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Biomedical subjects

D F Miller

Publications and source records attributed to D F Miller.

At least 19 recordsLinked to original sources
PubMed2001

Homeotic Complex (Hox) gene regulation and homeosis in the mesoderm of the Drosophila melanogaster embryo: the roles of signal transduction and cell autonomous regulation.

In this paper we evaluate homeosis and Homeotic Complex (Hox) regulatory hierarchies in the somatic and visceral mesoderm. We demonstrate that both Hox control of signal transduction and cell autonomous regulation are critical for establishing normal Hox expression patterns and the specification of segmental identity and morphology. We present data identifying novel regulatory interactions associated with the segmental register shift in Hox expression domains between the epidermis/somatic mesoderm and visceral mesoderm. A proposed mechanism for the gap between the expression domains of Sex combs reduced (Scr) and Antennapedia (Antp) in the visceral mesoderm is provided. Previously, Hox gene interactions have been shown to occur on multiple levels: direct cross-regulation, competition for binding sites at downstream targets and through indirect feedback involving signal transduction. We find that extrinsic specification of cell fate by signaling can be overridden by Hox protein expression in mesodermal cells and propose the term autonomic dominance for this phenomenon.

Animals↗
PubMed2001

Cross-regulation of Hox genes in the Drosophila melanogaster embryo.

Cross-regulation of Homeotic Complex (Hox) genes by ectopic Hox proteins during the embryonic development of Drosophila melanogaster was examined using Gal4 directed transcriptional regulation. The expression patterns of the endogenous Hox genes were analyzed to identify cross-regulation while ectopic expression patterns and timing were altered using different Gal4 drivers. We provide evidence for tissue specific interactions between various Hox genes and demonstrate the induction of endodermal labial (lab) by ectopically expressed Ultrabithorax outside the visceral mesoderm (VMS). Similarly, activation and repression of Hox genes in the VMS from outside tissues seems to be mediated by decapentaplegic (dpp) gene activation. Additionally, we find that proboscipedia (pb) is activated in the epidermis by ectopically driven Sex combs reduced (Scr) and Deformed (Dfd); however, mesodermal pb expression is repressed by ectopic Scr in this tissue. Mutant analyses demonstrate that Scr and Dfd regulate pb in their normal domains of expression during embryogenesis. Ectopic Ultrabithorax and Abdominal-A repress only lab and Scr in the central nervous system (CNS) in a timing dependent manner; otherwise, overlapping expression in the CNS in tolerated. A summary of Hox gene cross-regulation by ectopically driven Hox proteins is tabulated for embryogenesis.

Animals↗
PubMed2001

Functional equivalence of Hox gene products in the specification of the tritocerebrum during embryonic brain development of Drosophila.

Hox genes encode evolutionarily conserved transcription factors involved in the specification of segmental identity during embryonic development. This specification of identity is thought to be directed by differential Hox gene action, based on differential spatiotemporal expression patterns, protein sequence differences, interactions with co-factors and regulation of specific downstream genes. During embryonic development of the Drosophila brain, the Hox gene labial is required for the regionalized specification of the tritocerebral neuromere; in the absence of labial, the cells in this brain region do not acquire a neuronal identity and major axonal pathfinding deficits result. We have used genetic rescue experiments to investigate the functional equivalence of the Drosophila Hox gene products in the specification of the tritocerebral neuromere. Using the Gal4-UAS system, we first demonstrate that the labial mutant brain phenotype can be rescued by targeted expression of the Labial protein under the control of CNS-specific labial regulatory elements. We then show that under the control of these CNS-specific regulatory elements, all other Drosophila Hox gene products, except Abdominal-B, are able to efficiently replace Labial in the specification of the tritocerebral neuromere. We also observe a correlation between the rescue efficiency of the Hox proteins and the chromosomal arrangement of their encoding loci. Our results indicate that, despite considerably diverged sequences, most Hox proteins are functionally equivalent in their ability to replace Labial in the specification of neuronal identity. This suggests that in embryonic brain development, differences in Hox gene action rely mainly on cis-acting regulatory elements and not on Hox protein specificity.

Animals↗
PubMed1997

Total clinical laboratory test volume in Connecticut, 1994-1995.

