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Biomedical subjects

M Cooper

Publications and source records attributed to M Cooper.

At least 163 records · Page 9Linked to original sources
PubMed1992

Facial recognition: a cognitive study of elderly dementia patients and normal older adults.

Dementia patients' and normal elderlies' recognition of familiar, ordinary emotional and facial expressions was tested. In three conditions subjects were required to name the emotions depicted in pictures and to produce them while presented with the verbal labels of the expressions. The dementia patients' best performance occurred when they had access to the verbal labels while viewing the pictures. The major deficiency in facial recognition was found to be dysnomia related. Findings of this study suggest that the connection between the gnostic units of expression and the gnostic units of verbal labeling is not impaired significantly among the dementia patients.

Aged↗
PubMed1992

The osmotic integrity of the yeast cell requires a functional PKC1 gene product.

Seven temperature-sensitive cell lysis (cly) mutant strains of Saccharomyces cerevisiae were isolated which lyse at the restrictive temperature on hypotonic but not on osmotically supported medium. The seven mutants fell into four complementation groups, CLY12 to CLY15. The wild-type CLY15 gene was isolated by complementation of the cly15 temperature-sensitive growth defect. Sequence analysis revealed that the complementing DNA fragment encoded a partial PKC1 gene, which has previously been isolated as an S. cerevisiae homolog of mammalian protein kinase C genes (D. E. Levin, F. O. Fields, R. Kunisawa, J. M. Bishop, and J. Thorner, Cell 62:213-224, 1990). Subsequent genetic analysis showed that CLY15 and PKC1 represent identical loci in the yeast genome. A truncated PKC1 gene encoding only the predicted catalytic domain of Pkc1p was able to complement pkc1 mutant strains. Similar to what has been reported recently (D. E. Levin and E. Bartlett-Heubusch, J. Cell Biol. 116:1221-1229, 1992), we observed that cells deleted for the PKC1 gene are viable when grown on osmotically stabilized medium but are osmotically fragile and lyse rapidly after a shift to hypotonic medium. As shown by light and electron microscopic examinations, the delta pkc1 strain exhibits many cells with a strongly elongated bud or chains of incompletely budded cells when grown on solid medium.

Culture Media↗
PubMed1992

Suramin: a novel growth factor antagonist with activity in hormone-refractory metastatic prostate cancer.

PURPOSE: Suramin is known to inhibit the growth of malignant prostate carcinoma cells in vitro. This led us to evaluate the effectiveness of suramin in the treatment of 38 patients with prostate carcinoma refractory to hormone therapy. PATIENTS AND METHODS: Suramin was administered by continuous infusion at a rate designed to reach a peak of 300 micrograms/mL at the end of 14 days. Patients were given 8 weeks to recover from any toxicity before beginning the second cycle. Subsequent cycles were administered in the same manner except the starting dose rate was 280 mg/m2. RESULTS: In 17 patients with measurable soft tissue disease, three had complete disappearance of soft tissue disease for 4, 5, and 11 months, whereas three patients had a greater than or equal to 50% decrease in the sum of the products of the diameters of all measurable disease for greater than or equal to 1 month. Of these 17 patients, pretreatment prostate-specific antigen (PSA) decreased by 75% or more in five (29%) and normalized in one (6%). The remaining 21 patients had disease limited to bone, and only one of these experienced resolution of more than 50% of all lesions on bone scan. Of these 21 patients, pretreatment PSA decreased by 75% or more in eight (38%) and normalized in five (25%). Median time to progression for all patients was 26.3 weeks, and median survival was 42.3 weeks. Patients with bone involvement alone exhibited a better survival than patients with soft tissue involvement (P2 = .02). Survival was strongly correlated (P2 = .0001) with a decline in the pretreatment PSA of greater than or equal to 75% by the eighth week on therapy, with nearly an 85% survival at 1 year compared with a 20% survival for those whose pretreatment PSA did not decline by that amount. CONCLUSION: We conclude that suramin is an active agent in hormone-refractory prostate carcinoma.

Aged↗
PubMed1992

Congenital subglottic hemangioma: frequency of symmetric subglottic narrowing on frontal radiographs of the neck.

