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Biomedical subjects

L Miller

Publications and source records attributed to L Miller.

At least 217 records · Page 12Linked to original sources
PubMed1993

Resistive exercise in the rehabilitation of polymyositis/dermatomyositis.

OBJECTIVE: To determine the effect of a resistive exercise program in the rehabilitation of patients with polymyositis/dermatomyositis (PM/DM). METHODS: Five patients participated in a rehabilitation program that included resistive exercises. In 4 of the patients, these exercises were randomly alternated with nonresistive exercise. Each type of exercise was assigned for periods of 2 weeks, and at the end of each one, muscle strength was measured by means of manual muscle testing (MMT), an activities of daily living (ADL) score, and peak isometric torque (PIT) generated by muscle groups in the lower extremities. Creatine phosphokinase (CPK) levels were used to measure disease activity. The acute response to resistive exercise was studied in 4 of the patients by measuring serial levels of CPK following a session on an exercise bicycle. RESULTS: Of the 4 patients who participated in both types of exercises, 3 experienced increases in strength during both resistive and nonresistive exercise periods. The patient who participated only in resistive exercises had considerable improvements in muscle strength. One patient made no improvements in strength with either type of exercise. None of the patients experienced clinically significant elevations in CPK attributable to either type of exercise. Following a session of resistive exercise, the mean CPK elevation in 4 patients was 7.7%, returning to pre-exercise levels by 8 h in all cases. CONCLUSIONS: Patients with PM/DM may participate in a rehabilitation program which includes resistive exercises. Such programs may be accompanied by increased strength without clinically significant rises in serum levels of muscle enzymes.

Activities of Daily Living↗
PubMed1993

Serum amino acids following human orthotopic liver transplantation.

Our findings indicate that serum amino acid changes after OLT are complex and influenced by multiple factors including sepsis and use of parenteral hyperalimentation with exogenous amino acids. Additional factors which may influence the rate of normalization of amino acids after OLT include the presence of malnutrition (frequently observed before OLT) and the extent of pretransplant portal-systemic shunting. Our results demonstrate that the presence of septic complications and the use of CPN are important determinants of the postoperative levels of several amino acids, including the BCAA/AAA ratio. Our logistic regression model using the BCAA/AAA ratio predicted the occurrence of sepsis after OLT 77% of the time. Prospective assessment and validation of this model is under way.

Amino Acids↗
PubMed1992

Modulation of melphalan uptake in murine L5178Y lymphoblasts in vitro by changes in ionic environment.

The alkylating agent melphalan is actively transported in mammalian cells by two amino acid transport carriers: the sodium-dependent carrier with substrate preference for alanine-serine-cysteine (system ASC), and a sodium-independent carrier with preference for leucine (system L). The effect of altering the ionic environment of murine L5178Y lymphoblasts was investigated in order to determine not only the direct effects of hydrogen and calcium ions on these transport systems, but also the indirect effects of agents or modulators known to alter intracellular calcium. Melphalan transport followed a bell-shaped distribution curve over a pH range from 3 to 9 with a pH optimum of 4.3 and 4.6 for transport by systems ASC and L, respectively. Those agents that could cause a decrease in cytosolic calcium such as the calcium channel blockers verapamil, diltiazem and nitrendipine, the calcium chelator (ethyleneglycol-bis-(beta-aminoethylether) N,N,N',N'-tetraacetic acid (EGTA) and reduction of pH were found to augment melphalan uptake, whereas conditions that would elevate intracellular calcium such as the calcium ionophore A23187, the calcium channel agonist (-) Bay K 8644, elevation of extracellular calcium and the calcium pump inhibitor trifluoperazine were all found to decrease melphalan uptake. These findings suggest that modification of ionic environment directly or indirectly by agents known to alter intracellular calcium can modulate melphalan uptake.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1992

Articular-cartilage matrix gamma-carboxyglutamic acid-containing protein. Characterization and immunolocalization.

