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Biomedical subjects

C Benson

Publications and source records attributed to C Benson.

At least 37 records · Page 2Linked to original sources
PubMed1995

Neurologic antecedents to patient falls.

Neurological illness often impairs a patient's mental status, sensory /perceptual and motor functions, creating significant disability. These deficits have been identified as factors that increase the fall risk in these patients. A review of the literature reveals three common manifestations of neurologic disease are related to inpatient falls. These antecedents are altered mental status, sensory/perceptual alteration and impaired physical mobility. These antecedents are found to influence a patient's risk to fall to some extent; however, further research is recommended to further quantify the risk.

Accidental Falls↗
PubMed1994

Disseminated Mycobacterium avium complex disease in patients with AIDS.

Disseminated Mycobacterium avium complex (MAC) infection is a common complication of advanced HIV disease that is associated with significant morbidity. After diagnosis of MAC by recovery of organisms from blood or other normally sterile sites, specific treatment with multiple-drug regimens is appropriate and may reduce morbidity. Multiple-drug regimens with agents active against MAC should be employed to reduce the development of drug resistance. Unfortunately, as most clinical trials of anti-MAC agents have lasted 12 weeks or less and have not compared specific agents, the most effective multiple-drug regimen has not been established. The U.S. Public Health Service Task Force on Prophylaxis and Therapy of MAC recommends treatment of disseminated disease with at least two antimycobacterial agents, one of which should be clarithromycin or possibly azithromycin. Ethambutol, which may have an additive or synergistic effect in combination with other anti-MAC agents, is a reasonable second drug. Other agents with activity include rifampin or rifabutin, clofazimine, ciprofloxacin, or parenteral amikacin. A microbiological response may require up to 2 to 8 weeks. The clinical response generally parallels the microbiological response. Rifabutin, which is licensed for prophylaxis of MAC, reduces the incidence of and delays the time to MAC bacteremia. Individuals at highest risk of MAC bacteremia (i.e., CD4+ cell counts of < 75-100 cells/microliters) had the most benefit from rifabutin prophylaxis. Tuberculosis must be ruled out before rifabutin prophylaxis is initiated. Careful observation without prophylaxis is an acceptable alternative for those who are not able to take rifabutin or alternative agents.

AIDS-Related Opportunistic Infections↗
PubMed1994

Management of acyclovir-resistant herpes simplex and varicella-zoster virus infections.

Persons with AIDS who have CD4+ counts < or = 100 and transplant patients, especially bone marrow allograft recipients, may experience clinically significant infections with acyclovir-resistant herpes simplex virus (HSV) or varicella-zoster virus (VZV). Patients who have received prior repeated acyclovir treatment appear to be at the highest risk of harboring acyclovir-resistant strains. Algorithms for the management of these infections were developed at a recent roundtable symposium. The consensus of the panelists was that treatment with foscarnet should be initiated within 7-10 days in patients suspected to have acyclovir-resistant HSV or VZV infections. Foscarnet therapy should be continued for at least 10 days or until lesions are completely healed.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Neovaginal reconstruction with a rectus abdominis myocutaneous flap.

BACKGROUND: Neovaginal reconstruction after pelvic exenteration has several advantages. Besides the obvious psychosocial benefit to the patient and her partner, the incorporation of viable tissue into the pelvic cavity decreases the incidence of infection and small-bowel complications. Several surgical techniques are available to the gynecologic oncologist for construction of a functional vagina. Recently, myocutaneous flaps incorporating the rectus abdominis and gracilis muscles have been used. Disadvantages of the gracilis myocutaneous flap are the 10-20% incidence of flap loss due to vascular compromise and the potential for prolapse. The rectus abdominis myocutaneous flap is a large flap with a reliable blood supply that allows mobilization without tension on the vascular pedicle, resulting in a much lower incidence of vascular compromise. CASE: We present two case reports, a review of the gynecologic and surgical literature, and the techniques for vaginal reconstruction using the rectus muscle as a myocutaneous flap. CONCLUSIONS: The outcome for both patients was a satisfactory functional vagina that was technically easy to construct. The rectus abdominis myocutaneous flap can provide an adequate neovagina with minimal morbidity.

Abdominal Muscles↗
PubMed1992

Creation of a semiannual report for a multicentre co-operative clinical trials group.

The Southwest Oncology Group (SWOG) is a multicentre co-operative group that performs prospective clinical trials in cancer. The SWOG Statistical Center is responsible for preparing a report of studies for the semiannual meetings. The report includes a summary of study design and eligibility criteria, current accrual, baseline patient characteristics, toxicity, and, for studies closed to accrual and with sufficiently mature outcome data, tumour response or patient survival. A software program, Statisticians' Report Worksheet (SRW), has been developed by the programming staff at the SWOG Statistical Center. This program enables each disease specific chapter to be created independently, but ensures that tables and graphs for all chapters are of uniform style. We describe here the coordination of the report, and the use of the SRW program. This reporting system can serve as a model for other groups.

