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Biomedical subjects

R L Anderson

Publications and source records attributed to R L Anderson.

At least 307 records · Page 17Linked to original sources
PubMed1986

Significance of opaque discolored amniotic fluid at second-trimester amniocentesis.

From June 1978 to December 1983, 100 patients with viable pregnancies involving opaque, discolored, second-trimester amniotic fluid were identified. During this period 7018 genetic amniocenteses were performed for an incidence of discolored fluid of 1.4%. Compared with case matched control subjects there were no statistically significant differences in the incidence of elevated amniotic fluid alpha-fetoprotein, preterm labor, fetal distress during labor, intrauterine growth retardation, or stillbirth. The rate of spontaneous abortion (7 versus 0%; P less than .05) was increased in the discolored fluid group. The patients with discolored fluid also had an increased incidence of prior vaginal bleeding (P less than .001).

Amniocentesis↗
PubMed1986

Heat shock protein levels are not elevated in heat-resistant B16 melanoma cells.

Heat-resistant variants have been selected from B16 melanoma cells and from surface mutants previously derived from them. The aim of the present study was to explore the possible role of heat shock proteins in the manifestation of this heat resistance. The major heat shock proteins evident after heating have subunit molecular weights of 68, 70, 89, and 110K on sodium dodecyl sulfate-polyacrylamide gels. The 68-kDa protein is not evident in any of the unheated B16 cell lines while the levels of the other heat shock proteins are elevated after heating. The constitutive levels of the 70, 89, and 110-kDa heat shock proteins were assessed after gel electrophoretic separation of proteins in several of the heat-resistant variants. No major differences were found in the levels of these proteins between the heat-sensitive parent lines and the heat-resistant variants. We therefore conclude that heat shock proteins are not a determining factor in the heat-resistant phenotype of B16 melanoma cells.

Acclimatization↗
PubMed1985

Idiopathic inflammatory perioptic neuritis simulating optic nerve sheath meningioma.

Between 1976 and 1982, we examined 13 patients with clinical and radiographic findings consistent with optic nerve sheath meningioma. All patients had visual loss, evidence of optic nerve dysfunction, centrocecal visual field defects, and echographic and computed tomographic evidence of optic nerve or sheath enlargement. All underwent surgery for biopsy or excision of their presumed tumors. However, adequate histologic sampling of all lesions failed to demonstrate meningioma in four patients; two of these four showed inflammatory infiltration of the dural sheath, whereas the other two showed only edematous or dense fibrous tissue. There was no evidence of other systemic disease in any of these cases. We conclude that optic nerve or sheath enlargement, probably induced by an idiopathic inflammatory perioptic neuritis, may simulate a sheath meningioma. Proper diagnosis requires biopsy confirmation.

Adult↗
PubMed1985

Effects of cardioselective and nonselective beta-adrenergic blockade on the performance of highly trained runners.

Twenty-five highly trained runners with a maximal oxygen uptake (VO2 max) of 64.7 +/- 4.3 ml . kg-1. min-1 were administered clinically equivalent doses of a nonselective (propranolol) and a cardioselective (atenolol) beta-blocking agent as well as a placebo. The subjects performed a horizontal treadmill test on the eighth day and a 10-km track race on the tenth day of each treatment. Beta blockade decreased submaximal heart rate and propranolol caused the largest decrease. Beta blockade caused a decrease in maximal heart rate, VO2 max, maximal ventilation, maximal respiratory exchange ratio and treadmill time. Propranolol caused a greater decrease than atenolol in each of these values. The 10-km race times were significantly slower during beta blockade, and propranolol race times were significantly slower than atenolol race times. It is concluded that the performance of highly trained distance runners is significantly altered by beta-adrenergic blockade and that nonselective agents reduce performance to a greater extent than cardioselective agents.

Adult↗
PubMed1985

The use of a periosteal strip for eyelid reconstruction.

Strips of periosteum from the zygoma were used to reconstruct very extensive lateral canthal and temporal eyelid defects in 11 patients. The strips were reflected nasally, sutured to residual tarsal stumps, and covered anteriorly with myocutaneous flaps. After a minimum follow up of one year, cosmesis was excellent in five patients, satisfactory in five, and poor in one. Minor complications related to this procedure included ectropion and low lateral contour (one patient each), blunting of the lateral canthal angle (three patients), eyelid notching and dehiscence (one patient each), and symblepharon formation (one patient). However, only one patient had a complication that was significant enough to require a second surgery. This technique allows for one-stage reconstruction, an open palpebral fissure, and the ability to reconstruct extensive loss of the temporal portion of two adjacent eyelids when sharing techniques are not possible.

Adenocarcinoma↗
PubMed1985

The medial spindle procedure for involutional medial ectropion.

