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Biomedical subjects

C L Barnes

Publications and source records attributed to C L Barnes.

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

An Rh-105 complex of tetrathiacyclohexadecane diol with potential for formulating bifunctional chelates.

1,5,9,13-Tetrathiacyclohexane-3,11-diol (16S4-diol), a sulfur crown ether analog, was studied as a potential chelating agent to complex no-carrier-added (NCA) grade 105Rh(III) in high yield at low ligand concentrations. trans-[RhCl2(16S4-diol)]chi (chi = Cl, PF6) was prepared using nonradioactive RhCl3.3H2O and characterized by UV-Vis, nuclear magnetic resonance (NMR) and X-ray crystallography. It was shown to have a +1 charge with the Rh(III) metal center coordinated to the four S atoms equatorially and two Cl atoms in trans axial positions. The 105Rh-16S4-diol complex prepared with NCA 105Rh(III)-chloride reagent was found to exhibit identical chromatographic properties as trans-[Rh(III)Cl2(16S4-diol)]+ (including silica and C-18 thin-layer chromatography [TLC] and electrophoresis). The preparation of 105Rh-16S4-diol complex formation optimized for conditions of pH, temperature, time, % ethanol and quantity of 16S4-diol resulted in yields > 90%. Very low quantities of 16S4-diol (3 nmol) complex NCA 105Rh(III) under relatively mild reaction conditions (heating at 64 degrees C for 90 min) in the presence of ethanol (10%), yielded the high specific activity 105Rh-16S4-diol complex as a single cationic species. The 105Rh-16S4-diol complex was shown to be stable for > or = 4 days in physiological buffers at room temperature and in human serum at 37 degrees C.

Chelating Agents↗
PubMed1996

Age as a prognostic factor in open tibial fractures in children.

Thirty-one consecutive open fractures of the tibia were reviewed prospectively. Duration from injury until last examination averaged 3.7 years. The patients were divided into 2 groups for comparison: Group A consisted of children younger than 12 years of age and Group B of patients 12 years of age or older. The fractures were graded according to the system of Gustilo and Anderson. The severity of patient injuries in each group was similar. The treatments were likewise similar, but for all parameters studied, the younger patients fared better than their older counterparts. This study suggests that open fractures in children younger than 12 years of age require less aggressive surgical treatment, heal faster, are more resistant to infection, and have fewer complications than those in older children.

Adolescent↗
PubMed1995

The reaction of D-glucose with aminoguanidine.

The reaction of D-glucose with aminoguanidine was examined at pH 7.0 and 37 degrees C (phosphate buffer). Under these conditions, the reaction requires ca. 42 days for 50% of the sugar to react, as measured by the disappearance of D-glucose, and at 60 degrees C all the aminoguanidine had reacted within 72 h. The initial product, a beta-D-glucopyranosyl aminoguanidine (1) was obtained in the crystalline state as the trifluoroacetate salt. Data collected on this compound suggests that, in solution, it is largely a glycosylamine in the beta pyranose form. Acetylation gave a crystalline heptaacetate (2), which, in solution (as evidenced by NMR spectroscopy) exists in two different conformational forms. The crystal structure of the heptaacetate also includes two conformers. Both crystallographically independent molecules are in the normal beta pyranose form, with the acetylated guanyl residue occupying different spatial positions relative to the ring.

Carbohydrate Conformation↗
PubMed1995

Crystal structure of an Amadori compound, N-(1-deoxy-beta-D-fructopyranos-1-yl)-glycine ("D-fructose-glycine").

The first crystal structure data on an Amadori compound, N-(1-deoxy-beta-D-fructopyranos-1-yl)-glycine, are reported. The space group is P2(1) with Z = 2 and cell parameters a = 7.246(1), b = 10.009(1), c = 7.060(1) A, and beta = 101.085(6) degrees. The structure was solved by direct methods and refined to a final R of 2.9% and Rw of 3.8% for 1385 reflections to give esd's of 0.002 A in bond lengths and 0.2 degree in angles. The conformation of the carbohydrate is the normal 2C5 pyranose chair. Bond lengths and valence angles compare well with average values from a number of pyranose structures. The molecule of the Amadori compound exists in the zwitterion form and has the C-6-O-6-C-2-C-1-N-C-2'-C-1'-O-1' chain in a zig-zag conformation, that is (together with O-2') substantionally planar. All hydroxyl, carboxyl, and ring oxygen atoms, and the secondary ammonium group are involved in hydrogen bonding, which forms a three-dimensional network of two infinite chains that have an ammonium group as a common segment. The shortest intra- and inter-molecular hydrogen bonds involved donors of the pyranosyl moiety and acceptors of the amino acid portion, and vice versa.

