Search PubMed⌕ Search

Biomedical subjects

R Bryant

Publications and source records attributed to R Bryant.

At least 37 records · Page 2Linked to original sources
PubMed1996

Regulation of murine osteoblast macrophage colony-stimulating factor production by 1,25(OH)2D3.

Macrophage colony stimulating factor (MCSF) is important for formation of osteoclasts. We investigated the ability of 1,25(OH)2D3 to regulate osteoblast production of MCSF. Mouse calvarial osteoblasts were cultured for 2 days +/- 1,25(OH)2D3. Since 1, 25(OH)2D3 decreased osteoblast proliferation by 17.6 +/- 1% at 10 nM and 11 +/- 4% at 1 nM, the effect of growth rate on MCSF secretion was examined. Limiting cell proliferation by serum did not affect MCSF production. 1,25(OH)2D3 (1 nM) increased MCSF production (U/10(5) cells) maximally by 68 +/- 33% (n = 3) with an ED50 for 1, 25(OH)2D3 of 5 x 10(-11) M. To investigate effects of 1,25(OH)2D3 on MCSF gene regulation, RT-PCR primers were designed to identify the mRNA coding for the membrane-bound isoform of MCSF. Simultaneous RT-PCR of glyceraldehyde-phosphate dehydrogenase (GAP) allowed semiquantitative assessment of MCSF mRNA between treatment groups expressed as the MCSF/GAP RT-PCR product ratio; both MCSF and GAP (+) primers were labeled with 32P-ATP for phosphorimage quantitation. The membrane-bound MCSF/GAP PCR product ratio was not affected by proliferative rate when growth was limited by [serum]. The MCSF/GAP RT-PCR product ratio was dose dependently increased by 1,25(OH)2D3, maximally at 1 nM at 2.2 +/- 0.2 = fold (n = 10). 1,25 (OH)2D3 also increased the expression of an RT-PCR MCSF/GAP product ratio which represented the secreted isoform of MCSF. The ability of 1,25(OH)2D3 to pretranslationally regulate expression of membrane-bound osteoblast MCSF may be important in osteoblast:osteoclast interactions.

Animals↗
PubMed1995

Phospholipase D inhibitors from a Myrsine species.

The phospholipase D-inhibitory activity of a methanol extract from the leaves of a New Zealand plant, Myrsine australis, has been attributed to two new saponins 1 and 2. Compound 1 was assigned as 3-0-[-beta-D-xylopyranosyl-(1-->2)-0-beta-D-glucopyranosyl-(1-->4)- -[0-beta-D -glucopyranosyl-(1-->2)]-alpha-L-arabinosyl]-16alpha-hydroxy-+ ++13beta,28-epoxyoleanane and 2 as 3beta-0-[-beta-rhamnopyranosyl-(1-->2)-0-beta-D-glucopyranosyl-(1-->4)-[ 0-beta-D-glucopranosyl]-alpha-L-arabinopyranosyl]-16alpha -hydroxy-13beta, 28-epoxyleanane. Compounds 1 and 2 showed IC50 values of 3 and 2 microM, respectively, versus phorbol 12-myrisate-13-acetate-stimulated phosphlipase D in human promyelocytic leukemic (HL-60) cells. Compounds 1 and 2 also inhibited fMLP (formyl-Met-Leu-Phe) stimulated phospholipase D with IC50 values of 8 and 24 microM, respectively.

Carbohydrate Sequence↗
PubMed1995

Staphylococcus aureus septic arthritis in patients on hemodialysis treatment.

We retrospectively reviewed hospital discharge diagnoses of septic arthritis over an 11-year period (1982 through 1992) at 3 medical centers; 11 episodes of septic arthritis were identified in patients on hemodialysis treatment. Of the 11 episodes, 9 were caused by Staphylococcus aureus; in 8 of 9, the blood cultures were positive for the organism and the infection was monoarticular. Concurrent infection of the dialysis access site occurred in 4 cases. Two patients died (22%). We postulate that repeated skin trauma and contact with health care personnel and facilities result in a high rate of nasal carriage of S aureus and, hence, an increased risk of bacteremia with its attendant complications such as septic arthritis. The use of mupirocin nasal ointment is reported to eradicate or suppress carriage in a high percentage of patients; some studies report that long-term suppressive therapy reduces the frequency of S aureus bacteremia.