Clinical Trials as Topic↗
PubMed1992

Identification of residues involved in polymorphic antibody binding epitopes on HLA-DR molecules.

Based on previous studies it was predicted that amino acids 4 or 25 of the DR4 beta 1 and DR7 beta 1 chains are involved in polymorphic antibody binding epitopes on DR4 or DR7 molecules. These predictions were tested by analyzing monoclonal antibody (mAb) binding to transfectants expressing mutant DR4 beta 1 or DR7 beta 1 chains with single amino acid substitutions at positions 4 or 25. Antibody binding to transfectants expressing additional DR4/7 beta 1 hybrids was also analyzed to assess further the contributions of four segments of the DR4 beta 1 or DR7 beta 1 chains: amino acids 1-20, 21-40, 41-97, and the beta 2 domain. Single amino acid substitutions at positions 4 and 25 of the DR4 beta 1 chain or DR7 beta 1 chain eliminate binding of several mAb to DR4 or DR7 molecules, documenting that these residues are involved in antibody epitopes. However, the data with the hybrid DR4/7 beta 1 chains indicate that some of these epitopes require contributions from both segments 1-20 and 21-40 of these DR beta chains, whereas other epitopes can be generated by placing the appropriate segment in the context of the other DR beta chain. In addition, the data with other mAb indicate that their epitopes are determined primarily by sequences within the 41-97 segment or in the beta 2 domain.

Amino Acids↗
PubMed1992

The current cavernosometric criteria for corporovenous dysfunction are too strict.

In an attempt to define the hemodynamic and radiographic parameters of normal erectile function 6 patients 20 to 41 years old (mean age 30.3 years) with erectile dysfunction that spontaneously resolved after a comprehensive evaluation were reviewed. The results included normal hormonal assays, normal penile biothesiometry and normal penile brachial index. The sleep tumescence and rigidity tracings were abnormal according to the criteria that sleep erections occur every 90 minutes, are associated with penile rigidity of greater than 550 gm. plus an increase in penile circumference of greater than 1.5 cm. and last longer than 15 minutes. High resolution ultrasonography, pulse wave Doppler ultrasound, dynamic pharmacocavernosometry and dynamic cavernosography were performed. After testing the patients were informed that no organic abnormalities had been detected. No medical or surgical treatment was given. The hemodynamic values are presented as suggested normal parameters: maintenance rate (mean 11 +/- 3 cc per minute), initial decompression rate (mean 59 +/- 17 mm. Hg/30 seconds) and radiographic findings (visualization of the cavernous, external pudendal and deep dorsal veins during pharmacocavernosography, performed at intracorporeal pressures of 100 mm. Hg). All 6 patients had maintenance rates of greater than 5 cc per minute. Of these 6 patients 5 had initial decompression rates of greater than 48 mm. Hg/30 seconds and 4 had 5-minute, post-infusion steady state values of less than 50 mm. Hg, criteria that have been used to define corporovenous dysfunction.

Adult↗
PubMed1990

Renal vein involvement with nephroblastoma: a report of the National Wilms' Tumor Study-3.

The records of children enrolled in the National Wilms' Tumor Study-3 who had Wilms' tumor and thrombosis into the renal vein were reviewed. There were 164 patients with gross involvement of the extrarenal vein and 47 patients with microscopic involvement, an incidence of 11.3% (211 of 1,865 evaluable patients). Two-year survival rates were 90, 79 and 72% for stages II, III and IV, respectively. The most important predictors of survival were histologic pattern and stage. Complete en bloc excision of the tumor and thrombus continues to be the most effective initial management.

Child↗
PubMed1988

Bilateral seminal vesiculitis and ampullitis in a stallion.

A Thoroughbred stallion suspected of having venereal disease was found to have an infection of the accessory sex glands. Purulent debris, blood, and Pseudomonas aeruginosa were recovered from all ejaculates. Treatment with gentamicin sulfate, tobramycin, and amikacin sulfate was unsuccessful in eliminating the infection. The stallion's seminal plasma, collected during treatment with gentamicin sulfate, did not contain any appreciable antibacterial activity. Apparently, negligible amounts of gentamicin diffused across the mucosal cell borders of the accessory sex glands into the seminal plasma. Bilateral seminal vesiculitis and ampullitis were evident on examination of the reproductive tract when the stallion was euthanatized.

