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Biomedical subjects

M E Smith

Publications and source records attributed to M E Smith.

At least 217 records · Page 12Linked to original sources
PubMed1992

A multinuclear magnetic resonance examination of the mineral grandidierite. Identification of a 27Al resonance from a well-defined AlO5 site.

11B, 27Al and 29Si magic angle spinning NMR results are reported for the boroaluminosilicate mineral grandidierite (Mg, Fe)Al3SiBO9. Three distinct aluminium sites are identified, two AlO6 and one AlO5. Despite overlap of the centrebands from these sites the use of three magnetic fields (9.4, 11.7 and 14.1 T) allows unambiguous values for the isotropic chemical shift (delta iso), quadrupolar coupling constant (Cq) and quadrupolar asymmetry parameter (eta) to be deduced for each site. The NMR spectrum from the AlO5 site is simulated with parameters Cq = 8.7 +/- 0.1 MHz, eta = 0.95 +/- 0.05 and delta iso = 41 +/- 1 ppm which are compared to values from other well-defined AlO5 units.

Aluminum↗
PubMed1992

A model for evaluating the cost-effectiveness of cholesterol-lowering treatment.

We describe and illustrate the use of a generalizable model for evaluating the cost-effectiveness of alternative cholesterol-lowering treatments. We combine standard incidence-based techniques for measuring the cost of illness with logistic risk functions from the Framingham Heart Study to project, for persons with known coronary risk characteristics, the likelihood of developing coronary heart disease (CHD) over a lifetime as well as a number of related outcomes, including the expected loss of years of life due to CHD, the expected lifetime direct and indirect costs of CHD, and the changes in these outcomes that would result from cholesterol-lowering treatment.

Adult↗
PubMed1992

The binding of human alloantibodies to recombinant glycophorin A.

Chinese hamster ovary (CHO) cells were transfected with the wild-type, M allele of glycophorin A cDNA. The binding of human alloantibodies to recombinant glycophorin A was assessed with a modified hemagglutination-inhibition assay. Patient sera were incubated with acetone powders derived from CHO cells, and the adsorbed supernatants were tested in standard hemagglutination assays. Five M antibodies and one sample containing anti-En(a) bound to transfected CHO cells expressing glycophorin A but did not bind to untransfected CHO cells. Three N antibodies as well as 21 other alloantibodies (representing other major red cell blood group specificities) bound to neither CHO cell line. The M allele specificity of recombinant glycophorin A was further verified by the demonstration that a high-titer D alloantibody maintained the same titer of agglutination after incubation with recombinant glycophorin A. Transfected CHO cells thus express an M blood group antigen that appears to be serologically equivalent to that found on human red cells. A panel of cell lines expressing mutant glycophorin A molecules with defined variations in amino acid sequence and carbohydrate composition will be useful in studies of the fine specificity of human glycophorin alloantibodies. This approach may also provide an abundant source of artificial antigens for clinical use in blood group serology.

Animals↗
PubMed1992

Case-mix groups for VA hospital-based home care.

The purpose of this study is to group hospital-based home care (HBHC) patients homogeneously by their characteristics with respect to cost of care to develop alternative case mix methods for management and reimbursement (allocation) purposes. Six Veterans Affairs (VA) HBHC programs in Fiscal Year (FY) 1986 that maximized patient, program, and regional variation were selected, all of which agreed to participate. All HBHC patients active in each program on October 1, 1987, in addition to all new admissions through September 30, 1988 (FY88), comprised the sample of 874 unique patients. Statistical methods include the use of classification and regression trees (CART software: Statistical Software; Lafayette, CA), analysis of variance, and multiple linear regression techniques. The resulting algorithm is a three-factor model that explains 20% of the cost variance (R2 = 20%, with a cross validation R2 of 12%). Similar classifications such as the RUG-II, which is utilized for VA nursing home and intermediate care, the VA outpatient resource allocation model, and the RUG-HHC, utilized in some states for reimbursing home health care in the private sector, explained less of the cost variance and, therefore, are less adequate for VA home care resource allocation.

Aftercare↗
PubMed1992

Otolaryngologic manifestations of the mucopolysaccharidoses.

A retrospective review of 45 children with mucopolysaccharidoses was performed to determine the frequency of complications related to the head and neck. In this series, every patient had at least one complication involving the head and neck region, and in over half, operative intervention by the otolaryngologist was required. Upper airway obstruction occurred in 17 (38%) and necessitated a tracheostomy in 7 (16%). Cervical spine instability occurred in 8 (18%), making airway management difficult. Recurrent respiratory infections occurred in 17 (38%), and chronic recurrent middle ear effusions were noted in 33 (73%). This review demonstrates that children afflicted with the mucopolysaccharidoses frequently have otolaryngologic-related complications that are common throughout their life span and often the primary management issue in their continuing care. The otolaryngologic management of these patients is outlined based on the results of this study and review of the relevant literature.

