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Biomedical subjects

B Miller

Publications and source records attributed to B Miller.

At least 307 records · Page 17Linked to original sources
PubMed1987

Causes of treatment failure with antiepileptic drugs vary over time.

The V.A. Epilepsy Cooperative Study Group evaluated monotherapy with carbamazepine, phenobarbital, phenytoin, and primidone in a total of 622 patients with previously untreated partial seizures. In the 24 months following onset of treatment, 223 patients failed treatment. Analysis of these failures reveals that the majority occurred during the first 6 months with equal contributions to failure from systemic toxicity, neurotoxicity, and seizures. The contribution of systemic toxicity to failure was significantly less in the next 18 months. An increase in the contribution of seizures to failure was seen in this latter period.

Adolescent↗
PubMed1987

Community care policies and gender justice.

The current approach in the United States to the provision of community care to the elderly interacts with the feminized structure of family care-giving to foster inequities for women, who provide the bulk of informal, unpaid care. The central concern of present policies with limiting eligibility and rationing benefits results in policies that reduce the choices of these carers, many of whom are already substantially disadvantaged by their economic position in society. What is necessary for gender justice is development of policies that address the needs and rights of carers and elders by providing necessary supports to families, including, when appropriate, adequate compensation to carers. We argue for an approach that takes into account the relationship of the adequacy of government support and the capacity of individuals to freely choose the caregiving role.

Aged↗
PubMed1987

[Role of Pseudomonas maltophilia and "Pseudomonas like bacteria group Va" in the etiology of Crohn disease].

In 1976, Parent and Mitchell isolated cell-wall defective bacteria of the species Pseudomonas maltophilia and Pseudomonas like bacteria group Va from resected bowel tissue of 8 consecutively operated patients with Crohn's disease. The control group, which included patients with ulcerative colitis, was negative in this respect. The isolated strains were available for our own investigations. New Zealand white rabbits were inoculated with killed bacteria to produce specific antisera. Frozen sections of affected tissue from 6 consecutively operated Crohn patients were incubated with the various antisera and investigated by indirect immunofluorescence. No positive reactions were demonstrable in repeated tests with different dilutions of antisera. Our results do not support the hypothesis that bacteria of the species Pseudomonas maltophilia and Pseudomonas like bacteria group Va are an etiologic factor in Crohn's disease.

Bacteriological Techniques↗
PubMed1987

Chemoendocrine therapy with prolonged estrogen priming in advanced breast cancer: endocrine pharmacokinetics and toxicity.

Recent efforts to improve response rates in advanced breast cancer have used short, alternating courses of antiestrogen therapy followed by estrogen priming to cytokinetically enhance tumor cell sensitivity to antimetabolites. Based on recent in vitro and in vivo studies, we have introduced a chemoendocrine regimen that uses prolonged courses of estrogen priming. The present protocol consists of alternating monthly cycles of tamoxifen (TAM) and estradiol during which sequential (24-hr) methotrexate, 5-fluorouracil, and leucovorin are administered at 2-week intervals. Twenty-five patients with metastatic breast cancer received greater than 80 endocrine cycles and greater than 300 courses of chemotherapy by this protocol; two-thirds of these patients had previously failed other endocrine or chemotherapy regimens. Most patients experienced grade 1 or 2 myelosuppression or gastrointestinal symptoms during at least one treatment cycle; however, overall toxicity was considered to be mild and therapy was very well tolerated. Serum levels of estradiol, estrone, TAM, and TAM metabolites were measured during all phases of the endocrine cycle in five patients on chronic therapy. Concentrations of TAM and its more abundant metabolite, N-desmethyltamoxifen (N-desTAM), rose twofold during antiestrogen therapy and fell during estrogen priming, with mean levels persisting greater than 100 ng/ml throughout the priming interval. Mean estradiol (E2) and estrone (E1) levels rose during priming and were sustained fivefold and tenfold above the basal postmenopausal levels measured during antiestrogen treatment. Calculating the serum molar ratios of [TAM + N-desTAM]/[E2 + E1] during each phase of the treatment cycle confirmed that estrogen priming was achieved pharmacologically by this endocrine schedule. Clinical remissions were observed in this small patient sample with seven of 18 patients achieving either complete (28%) or partial (11%) responses, and an additional 39% obtaining disease stabilization. Further clinical study is necessary to evaluate the optimal response rate of this regimen and to determine whether cyclic estrogen priming by this schedule results in enhanced tumor cell proliferation in vivo.

Adult↗
PubMed1987

Electron microscopic study of Bitot's spots.

The histological and structural features of Bitot's spots are described. Light microscopy revealed squamous metaplasia with keratinization. Electron microscopy showed severe loss and attenuation in height of microvilli as well as widening of the intercellular spaces. The amorphous material overlying the conjunctiva was composed of cellular debris containing edemetous endoplasmic reticular membranes and lysozomes.

Adolescent↗
PubMed1987

Crohn's disease in a married couple.

The aetiopathogenesis of Crohn's disease is still unknown. Multiple occurrence of inflammatory bowel disease among blood relatives of patients with either Crohn's disease or ulcerative colitis is seen much more frequently than would be expected by chance alone, whereas reports on the development of these diseases in spouses are very rare. We describe such a case here, and suggest that chance, rather than an infectious agent, is behind such occurrences.

Adult↗
PubMed1986

Experimental epiretinal proliferation induced by intravitreal red blood cells.

