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Biomedical subjects

C Miller

Publications and source records attributed to C Miller.

At least 649 records · Page 36Linked to original sources
PubMed1982

Chalktalk.

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Housekeeping, Hospital↗
PubMed1982

Effects of repeated, small aliquot, same donor transfusions of HL-A defined blood on prospective recipients.

A series of HL-A defined, nonrelated blood transfusions given in small aliquots from the same donor to prospective cadaveric and living-related donor recipients has been presented. The results to date show 100% kidney survival in this small series over a relatively short period of time. The rejections noted have been very mild, and easily reversed. Nonspecific antibodies appear to be produced by the recipients in response to the blood, and these antibodies seem to have no negative effect upon kidney survival. This method of small aliquot transfusion to produce the desired effect is cheaper, wastes less blood, is less likely to lead to a CMV or HAA infestation in the transfusion recipient, and appears to be a highly efficient method of producing the desired effect.

Blood Transfusion↗
PubMed1982

Salivation patterns of obese and normal subjects.

The salivation patterns of a group of nine obese and a group of 14 non-obese subjects were studied. Palatable food was presented and salivary responses were measured under two different conditions. In one condition, the subjects expected to eat, and in the other condition did not expect to eat. It was hypothesized that the obese group would exhibit a salivation pattern different from the non-obese group, and that this salivation pattern would be unrelated to whether or not eating was permitted. This hypothesis was not confirmed; no differences were found between the two groups. These findings conflict with those of earlier investigators and possible reasons for this are discussed.

Cues↗
PubMed1982

Transswitching in the treatment of obesity.

Transswitching is a variant of classical conditioning that entails the use of tonic stimuli of relatively long duration in addition to briefer, phasic stimuli which are paired or not paired with the unconditioned stimulus. The same conditioned stimulus can be conditioned to different conditioned responses in different environmental contexts. Using the transswitching procedure, the salivary response to food cues in two obese subjects was modified. The switching agent determined the relative amount of salivation. Techniques that alter alimentary responses to environmental food cues may be helpful in the treatment of obesity.

Adult↗
PubMed1981

Molar pregnancy: early diagnosis by ultrasound.

This report reviews four cases with vaginal bleeding and early ultrasound diagnosis of abnormal pregnancy before nine weeks gestation, who were followed by serial ultrasound examinations and subsequently diagnosed as hydatidiform mole. The findings support the view that hydatidiform mole may arise from a blighted ovum. It is concluded that vaginal bleeding in the first trimester should be investigated by diagnostic ultrasound, and the pregnancy by terminated if an abnormal development has been confirmed.

Adult↗
PubMed1981

Acute impact of an organophosphorus insecticide on microbes and small invertebrates of a mangrove estuary.

The effects of 24 to 72-hr exposure to fenthion (10(1)-10(3) ppb) were determined for a fungal community, nitrogen-fixing microbes, and representative meiofaunal and zooplankton invertebrates of a mangrove ecosystem. Also tested were the abilities of a benthic diatom and of fungi to grow in the presence of fenthion. Acute lethal, growth-inhibiting, or process-disrupting effects were not detected for exposures to less than 500 ppb fenthion. Results are compared with the findings of several other investigations of the impact of fenthion and other organophosphorus insecticides on non-target organisms.

Animals↗
PubMed1981

A K+-selective, three-state channel from fragmented sarcoplasmic reticulum of frog leg muscle.

Sarcoplasmic reticulum (SR) vesicles from frog leg muscle were fused with a planar phospholipid bilayer by a method described previously for rabbit SR. As a result of the fusion, K+-selective conduction channels are inserted into the bilayer. Unlike the two-state rabbit channel, the frog channel displays three states: a nonconducting ("closed") state and two conducting states "alpha" and "beta". In 0.1 M K+ the single-channel conductances are 50 and 150 pS for alpha and beta, respectively. The probabilities of appearance of the three states are voltage-dependent, and transitions between the closed and beta states proceed through the alpha state. Both open states follow a quantitatively identical selectivity sequence in channel conductance: K+ greater than NH4+ greater than Rb+ greater than Na+ greater than Li+ greater than Cs+. Both open states are blocked by Cs+ asymmetrically in a voltage-dependent manner. The zero-voltage dissociation constant for blocking is the same for both open states, but the voltage-dependences of the Cs+ block for the two states differ in a way suggesting that the Cs+ blocking site is located more deeply inside the membrane in the beta than in the alpha state.

Animals↗
PubMed1981

The importance of short term exposure of C3H 10T1/2 cells to polycyclic hydrocarbons: evidence for hydrocarbon-mediated anticarcinogenic activity.

