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Biomedical subjects

R L Anderson

Publications and source records attributed to R L Anderson.

At least 271 records · Page 15Linked to original sources
PubMed1987

A preliminary report on the Universal Implant.

Extrusion and time-consuming surgical techniques required of implantation have been the major criticisms of quasi-integrated implants such as the Iowa Implant. With these concerns in mind, the Universal Implant (Oculo-Plastik, Montreal) has been designed to offer the motility advantages seen with quasi-integrated implants and the ease of placement of a sphere. The Universal Implant incorporates most of the advantages seen in the Iowa Implant and other quasi-integrated implants. In addition, the Universal Implant (1) utilizes a faster surgical technique for implantation; (2) avoids cleaning the muscles; (3) has lower, more rounded, smaller mounds that should decrease the late extrusion rate; (4) can be used as an enucleation implant, evisceration implant, or secondary implant; and (5) has a greater girth and larger radius of the posterior surface that helps support orbital fat and tissues, resulting in a more natural superior sulcus. Considering that the Iowa Implant is presently not available, the Universal Implant should be used by those surgeons who were pleased with the former implant and should be considered as a reasonable alternative to other enucleation implants.

Equipment Design↗
PubMed1987

Turnover of sulfated glycosaminoglycans in fibroblasts derived from patients with Werner's syndrome.

Fibroblasts derived from patients with Werner's syndrome (WS) were incubated with radioactive sulfate to study the incorporation of 35S into glycosaminoglycans (GAGs). The accumulation of cell-associated 35S radioactivity in the GAGs of WS fibroblasts was consistently higher than parallel accumulation in normal human fibroblasts, but was substantially less than in fibroblasts derived from patients with Hurler's syndrome (HS). However, when fibroblasts were labeled with 35SO4(2-), trypsinized to remove extracellular and pericellular radioactive GAGs, replated, and chased to follow the fate of the intracellular radioactivity, both WS and normal cells showed a rapid release of the intracellular 35S, while HS cells showed little or no loss of intracellular radioactivity. The radioactivity released from WS and normal cells was of low molecular weight (LMW), eluting from gel filtration columns at the same position as free sulfate. These results establish that WS cells degrade intracellular sulfated GAGs and argue against the hypothesis that a defect in GAG degradation pathways is the basis for the increased level of cell-associated GAGs. Other possible explanations for the increased cell-associated [35S]GAGs in WS cells as compared with normal cells were also considered: increased GAG sulfation; an increase in GAG chain length; an increased rate of GAG synthesis; and a decreased rate of shedding of cell surface proteoglycan into the medium. No difference between normal and WS fibroblasts in any of the above parameters was observed. These results strongly imply that the primary biochemical defect in WS fibroblasts does not involve sulfated GAG metabolism.

Cell Line↗
PubMed1987

Inside the hidden mental health network. Examining mental health care delivery of primary care physicians.

Mental disorder diagnoses among 51 patients, made by a group of 20 family physicians, were compared with diagnoses generated by the Diagnostic Interview Schedule (DIS). Processes of diagnosis, decision making, and treatment planning were then examined through structured physician interviews and chart audits. In this study, 75 of 94 DIS diagnoses (79%) were undetected. During interview and chart audit, the physicians were found to have consistently underestimated, misinterpreted, or neglected psychiatric aspects of care among a majority of patients in the study. These physicians had all satisfactorily completed a psychiatry curriculum designed for family physicians. Analysis of these results suggests that a mental health role is often not integrated into primary care practice, regardless of physician performance during psychiatric training experiences. Assumption of this role appears to be state dependent on involvement with a psychiatric treatment setting. Primary care practice patterns do not seem to result in application of appropriate skills and therapeutic attitudes to detect, diagnose, and correctly manage the majority of mental disorders that occur. The need is reaffirmed for active collaboration between mental health professional and primary care providers in training and in incorporation of psychiatric skills into primary care practice.

Adult↗
PubMed1987

Effect of inherent urine output on the response of male rats to 7.5% dietary sodium saccharin.