OBJECTIVE: To measure the volume of clinical laboratory testing in Connecticut during a one-year period. To explore the potential value of such data. DESIGN: Summary and analysis of federal and state clinical laboratory registration/licensure/inspection forms. SETTING: 2,333 clinical laboratory test facilities registered in Connecticut. MAIN OUTCOME MEASURES: The total clinical laboratory output for Connecticut by type of facility and category of technology over a 12-month period. RESULTS: During 1995, 2,333 registered clinical laboratory test facilities performed approximately 65,427,103 analyses in Connecticut. This represents approximately 20 tests per person per year. Thirty-five acute care hospitals performed 59.4%, nine large commercial laboratories 33.2%, 30 small commercial laboratories 1.7%, 1,491 physicians' offices 3.9%, and a miscellaneous group 1% of the tests. Test volumes are further segregated into eight major categories of technology: chemistry 59%, hematology 23.3%, microbiology 5.6%, blood banking 2.9%, coagulation 2.8%, waived tests 2.7%, urine analysis 1.8%, cytology 0.9%, and histology 0.8%. CONCLUSION: For the first time mechanisms are in place to measure essentially all clinical testing for a given area. With minor changes the data collection system could be greatly improved. The possible uses for such a data bank are discussed.

Clinical Laboratory Techniques↗
PubMed1992

Growth in children after bone marrow transplantation: busulfan plus cyclophosphamide versus cyclophosphamide plus total body irradiation.

Growth was assessed during the first and second years following bone marrow transplantation (BMT) in 47 children treated by either busulfan plus cyclophosphamide (BU/CY) (n = 24) or cyclophosphamide plus fractionated total body irradiation (CY/TBI) (n = 23). Before transplant, the median height was only 0.2 SD below age- and sex-adjusted means (range, -2.5 to +3.0). Height was greater than 2.0 SD below normal in only three patients (6%). The pretransplant heights were comparable in the BU/CY and CY/TBI groups (-0.1 v -0.6 SD, P = .35). Following transplant, median 1- and 2-year heights were 0.7 and 0.9 SD below normal, respectively. Growth rates were 2.2 SD and 1.4 SD below normal during the first and second years, respectively. Growth rates were greater than 2.0 SD below normal in 24 of 47 (51%) at 1 year and in 12 of 31 (39%) at 2 years after transplant. Growth rates in patients treated with BU/CY were comparable to those treated with CY/TBI during both years: -2.5 versus -1.7 SD during the first year (P = .19, Wilcoxon), and -1.5 versus -1.1 SD during the second year (P = .61). Growth rates during the second year correlated with growth rates during the first year (r = .36, P = .046). Growth rates during the first year were lower in patients who had been given prior cranial irradiation, those who were near pubertal age at the time of transplant, and those who were transplanted for a disease other than acute lymphoblastic leukemia (ALL). During the second year, poor rates of growth were associated only with the use of corticosteroids after transplant.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Retroperitoneal necrotizing fasciitis.

Necrotizing fasciitis is a mixed infection of the skin and subcutaneous tissues with a characteristic clinical and pathological appearance. Early radical surgical excision of all affected tissue is the treatment of choice. In a series of 19 patients with necrotizing fasciitis, bacteriological assessment in 15 confirmed the mixed nature of the infection, with Bacteroides sp. isolated from ten patients. All 12 patients who underwent radical surgical excision survived. A subgroup of patients was identified in whom the appearance of necrotizing fasciitis in the abdomen or perineum was indicative of more extensive disease in the retroperitoneal tissues. Surgical resection of all affected tissue was not feasible in these cases and the outcome was uniformly fatal, giving an overall mortality rate for the series of 37 per cent.

Aged↗
PubMed1990

Functional implications of the unusual spatial distribution of a minor alpha-tubulin isotype in Drosophila: a common thread among chordotonal ligaments, developing muscle, and testis cyst cells.

Three of the four alpha-tubulin genes in Drosophila melanogaster are temporally regulated. mRNA from one of these genes, alpha 85E-tubulin, first appears in 6- to 8-hr embryos and persists, with marked fluctuations, through the end of pupal development. In adults, alpha 85E mRNA has been unequivocally identified only in testes. In the present study, isotype-specific antibodies have been used to localize alpha 85E tubulin protein in whole tissues. The results demonstrate a spatially restricted expression pattern of the alpha 85E gene that includes tissues of both ectodermal and mesodermal origins. Specifically, embryonic accumulation of alpha 85E tubulin is limited to support cells of chordotonal organs and the developing musculature of the viscera and body wall. In late third instar larvae, chordotonal organs and a subset of larval nerves, but not muscle, stain with anti-alpha 85E. The timing of protein accumulation during pupal development suggests that alpha 85E tubulin is involved in the construction of the adult as well as the larval musculature. In testis, only the somatically derived cyst cells that surround developing spermatid bundles accumulate alpha 85E-tubulin. The cell types that express alpha 85E share a requirement for extensive cell shape changes during development, suggesting that this minor alpha-tubulin may have distinct functional properties.

Animals↗
PubMed1989

Developmental distribution of RNA and protein products of the Drosophila alpha-tubulin gene family.

