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Biomedical subjects

C A Miller

Publications and source records attributed to C A Miller.

At least 235 records · Page 13Linked to original sources
PubMed1978

Induction and regulation of neuraminidase synthesis in Arthrobacter sialophilus.

A variety of N-acetylneuraminic acid (AcNeu) derivatives and analogs were examined as inducers of the extracellular neuraminidase of Arthrobacter sialophilus. Neuraminidase inductions were primarily studied with tryptone-yeast extract-grown cells after washing and resuspension in a defined replacement medium. The addition of readily metabolizable carbon sources to the latter, such as 0.1% casein hydrolysate, glutamate, or glucose, enhanced enzyme synthesis. Enzyme appearance occurred after a lag in the uptake of inducers, suggesting the participation of a co-inducible transport system. Neuraminidase formation during exponential growth in the presence of AcNeu ceased after depletion of this end product from the medium. It was found, besides AcNeu, that its methyl ester, 2-deoxy-2,3-dehydro-N-acetylneuraminic acid and 2-deoxy-2,3-dehydro-N-acetyl-neuraminic acid methyl ester are each active inducers, whereas beta-anomers of AcNeu-ketosides are not. These results, in comparison to known enzyme specificity, have revealed significant differences and parallels between the inductive and catalytic processes for neuraminidase. In particular, it would appear that the free carboxylate and oxygenation at C-2 of AcNeu, essential for enzyme catalysis with traditional AcNeu substrates, are not necessary for induction and, furthermore, that transition state analogs can specifically induce this enzyme. The failure to observe catabolite repression in this system is discussed in relation to the intermediary metabolism of the genus Arthrobacter.

Arthrobacter↗
PubMed1978

The relation of cerebral ischemia, hypoxia, and hypercarbia to the Cushing response.

A marked increase in intracranial pressure (ICP) produces a concomitant increase in systemic blood pressure (the Cushing response). In this study a comparison is made between this response of systemic blood pressure to increased ICP and the blood pressure responses produced by ischemia, hypoxia, and hypercarbia of the primate brain. A carotid-to-carotid cross-perfusion system was used to produce a purely cerebral hypoxia and hypercarbia. Each stimulus, except hypercarbia, produced a hypertensive response that was qualitatively and quantitatively similar. These responses were characterized by a short latent period, a rapid development, and an increase in mean arterial pressure of 60% or more. The similarity of the responses suggests that these stimuli act through a final common pathway independent of the purely mechanical effects of increased ICP upon the brain.

Animals↗
PubMed1978

A national health program for infants, children and youth.

Health care in the United States is widely considered to be a right of infants, children and youth. With our current national concern for the increase in the cost of health care, children and youth represent a possible candidate population for early special coverage under a national health program.

Adolescent↗
PubMed1978

Detection of lipopolysaccharide in suspected bacteriuric urine using a carbocyanine dye.

Currently practiced methods for the detection of gram negative bacteriuria require culturing and overnight incubation. Such an approach to bacteriuria detection is unacceptable for any screening program which requires rapid presumptive evidence of infection. In this study, the lipopolysaccharide-dependent formation of a unique dye absorption spectra of the cationic carbocyanine dye, 1-ethyl-2-[3-(1-ethylnaphtho[1,2d]-thiazolin-2-ylidene)-2-methylpropenyl] naphtho[1,2d]-thiazolium bromide, was used to detect bacteriuria caused by gram negative organisms in a hospitalized population. In an evaluation of 168 first morning and randomly collected suspected bacteriuric urines, the dye test detected 66% of the loop plate positive urines with false positive and false negative values of 28% and 34%, respectively. However, 37% of the false positive results occurred in urines containing less than 10(5) gram negative bacteria/ml and an additional 24% of the false positives were seen for patients currently receiving antibiotic treatment. Urine specimens were also evaluated using the limulus lysate assay for lipopolysaccharide.

Bacteriuria↗
PubMed1978

The cerebral malformation of the amnionic band syndrome.

The Amnionic Band Syndrome is a not uncommon disorder of the fetus which may result in cerebral malformations that mimic anencephaly. It is important to distinguish these two entities because of differences in pathogenesis and risk of recurrence. A preliminary stillborn female of 29 weeks gestation with multiple anomalies, including cerebral-placental fusion, cranial agenesis, cleft lip, syndactyly and ectopic liver is presented. These malformations are typical of the Amnionic Band Syndrome, an entity which has not been described in the neurologic literature.

Abnormalities, Multiple↗
PubMed1977

Inhibition of histidine decarboxylase. Derivatives of histidine.

Twenty-eight derivatives of histidine were tested as inhibitors of histidine decarboxylase from rat stomach. Potent inhibition was observed with the methyl ester of L-histidine (1) which had a Ki = 1.8 X 10(-6) M. Substitution on 1 at various positions resulted in a decrease or complete loss of inhibition. Substituent requirements for inhibition of histidine decarboxylase are discussed. A simple disposable apparatus for the radiometric assay of histidine decarboxylase is described.

Animals↗
PubMed1977

A survey of local public health departments and their directors.