Young male rats were preselected as high urine (57 g/kg body weight) or low urine (35 g/kg) voiders and were fed a diet containing 7.5% sodium saccharin (NaS) for 10 wk. Urine output was found to be a stable characteristic and high urine output was associated with increased water and feed consumption and increased weight gain. Rats responded in a very similar fashion to 7.5% dietary NaS regardless of their inherent urine output. NaS ingestion was associated with increases in water consumption, caecal mass and urine volume. Among rats that had ingested 7.5% dietary NaS for 10 wk there was a high incidence (12/20) of bladder epithelial hyperplasia. The results are discussed with regard to the concept that increased urine output is an important factor in NaS-induced bladder tumours.

Animals↗
PubMed1987

Effect of dietary carbohydrate type and content on the response of male rats to dietary sodium saccharin.

The role of dietary carbohydrate composition and concentration in the response of male rats to sodium saccharin (NaS) was ascertained by comparing the response to 5% dietary NaS in rats given diets containing 65% starch, 50% sucrose together with 15% starch, 65% glucose, or 3% sucrose. NaS induced similar levels of caecal enlargement and increases in urine volume and bladder mass when given with any of the three forms of carbohydrate at 65% in the diet. However with the 3% sucrose diet, NaS caused a lesser caecal enlargement and no increase in urine volume or bladder mass. These findings suggest that NaS not only inhibits saccharide hydrolysis but also inhibits glucose transport. The significance of these findings in relation to NaS-associated bladder tumours is discussed.

Animals↗
PubMed1987

Intestinal responses in the male rat to gavaged corn oil.

Gavaged corn oil is readily hydrolyzed and taken up by the rat small intestine but resynthesis to triglyceride and transport are slow. Multiple doses of corn oil caused increases in the non-lipid dry mass, protein and DNA content of the luminal surface of the small intestine. The possible relationship of these effects of gavaged corn oil to pancreatic acinar cell neoplasias is discussed. The fact that corn oil dosed by gavage causes changes in the composition of the small intestinal surface argues against the use of this technique in the assessment of the toxicological characteristics of compounds.

Administration, Oral↗
PubMed1987

Altered turnover and synthesis rates of lung surfactant following thoracic irradiation.

Between 2-6 weeks after thoracic irradiation with 10 Gy X rays, when levels of surfactant in the alveoli show the greatest increase, there is a reduction in the rate of radioactivity loss from 3H-choline labeled disaturated phosphatidylcholine from the lung. This indicates a reduced turnover of surfactant. Discrepancies between the halving times for specific activity and for total radioactivity of the disaturated phospholipids suggest that at between 2 and 3 weeks post-irradiation, removal and degradation of surfactant almost ceases, but that synthesis continues normally. However, by 3 weeks post-irradiation, choline-3H incorporation into disaturated phosphatidylcholine suggests that surfactant synthesis is increased about two-fold. The reduced number of macrophages recovered from alveolar lavage between about 2 and 6 weeks post-irradiation may indicate a reason for the lengthened turnover times of surfactant over this period. Nevertheless the stimulated surfactant production that takes place from about 3 weeks onward suggests an additional active response to radiation or to radiation damage by the type II pneumonocytes. These studies confirm that the maximum levels of alveolar surfactant seen at 3 weeks post-irradiation result from a different lung response than that responsible for the increase in surfactant, which occurs within hours of irradiation.

Animals↗
PubMed1987

Fetal hydronephrosis: selection and surgical repair.

Newly developed diagnostic techniques allowed us to select a fetus with potentially reversible renal damage from the usually fatal group with bilateral hydronephrosis and severe oligohydramnios early in gestation. Fetal surgery to marsupialize the fetal bladder at 24 weeks gestation restored normal amniotic fluid dynamics and allowed sufficient pulmonary and renal development to insure survival after delivery near term.

Adult↗
PubMed1987

Orbital cyst formation associated with Gelfilm use.

Two patients developed cystic lesions in the anterior orbit 21 and 26 months after repair of blow-out fracture with orbital floor Gelfilm implants. Both patients had associated motility disturbances. Both lesions were surgically excised and found to be cystic in nature and filled with glistening gelatinous material consistent with partially absorbed, encysted gelatin film (Gelfilm). Histologically, a fibrous capsule was present; the contents of the cyst were not pathologically identifiable since they dissolved during fixation. Postoperatively, the motility disturbances improved in each patient.

Adult↗
PubMed1987

Ewingella americana: recurrent pseudobacteremia from a persistent environmental reservoir.