Adolescent↗
PubMed1992

Phonation and swallowing considerations in pediatric laryngotracheal reconstruction.

Experience with laryngotracheal reconstruction (LTR) has resulted in and continues to yield modifications and refinements in approach and technique with the goal to restore and maintain total laryngeal function. In addition to airway obstruction, the laryngeal functions of phonation and swallowing also may be affected by the underlying injury as well as by procedures designed to enlarge the airway. This paper discusses various problems encountered with phonation and swallowing in pediatric patients who underwent LTR and postoperative patients who were seen during the year July 1, 1990, through June 30, 1991. Phonation problems became apparent as long-term difficulties that persisted after tracheotomy decannulation. Swallowing was frequently a short-term perioperative problem while a stent was in place following LTR. The approaches and techniques that have been employed to treat, minimize, and prevent these problems are discussed.

Adolescent↗
PubMed1992

Resource-limited information processing in alcoholism.

A concurrent-task paradigm was utilized to examine the availability of limited-capacity information-processing resources in long-term chronic alcoholism. Normal control subjects and detoxified long-term alcoholics did not differ in their performance of a primary task that required an assessment of the meaning of foveally-presented words. However, reaction time measures indicated that the abstinent alcoholics were relatively impaired in their ability to concurrently perform a secondary task that required them to detect randomly-occurring and spatially-distributed visual probe stimuli. This impairment is interpreted as reflecting an abnormal limitation in the attentional resources abstinent alcoholics have available for task performance. The relationship between this deficit and the types of biological abnormalities and neuropsychological impairments commonly observed in alcoholism is discussed.

Alcoholism↗
PubMed1992

Laryngeal paralyses: theoretical considerations and effects on laryngeal vibration.

The neurological causes of vocal fold paralyses have been well documented. However, the effect of these disorders on laryngeal vibration is not well understood. A theoretical four-mass model of the larynx, based on the work of Ishizaka and Isshiki (1976) and Koizumi, Taniguchi, and Hiromitsu (1987), was developed and adapted to simulate laryngeal biomechanical behavior. The model was used to evaluate various states of asymmetric laryngeal vibration. Input parameters that relate observed laryngeal function and model simulation were developed. Laryngeal paralyses were simulated by their predicted effect on these parameters. Simulations were compared with available data on glottal vibration in laryngeal paralyses. Complex modes of vibration were seen with certain combinations of asymmetrical lower mass stiffness and initial glottal gap.

Computer Simulation↗
PubMed1991

The effects of a diacylglycerol kinase inhibitor at mammalian and amphibian neuromuscular junctions in vitro.

Miniature endplate potentials were studied in mouse phrenic nerve-hemidiaphragm and frog pectoris-cutaneous neuromuscular preparations. The diacylglycerol kinase inhibitor R59022 increased the frequency of miniature endplate potentials in both preparations. The results indicate that endogenous diacylglycerol regulates acetylcholine release via activation of protein kinase C. Continuous monitoring of miniature endplate potential frequency in the frog preparation showed that higher doses of the inhibitor caused a large rise in release rate, which subsequently settled at a lower, though still augmented, level. It is suggested that a negative feedback may occur in response to high protein kinase C activity, possibly to inhibit diacylglycerol generation.

Animals↗
PubMed1991

Localized brain metabolic response correlated with potentials evoked by words.

Evoked potentials (EPs) measure synaptic current flows that propagate from brain to scalp, Alternatively, positron emission tomography (PET) using fluoro-deoxyglucose (FDG) can measure the increased glucose metabolism supporting this synaptic activation. It is difficult to localize the brain activity-generating EPs from their scalp distribution, because activity originating in different regions tends to produce overlapping scalp topographies. In contrast, FDG-PET provides better spatial resolution for activity throughout the brain, but shows only the total metabolism integrated over a 30-min uptake period. We combined the temporal and psychological resolution of EPs with the spatial resolution of PET to help define when and where in the brain words are encoded for meaning.

Adult↗
PubMed1991

Structure of 2,2,2-tricarbonyl-1,1-bis(ethylene)-mu-(eta 5:eta 5-fulvalene)-2-methylrhodiumtungsten.