Administration, Intranasal↗
PubMed1993

Root canal morphology of maxillary permanent first molar teeth at various ages.

The root canal anatomy and pulp chamber morphology of 216 maxillary permanent first molar teeth of known age was examined using a radiographic technique after infusion of the root canal system with a radiopaque sodium iothalomate gel. This technique proved to be a rapid and effective method for the examination of root canal morphology and is recommended when root canal anatomy needs to be examined before further investigations are carried out. Over 95% of palatal and disto-buccal roots contained a single root canal. The mesio-buccal root was more complex. All types of configurations were seen. Only 26% of mesio-buccal roots showed a single canal. The pulp canal in all roots appeared to narrow at an early age. In the mesio-buccal root, a definite two-directional calcification pattern was apparent in most teeth by the age of 10. The rate of progress of root formation was very variable. There was no apparent relationship between the type of canal system in the mesio-buccal root and the type of canal orifice present. The transverse cross-sectional shape of the pulp chamber was trapezoidal in 81% of teeth.

Adolescent↗
PubMed1991

A measure of linear influence between patient and therapist.

This paper describes the application of the cross-correlation function (CCF) to four quantified dimensions of the therapeutic consultation dialogue: newness of themes, degree of narration, and positive and negative thematic tone of images. A 10-min. window was used to study lag relationships in both directions of effect--from therapist to patient and the reverse. This measure of linear influence was applied to six psychotherapeutic consultation sessions carried out by different well known psychoanalysts with two women patients. Analysis showed a range of significant CCF effects that totaled from zero to 1360 sec. depending on the consultation. The implications of these and other findings are discussed in the context of viewing the present study as part of a program of investigations into the nonexperimental nature--the underlying laws, structures, and transactions--of therapeutic and everyday emotional dialogues.

Communication↗
PubMed1990

Public health implications of the microbial pesticide Bacillus thuringiensis: an epidemiological study, Oregon, 1985-86.

Bacillus thuringiensis var. kurstaki (B.t.-k) is a microbial pesticide which has been widely used for over 30 years. Its safety for a human population living in sprayed areas has never been tested. Surveillance for human infections caused by B.t.-k among Lane County, Oregon residents was conducted during two seasons of aerial B.t.-k spraying for gypsy moth control. Bacillus isolates from cultures obtained for routine clinical purposes were tested for presence of Bacillus thuringiensis (B.t.). Detailed clinical information was obtained for all B.t.-positive patients. About 80,000 people lived in the first year's spray area, and 40,000 in the second year's area. A total of 55 B.t.-positive cultures were identified. The cultures had been taken from 18 different body sites or fluids. Fifty-two (95 percent) of the B.t. isolates were assessed to be probable contaminants and not the cause of clinical illness. For three patients, B.t. could neither be ruled in nor out as a pathogen. Each of these three B.t.-positive patients had preexisting medical problems. The level of risk for B.t.-k and other existing or future microbial pesticides in immunocompromised hosts deserves further study.

Abscess↗
PubMed1989

Experience with minimal complications in implanted catheters in children.

Eighty-two patients, ranging in age from 11 months to 24 years, underwent the percutaneous placement of an implanted catheter in order to have improved venous access. Thirty-five patients (43%) were beginning chemotherapy for cancer, four (5%) had a chronic hematologic disorder, and the remaining 43 (52%) were on chemotherapy for cancer. The mean duration of catheter function was 168 days (range of 7-1,030 days), with a cumulative experience of 18,812 days of catheter use. Complications were minimal. Only four catheters (5%) required removal secondary to infection, infiltration, or tissue breakdown. Substantially reduced complication rates were observed as compared to other studies using implanted central venous catheters. Implanted central venous catheters were proven to be safe in patients with hematologic disorders. These catheters enhance the ability to infuse chemotherapy, hyperalimentation, blood products, anesthesia, and imaging solutions and are safe to use in patients with a hemostatic or host defense deficiency.

Adolescent↗