From September 1981 through April 1984, 20 patients at one hospital were identified with Ewingella americana pseudobacteremia. Case-control studies demonstrated an association between having a positive blood culture for E. americana and having blood for culture obtained simultaneously with blood obtained for coagulation studies (15 of 19 case patients versus 4 of 38 controls; P = 4.5 X 10(-7)). Review of blood-drawing procedures showed that blood for coagulation studies and culture was drawn with the same syringe, and coagulation tubes were filled before blood culture tubes. Some phlebotomists were not using new sterile needles to inoculate blood culture bottles. Collection tubes for coagulation studies were prepared in the hospital, and E. americana was isolated from all 52 unused coagulation tubes tested. Solutions prepared in the hospital may constitute a persistent inanimate environmental reservoir for this uncommon microorganism. Pseudobacteremia can result in unnecessary antimicrobial therapy for some patients, incurring the risks of adverse drug reactions, selection of drug-resistant bacteria, and increased health care costs.

Adolescent↗
PubMed1987

Plasmids of Ewingella americana: supplementary epidemiologic markers in an outbreak of pseudobacteremia.

During an outbreak of pseudobacteremia in a children's hospital, Ewingella americana was found in blood cultures from 20 patients. E. americana was inoculated into blood culture bottles at the time of specimen collection due to cross contamination from nonsterile, citrated blood collection tubes used for coagulation studies. Antimicrobial susceptibility testing and plasmid profiling were used to assess the association between patient isolates and isolates from unused blood collection tubes. All E. americana isolates had similar antibiograms (i.e., resistance only to cephalothin) when tested at 37 degrees C. However, when the same isolates were tested for antimicrobial susceptibility at 25 degrees C, a different antibiogram (i.e., resistance to chloramphenicol, ampicillin, and cephalothin) was found. The majority of these isolates also demonstrated a unique four-plasmid profile (130, 56, 4.6, and 3.1 megadaltons), and two of these plasmids (130 and 56 megadaltons) were characterized as temperature-sensitive plasmids. An epidemiologic link between outbreak-associated isolates obtained from different time periods in the outbreak was supported by evidence of a significant trend in the ability of the outbreak-associated isolates to reduce nitrate, together with the presence of the resistance antibiogram at 25 degrees C and the demonstration of the unique four-plasmid profile.

Adolescent↗
PubMed1987

Epidemic septic arthritis caused by Serratia marcescens and associated with a benzalkonium chloride antiseptic.

During a 6-week period, 10 patients were admitted to a hospital for treatment of knee or shoulder joint infections due to Serratia species. Isolates from eight patients were identified as Serratia marcescens with identical biochemical characteristics and antibiotic susceptibility patterns. Before the onset of infections, all patients had been treated by two orthopedic surgeons who shared an office. Studies revealed that infections were associated with previous joint injections (P = 4.44 X 10(-5] of methylprednisolone and lidocaine. Environmental cultures revealed that a canister of cotton balls soaked in aqueous benzalkonium chloride and two multiple-dose vials of methylprednisolone previously used by office personnel were contaminated with the epidemic strain of S. marcescens. The canister may have served as a potential reservoir for contamination of sterile solutions and equipment used for joint injections, of skin at the injection site, and of hands of personnel. No further cases occurred after the use of aqueous benzalkonium chloride was discontinued.

Adult↗
PubMed1987

Gastroschisis: prenatal diagnosis and management.

Ten fetuses with gastroschisis on whom a prenatal sonographic diagnosis and evaluation were available and who delivered at the University of California, San Francisco, were evaluated retrospectively. Six fetuses were delivered vaginally without mortality and minimal or absent morbidity. Four were delivered abdominally, 2 for unrelated obstetrical indications. A 3rd fetus had a suspected prenatal bowel perforation and was the sole mortality. Only 1 mother underwent primary cesarean section, specifically due to the fetal gastroschisis. Umbilical cord pH values were normal in those delivered vaginally. With careful ultrasound examination and immediate neonatal surgical capability in a level III perinatal center, vaginal delivery of fetuses with gastroschisis can be associated with excellent outcome. A multinational randomized study of the delivery mode of fetuses with gastroschisis is necessary and appropriate at this time.

Abdominal Muscles↗
PubMed1987

Perinatal management of the fetus with an abdominal wall defect.