Animals↗
PubMed1988

Microassay for adenosine deaminase, the enzyme lacking in some forms of immunodeficiency, in mouse preimplantation embryos.

A highly sensitive biochemical microassay has been developed for adenosine deaminase (ADA; EC 3.5.4.4), the enzyme deficient in approximately 20% of cases of severe combined immuno-deficiency disease (SCID). The microassay is capable of detecting femtomolar amounts of reaction product in a single blastomere from a mouse 8-cell embryo and thus is sensitive enough to be considered for the possible preimplantation diagnosis of SCID in human embryos.

Adenosine Deaminase↗
PubMed1987

Comparative in vitro activity of A-56268 (TE-031) against gram-positive and gram-negative bacteria and Chlamydia trachomatis.

The in vitro activity of A-56268 (TE-031) was determined and compared with that of 13 antibiotics against 401 gram-positive and gram-negative bacteria and 11 strains of Chlamydia trachomatis. A-56268 was very active against methicillin-susceptible Staphylococcus aureus and Neisseria gonorrhoeae, and was among the most active of the agents tested against Listeria monocytogenes, streptococci and Chlamydia trachomatis. It was moderately active against Haemophilus spp., Vibrio spp., Campylobacter jejuni and Campylobacter fetus subsp. fetus. It was inactive against enterococci, methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Campylobacter coli, Salmonella spp., Shigella spp. and Yersinia enterocolitica. A-56268 was not consistently bactericidal or more active than erythromycin for any organism except Chlamydia trachomatis.

Animals↗
PubMed1987

Cavernous hemangioma of the liver: detection with single-photon emission computed tomography.

The roles of single-photon emission computed tomography (SPECT) and planar imaging with technetium-99m-labeled red blood cells in the diagnosis of cavernous hemangioma of the liver were evaluated. The study group consisted of 26 consecutive patients referred for evaluation of liver lesions. A total of 23 cavernous hemangiomas were found, all of which showed decreased or normal flow and delayed uptake of the radiotracer. SPECT demonstrated 13 hemangiomas that were not detected with planar imaging; both modalities demonstrated the other ten lesions. Lesions that were not cavernous hemangiomas showed either normal (n = 6) or increased (n = 4) flow; none had delayed increased uptake on either planar or SPECT images. SPECT with labeled red blood cells is an accurate method for the detection of cavernous hemangiomas of the liver and is more sensitive than planar imaging in depicting small lesions.

Adult↗
PubMed1987

On the albumin-dependence of measurements of free thyroxin. II. Patients with non-thyroidal illness.

We studied the relation between thyroxin-binding proteins and free thyroxin (FT4) measurements by five radioimmunoassays (RIA) and an FT4 index (FT4I) in patients with non-thyroidal illness (NTI). The one-step FT4 RIAs and the FT4I frequently failed to identify the true FT4 status (as determined by equilibrium dialysis) of NTI patients. In these patients, falsely low FT4 results with one-step RIAs and FT4I were associated with decreasing total T3 and T4 concentrations, which, furthermore, paralleled decreasing serum albumin concentrations. All NTI patients with "low T3, low T4 syndrome" had subnormal albumin concentration. The two-step RIAs and equilibrium dialysis showed normal FT4 concentrations in most patients with NTI. However, sera from a subset of NTI patients with "low T3 syndrome" gave above-normal FT4 results with these methods. From their predictably poor performance in the presence of a subnormal albumin concentration, we conclude that the one-step FT4 RIAs and FT4I are inappropriate for testing the thyrometabolic status of NTI patients.

Diagnostic Errors↗
PubMed1986

On the albumin dependence of measurements of free thyroxin. I. Technical performance of seven methods.

We evaluated three one-step (analog) and two two-step radioimmunoassay for free thyroxin (FT4), and a FT4 index calculated from the total T4 (TT4) and thyroxin-binding globulin (TBG) ratio for technical performance, for correlation with the reference FT4 method (equilibrium dialysis), and for dependence on TBG and albumin concentrations. The one-step methods (Amerlex, Coat-A-Count, and GammaCoat) showed greater precision than the two-step procedures (GammaCoat and Spiria). Results by the latter two techniques, however, correlated better with those by equilibrium dialysis than did those by the analog methods or by TT4/TBG. Only the GammaCoat two-step method had a slight but statistically significant (inverse) correlation with TBG concentration. All three analog methods and TT4/TBG showed a marked dependence on albumin concentration, whereas the Spiria technique showed only a slight dependence. Only equilibrium dialysis was independent of both the TBG and albumin concentration. Thus, despite their good precision, the analog (one-step) FT4 methods and the TT4/TBG approach cannot be expected to produce valid results when the concentration of albumin in serum is abnormally low or high.

Dialysis↗