Involutional medial ectropion responds poorly to traditional ectropion procedures. Eversion of the lacrimal punctum must be functionally corrected to reestablish normal corneal wetting physiology as well as tear-lake drainage. We describe our retropunctal approach with emphasis on a new, enhanced closure that utilizes the lower eyelid retractors. This stabilizes the medial eyelid margin in order to obtain and maintain good functional and cosmetic results. This procedure allows a predictable anatomic approach that is easily performed and can be combined with other procedures, such as a lateral tarsal strip, medial canthal tendon plication, or skin graft or flap, when required.

Aged↗
PubMed1985

Management of the fetus with congenital hydronephrosis II: Prognostic criteria and selection for treatment.

Selecting appropriate management for the fetus with bilateral congenital hydronephrosis depends on our ability to accurately assess the severity of existing renal damage and to predict the potential for recovery of renal and pulmonary function if the obstruction is relieved. We reviewed our experience with 20 fetuses with congenital bilateral hydronephrosis to determine the prognostic value of various criteria used to assess functional potential, including temporary catheter exteriorization to measure fetal urine output and composition. Based on autopsy, biopsy, or clinical outcome, ten fetuses were classified retrospectively as "poor function," and ten fetuses as "good function." The good function group could be distinguished from the poor function group by the following criteria: Amniotic fluid (AF) status at presentation (P less than .001), ultrasound appearance of the fetal kidneys (P less than .05), fetal urine sodium and chloride concentration and osmolarity (P less than .001), and hourly urine output (P less than .02), but not by fetal urine iothalamate excretion or potassium and creatinine concentrations (P greater than .05). Based on these results, we have identified prognostic criteria that accurately identify the fetus with "good function" from the fetus with "poor function." We also reviewed the clinical management of our last 12 unreported cases. Ten fetuses had undergone diagnostic catheter placement and in utero renal function testing. This led to placement of a therapeutic indwelling catheter-shunt in seven fetuses (three required multiple shunts) and a suprapubic vesicostomy in another. Catheter related complications, including three cases of chorioamnionitis, emphasize the need for better methods of in utero decompression in selected cases. Our ability to select appropriate management has improved markedly.

Biopsy↗
PubMed1985

Fetal cystic adenomatoid malformation: prenatal diagnosis and natural history.

We studied the natural history and pathophysiology of congenital cystic adenomatoid malformation (CCAM) detected prenatally by ultrasound in twelve fetuses. Two types of fetal CCAM can be distinguished by gross anatomy, ultrasound findings, and prognosis. Microcystic lesions are usually associated with fetal hydrops and have a poor prognosis (five cases with one survivor). Antenatal diagnosis, maternal transport, and immediate thoracotomy after birth allowed the first reported survival of a newborn with a large microcystic CCAM. Macrocystic lesions are not usually associated with hydrops and have a favorable prognosis (five of seven survived). We conclude that fetuses with hydrops are at high risk for fetal or neonatal demise without intervention. Fetuses with CCAM but without hydrops have a good chance for survival with maternal transport, planned delivery, and immediate neonatal resuscitation and surgery.

Adult↗
PubMed1985

The role of orbital exenteration in choroidal melanoma with extrascleral extension.

The management of choroidal melanoma with extrascleral extension has been a subject of controversy with some proposing orbital exenteration whenever extrascleral extension is demonstrated and others feeling it to be of no value in increasing survival. We reviewed the cases of 43 patients with extrascleral extension of choroidal melanoma. Although five-year survival had previously been demonstrated to be significantly improved in patients undergoing early orbital exenteration at our institution, extended follow-up in 16 consecutive cases revealed ultimate tumor related mortality to approach that of patients refusing exenteration. Only in cases with nonencapsulated or surgically transected extension did exenteration appear to improve survival. In ten cases with delayed recurrence of tumor in the orbit, exenteration proved to be palliative rather than curative.

Aged↗
PubMed1985

Responses of mouse lung to irradiation. 1. Alterations in alveolar surfactant after neutrons and X-rays.

Surfactant levels in the alveolus after X-irradiation are shown to be increased over a period of about 6-8 weeks. Although the increase in phospholipid in alveolar lavage commences shortly after irradiation, peak levels occur about 3 weeks post-irradiation. The time course of the response was independent of radiation dose and quality but its magnitude was dose related with X-rays and neutrons being comparable in effectiveness (i.e. RBE approximately 1). Amounts of alveolar surfactant subsequently return to about control level and, during the period of radiation pneumonitis some 3-5 months post-irradiation, there is no indication of a further response by the surfactant system. Analysis of the amount of disaturated lipids in both lung tissue and alveolar lavage fluid suggests that increased surfactant levels are at least partly due to reduced turnover. Post-radiation changes in alveolar lavage phospholipid composition were not detected.

Animals↗
PubMed1985

Responses of mouse lung to irradiation. 2. Levels of alveolar protein in lung lavage fluid following neutrons or X-rays.