OBJECTIVE: This study was undertaken to determine how often symmetric subglottic airway narrowing is present in cases of infantile subglottic stenosis and to determine if the radiographic finding has any association with the anatomic location of the hemangioma. MATERIALS AND METHODS: All cases (n = 12) of endoscopically proved subglottic hemangioma from 1976 to 1991 were collected from the records at Children's Hospital of Michigan. In 10 cases, high-kilovoltage magnification studies or frontal radiographs of the neck were available for review by two observers who classified the subglottic narrowing as either symmetric or asymmetric. The radiographic findings in these 10 cases were then compared with the location and extent of the lesion as described endoscopically. RESULTS: In 50% of cases (n = 5), narrowing of the subglottic airway was symmetric. In four of these the hemangioma was either situated on the posterior wall or was circumferential, and in the remaining one an associated marked fibrotic reaction to a lateral wall lesion was present. All other lesions were on the lateral wall, and asymmetric subglottic airway narrowing was consistently shown on radiographs. CONCLUSION: Our results show that subglottic hemangioma often manifests as a symmetric subglottic airway narrowing and that the anatomic location of the hemangioma appears to be associated with the appearance on radiographs.

Glottis↗
PubMed1992

Incidental finding of endolymphatic stromal myosis during luteinizing hormone releasing hormone agonist therapy for suspected benign uterine myomata. A case report.

A 39-year-old woman with an enlarging myomatous uterus underwent a three-month course of luteinizing hormone releasing hormone (LHRH) agonist treatment. Despite a 50% reduction in uterine size, pathologic examination after uncomplicated hysterectomy revealed a low-grade endometrial stromal sarcoma. As the use of LHRH agonists for myoma reduction increases, delay in the diagnosis of sarcomatous disease will become more widespread. With current available diagnostic modalities, differentiation between sarcomatous and myomatous growth within the uterus is difficult. The possibility of delay in the diagnosis of unsuspected sarcoma when using LHRH agonists is an inherent and apparently unavoidable complication in some cases.

Adult↗
PubMed1992

Characterization of in vitro translated human mineralocorticoid receptor. Structure and activation.

The structures of the unactivated and activated mineralocorticoid receptors have been difficult to characterize because of receptor lability and steroid dissociation. Therefore, human mineralocorticoid receptor mRNA was translated in rabbit reticulocyte lysate in the presence and absence of [35S]methionine to compare the structure of [3H]aldosterone-bound and [35S]labeled receptor. In vitro synthesized receptor was able to specifically bind [3H]aldosterone. Unactivated [3H]aldosterone-bound and 60% of unactivated [35S]labeled receptor eluted from DEAE-cellulose with 250 mM salt and had a Rs of 72A. Forty percent of unactivated [35S]labeled receptor eluted from DEAE-cellulose with 100 mM salt and had a Rs of 54A. SDSPAGE showed intact hMR was present in both DEAE-cellulose eluates as three bands between M(r) 110,000-120,000. However, the low salt eluate contained less intact receptor and more lower MW bands. Neither [3H]aldosterone-bound nor [35S]labeled receptor was activated by incubation at 25 degrees C as readily as glucocorticoid receptor studied under identical conditions. Activated [3H]aldosterone-bound receptor eluted from DEAE-cellulose at 100 mM salt and had a Rs of 37A. After activation, 60% of [35S]labeled receptor eluted from DEAE-cellulose with 100 mM salt and had a Rs of 91A. SDS-PAGE of the high and low salt DEAE-cellulose eluates showed that 50% of intact receptor eluted in the low salt peak after activation. These data indicate that: 1. Some in vitro synthesized mineralocorticoid receptor assembles into the heteromeric unactivated form; 2. The remaining intact receptor remains monomeric and unable to bind steroid; 3. Activation causes dissociation of intact receptor from a larger complex; and 4. Activated receptor tends to aggregate.

Aldosterone↗
PubMed1992

The quality assurance committee in a general hospital: its use in improvement of the medical record.

A twice-yearly audit of a sample of medical records from each department of a general hospital was initiated by a quality assurance committee and pursued for 8 years. Missing entries that were considered obligatory for good medical performance of each service were identified, and the results (expressed as percent of missing entries of the total) were communicated in graphic form to the specific departments and the senior staff of the hospital. This approach led to an improvement in the medical records (decrease of missing entries), which may reflect a higher quality of medical care. Thus, a sequential audit of medical records by a quality assurance committee may constitute a simple and effective method of monitoring and improving physicians' knowledge and performance.

