York Heart Association class IV (GEA group, 28%; IEA group, 6%; P = .001). The IEA group was generally slightly older (IEA group, 56 years; GEA group, 52 years; P = .001). Hospital mortality (GEA group, 4%; IEA group, 0.8%) and postoperative morbidity (mediastinal bleeding, infection, stroke, MI, and low cardiac output) were not significantly different between the two groups or from our experience with routine CABG using the ITA. Three intraabdominal complications occurred in the GEA group: 2 episodes of bleeding and 1 of pancreatitis. One patient in the IEA group had abdominal wall bleeding. With overall short follow-up, angiographic patency in a small number of patients has been good: 80% for the GEA group and 85.7% for the IEA group. CONCLUSIONS: We conclude that the morbidity associated with these additional arterial conduits is low and is comparable with that associated with routine CABG using the ITA. Currently we use the ITA for primary targets and alternative arterial conduits for vessels of secondary importance or when the ITA and/or saphenous vein is not available.

Abdominal Muscles↗
PubMed1994

Gallbladder surgery for Medicare patients in Mississippi.

Mississippi Foundation for Medical Care (MFMC) conducted a review of gallbladder surgery performed on Mississippi Medicare Patients using hospital claims files and limited record review for verification of claims file data. Significant error rates in the surgeon identification number were found in the claims files. It should also be noted that the current ICD-9-CM coding system does not allow for identification of laparoscopic cholecystectomies converted to open procedures. Past studies have attempted to use claims data alone for these types of analyses. These findings demonstrate the importance of using caution by those attempting to use claims data (without verification) to define patterns of hospital utilization, clinical outcomes and/or physician profiling. Claims data must be tested for validity for reliable pattern analysis. In addition, considerable variation was found among providers in elements such as conversion rates, complication and readmission rates. A few surgeons showed patterns for critical variables that were quite different from the universe. There was however, no statistically significant differences associated between volume of cases performed and outcomes. Time frame comparisons over several years show significant (> 80%) increase in gallbladder surgery since the introduction of the laparoscopic procedure.

Cholecystectomy↗
PubMed1993

Endophthalmitis caused by Staphylococcus aureus.

The medical records of 27 patients (27 eyes) with culture-positive Staphylococcus aureus endophthalmitis, diagnosed between December 1984 and February 1992, were reviewed. In 20 of the 27 eyes, endophthalmitis occurred within seven days of ocular surgery. All tested isolates were sensitive to vancomycin, gentamicin, and ceftazidime. In 13 eyes treated by initial vitrectomy and intraocular antibiotic injection, ten eyes achieved 20/400 or better visual acuity, compared to seven of 14 eyes in the initial vitreous tap and intraocular antibiotic injection group. For the eight eyes treated initially with intraocular corticosteroids, seven eyes achieved 20/400 or better visual acuity, compared to ten of 19 eyes in the group receiving no initial intraocular corticosteroids (P = .190). The use of vitrectomy and intraocular corticosteroids with intraocular antibiotics was associated with the best visual outcomes in this group of eyes with endophthalmitis caused by S. aureus.

Aged↗
PubMed1993

Pertussis immunisation and serious acute neurological illnesses in children.

OBJECTIVE: To determine long term outcome in children who had a severe acute neurological illness in early childhood associated with pertussis immunisation. DESIGN: Follow up study of cases and matched controls. SETTING: Assessment of children at home and at school throughout Britain. SUBJECTS: Children recruited into the national childhood encephalopathy study in 1976-9 were followed up, with one of their two original matched controls, in 1986-9. MAIN OUTCOME MEASURES: Performance in educational attainment tests; behaviour problems reported by teachers and parents; continuing convulsions; evidence of other neurological or physical dysfunction. RESULTS: Over 80% of cases and controls were traced. Case children were significantly more likely than controls to have died or to have some form of educational, behavioural, neurological, or physical dysfunction a decade after their illness. The prevalence of one or more of these adverse outcomes in case children who had been immunised with diphtheria, tetanus, and pertussis vaccine within seven days before onset of their original illness was similar to that in case children who had not been immunised recently. The relative risk for recent diphtheria, tetanus, and pertussis immunisation in children who had died or had any dysfunction in comparison with controls was 5.5 (95% confidence interval 1.6 to 23.7). However, the number of cases associated with vaccine (12) was extremely small and statistically vulnerable, and other possible agents or predisposing factors could not be excluded. CONCLUSIONS: Diphtheria, tetanus, and pertussis vaccine may on rare occasions be associated with the development of severe acute neurological illnesses that can have serious sequelae. Some cases may occur by chance or have other causes. The role of pertussis vaccine as a prime or concomitant factor in the aetiology of these illnesses cannot be determined in any individual case. The balance of possible risk against known benefits from pertussis immunisation supports continued use of the vaccine.

Acute Disease↗
PubMed1993

Evidence for multiple binding sites for several components of human lymphoblastoid interferon-alpha.

The antiproliferative and competitive binding activities of 20 purified components of human lymphoblastoid interferon (IFN)-alpha were compared with that of recombinant human IFN-alpha 2b on Daudi and AU937 cells. We observed broad ranges of antiproliferative activities of the IFN-alpha components on these cell lines. Daudi cells were more sensitive to the IFN-alpha components than AU937 cells; the concentrations of the components that resulted in 50% inhibition of cell growth ranged from 0.003 ng/ml to > 10 ng/ml on Daudi cells and 0.05 ng/ml to > 200 ng/ml on AU937 cells. Component o was the most active human IFN-alpha on both cell lines. Scatchard analysis demonstrated that the number of IFN-alpha 2b binding sites is greater on Daudi cells (12,700 binding sites/cell) than AU937 cells (3,300 binding sites/cell); however, their receptor affinities were similar. Component o, which exhibited high antiproliferative activity on both cell lines, had low affinity for the IFN-alpha 2b binding site on AU937 and Daudi cells. Several human IFN-alpha s (components b', b", and e) appeared to have high affinity binding sites but low antiproliferative activity on both Daudi and AU937 cells. These data suggest that there may be more than one binding site or receptor for human IFN-alpha, and/or there may be a multicomponent receptor involved in the biological actions of these molecules.

Binding Sites↗