[RhW(C10H8)(CH3)(C2H4)2(CO)3], Mr = 570.10, monoclinic, P2(1)/c, a = 7.3358(8), b = 10.8640(15), c = 21.6310(20) A, beta = 90.924(8) degrees, V = 1723.7(3) A3, Z = 4, Dm = 2.16, Dx = 2.196 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 77.7 cm-1, F(000) = 1080, T = 298 K, R = 0.021, wR = 0.029 for 4453 observed reflections with I greater than or equal to 3 sigma(I). The compound is a bimetallic fulvalene complex with rhodium and tungsten oriented trans to each other across an essentially planar fulvalene dianion.

Molecular Structure↗
PubMed1991

Endogenous Pseudallescheria boydii endophthalmitis. Clinicopathologic findings in two cases.

Two cases of endogenous Pseudallescheria boydii endophthalmitis are presented. One patient had severe pulmonary fibrosis but no history of ocular trauma and no clinical or laboratory evidence of immunocompromise. Despite therapy with repeated intravitreal miconazole nitrate injections and systemic fluconazole, enucleation of the globe was required, and the patient eventually died with disseminated pseudallescheriasis. The other patient was an immunosuppressed cardiac transplant recipient who also received systemic fluconazole therapy. The infected eye eventually required evisceration, but there was no evidence of disseminated pseudallescheriasis before his death of unrelated causes.

Antifungal Agents↗
PubMed1991

Induction of anti-myelin antibodies in EAE and their possible role in demyelination.

Experimental allergic encephalomyelitis is characterized by invasion of lymphocytes and macrophages into the central nervous system resulting in inflammation, edema, and demyelination. Sera from Lewis rats from 7-95 days after immunization with purified guinea pig CNS myelin were examined with respect to their ability to opsonize myelin. This was correlated with the appearance of antibody components and the relative amounts of antibody to myelin basic protein (MBP) and proteolipid protein (PLP). Sera from rats 10-95 days after immunization preincubated with purified myelin induced phagocytosis of myelin by cultured macrophages with the resulting production of cholesterol ester. This opsonization activity as measured by the percentage of cholesterol esterified reached a peak at 26-27 days after immunization but remained significantly elevated up to 95 days post-immunization compared to the activity of serum from the Freund's adjuvant-injected controls. Immunoblots of the sera revealed a gradual increase in antibody activity against myelin components. ELISA assays for MBP and PLP antibody showed a similar pattern. Antibody to galactocerebroside (GC) was not detected by immunostains nor by the ELISA assay. Areas of demyelination were observed histologically by luxol-fast blue stained spinal cords up to 60 days post-immunization. These results indicate that antibodies to myelin protein when given access to myelin through or within the blood brain barrier could initiate or enhance the phagocytic response by peripheral or resident macrophages.

Animals↗
PubMed1991

Distraction and relaxation training in the treatment of anticipatory vomiting: a single subject intervention.

A within-series phase change design (ABABC) was used to evaluate the effect of video distraction and relaxation in the treatment of a 29-year-old male with anticipatory vomiting associated with cancer chemotherapy. Heart rate, blood pressure, nausea ratings, and the occurrence of emesis were recorded during 18 chemotherapy treatments over a 9 month period. Video distraction initially inhibited vomiting but the treatment effects were not maintained. Subsequent relaxation training inhibited vomiting after two sessions. These effects were maintained for the remainder of the patient's chemotherapy protocol.

Adenocarcinoma↗
PubMed1991

Evaluation of CD68 and other histiocytic antigens in angiomatoid malignant fibrous histiocytoma.

Immunohistochemistry for the histiocyte antigens CD68, L1, factor XIIIa, and S100 protein was performed on 19 cases of angiomatoid malignant fibrous histiocytoma (MFH) and for keratin, leukocyte common antigen, factor VIII-related antigen, muramidase, and desmin on six of these cases. Nine of 19 cases expressed the histiocyte differentiation antigen CD68, and in three cases expression was seen in greater than 90% of cells. Of the 19 cases studied, three contained rare S100-positive tumor cells, and two expressed factor XIIIa within tumor cells. In three of the six cases, rare desmin-positive tumor cells were identified. The neoplastic cells did not express the other antigens studied. CD68 was not detected in any of 12 cases of storiform-pleomorphic and myxoid MFH or in any of 24 cases of normal tissues or nonfibrohistiocytic mesenchymal tumors except for granular cell tumors. These results indicate that either the cells of angiomatoid MFH differentiate along lines of a tissue macrophage or alternatively, and perhaps more likely, are mesenchymal tumors with a phenotypic alteration, paralleling an enhanced capacity for phagocytosis and acquisition of lysosomes. In either event, the immunophenotype contrasts with conventional MFH and provides another independent set of observations in support of a separation of angiomatoid from conventional MFH.

Antibodies, Monoclonal↗