Alveolar protein exudate is shown to exhibit a biphasic increase after irradiation. During the first 6 weeks after doses of between 5 and 28 Gy X-rays or 3.5 and 14 Gy neutrons, mean alveolar protein levels increase to about 4 times control levels. Over this period there was no suggestion of any dose-response nor of an RBE greater than 1. It seems probable that this response is unrelated to cell killing by radiation. After sublethal doses there was recovery from this first phase of leakage. However, although after 5 Gy X-rays this recovery was complete, after higher doses a second and greater increase in alveolar protein took place. After 10 Gy X-rays and 8 Gy neutrons this peaked at about 15 weeks post-irradiation and 20-30 times control levels. This second dose-dependent response corresponded with the times of animal death after doses close to the LD50. A comparison of these changes in alveolar protein exudate with previously published data on surfactant level suggests that the surfactant and protein responses are largely unrelated.

Animals↗
PubMed1985

Advances in orbital surgery.

Advances in diagnostic modalities, orbital anatomy, pathophysiology of orbital disorders, and surgical techniques have allowed a more functional and safer approach to orbital surgery. Recent and future research commitments to orbital disease will continue to advance our knowledge in this complex, rapidly evolving field.

Biopsy↗
PubMed1985

Factors associated with Pseudomonas pickettii intrinsic contamination of commercial respiratory therapy solutions marketed as sterile.

Laboratory investigations were conducted to study the growth dynamics of Pseudomonas pickettii in commercial 0.9% sodium chloride solution under various environmental conditions and to determine the retention of these organisms after challenge through a 0.2-micron cartridge filter system. Low numbers of P. pickettii (1 to 10 CFU/ml of test solution) inoculated into commercial vials containing 5 ml of 0.9% sodium chloride solution and 500-ml volumes of 0.9% sodium chloride solution were shown to proliferate over a 168-h incubation period. These organisms demonstrated growth over a wide range of temperatures (15 to 42 degrees C) in this salt solution, and survival studies at 50, 55, and 60 degrees C indicated that this strain was not unusually resistant to heat (with the times required at a given temperature to reduce the surviving microbial population 10-fold [D-values] being 26.0, 1.9, and 0.7 min, respectively). A challenge test demonstrated that P. pickettii organisms were not completely retained by a 0.2-micron cartridge filter. The number of organisms detected increased from 1 CFU/liter of effluent at 1 to 2 min to a maximum of 176 CFU/liter at 4 to 5 min. Our results indicate that P. pickettii can penetrate a 0.2-micron filtration system and that the passage of organisms and subsequent microbial growth in the filter effluent probably are the mechanisms by which these organisms were recovered from "sterile" commercial 0.9% sodium chloride solution.

Drug Contamination↗
PubMed1985

Mechanism of cross-contamination of blood culture bottles in outbreaks of pseudobacteremia associated with nonsterile blood collection tubes.

Several studies have identified nonsterile blood collection tubes as the reservoir for contaminating microorganisms in outbreaks of pseudobacteremia. Microorganisms are thought to be transferred from the nonsterile tubes to the blood culture tubes when blood is drawn for cultures, but the validity of this hypothesis has not previously been tested. We recently investigated an outbreak of Ewingella americana pseudobacteremia in which an epidemiological association was found between pseudobacteremia and the practice of drawing blood for culturing at the same time that blood for coagulation studies is drawn. The nonsterile coagulation tubes, prepared in the hospital, were contaminated with E. americana. We studied three different procedures that personnel reported using to inoculate blood culture tubes after dispensing blood into the coagulation tubes. Although the failure to change or remove the needle before inoculating the blood culture tubes resulted in the highest percentage of cross-contamination, we found that all the techniques we simulated carried some risk of cross-contamination when coagulation tubes were filled first.

Blood↗
PubMed1985

Nosocomial Pseudomonas pickettii colonization associated with a contaminated respiratory therapy solution in a special care nursery.

Pseudomonas pickettii caused respiratory tract colonization in five infants in the special care nursery of a Chicago hospital. All organisms had the same antimicrobial susceptibilities. Endotracheal suctioning with saline from 5-ml unit-dose vials was identified by epidemiologic investigation as a risk factor for colonization. The vials of saline were contaminated with a strain of P. pickettii having the same antimicrobial susceptibility pattern as the isolates from patients. As part of an investigation of the manufacturing plant where the saline solution was produced, P. pickettii was recovered from deionized water used to make the product and from several sites in the processing line. Bypassing of a 180 degrees F (ca. 82 degrees C) water-holding tank appeared to be temporally related to product contamination. The ability of P. pickettii to survive and grow in this solution has been demonstrated in the laboratory. This outbreak demonstrates that, despite pertinent Food and Drug Administration regulations and company programs for identifying such contamination, intrinsically contaminated solutions can occasionally reach the bedside of the patient.

Cross Infection↗