The antenatal diagnosis of abdominal wall defects has allowed improved perinatal management. For fetuses with associated anomalies, the options of elective termination or minimal intervention can be offered. Our ability to predict the extent of bowel damage in gastroschisis based on the ultrasound findings enables us to offer early delivery to those fetuses who are at high risk. The data are not clear at the present time whether cesarean section offers any advantage. These fetuses should, however, be delivered at a center which is capable of providing high level medical and surgical care to these potentially ill infants. Initial resuscitation of these neonates requires early insertion of an intravenous line and a nasogastric tube, the administration of antibiotics, sterile coverage of the eviscerated bowel, and careful attention to temperature instability. Neonates with gastroschisis should be operated on as soon as they are stable, whereas infants with omphalocele can be investigated for associated anomalies prior to surgery. Primary fascial closure is performed whenever possible. Where this is not possible, a staged repair using a silastic chimney achieves closure within 3-6 days. Skin coverage alone or nonoperative management is reserved for the few cases with giant omphalocele, associated anomalies, or poor operative risk. Decisions about primary versus delayed closure, while usually dictated by clinical judgement, can be aided by indirect measurement of intraabdominal pressure. Postoperative ventilation, and consideration of long-term nutritional needs, are also important parts of the perioperative management.

Abdominal Muscles↗
PubMed1987

Carbon dioxide (CO2) laser therapy for conjunctival lymphangioma.

Lymphangiomatous tissue involving the ocular adnexa may be difficult to manage because this highly vascular, unencapsulated tissue intermingles freely with normal adnexal structures. Hemostasis is difficult to obtain, and important ocular and periocular structures are damaged easily. We have successfully treated two individuals who had extensive conjunctival involvement of their lymphangioma with the carbon dioxide (CO2) laser. The CO2 laser permits a precise form of treatment with the ultimate form of hemostasis (tissue vaporization), resulting in minimal trauma, edema, and scarring, and thus offers a safe alternative to surgical excision of these lesions.

Adult↗
PubMed1987

Macrocystic enlargement of orbital dermis-fat grafts.

Acquired cysts represent an unusual but significant complication of orbital dermis-fat grafts. We report two cases of late postoperative enlargement of dermis-fat grafts: First, macrocystic enlargement occurring in both orbits with severe microphthalmia; second, cystic enlargement occurring in a dermis-fat graft for anophthalmia following an earlier evisceration. Both graft enlargements were due to epithelial-lined cysts that developed within the graft tissue. These cysts were treated by excising the cysts walls and allowing the resultant cavity to heal spontaneously. Light microscopy of the excised tissue revealed that the clear cysts were lined by a non-keratinizing, stratified squamous epithelium. The histogenesis of the cysts is unclear, but most likely they are the result of incompletely removed or implanted conjunctival or corneal epithelium. Several other possibilities are discussed. Due to the difficulty of removing all corneal and conjunctival epithelium, cystic complications of dermis-fat grafts make unattractive their use for volume enhancement in patients with microphthalmia or following evisceration.

Adipose Tissue↗
PubMed1987

Hemifacial spasm. Results of unilateral myectomy.

Hemifacial spasm (HFS) is a disorder characterized by unilateral involuntary spasm of the muscles innervated by the facial nerve (cranial nerve VII). The etiology is often a redundant or ectatic artery in the cerebellopontine angle that compresses the facial nerve. Neurosurgical decompression with implantation of a sponge between the ectatic artery and the facial nerve produces good results, but has a high complication rate and a poor patient acceptance rate. Various modes of peripheral neurectomy have also been advocated, but the recurrence rate is high and the preexisting functional and cosmetic eyelid deformities are exacerbated. The results of unilateral periorbital myectomy in 21 HFS patients are presented. Follow-up ranging from 1 to 7 years was available on 16 patients. Excellent or good results were obtained in 94% of these cases, and postoperative complications were minor. Transient lymphedema and forehead anesthesia are the most common complications. An unforseen benefit of periorbital myectomy surgery is the improvement or relief of lower facial contractions that occurred in 75% of patients. The authors believe the myectomy procedure is a safe, effective, predictable therapy for those HFS patients unwilling to risk a neurosurgical operation, and allows simultaneous reconstruction of associated eyelid and eyebrow deformities.

Adult↗