Hospitals, District↗
PubMed1992

Photodynamic therapy for the treatment of basal cell carcinoma.

BACKGROUND: Photodynamic therapy is an investigational method for the treatment of a variety of solid tumors. The purpose of this study was to determine the optimum factors and illustrate the effectiveness of photodynamic therapy in the treatment of basal cell carcinomas. This was a prospective study in which patients presenting with primary or recurrent basal cell tumors, particularly but not exclusively widespread tumors or large single tumors, were offered the option of photodynamic therapy in their treatment regimen. RESULTS: Patients were administered 1 mg/kg of a photosensitizer (Photofrin II). Light doses (630 nm) ranged from 72 to 288 J/cm2. A total of 37 patients with 151 sites were treated in this study. A complete response rate of 88% was achieved with one application. Morbidity was low; the most significant side effects were moderate pain and edema. CONCLUSIONS: Photodynamic therapy is a modality that offers localized treatment of primary or recurrent nonmelanoma skin cancer. By applying reciprocal doses of photosensitizer and light, the efficacy of photodynamic therapy in the treatment of skin lesions is demonstrated achieving significant light penetration into tissue with a high complete response rate of the lesions and acceptable normal tissue response.

Basal Cell Carcinoma↗
PubMed1992

[Poststreptococcal reactive arthritis].

Reactive arthritis is defined as arthritis of 1 or more joints, in association with infection at a distant site, but without the infective agent being found in the synovial fluid. Patients with Group A beta-hemolytic streptococcal infection and articular disease, who do not fulfill the modified Jones criteria for diagnosis of acute rheumatic fever, have been classified as having poststreptococcal reactive arthritis. We describe 6 patients seen during the winter of 1991 who had various clinical presentations of poststreptococcal reactive arthritis. This condition is considered by some as a distinct disease, but by others as part of the spectrum of acute rheumatic fever.

Adolescent↗
PubMed1992

Leg muscle scintigraphy with 99Tcm-MIBI in the assessment of peripheral vascular (arterial) disease.

A technique for using 99Tcm-methoxyisobutylisonitrile (MIBI) to evaluate leg muscle perfusion in the assessment of peripheral vascular disease (PVD) is described and evaluated. The uptake of MIBI in muscle groups is quantified and normalized to whole body activity. Eleven patients with PVD undergoing angiography and nine controls were studied. There was a significant difference in MIBI uptake in the calf (P less than 0.000 01) and thigh (P less than 0.0001) between the two groups on exercise. The technique has a sensitivity of 91% and specificity of 94% for the diagnosis of PVD. The technique can also effectively evauate the severity of disease as shown by significant correlations between exercise calf flow and angiographic severity (P less than 0.05) and Doppler ankle/arm pressure measurements (P less than 0.0005). Single photon emission tomography (SPET) of the calves was also performed in five controls and five patients with PVD. Uptake was significantly reduced in all muscle areas in patients with PVD and, amongst those with PVD, uptake was lower in muscle groups by occluded arteries. The potential role of 99Tcm-MIBI in the assessment of PVD and its advantages over other methods of assessment are discussed.

Aged↗
PubMed1991

The hypnotics triazolam and zolpidem have identical metabolic effects throughout the brain: implications for benzodiazepine receptor subtypes.

Using Sokoloff's 2-deoxyglucose autoradiography procedure, the effects of trizolam, a classical benzodiazepine (BZ) hypnotic, were compared to those of zolpidem, which preferentially binds to BZ1 receptor subtypes. Triazolam depressed metabolism in 40 of the more than 60 brain regions evaluated. Zolpidem depressed metabolism in all of these areas, including the spinal cord, an area where the BZ1 receptor subtype is not supposed to exist. Zolpidem and triazolam also depressed metabolism in the molecular layer of the dentate gyrus, an area low in BZ1 receptors. Neither drug affected metabolism in 21 areas, including the regions most specific for the BZ1 subtype (cerebellum, inferior colliculus, globus pallidus, and substantia nigra pars reticularis). It is concluded that: (i) zolpidem and triazolam depress energy metabolism of the same areas of the brain, (ii) zolpidem's effects may not be mediated solely through the BZ1 receptor subtype, and (iii) the BZ2 receptor may be functionally more significant than the BZ1 receptor.

