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Biomedical subjects

R L Anderson

Publications and source records attributed to R L Anderson.

At least 181 records · Page 10Linked to original sources
PubMed1990

Urinary and bladder responses to immobilization in male rats.

Immobilization of groups of five to nine male rats for 2-5 days results in a 50% increase in urinary bladder fresh weight compared with normally caged controls. The increase in urinary bladder weight was not due to tissue oedema and was accompanied by epithelial hyperplasia in some urinary bladders. Immobilization did not alter total urine volume, but it did decrease the frequency of urine voiding and doubled the mean urine weight/voiding. Thus, bladder distention caused by the increased volume per voiding caused a rapidly induced increase in bladder tissue growth, and was accompanied by an increase in bladder epithelial cell division.

Animals↗
PubMed1990

Correction of congenital diaphragmatic hernia in utero, V. Initial clinical experience.

Review of our experience with 45 cases of prenatally diagnosed congenital diaphragmatic hernia (CDH) confirms that most fetuses (77%) will not survive despite optimal pre- and postnatal care. Polyhydramnios, associated anomalies, early diagnosis, and a large volume of herniated viscera (including liver) are associated with a particularly dismal prognosis. After extensive experimental work demonstrated the efficacy, feasibility, and safety of repair in utero, we attempted to salvage six highly selected fetuses with severe CDH by open fetal surgery. Five had liver incarcerated in the chest: three died at operation because attempts to reduce the liver compromised umbilical venous return. In one, a Goretex diaphragm was constructed around the liver, but the baby died after birth. The last two fetuses, one with incarcerated liver, were successfully repaired. Both demonstrated rapid growth of the lung in utero, had surprisingly good lung function after birth despite prematurity, had the abdominal patch removed at 2 weeks, and subsequently died of nonpulmonary problems (an unrelated nursery accident in one and intestinal complications in the other). The only maternal complication was amniotic fluid leak and preterm labor. All six women are well and four have had subsequent normal children. From this phase I experience, we conclude that fetal surgery appears safe for the mother and her reproductive potential, that fetal CDH repair is feasible in selected cases, and that the fetal lung responds quickly after decompression. However, fetal repair remains a formidable technical challenge.

Adolescent↗
PubMed1990

Epidemic bacteremia due to Acinetobacter baumannii in five intensive care units.

From March 5, 1986 to September 4, 1987, Acinetobacter baumannii (AB) was isolated from blood or vascular catheter-tip cultures of 75 patients in five intensive care units at a hospital in New Jersey. To identify risk factors for AB bacteremia in the intensive care units, a case-control study was conducted. Characteristics of 72 case-patients were compared with those of 37 controls. Case-patients were more likely than controls to have had peripheral arterial catheters (odds ratio (OR) = 7.0, p less than 0.001), mechanical ventilation (OR = 5.8, p less than 0.001), hyperalimentation (OR = 5.7, p less than 0.001), or pulmonary arterial catheters (OR = 3.9, p less than 0.001). Arterial catheters were used with reusable pressure transducers for intravascular pressure monitoring. A logistic regression analysis identified four independent risk factors: transducers, ventilation, hyperalimentation, and days of transducer use at an insertion site. The strongest influence on the risk of AB bacteremia was exerted by number of days of transducer usage. Cultures of 70 transducer diaphragms or domes, 42 in-use and 28 in-storage, were positive for AB in 21% and 46%, respectively. Plasmid analysis showed that patient blood cultures and transducer isolates were identical. Transducers were wiped with alcohol in the units between patient uses. Since reusable transducers appeared to be the source of this outbreak, it is recommended that reusable transducers receive either high level disinfection or sterilization between patient uses.

Acinetobacter↗
PubMed1990

Botulinum A toxin injection. Failures in clinical practice and a biomechanical system for the study of toxin-induced paralysis.

Botulinum A toxin injection has great utility in the treatment of essential blepharospasm and other facial spasm disorders. Several investigators have noted the failure of botulinum toxin injections to relieve lid spasm in occasional patients and a decrease in effectiveness or duration of effect following multiple injections in other patients. We reviewed the charts of 30 consecutive patients presenting for the evaluation or treatment of facial dystonia. Of 20 patients who had received multiple injections of botulinum toxin, 10 patients were felt to be treatment failures. A new biomechanical system was developed to investigate the duration and degree of paralysis induced in the gastrocnemius muscle of the rat. Animals were treated with four sequential injections at 6-week intervals to the same muscle, resulting in muscle atrophy and an increase in the duration and degree of muscle paralysis, contrary to clinical findings in humans. The review of patient data confirms that, for many patients, repeated injection of botulinum toxin results in a decrease in duration and degree of effect despite an increased toxin dose. An opposite effect was noted in our experimental model because of progressive muscle atrophy.

Adult↗
PubMed1990

The tarsal tuck procedure: avoiding eyelid retraction after lower blepharoplasty.

Eyelid retraction and ectropion are the most common complications of lower blepharoplasty. These complications often occur as a result of removing excessive skin and muscle in the face of a lax lower eyelid. The tarsal tuck technique tightens and stabilizes the lower eyelid, thereby minimizing these complications. The lateral canthus and lower eyelid are elevated with the tarsal tuck, which reduces the amount of skin removal required and avoids the "round eye" appearance.

Eyelids↗
PubMed1990

Prolonged survival of Pseudomonas cepacia in commercially manufactured povidone-iodine.

