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Biomedical subjects

M E Miller

Publications and source records attributed to M E Miller.

At least 235 records · Page 13Linked to original sources
PubMed1981

Regulatory mechanism of erythropoietin production: effects of hypoxemia and hypercarbia.

The purpose of this study was twofold: (1) to define the relationship between erythropoietin (Ep) production and some of the coincident variables which control oxygen delivery in hypoxic and hypoxic-hypercarbic rats (2) to define the mechanism whereby hypercarbia suppresses Ep production in hypoxemic rats. Rats were exposed to O2 concentrations ranging from 5% to 9% O2 for either 3 or 16 h. Arterial whole blood pH, pCO2, pO2, O2 saturation, p50 and Ep levels were measured in each rat. There was a highly significant inverse correlation between both the arterial pO2 and O2 saturation and the Ep level. Ep levels were not increased above normal if the pO2 was greater than 50 mm Hg or the O2 saturation was greater than 80%. The addition of 5% CO2 to all inhaled gas mixtures was associated with a 10 mm Hg increment in the pO2 together with a marked reduction in plasma Ep levels. Of the measured variables only the pO2 and O2 saturation showed a consistent correlation with the Ep levels when rats exposed to hypoxia were compared with rats exposed to hypoxia + CO2.

Alkalosis, Respiratory↗
PubMed1981

Short umbilical cord: its origin and relevance.

A short umbilical cord was found in newborns for whom there was evidence of early intrauterine constraint and in those with gross structural or functional limb defects that limited intrauterine movement. These findings were interpreted as showing that umbilical cord growth occurs in response to tensile forces relating to intrauterine space availability and fetal movement during early development. Thus, the finding of a short umbilical cord may indicate diminished fetal movement from either early intrauterine constraint or fetal limb dysfunction.

Female↗
PubMed1981

Cell elastimetry in the detection of antineutrophil antibodies.

Cell elastimetry has been applied to the measurement of antineutrophil antibodies. This technique measures, under direct visualization, the negative pressure required of aspirate PMNs into small-pored pipettes. Two groups of studies were carried out: (A) In the first group of studies, normal PMNs were incubated with 1 of 8 known antineutrophil serums. Each serum significantly decreased membrane deformability--i.e., cells became more rigid. The study was conducted in an entirely blind fashion. Randomly coded serums from patients and controls were studied for deformability by observers unaware of the code. (B) In the second group of studies, sera containing immune complexes were incubated with normal PMNs. No significant effects were noted upon deformability. As a single cell assay that partially reflects membrane rigidity, elastimetry may, therefore, have potential in the further characterization of mechanisms by which such antineutrophil antibodies compromise neutrophil functions.

Adult↗
PubMed1981

Further evidence of the in vivo role of erythropoietin or companion molecules induced by hypoxia on proliferation and continuing differentiation of BFU-e in PCDC.

Normal and plethoric bone marrow cells were grown in plasma clot diffusion chambers (PCDC) implanted into the peritoneum of normal mice or mice submitted to 7 her of hypoxia (23,000 ft) daily, on a single day or on 2 consecutive days at different times after implantation of the PCDC's. Daily discontinuous hypoxia (DDH) produced more 6-day bursts than other treatments. Hypoxia on days 1 and 2 after implantation was nearly as effective as DDH on day-6 bursts. Later bouts of hypoxia or a singly hypoxic exposure on day 1 or 2 was less effective. Erythropoietin (Ep) levels were measured by bioassay on both diffusion chamber (DC) contents and serum. Serum Ep levels peaked at 160 mU/ml after a 7-hr hypoxic exposure while the DC content Ep levels were in the nondetectable range (less than 50 mU/ml). The data implies that either higher than normal Ep levels or a companion molecules (s) produced by hypoxia are required for 1-2 days early in the culture period of force an increasing number of BFU-d-e down the erythrocytic pathway and thus increase red cell production at times of need in vivo.

Animals↗
PubMed1980

Limb reduction anomalies and early in utero limb compression.

Seven instances of limb reduction defects are reported with a presumed common underlying etiologic theme of early in utero limb compression, deduced as being due to a bicornuate uterus in four instances, a large fibroid in one instance, and early amnion rupture with transient amniotic fluid loss in two instances. Similar types of limb reduction defects have been experimentally produced as a consequence of early withdrawal of amniotic fluid with resultant compression of the developing limbs, leading to vascular disruption. A similar mechanism is hypothesized to have caused these seven instances of limb reduction defects.

Adult↗
PubMed1980

Cutaneous infections and disorders of inflammation.