Animals↗
PubMed1991

Effects of neuroleptic treatment on symptoms of schizophrenia and plasma homovanillic acid concentrations.

Measurement of plasma concentrations of the dopamine metabolite, homovanillic acid, is an indirect tool to assess changes in dopamine turnover in schizophrenic patients. Plasma homovanillic acid concentrations have been reported to decrease during neuroleptic treatment, with the decrement correlating with symptomatic improvement in symptoms of schizophrenia. The present study tested the hypothesis that neuroleptic drugs decrease plasma homovanillic acid concentrations in those schizophrenic patients who improve with administration of neuroleptic drugs but not in patients who fail to display a treatment response. Twenty schizophrenic men who remained drug free for at least 2 weeks were treated with 20 mg/d of haloperidol for 5 weeks. Symptoms and plasma homovanillic acid concentrations were assessed on the last drug-free day and weekly for 5 weeks. Mean plasma homovanillic acid concentrations decreased in the group of patients who responded to neuroleptic treatment and did not change in the group of patients who did not improve. These findings suggest that there may be a qualitative distinction between responders and nonresponders to dopamine antagonists.

Administration, Oral↗
PubMed1991

The effect of aldose reductase inhibitors on glomerular prostaglandin production and urinary albumin excretion in experimental diabetes mellitus.

The effect of two structurally unrelated aldose reductase inhibitors, sorbinil and ponalrestat, on glomerular prostaglandin production and urinary albumin excretion was investigated in rats with diabetes induced by streptozotocin. It was found that both aldose reductase inhibitors, when administered from the time of induction of the diabetes, significantly decreased the raised urinary albumin excretion in the diabetic rats, although it remained elevated compared with non-diabetic rats. Glomerular prostaglandin E and 6-keto-prostaglandin F1 alpha production was significantly increased in glomeruli obtained from the diabetic rats. Inhibition of aldose reductase caused a reduction in the raised glomerular prostaglandin production, although this remained above that observed in the non-diabetic rats. Subsequent experiments were performed to determine whether the effects of the aldose reductase inhibitors could be explained by effects on glomerular filtration rate. It was found that ponalrestat, at a dose which markedly reduced urinary albumin excretion, did not significantly affect glomerular filtration rate in non-diabetic rats, rats with untreated streptozotocin-induced diabetes and rats with diabetes partially treated with low dose insulin. Glomerular sorbitol concentrations were significantly elevated in untreated diabetic rats as early as two weeks after the induction of diabetes. It is concluded that the administration of aldose reductase inhibitors from the time of induction of diabetes significantly reduces glomerular prostaglandin production and urinary albumin excretion. The latter effect is not due to an effect on glomerular filtration rate. Increased polyol pathway activity may account in part for the increased glomerular prostaglandin production and urinary albumin excretion in early experimental diabetes.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Size and frequency characteristics of alpha beta and gamma delta T cells in the spleens of normal and cyclophosphamide-suppressed virus-infected chickens.

The characteristics of avian lymphocytes expressing surface CD8 (CT8) and T cell receptor (TCR) glycoproteins have been monitored by two-color flow microfluorimetry. Exposure of 1-month-old birds to a lethal influenza A virus, which is known to be lympholytic, significantly decreased the frequency of both the alpha beta TCR2+CT8+ and gamma delta TCR1+CT8- subsets in spleen. However, all categories of T cells showed evidence of greater mean cell size, indicating that they are responding. Inoculation of baby chicks with fowl pox virus induced a response more typical of specific immunity in the TCR2+CT8+ set, in that the lymphocytes increased in both frequency and mean cell size. Greater numbers of lymphoblasts were also found for the TCR2+CT8-, TCR1+CT8+, and TCR1+CT8- subsets, but the total cell counts for the minority TCR1+CT8- cells in spleen were consistently decreased. Immunosuppression with cyclophosphamide prior to infection eliminated 90% of the white blood cells from spleen, with the greatest effect being on the TCR1+ populations. The CT8+ alpha beta T cell response in chick spleen following exposure to a poxvirus is thus comparable to the situation observed for this subset of lymphocytes in mice infected with other viruses. However, although the gamma delta T cells increase in size, their frequency in spleen either does not change (CT8+) or is significantly decreased (CT8-).

Animals↗