We describe a reproducible animal model of epiretinal proliferation, based on intravitreal injection of red blood cells, that closely simulates the more benign proliferative extraretinopathies. Using light microscopy and scanning and transmission electron microscopy, we monitored the development and behavior of the experimental epiretinal membranes. We found breaks in the integrity of the retinal surface through which glial cells migrated onto the retina, proliferated into thick epiretinal tissue, and contracted to cause retinal pucker. All these steps were associated with the chronic inflammatory response to the long-lasting presence of red blood cells in the vitreous. Thus, the development of epiretinal membranes requires continuous intraocular stimulation in addition to a break in retinal integrity.

Animals↗
PubMed1986

Retinal wound healing. Cellular activity at the vitreoretinal interface.

Cellular activity at the vitreoretinal interface after full-thickness retinal wounds was studied in rabbit eyes, using light and electron microscopy. Glial cell extensions grew initially on the retinal surface around the wound site. This brief period of glial proliferation was associated with the posttraumatic inflammatory response and, more specifically, with phagocytic monocyte accumulation at the vitreoretinal interface. Once the inflammation subsided, this abortive attempt to grow membranes on the retinal surface stopped and true epiretinal membranes did not develop. Our observations suggest that intraocular inflammation and macrophage response determine the extent of healing and scarring on an injured retinal surface, and thus may play a key role in the pathogenesis of epiretinal membranes.

Animals↗
PubMed1986

Effect of the vitreous on retinal wound-healing.

The healing process of experimental retinal wounds in nonvitrectomized and vitrectomized rabbit eyes was compared. Using light, transmission and scanning electron microscopy, a significant difference was observed at the late stages of the healing process. The retinal wounds in the nonvitrectomized eyes healed properly, forming regular and smooth scars, while the scars that developed in the vitrectomized eyes were irregular and hypertrophic. Our observations suggest that the vitreous plays a role in normal healing of retinal wounds.

Animals↗
PubMed1986

Monozygotic triplets with Crohn's disease of the colon.

Female monozygotic triplets all developed Crohn's disease within a period of 11 mo. The monozygosity was demonstrated by analysis of 24 genetic markers of different chromosomal localization. Crohn's disease was diagnosed using clinical, radiologic, and endoscopic findings. Histologic evaluation of bowel tissue was consistent with Crohn's disease. All 3 patients had colon involvement; the terminal ileum appeared normal. The patient in whom Crohn's disease was first diagnosed had the severest course. Our observations support the role of a genetic influence in the manifestation of Crohn's disease. Nevertheless, environmental factors or microorganisms, or both, have to be taken into account, perhaps as factors promoting the outbreak of Crohn's disease.

Adult↗
PubMed1986

Ornithine decarboxylase activity during formation of experimental epiretinal membranes.

This study demonstrates in a rabbit model of epiretinal membrane formation that retinal-associated ODC activity increases during this pathological process. These changes in retinal-associated ODC activity most likely occur in relationship to the proliferative lesion itself, since the retina consists primarily of nonproliferative tissues. Further knowledge of intraocular polyamine metabolism during epiretinal membrane formation which can result in retinal detachment may lead to the development of an effective pharmacological treatment.

Animals↗
PubMed1986

Newly-formed subretinal vessels. Fine structure and fluorescein leakage.

The ultrastructure of experimentally induced newly formed subretinal vessels was correlated with the amount of fluorescein leakage demonstrated by the neovascular membranes during angiography. The membranes that demonstrated leakage contained subretinal vessels with a fenestrated endothelial wall and intermediate interendothelial cell junctions. As these subretinal plexi matured, they stopped demonstrating leakage. This involution process was accompanied by the formation of focal interendothelial tight junctions; however, loss of fenestrations was not observed. The membranes that never demonstrated fluorescein leakage also contained fenestrated subretinal vessels at both early and late stages of development; and their interendothelial junctions showed similar maturation from open to focal tight junctions. Thus all subretinal vessels had "leaky" morphology strongly resembling that of the normal choriocapillaris, whether they demonstrated fluorescein leakage or not. The authors conclude that newly formed subretinal vessels retain the characteristics of the choriocapillaris from which they are believed to proliferate; they have the potential to leak fluorescein at all stages of their development. The absence of fluorescein leakage during angiography cannot always be correlated with the absence of "leaky" morphology.

Animals↗
PubMed1986

The role of retinal pigment epithelium in the involution of subretinal neovascularization.

The extravascular milieu around laser-induced experimental subretinal neovascularization (SRN) was studied during the evolution of the neovascular membrane from its early leaky stage to its late involuted stage. When the first signs of visible leakage appeared on angiography, newly formed vessels were spread in the subretinal space around the break in Bruch's membrane, fluid was accumulating in the subretinal space, and retinal pigment epithelial (RPE) cells were proliferating in a papillary pattern around the newly formed vessels; the RPE proliferation began with the undamaged cells at the edges of the laser injury. With further maturation, the RPE continued to envelope the subretinal vessels. This RPE proliferation was associated with the disappearance of fluid between the enveloped vessels and the sensory retina, and the gradual cessation of fluorescein leakage during angiography. At the end of the involution process, when the neovascular membrane no longer demonstrated any leakage, the subretinal vessels were found to be tightly enveloped by RPE cells, and no fluid separated them from the sensory retina. The authors' results suggest that involution of the neovascular membrane with maturation, as demonstrated by the cessation of visible fluorescein leakage, is the result of RPE proliferation that tightly envelopes the newly formed vessels and probably resorbs the previously accumulated subretinal fluid, as well as preventing its further accumulation in the subretinal space.

Animals↗