Since it has been shown that transformation frequencies (TF) of cultured mammalian cells exposed to polycyclic aromatic hydrocarbons (PAH) reach a maximum with increasing PAH concentration and then decline, we have examined TF in C3H 10T1/2 CL8 (10T1/2) cells as a function of an additional parameter of treatment, length of exposure. A 15-min exposure to either benzo[alpha]pyrene (BP) or 3-methylcholanthrene (3-MC), at concentrations ranging from 0.3 to 10 micrograms/ml, was sufficient to induce transformation suggesting that in 10T1/2 cells, non-induced enzymes of the cytochrome P-450 system are involved in the metabolic activation of PAH. At lower BP concentrations (0.3-1.25 micrograms/ml), TF generally increased with exposure time; at higher BP concentrations (2.5-10 micrograms/ml) maximal TF were achieved with 3 h of exposure. For 3-MC, maximal TF occurred at 0.5-1 h with a concentration of 10 micrograms/ml and at 1-6 h with lower concentrations. Moreover, low TF were obtained after 12-h and 24-h exposures to 10 micrograms/ml BP or 3-MC. These results show that TF depend on both the length of exposure and concentration of PAH. Since both BP and 3-MC are extensively metabolized to polyoxygenated derivatives and conjugates, we suggest that certain metabolites may be anticarcinogenic or antipromoting agents. The identities of such metabolites are yet to be determined.

Animals↗
PubMed1981

Chloride permeability of membrane vesicles isolated from Torpedo californica electroplax.

The Cl- permeability of membrane vesicles prepared from the electric organ of the marine ray Torpedo californica was studied by means of radioactive tracer exchange and by measuring the changes in the scattered-light intensity caused by osmotically induced volume changes. Both types of experiments indicate that a substantial fraction of the vesicles is extremely permeable of Cl-. Furthermore, this permeability pathway is inhibited by 4,4'-diisothiocyano-2,2'-disulfonic acid stilbene, a well-known inhibitory of anion transport in a variety of systems. The properties of this permeability pathway are consistent with its identification as the voltage-aged Cl- channel studied in planar bilayers.

Animals↗
PubMed1981

Probes of the conduction process of a voltage-gated Cl- channel from Torpedo electroplax.

The open-channel conductance properties of a voltage-gated Cl- channel derived from Torpedo californica electroplax and incorporated into planar bilayers were studied by several approaches. In neutral bilayers the channel conductance saturates with Cl- activity according to a rectangular hyperbolic relation with a half-saturation activity of 75 mM and a maximum conductance of 32 pmho. The observation of identical behavior in charged membranes implies that ions permeating the channel do not sense the surface potential of the bulk membrane. The Cl-:Br- permeability ratio, measured under biionic conditions, is independent of salt concentration. SCN- ion reversibly blocks the channel. The voltage dependence of the block implies the existence of two separate blocking sites within the channel: one accessible from the cis side only (the side to which vesicles are added) and the other accessible from the trans side only. The block at each site is competitive with Cl-. The results are consistent with a single-ion Eyring model of the conduction process in which the ion must traverse three kinetic barriers as it permeates the channel and in which the channel can accommodate at most one ion at a time.

Animals↗
PubMed1981

Isolation and characterization of cloned DNA: the delta and beta globin genes in homozygous beta + thalassemia.

We have isolated and characterized a clone of human DNA from a patient with beta+ thalassemia containing the entire delta and beta structural genes and their flanking sequences. Partial Eco RI digestion of spleen DNA was used to obtain 15 to 20 kilobase (kb) pieces of human DNA that were then ligated to charon 4A lambda phage DNA. The 8 x 10(5) recombinants obtained were grown and screened for their content of beta gene sequences. Four positive clones were found, and one (beta T1-1) has been extensively analyzed. Subclones containing the entire beta gene and the large beta intervening sequence (IVS 2) have been isolated in the plasmid pBR 322. The fragments generated by restriction enzyme digestion in these subclones have been compared to those in similar subclones from normal beta genes. No differences have been found indication no significant rearrangements of deletions of the delta and beta genes. With the enzymes used, 11.2% of IVS 2 have been compared, and thus far no differences between the thalassemic and normal genes have been detected. The 24 enzymes used include Hph I, which recognizes the 5' end of IVS 2, and AIu I that cleaves at the 3' end. Thus, there appears to be conservation of nucleotide sequences at the ends of IVS 2 in this beta + thalassemia patient, although RNA metabolism studies suggest a possible defect in RNA processing.

Adult↗