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Biomedical subjects

L H Miller

Publications and source records attributed to L H Miller.

At least 253 records · Page 14Linked to original sources
PubMed1977

MSH/ACTH4-10 influences on the CAR in human subjects: a negative finding.

Twenty normal, male, paid volunteers were randomly assigned to MSH/ACTH4-10 or diluent control groups. Following a subcutaneous injection of either 30 mg MSH/ACTH4-10 or diluent, all subjects were placed in an active conditioned avoidance response situation where they learned to avoid a painful electric shock by pressing a key during a safe interval between a warning signal (light) and shock onset. MSH/ACTH4-10 did not influence any parameter of the acquisition or extinction process. The between subjects' variability of autonomic variables was significantly less for the MSH/ACTH4-10 group. Results indicate that inhibition of extinction of conditioned avoidance responding does not generalize across species from rat to man.

Adrenocorticotropic Hormone↗
PubMed1977

Spleen function in quartan malaria (due to Plasmodium inui): evidence for both protective and suppressive roles in host defense.

For investigation of the role of the spleen in host defense and chronicity in quartan malaria, the course of Plasmodium inui infection was studied in 39 intact rhesus monkeys, 16 monkeys splenectomized before infection, and 22 monkeys splenectomized after infection. Splenectomized animals consistently had peak parasitemias greater than 10-fold higher than those of intact animals, but the mortality rate at peak parasitemia was only higher in monkeys splenectomized before infection. Whereas intact animals had persistent infections for one to 13 years, splenectomized animals achieved self-cure (persistently negative blood smears for three or more months) within less than a year. These observations suggest that the spleen exerts a protective role during the acute stage and a suppressive role during the chronic stage of quartan malarial infection.

Animals↗
PubMed1977

The Duffy blood group determinants: their role in the susceptibility of human and animal erythrocytes to Plasmodium knowlesi malaria.

Duffy blood group negative erythrocytes from blacks are refractory to invasion by Plasmodium knowlesi merozoites in vitro, and blacks with this genotype are resistant to infection by P. vivax in vivo. In order to evaluate in a direct manner the role of Duffy blood group determinants in invasion by P. knowlesi merozoites, we studied erythrocytes from three rare non-black Duffy negative individuals, Fy(a-b-), in whom the Duffy negative phenotype probably represents a mutation and not the introduction of the black Fy gene. These cells were resistant to invasion by P. knowlesi in vitro indicating that resistance to invasion is mediated by the FyFy genotype and not another closely linked factor. The erythrocyte receptors for invasion, however, may not be the Fya or Fyb Duffy antigens themselves, or at least not restricted to these determinants, since refractory Duffy negative human erythrocytes were invaded after treatment with trypsin or neuraminidase although these enzyme-treated cells still lacked Fy a and Fy b determinants. Furthermore, new world monkey erythrocytes and chymotrypsinized chimpanzee and kra monkey erythrocytes were invaded, although there was no serologic evidence of Fya or Fyb determinants on these cells.

Animals↗
PubMed1977

Further evidence for the parasitic origin of the surface coat on Malaria merozoites.

It has been observed that a surface coat, 20 nm in thickness, extends from the plasma membrane of extracellular merozoites and that this coat contains strain-specific antigens. In the present study we determined the possible effect of protein in the culture medium on this structure. The surface coat on merozoites in culture medium devoid of protein was indistinguishable by transmission electron microscopy from the coat in a protein-containing medium. This supports the hypothesis that the surface coat originates from the parasite rather than from adsorbed serum protein.

Animals↗
PubMed1977

CNS and pituitary effects of hypothalamic peptides and MSH.

The first part of this essay discussed the CNS effects of the pituitary peptide MSH. These investigations anticipated studies of the CNS effects of peptides found in the hypothalamus which were discussed in the second part of the essay. Some of the endocrine actions of the hypothalamic peptides upon the release of pituitary hormones were discussed in the last part of the essay. Together, the CNS and pituitary effects of hypothalamic peptides and MSH provide intriguing examples of areas of investigation which can be expected to be greatly expanded in the future.

Adrenocorticotropic Hormone↗
PubMed1977

Hypothesis on the mechanism of erythrocyte invasion by malaria merozoites.

Plasmodium knowlesi merozoites invade erythrocytes by a sequence of events: attachment, widespread deformation of the erythrocyte membrane, endocytosis, and resealing of the membrane and vesicle. The possible mechanisms by which these events occur are discussed. In particular, there is a detailed discussion of the role of the Duffy blood group system in invasion.

Adhesiveness↗
PubMed1976

The resistance factor to Plasmodium vivax in blacks. The Duffy-blood-group genotype, FyFy.

