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Biomedical subjects

A J Richard

Publications and source records attributed to A J Richard.

At least 37 records · Page 2Linked to original sources
PubMed1987

Effects of diadenosine 5',5'''-P1, P4-tetraphosphate and of adenosine 5'-triphosphate on the higher order structure of calf thymus DNA.

The effective length and the hard core radius were calculated by scaled particle theory for high molecular weight calf thymus DNA in the presence of varying concentrations of diadenosine 5',5'''-P1, P4-tetraphosphate and of adenosine 5'-triphosphate in aqueous millimolar NaCl. DNA became slightly more flexible in the presence of diadenosine 5',5'''-P1, P4-tetraphosphate at concentrations of 10(-9)-10(-7) M. DNA was denatured in the presence of 5 X 10(-5) M adenosine triphosphate.

Adenine Nucleotides↗
PubMed1987

A comparison by ultracentrifugation of the effects on DNA of ethidium bromide and of acridine orange at low ionic strength.

The application of scaled particle theory to the gels formed by DNA in the ultracentrifuge has provided values for the effective length and the effective radius of the DNA particle. Ethidium bromide has been shown to cause extensive lengthening of the DNA in dilute salt. Acridine orange interaction with DNA resulted in modest changes in DNA dimensions. These results are explained in terms of binding for acridine orange and of denaturation of DNA by ethidium bromide.

Acridine Orange↗
PubMed1983

Factors influencing bonding of bromelain agglutinators and their Fab fragments.

The complex of bromelain agglutinators and their homologous Fab fragments is dissociated by gel chromatography under certain conditions. When albumin is present as a source of thiol groups, Fab fragments previously treated with N-ethylmaleimide (NEM) will dissociate from the agglutinators (fluid phase). If anti-Rh Fab fragments are bound to Rh-positive erythrocytes, the agglutinates are not dissociated by thiols (cellular phase). Prior to erythrocyte sensitization, the agglutinator site on Fab fragments can be blocked by thiol-disulfide exchange. Once the Fab fragments are coated on erythrocytes, the agglutinator site is more readily available than it was prior to sensitization, as evidenced by inhibition with 0.01 M NEM. The differences between the bonding characteristics of the fluid phase and the cellular phase and the influence of mercaptoalbumin on the agglutinator-Fab complex suggest that the agglutinators are not antibodies.

Antibodies, Anti-Idiotypic↗
PubMed1976

The frequency of 7S rheumatoid factors and 22S complexes in human sera with positive latex tests for rheumatoid factor.

In sera with positive latex tests for rheumatoid factors, the immunoglobulin class of the antiglobulins is influenced by the quantity of immunoglobulins present in the serum. Sera with 7S antiglobulins have high levels of IgG and IgA immunoglobulins. 22S complexes tend to be found in sera with high levels of IgM immunoglobulins. These findings suggest that the occurrence of antiglobulins and 22S complexes may be influenced by the hypergammaglobulinemia.

Adsorption↗
PubMed1975

Ultracentrifugal study of effect of sodium chloride on micelle size of fusidate sodium.

Apparent micellar molecular weights were determined with the antibiotic fusidate sodium by ultracentrifugation in varying counterion concentrations (Na+). The effects of buffer salts, pH, sodium chloride concentration, and drug concentration were studied. The results strongly support the concept of the formation of primary micelles composed of five monomer units, followed by aggregation of the pentomers into larger micelles as salt concentration increases.

Buffers↗
PubMedDate not supplied

Managed care, cost-effectiveness, and rehabilitation: the case of HIV.

Because of its cost-effective approach to impairment and disability, rehabilitation therapy is uniquely positioned to assume a significant role in today's healthcare environment. As the cost of health care has become a major concern, both the government and the private insurance industry have turned toward rehabilitation services as resources for preventing more costly use of the healthcare system in the future. Although funding in the area of injury research scarce, funding for demonstrating the success of therapies for chronic illness such as HIV is more plentiful. In the case of HIV, rehabilitation nursing techniques and principles can be used as a model for reducing the substantial social costs of the disease. Specifically, rehabilitation nurses can assume a leadership role as service coordinators for HIV-positive patients. If rehabilitation nurses perform this role effectively and participate fully in research efforts aimed at measuring the success of rehabilitation therapy, their efforts have the potential of permanently raising the status of the rehabilitation nursing specialty.

Cost-Benefit Analysis↗
PubMedDate not supplied

Mediators of drug treatment outcomes.

Treatment for drug use, like the process by which a person comes to use illicit drugs, may be seen to be at least in part a psychosocial process involving emotional, cognitive, and relationship domains. Treatment programs attempt to improve the psychosocial functioning of clients with the ultimate goal of effecting change in drug-use behaviors. In a longitudinal study of clients in an intensive outpatient treatment program using a cognitive behavioral model to treat crack cocaine use, it was found that length of treatment was directly associated with improvement in emotional well-being, cognitive functioning, and relationships. Of the three psychosocial domains, improvement in relationships had the strongest effect on self-reported decreases in cocaine usage, verified by urinalysis. Improvement in cognitive functioning had a small impact on cocaine use, whereas improvement in emotional well-being had almost no independent effect in this cognitive behavioral treatment program.

Adult↗
PubMedDate not supplied

Effectiveness of adjunct therapies in crack cocaine treatment.

Although intensive outpatient therapy is recommended for treatment of cocaine, psychosocial characteristics associated with crack cocaine abuse are also implicated in attrition from outpatient programs. Acupuncture, medications, and brainwave therapy (biofeedback), have all been used to encourage treatment retention and drug use outcomes. The effectiveness of three adjunct therapies in improving retention and drug use outcomes in intensive outpatient cocaine treatment was tested in a primarily young, indigent African-American sample of crack cocaine users at a community hospital in a low-income, high drug use neighborhood in Houston. Subjects were assigned to receive either neurobehavioral treatment alone or neurobehavioral with one of three adjunct therapies. These included acupuncture, anticraving medication, or brainwave therapy. Comparative results indicated that dosage of any adjunct therapy was associated with days in treatment and standard treatment sessions attended, and that standard treatment sessions attended was associated with negative urinalysis results at follow-up. None of the adjunct therapies were directly associated with drug use outcomes.

Acupuncture Therapy↗