Matrix gamma-carboxyglutamic acid (Gla)-containing protein (MGP) was found to be present in articular cartilage by Western-blot analysis of guanidinium chloride extracts of human and bovine cartilage and was further localized by immunohistochemical studies on human and monkey specimens. In newborn articular cartilage MGP was present diffusely throughout the matrix, whereas in growth-plate cartilage it was seen mainly in late hypertrophic and calcifying-zone chondrocytes. In adult articular cartilage MGP was present primarily in chondrocytes and the pericellular matrix. Immunoelectron microscopy studies revealed an association between MGP and vesicular structures with an appearance consistent with matrix vesicles. MGP may be an important regulator of cartilage calcification because of its localization in cartilage and the known affinity of Gla-containing proteins for Ca2+ and hydroxyapatite.

1-Carboxyglutamic Acid↗
PubMed1992

Induction of heat-shock proteins and phagocytic function of chicken macrophage following in vitro heat exposure.

The protein profiles and phagocytic ability of Sephadex-elicited chicken peritoneal macrophages were examined following heat-shock exposure. Macrophage cultures were exposed to various temperatures, time exposures and recovery periods. Densitometric analysis of SDS-PAGE autoradiographs revealed that heat-induced macrophages synthesized three major (23, 70 and 90 kD) heat-shock proteins (HSPs). The optimal temperature and time for induction of these HSPs was 45-46 degrees C for 1 h, with a variable recovery period for each HSP. Macrophages exposed to 45 degrees C for 30 and 60 min were significantly depressed in phagocytosis of uncoated sheep erythrocytes (SE) under 45 degrees C incubation conditions. However, phagocytosis of antibody-coated SE was not affected when compared to 41 degrees C control cultures. Macrophages allowed to recover at 41 degrees C following heat-shock exhibited no alterations in their phagocytic ability for either antibody-coated or uncoated SE. This study suggests that heat shock induces three major HSPs in chicken peritoneal macrophages in addition to maintaining their Fc-mediated phagocytic function while significantly depressing their nonspecific phagocytosis.

Animals↗
PubMed1992

The Columbia University Scale for Psychopathology in Alzheimer's disease.

The Columbia University Scale for Psychopathology in Alzheimer's disease is a new screening instrument developed for use by clinicians or trained lay interviewers. Interrater reliability was established between a psychiatrist and a lay interviewer in 20 patients. In an independent sample of 91 outpatients with very mild to moderate probable Alzheimer's disease, caregiver informants reported that depressed mood was common (46.2%) but rarely persistent (2.2%), and that sleep disturbance occurred frequently (41.8%) but was never severe (0%). There were significant but weak associations between the presence of specific subtypes of delusions and severity of dementia. Although a variety of delusional symptoms were reported, they were frequently transient and patients often accepted the truth if corrected by the caregiver. As a result, few patients met broad or narrow operational criteria used to define delusions. Prior studies may have overestimated the prevalence of psychotic features in Alzheimer's disease by not employing standard definitional criteria. The findings also indicate that new methodology such as that employed in this instrument needs to be evaluated more widely.

Aged↗
PubMed1992

A widely unappreciated cause of failure of an automatic noninvasive blood pressure monitor.

Many anesthesiologists have come to depend on automatic noninvasive blood pressure monitoring to obtain blood pressure (BP) readings. A case is presented in which, during a critical phase of the anesthetic, an automatic noninvasive blood pressure (ANIBP) device not only failed to provide meaningful clinical data but, in fact, gave an error message that was misleading. At the time of the message, the patient was noted to be in ventricular trigeminy at a rate of 92 beats/min. It appears that the repetitive beat-to-beat fall in blood pressure due to the dysrhythmia "fooled" the automatic noninvasive blood pressure device's software algorithm into believing that there was an air leak in the system. Thus, in addition to pointing out an unappreciated and potentially troubling device-related critical event, the present case demonstrates the importance of good human factors design for medical devices used in the critical care setting. In particular, the issue is raised of how medical devices should deal with uncertain or potentially misleading data.