The developmental pattern of gene expression of the Drosophila melanogaster alpha-tubulin family has been examined in detail at both the mRNA and protein levels. Northern data from 16 stages of development have been quantified to produce estimates of pool sizes of each of the alpha-tubulin transcripts through development. The in situ pattern of alpha 67C RNA localization in developing oocytes and early embryos has also been determined. At the protein level, two of the three previously unidentified products of alpha-tubulin genes (alpha 67C and alpha 85E) have been identified. Evidence that protein from the fourth gene comigrates with the ubiquitously expressed alpha 84B is presented. In addition to the primary translational products of the alpha-tubulin genes, an elaborate series of post-translationally modified alpha-tubulins has been resolved. The developmental profiles of both synthesis and accumulation of these alpha-tubulin proteins are described.

Animals↗
PubMed1989

Predictors of death from chronic graft-versus-host disease after bone marrow transplantation.

Chronic graft-v-host disease (chronic GVHD) is a frequent cause of late morbidity and death after bone marrow transplantation (BMT). The actuarial survival after onset of chronic GVHD in 85 patients was 42% (95%Cl = 29%, 54%) at 10 years. Baseline characteristics present at the onset of chronic GVHD (before therapy) in 85 patients were reviewed to determine which were risk factors for death. In a multivariate proportional hazards analysis, three baseline factors emerged as independent predictors of death: progressive presentation (chronic GVHD following acute GVHD without resolution of acute GVHD; hazard ratio of 4.1, 95% Cl = 2.1 to 7.8), lichenoid changes on skin histology (hazard ratio of 2.2, 95% Cl = 1.1 to 4.3), and elevation of serum bilirubin greater than 1.2 mg/dL (hazard ratio = 2.1, 95% Cl = 1.1 to 4.1). Actuarial survival of 23 chronic GVHD patients with none of these risk factors was 70% at 6 years (95% Cl = 38%, 88%). Thirty-eight patients with one of these risk factors had a projected 6-year survival of 43% (95% Cl = 21%, 63%). The 29 patients with any combination of two or more of these factors had a projected 6-year survival of only 20% (95% Cl = 8%, 37%). Identification of baseline risk factors should facilitate design of trials of chronic GVHD therapies and assignment of high-risk patients to more aggressive innovative therapeutic regimens.

Actuarial Analysis↗
PubMed1985

Ocular and orbital toxicity following intracarotid injection of BCNU (carmustine) and cisplatinum for malignant gliomas.

Eleven patients treated with intracarotid BCNU, cisplatinum, or BCNU and cisplatinum in combination for recurrent malignant gliomas were followed with serial ophthalmologic examinations for 2 to 11 months. Eight patients developed significant visual loss ipsilateral to the side of infusion. Secondary glaucoma and internal ophthalmoplegia were new complications observed after BCNU treatment. An unusual pigmentary retinopathy, previously unreported, was seen in patients treated with cisplatinum. One patient also developed a cavernous sinus syndrome after the intracarotid administration of cisplatinum.

Adult↗
PubMed1983

International students at an American university: health problems and status.

Eighty-eight international students enrolled at the University of Toledo were surveyed in order to ascertain their health care needs since arriving at the university. This study of the health status of international students indicated that the four leading problems experienced since arriving at the university were fatigue, homesickness, headaches and colds. Fatigue and colds were more commonly reported by students from Latin America than those from Asia or the Middle East. Both community health services and the university health service are not used by a majority of international students. Friends and the telephone book yellow pages are the most commonly used sources for finding a physician if one becomes sick. The drug store was indicated as being the place the international students would go for medicine if they became sick. The findings of this study suggest that international students must be oriented to the health services available in the community and at the university health service. A health education program needs to be conducted to inform these students about personal health practices and available services.

Asia↗
PubMed1979

Mental health and the teacher.

The emotional atmosphere in a classroom setting is important to the experiences of all students. That atmosphere is affeected by the emotional stability of the teacher. A teacher with personal mental health problems can have a detrimental effect upon all of those students who are associated with him or her. There are a variety of courses and contributing factors of mental health problems. Certain signs and symptoms, at times, can be identified that relate to emotional difficulties. It is important that measures be identified to help teachers with emotional problems. This is not always an easy task, yet it is necessary if the teaching-learning environment is to be of a positive nature. School administrators, teacher preparation programs, teaching peers, and self-analysis all should play a role in identifying one's teaching. This is a task that no one person or agency can accomplish alone. Though often felt to be an uncomfortable issue with which to deal, all educators must become increasingly aware of the problem and be willing to work toward greater emotional health of all teachers.

Adaptation, Psychological↗