In 1908, the Nobel Prize in Physiology and Medicine was shared by Elie Metchnikoff and Paul Ehrlich. Their joint commendation acknowledged the vigorous debate which then existed and, in a sense, paved the way for our modern recognition that both cellular and humoral mechanisms might participate in immunity. Of Ehrlich's and Metchnikoff's many accomplishments, those concerning the basic nature of the inflammatory reaction suggested a clinical potential that has been realized only in the last decade. Central to their theories was the implication that normal inflammatory processes were of benefit to the host and that disordered inflammation was likely to lead to disease. Over the past decade or so, we have recognized an extensive set of diseases associated with primary or acquired deficiencies of inflammation, thus beginning to catch up to the genius of Ehrlich and Metchnikoff. Most, if not all, of these disorders demonstrate major cutaneous involvement in their clinical and biologic presentations. It is thus of essential importance that the dermatologist be familiar with this fascinating spectrum of disease, and it is to this end that this review is directed.

Complement System Proteins↗
PubMed1980

Breast milk lymphocyte response to K1 antigen of Escherichia coli.

Comparison milk and blood lymphocyte blastogenic responses to the K1 antigen of Escherichia coli and lipopolysaccharide (LPS) from E. coli O127,B8 were examined in 16 postpartum women by [3H]thymidine uptake. Rabbit hemolysincoated sheep erythrocyte monolayers were used to deplete macrophages from milk lymphocyte preparations and to enrich for T lymphocytes in order to make milk preparations more comparable to blood preparations. Response was defined as a stimulation index of greater than or equal to 2.0. There was no evidence of selective response to K1 antigen by milk lymphocytes, since both blood and milk lymphocytes responded in four women and neither blood nor milk lymphocytes responded in nine. Milk lymphocytes alone responded to K1 in one woman, whereas blood lymphocytes alone responded in two women. Additional nonpaired milk or blood cultures were available from three women. None of these responded to K1 antigen. Corresponding lymphocyte cultures were stimulated with LPS. A positive K1 response was always accompanied by an LPS response, and the LPS response correlated with the K1 response in 17 of 19 women. Stool cultures examined with an antiserum agar showed no correlation between the presence of K1 E. coli in the stool and milk or blood lymphocyte response to K1 antigen. In the system used here, no selectivity of response of breast milk lymphocytes to K1 antigen was noted.

Antigens, Bacterial↗
PubMed1979

Uterine malformation and fetal deformation.

Beyond the enhanced miscarriage and prematurity associated with the structurally abnormal uterus, we have found 14 examples of fetal deformation secondary to uterine malformation with its consequent uterine constraint. In several instances the constellation of deformations had been misinterpreted as a multiple malformation disorder. One patient died of pulmonary hypoplasia, but all the survivors showed restoration toward normal form postnatally. Recognition of the basic problem allows for surgical reconstruction of the uterus, which is generally accompanied by an improved outlook for subsequent pregnancies.

Congenital Abnormalities↗
PubMed1979

Comparison of microchromatography and electrophoresis with elution for hemoglobin A2 (Hb A2) quantitation.

Microcolumns prepared in the authors' laboratory, two commercial microchromatography kits, and electrophoresis with elution were compared for Hb A2 quantitation. Day-to-day imprecision of microchromatographic methods was similar (CV 4.7--6.6%) and somewhat less than electrophoresis with elution (CV 8.0--9.1%). Both commercial kits showed variable imprecision in different lots; one lot of Kit B gave erratic results due to resin leakage. From 49 patient specimens, Kit A microcolumns and those of the authors identified the same 14 patients with an elevated percentage of Hb A2 and showed good correlation (P = 0.90), although Kit A showed constant bias toward higher values. Electrophoresis with elution resulted in a false-positive and a false-negative value, did not correlate well with microcolumns (P = 0.78 and 0.76), and showed proportional bias toward lower values for an elevated percentage of Hb A2. Commercial kits were convenient, relatively quick, and cost-effective. Frozen, stabilized hemolysates performed well for quality control.

Blood Protein Electrophoresis↗
PubMed1979

Modulation of erythropoietin concentrations by manipulation of hypercarbia.

The present studies were done to determine whether preventing the respiratory alkalosis, which is known to occur with acute "hypoxic" stimuli, would lead to alterations in plasma concentrations of erythropoietin (Ep). Rats were subjected to two acute stresses, hypoxia and blood loss, separately and in combination, with and without the added stress of hypercarbia. Hypercarbia in all experimental groups was associated with a decrease in plasma concentrations of Ep. This reduction in plasma Ep with hypercarbia could not be fully explained by the higher arterial pO2S or p50S of the hypercarbic rats. Hypercarbia may have indirectly suppressed Ep production by increasing blood flow to the site of Ep production. Alternatively, the cell of origin of Ep could be sensitive to changes in pH and/or PCO2. It was further demonstrated that neither the onset nor the degree of reticulocytosis could be predicted by the plasma Ep concentrations. It is likely that the removal of red blood cells led to a decrease in marrow transit time with the early emergence of reticulocytes after acute blood loss.

Anemia↗