In 1974 a questionnaire was mailed to the nation's local health officers. Responses were received from 1,345, at least 68 per cent of all local health departments. The present paper presents selected summary data from respondents concerning the health departments, their jurisdictions, organization, finance, functions, staffing, and about the training, salaries, and other characteristics of local health officers. Health departments are extensively involved in rendering health services, including direct personal services (25 per cent of all departments). For many services the health department is the sole provider of essential services in the area of jurisdiction. These services include ambulatory care (8 per cent), maternal and child health (48.5 per cent), home care (44.8 per cent), and family planning (38 per cent). The major constraints to improvement and expansion of programs are perceived as limited financial support, insufficient staff, and inadequate facilities.

Administrative Personnel↗
PubMed1977

Statutory authorizations for the work of local health departments.

A study of public health statutes of the 50 states identifies 44 specific services or functions that are assigned to local health departments by all or some of the states. Authorizations are most commonly assigned conjointly both to local and state health departments; exceptions are identified. Data suggest striking inconsistencies between what local health departments are authorized to perform and the services they actually render with regard to a selected group of programs that involve personal health services. The full scope of authorizations for local health departments is not revealed by examination of public health statutes. For this reason, among others, development of up-to-date health codes for all states would be beneficial.

Humans↗
PubMed1977

Maternal serum unconjugated estriol and urine estriol concentrations in normal and high-risk pregnancy.

Serum unconjugated estriol levels and urinary estriol levels of concurrent specimens were compared for 6 normal and 6 high-risk subjects throughout the last trimester of pregnancy. Free estriol values in serum exhibited a close correlation with urinary estriol values for both the normal (r = 0.91) and high-risk (r = 0.92) groups. The results of this study indicate that the assessment of high-risk pregnancies now accomplished principally by urinary estriol assays may be performed by more convenient and rapid radioimmunoassays developed for quantification of free estriol in serum.

Estriol↗
PubMed1977

A rapid radioimmunoassay for serum unconjugated estriol with a directly iodinated estriol radioligand.

Radioiodinated estriol not previously derivatized was found to be immunoreractive and is shown to possess Sephadex-adsorptive characteristics similar to those of tritium-labeled estriol and nonlabeled estriol. Because of these characteristics, radioiodinated estriol is shown to be an acceptable radioligand for use in a rapid and reliable column radioimmunoassay for determination of unconjugated estriol in serum. An evaluation of the estriol column RIA assay with this radioligand is presented.

Chromatography, Gel↗
PubMed1976

Spinal epidural hematoma.

A diagnosis of acute, cervical, spontaneous spinal epidural hematoma was made in two patients by combining clinical signs and myelographic findings. If surgical decompression can be accomplished early, the results are favorable.

Acute Disease↗
PubMed1976

Bacteriophage phiX174 single-stranded viral DNA synthesis in temperature-sensitive dnaB and dna C mutants of Escherichia coli.

We asked if phiX174 single-stranded DNA synthesis could reinitiate at the nonpermissive temperature in dnaB and dnaC temperature-sensitive host mutants. The rates of single-stranded DNA synthesis were measured after the removal of chlorampheicol that had been added at various times after infection to specifically stop this stage of phiX174 DNA synthesis. Reinitiation was not defective in either mutant host. Our data suggested that the reinitiation of the single-stranded stage of phiX174 DNA synthesis in these experiments was analogous to the normal initiation of this stage of phiX174 DNA synthesis in infections without chloramphenicol. Assuming this to be the case, we conclude that the host cell dnaB and dnaC proteins are not essential for the normal initiation of the single-stranded synthesis stage of phiX174 DNA synthesis. In related experiments we observed that in the dnaC mutant host at the permissive temperature, phiX174 replicative form DNA synthesis continued at its initial rate even during the single-stranded DNA synthesis stage. This indicates that these two stages of phiX174 DNA synthesis are not necessarily mutually exclusive.

Bacterial Proteins↗
PubMed1976

Bacteriophage G4 DNA synthesis in temperature-sensitive dna mutants of Escherichia coli.

The synthesis of bacteriophage G4 DNA was examined in temperature-sensitive dna mutants under permissive and nonpermissive conditions. The infecting single-stranded G4 DNA was converted to the parental replicative form (RF) at the nonpermissive temperature in infected cells containing a temperature sensitive mutation in the dnaA, dnaB, dnaC, dnaE, or dnaG gene. The presence of 30 mug of chloramphenicol or 200 mug of rifampin per ml had no effect on parental RF synthesis in these mutants. Replication of G4 double-stranded RF DNA occurred at a normal rate in dnaAts cells at the nonpermissive temperature, but the rate was greatly reduced in cells containing a temperature-sensitive mutation in the dnaB, dnaC, dnaE, or dnaG gene. RF DNA replicated at normal rates in revertants of these dna temperature-sensitive host cells. The simplest interpretation of these observations is that none of the dna gene products tested is essential for the synthesis of the complementary DNA strand on the infecting single-stranded G4 DNA, whereas the dnaB, dnaC, dnaE, (DNA polymerase III), and dnaG gene products are all essential for replication of the double-stranded G4 RF DNA. The alternate possibility that one or more of the gene products are actually essential for G4 parental RF synthesis, even though this synthesis is not defective in the mutant hosts, is also discussed.

Chloramphenicol↗