Duffy-blood-group-negative human erythrocytes, FyFy, are resistant to invasion in vitro by Plasmodium knowlesi. The FyFy genotype is found predominantly in African and American blacks, who are the only groups completely resistant to infection by P. vivax. To determine if the FyFy genotype is the vivax resistance factor, we performed blood typing on 11 black and six white volunteers who had been exposed to the bites of P. vivax-infected mosquitoes. Only the five FyFy blacks were resistant to erythrocytic infection; the remaining six blacks and all whites had the Duffy-positive determinants (Fya or Fyb or both) and had contracted malaria. We conclude that Duffy determinants (Fya or Fyb or both) on the erythrocyte surface are required for invasion of erythrocytes by vivax merozoites.

Adult↗
PubMed1976

Neuroheptapeptide influence on attention and memory in man.

Twenty normal, male volunteers were administered a subcutaneous injection of either ACTH/MSH 4-10 or diluent and two weeks later received the alternate injection in a complete crossover, double-blind design with order balanced. Subjects were given a battery of psychological tests, including a continuous performance task (CPT), following each injection. Visual evoked responses were recorded during the CPT. Resting, eyes-closed EEGs were also obtained. ACTH/MSH 4-10 improved attention and in so doing improved visual-motor learning and visual, but not verbal, memory, EEG data were consistant with activation of the diffuse thalamic projection system.

Adrenocorticotropic Hormone↗
PubMed1976

An evaluation of malaria fluorescent antibody patterns in several remote island populations of the New Hebrides, Solomons, Western Carolines, and New Guinea.

From a representative sampling of several remote populations living on the Banks and Torres Islands (New Hebrides), the Eastern and Southern Districts of the Solomon Islands, the Western Caroline Islands (U.S. Pacific Trust Territory), West New Guinea (Indonesia), and Papua New Guinea, 752 sera were examined for fluorescent antibodies to the four species of human malaria, and the results were compared to already published parasite survey data based on blood smears and medical examinations. Antibody prevalence data confirmed the presence of significant endemic malaria among most of the visited islands in the New Hebrides, and a variable but smaller amount of malaria in the Solomons. On those islands known to be free of malarial vectors, data were compatible with importation of self-limited infection by travelling residents. Malarial infection occurred in from 40% to 100% of the New Guinea villages that were visited, and was entirely absent from the Western Caroline Islands. The actual proportions of malarial species in endemic areas were not accurately reflected by relative antibody titer levels to the different species, possibly due to unpredictably high heterologous antibody reacitons following multiple mixed infections.

Adult↗
PubMed1976

Herpes zoster in the elderly.

Herpes zoster is a self-limited disorder which in most cases resolves without complications. The specific defect in host immunity that permits activation of latent V-Z virus and the occurrence of herpes zoster in both healthy and debilitated individuals has not yet been identified. In some patients, particularly the aged, complications occur during the acute phase of the disease or there are sequelae that may incapacitate the patient later. The most important of these is postherpetic neuralgia. In the elderly the chance of developing neuralgia following herpes zoster is about 50%. Involvement of the eye may produce minimal scarring or permanent blindness. There is an increasing incidence and severity of herpes zoster in association with malignant disease and in particular with Hodgkin's disease. Treatment of herpes zoster in the elderly should be determined by presenting symptoms. Topical medication such as the basic shake lotion is helpful. Personal experience and published reports suggest that early systemic administration of corticosteroids to healthy patients with severe herpes zoster pain with lessen the occurrence of postherpetic neuralgia. Administration of herpes zoster immune globulin is only effective in reducing the morbidity or preventing varicella in high risk individuals. ZIG does not affect the clinical course of herpes zoster.

Adrenal Cortex Hormones↗
PubMed1976

Some questions related to melanocyte-stimulating hormone.

A number of questions remain unsettled about the release of melanocyte-stimulating hormone (MSH) and about its function. Even though relatively few investigators are studying this area, some generalities have emerged during the last 10 years. It now seems that release of MSH from the pituitary is inhibited by a substance present in the hypothalamus. The structure of this physiologic inhibitor of MSH release may still not be considered an established entity but there is evidence for additional mechanisms capable of exerting a fine control on the release of MSH. Contrary to some opinions, the release of MSH does not always occur together with the release of ACTH, and the release of the two hormones can be dissociated in several laboratory and clinical situations. In addition, many studies have shown that the pituitary peptide, MSH, exerts behavioral and electroencephalographic effects in both the rat and man. The hypothalamic peptide Pro-Leu-Gly-NH2 (MIF-I) also has direct effects on the central nervous system that may include alleviation of the symptoms of Parkinson's disease.

Animals↗