Crystallization↗
PubMed1995

Beta-particle dosimetry in radiation synovectomy.

Beta-particle dosimetry of various radionuclides used in the treatment of rheumatoid arthritis was estimated using Monte Carlo radiation transport simulation coupled with experiments using reactor-produced radionuclides and radiachromic film dosimeters inserted into joint phantoms and the knees of cadavers. Results are presented as absorbed dose factors (cGy-cm2/MBq-s) versus depth in a mathematical model of the rheumatoid joint which includes regions of bone, articular cartilage, joint capsule, and tissue (synovium) found in all synovial joints. The factors can be used to estimate absorbed dose and dose rate distributions in treated joints. In particular, guidance is provided for those interested in (a) a given radionuclide's therapeutic range, (b) the amount of radioactivity to administer on a case-by-case basis, (c) the expected therapeutic dose to synovium, and (d) the radiation dose imparted to other, nontarget components in the joint, including bone and articular cartilage.

Arthritis, Rheumatoid↗
PubMed1995

Crystallization and structure determination of RNA.

Progress in the synthesis, purification and crystallization of RNA has resulted in the determination of several X-ray crystal structures of RNA molecules over the past few years. Methods proven and under development will lead to future structure determinations and shed light on the structural basis for RNA's many functions.

Crystallization↗
PubMed1995

Popliteus tendon dysfunction following total knee arthroplasty.

The popliteus tendon can be a potential source of internal derangement after total knee arthroplasty. It can subluxate anteriorly and posteriorly over a retained lateral femoral condylar osteophyte or over the overhanging edge of the metallic posterior femoral condyle. Surgical release of the tendon from its femoral insertion relieves the problem.

Aged↗
PubMed1995

Dislocation after bipolar hemiarthroplasty of the hip.

Although bipolar hemiarthroplasty of the hip is a frequently performed procedure, little information is available about the frequency of postoperative dislocation and its treatment. For this study, 1,934 hips treated consecutively with primary bipolar hemiarthroplasty were reviewed. A postoperative dislocation developed in 29 patients (1.5%): during the first month after surgery in 24 patients and between 1 month and 5 years after surgery in five patients. Of the 29 dislocations, 25 were successfully reduced with with routine closed methods. Among these 25 hips, 13 (52%) subsequently redislocated, and 7 of these required operative treatment for the recurrent dislocation. Dislocation after primary bipolar hemiarthroplasty is infrequent, can usually be reduced by routine closed methods, but is associated with a high rate of recurrent dislocation.

Adolescent↗
PubMed1995

Parent caregivers: a comparison of employed and not employed daughters.

A major task for social workers is sorting out the kinds of assistance needed by families who care for an elderly parent. In particular, information is needed about the differential effects of employment on daughters who care for their elderly parent. This study describes parental caregiving among three groups: daughters who were employed, daughters who were never employed while caregivers, and daughters who ended their employment to continue caregiving. The effects of caregiving on these three groups, as well as the daughters' involvement with care tasks and use of formal and informal assistance, are examined.

Adult↗
PubMed1994

Intra-articular radiation treatment of rheumatoid synovitis of the ankle with dysprosium-165 ferric hydroxide macroaggregates.

Intra-articular radiation treatment using dysprosium-165 ferric hydroxide macroaggregate has been performed on eight patients with refractory synovitis of the ankle. Seventy-five percent (six patients) responded well to the treatment, and there were no complications from the injection. Although ankle synovectomy is not often indicated, those patients with rheumatoid synovitis without significant joint destruction respond favorably to radiation treatment.

Adult↗
PubMed1994

Catastrophic failure of the polyethylene liner of uncemented acetabular components.