Aged↗
PubMed1992

Spatial, temporal, and hormonal regulation of epidermal keratin expression during development of the frog, Xenopus laevis.

To study the mechanism of hormone-induced keratin expression in the epidermis during Xenopus metamorphosis, a monospecific antibody was raised against a unique carboxy-terminal peptide of the 63-kDa keratin. Immunohistological analysis demonstrated that the onset of 63-kDa keratin expression showed distinct regional and temporal differences. The expression started at stage 54 in the hindlimb epidermis, at stage 57 in the head, and over 1 month later at stage 63 in the tail. The amount of 63-kDa keratin was further regulated during epidermal stratification and differentiation. The 63-kDa keratin was expressed first in basal epidermal cells before stratification began. The outer layer of the larval epidermis (periderm) did not express the 63-kDa keratin. As the cells moved out of basal layer, they stained more intensely with the anti-keratin antibody indicating that 63-kDa keratin synthesis is up-regulated during differentiation. Similar results were obtained with cultures of purified epidermal cells grown in high calcium conditions. Since we have shown that thyroid hormone (T3) induces 63-kDa keratin gene expression and hydrocortisone (HC) modulates T3 action we examined the effects of T3 and HC at the single cell level with the anti-keratin antibody. Immunostaining demonstrated that T3 alone and T3 plus HC increased the number of 63-kDa keratin-positive cells as well as the amount of 63-kDa keratin per cell. Unexpectedly these hormones had the same effects on head and tail epidermal cells even though the latter cells degenerate during metamorphosis. The major difference between tail and head cells was that the percentage 63-kDa keratin-producing cells was much greater in the head than in the tail.

Animals↗
PubMed1992

Effects of multiple injections of HCG on testis blood flow.

In attempting to determine whether or not multiple injections of human chorionic gonadotropin (hCG) augment testis blood flow, adult male rats were injected with three doses of 10 IU of hCG every other day and testis blood flow was determined on day 5, the day of the final injection. Testis blood flow (mL/100 g testis tissue/min +/- SEM) as measured by the 133Xe washout method increased from 10.8 +/- 1.3 to 20.4 +/- 4.5 (p less than 0.05) after the three doses of hCG. These observations suggest that multiple injections of hCG appear to have the same effect as a single dose of hCG in increasing testis blood flow. This supports the hypothesis that hCG should be administered to all patients undergoing orchiopexy in the hope that the increased perfusion of the gonad will make it less susceptible to ischemia during the surgical procedure.

Animals↗
PubMed1992

Cognitive failure in patients with terminal cancer: a prospective study.

In a prospective open study, 61 consecutive patients with terminal cancer admitted to the hospital underwent cognitive assessment using the Mini-Mental State Questionnaire three times a week between admission and discharge or death. Mini-Mental State Questionnaire score upon admission was 28 +/- 1.5 in patients who were discharged (N = 14), and 25 +/- 3 in patients who died in the hospital (N = 47, P less than 0.01). The forty-seven patients who died in the hospital presented a total of 66 episodes of cognitive failure (CF) that were defined as a score of less than 24 or a drop of greater than 30% in the score on the Mini-Mental State Questionnaire. Of these 47 patients, 39 (83%) presented CF an average of 16 days before death. Upon detection of CF, a complete medical examination, laboratory evaluation, computerized tomography of the brain if indicated by abnormal findings on medical examination, and a complete medication review were performed. The cause of CF could not be established in 37 (56%) cases. Drugs, sepsis, and brain metastasis were the most frequently detected causes and were present in 6, 4, and 4 cases, respectively. In addition, 22 episodes (33%) of CF improved (10 episodes spontaneously and 12 episodes as a result of treatment). Our findings suggest that CF is extremely prevalent during the last weeks of life and, consequently, informed consent for therapeutic or research procedures or resuscitation may be impossible to obtain reliably at that stage.

Aged↗