Ten cases are described of catastrophic failure of the polyethylene liner of three different designs of uncemented acetabular component. Failure occurred as a result of either 'wearthrough' to the metal backing, liner fracture or a combination of both, at a mean of 4.6 years after implantation (2 to 7.6). At revision there was metallosis in all hips and osteolysis of the femur or the pelvis in six. Catastrophic failure was seen only in cups with a minimum polyethylene thickness of less than 5 mm.

Acetabulum↗
PubMed1993

Two new modified trichothecenes from Fusarium sporotrichioides.

Two new modified trichothecenes, 2-deoxy-11-epi-3 alpha-hydroxysambucoin [1] and 2-deoxy-11-epi-12-acetyl-3 alpha-hydroxysambucoin [2], were isolated from Fusarium sporotrichioides culture. This is the first report of modified trichothecenes where the two six-membered rings are cis-fused. Structures were elucidated using gc-ms, nmr, X-ray crystallography, and other spectroscopic techniques. Compounds 1 and 2 were screened for relative cytotoxicity in cultured baby hamster kidney (BHK-21) cells and found to be non-toxic.

Animals↗
PubMed1993

Cetirizine: a new, nonsedating antihistamine.

OBJECTIVE: To introduce cetirizine, a nonsedating antihistamine, and discuss its mechanism of action, chemistry, clinical and comparative trials, and adverse effects. DATA SOURCES: An English-language literature search of MEDLINE was conducted. STUDY SELECTION: Human clinical trials were selected for evaluation. DATA SYNTHESIS: Cetirizine, an investigational agent and a potent histamine1-antagonist is a piperazine derivative and carboxylated metabolite of hydroxyzine. As a second-generation, nonsedating antihistamine, cetirizine is associated with fewer adverse effects compared with first-generation antihistamines. It appears to be at least as effective as the other nonsedating antihistamines in the treatment of allergic rhinitis, chronic idiopathic urticaria, and pollen-induced asthma. The recommended adult dosage of this agent is 5 or 10 mg/d. CONCLUSIONS: Clinical studies indicate that cetirizine may be more beneficial in some ways than other available agents. Two of these advantages are a rapid onset of action and a once-daily dosing regimen. Future postmarketing surveillance is warranted to further document these findings.

Asthma↗
PubMed1993

Patellofemoral complications of total knee replacement.

Patellofemoral complications account for the majority of problems following total knee replacement. Many of these problems are technical, and attention to detail at the time of surgery can help avoid them. An understanding of the potential postoperative complications should help one to diagnose these early and prevent catastrophic problems.

Arthritis, Rheumatoid↗
PubMed1992

Efferent cortical connections of multimodal cortex of the superior temporal sulcus in the rhesus monkey.

The cortex of the upper bank of the superior temporal sulcus (STS) in the rhesus monkey contains a region that receives overlapping input from post-Rolandic sensory association areas and is considered multimodal in nature. We have used the fluorescence retrograde tracing technique in order to answer the question of whether multimodal areas of the STS project back to post-Rolandic sensory association areas. Additionally, we have attempted to answer the question of whether the projections from the multimodal areas directed to the parasensory association areas originate from common neurons via axon collaterals or from individual neurons. The results show that multimodal area TPO of the STS projects back to specific unimodal parasensory association areas of the parietal lobe (somatosensory), superior temporal gyrus (auditory), and posterior parahippocampal gyrus (visual). In addition, a substantial number of projections from area TPO are directed to distal parasensory association areas, area PG-Opt in the inferior parietal lobule, areas Ts1 and Ts2 in the rostral superior temporal gyrus, and areas TF and TL in the parahippocampal gyrus. These latter regions are themselves considered to be higher-order association areas. It was also noted that the majority of the projections to these higher-order association areas originate from the middle divisions of area TPO (TPO-2 and TPO-3). These neurons are organized in a significantly overlapping manner. Despite this overlap of the projection neurons, only an occasional double labeled neuron was observed in area TPO. Thus, our observations indicate that the multimodal region of the superior temporal sulcus has reciprocal connections with the unimodal parasensory association cortices subserving somatosensory, auditory and visual modalities, as well as with other post-Rolandic higher-order association areas. These connections from area TPO to post-Rolandic association areas may have a modulating influence on the sensory association input leading to multimodal areas in the superior temporal sulcus.

Animals↗