Pseudomonas cepacia organisms were recently recovered from a povidone-iodine antiseptic solution. During the subsequent investigation, laboratory studies were initiated to determine the survival time of these organisms in the iodophor solution, which contains 1% titratable iodine. The solution was sampled weekly upon receipt in our laboratory, and P. cepacia was subsequently recovered through 29 weeks of sampling. Current laboratory data and lot production date information from the manufacturer indicate that P. cepacia survived for up to 68 weeks from the time of manufacture. Scanning electron microscopic examination of contaminated solution demonstrated bacterial cells embedded in extracellular material.

Colony Count, Microbial↗
PubMed1990

Effect of disinfectants on pseudomonads colonized on the interior surface of PVC pipes.

We investigated the effect of disinfectants on microbial contamination present on the interior surface of polyvinyl chloride (PVC) pipes filled with 600 ml of water contaminated with Pseudomonas pickettii and P. aeruginosa. After eight weeks, water was removed, and the test pipes exposed to various types of aqueous disinfectants. Disinfectant samples were removed, neutralized, and examined for recovery of microorganisms by membrane filtration. After seven-days exposure, disinfectant solutions were removed and pipes filled with sterile distilled water. Water was examined by membrane filtration at seven-day intervals to determine whether the organisms had survived in the pipes. Colonization of PVC surfaces were examined during each study phase by scanning electron-microscopy (SEM). P. aeruginosa was isolated directly from iodophor disinfectant, phenolic germicide, and iodophor antiseptic solutions. After addition of sterile water, P. aeruginosa was recovered from PVC pipes previously exposed to chlorine, phenolic, quaternary-ammonium, and iodophor disinfectants; P. pickettii was recovered from water in pipes treated with iodophor disinfectant, chlorine, and ethanol. The existence of glycocalyx-like cellular masses on the interior wall of PVC pipes most likely protected embedded organisms from the microbicidal action of some of the disinfectants tested and served as the reservoir for continuous contamination.

Colony Count, Microbial↗
PubMed1990

Mucinous adenocarcinoma of the orbit arising from a stable, benign-appearing eyelid nodule.

Mucinous adenocarcinoma is a rare eyelid tumor which should be considered in the differential diagnosis of a nodular or cystic lesion of the eyelid. This lesion may be locally aggressive and requires complete excision to prevent local recurrence or regional metastases. We present what we believe is the first report of a mucinous adenocarcinoma manifesting as a stable, benign-appearing nodule that has already given rise to a much larger secondary lesion. This case underscores the importance of performing a biopsy on even benign-appearing eyelid nodules.

Adenocarcinoma, Mucinous↗
PubMed1990

The universal orbital implant: indications and methods.

Major criticisms of quasi-integrated implants, such as the Iowa Implant, have been the time-consuming surgical technique needed to implant the prosthesis, and the high rate of extrusion. The Universal Implant (Oculo-Plastik, Montreal) is designed with these concerns in mind. In addition, those qualities that produce the motility advantages of a quasi-integrated implant and the ease of placement of a sphere have been incorporated into the design of the Universal Implant. The Universal Implant also (1) uses a faster implantation technique at surgery, (2) avoids cleaning the muscles, (3) has smaller mounds that are lower and more rounded, and should decrease the late extrusion rate, (4) can be used as an evisceration implant, enucleation implant, or secondary implant, and (5) has a larger girth and radius on the posterior surface that, in turn, helps support orbital fat and tissues and results in a more natural superior sulcus. It is recommended that the Universal Implant be used by surgeons who were pleased with the Iowa Implant, as the Universal implant represents an excellent alternative with major advantages over most other enucleation implants.

Humans↗
PubMed1990

Multiple orbital tumors were cavernous hemangiomas.

Two distinct masses in the left orbit were incidentally found in a 48-year-old woman during a computed tomographic scan done to evaluate neurologic complaints. Initial diagnostic considerations focused on a lymphoproliferative disorder or other systemic disease. Orbitotomy revealed two discrete tumors, both cavernous hemangiomas. Although uncommon, cavernous hemangioma should be considered in the differential diagnosis of the patient with multiple orbital lesions.

Female↗
PubMed1990

Irradiated homologous tarsal plate banking: a new alternative in eyelid reconstruction. Part I. Technique and animal research.

Reconstruction of full thickness eyelid defects requires the correction of both posterior lamella (tarsus, conjunctiva) and anterior lamella (skin, muscle). Tarsal substitutes including banked sclera, nasal cartilage, ear cartilage, and periosteum can be beneficial for posterior lamellar repair, while anterior lamellar replacement, including skin grafts, pedicle flaps, advancement flaps, etc., is important to cover the posterior reconstructed portion. At times, due to extensive tissue loss, the eyelid reconstruction can be particularly challenging. We have found an alternative posterior lamellar reconstructive technique utilizing irradiated homologous tarsal plate that can be particularly useful in selected cases of severe tissue loss. The experimental surgical procedure in monkeys and the histological fate of the implanted tarsus is described in Part I, and followed in Part II by our experience with this tissue in six human patients.

Animals↗
PubMed1990

Lower eyelid retraction: a minimal incision surgical approach to retractor lysis.

Lower eyelid retraction associated with prior blepharoplasty, trauma, or other conditions is a challenging problem for the ophthalmic surgeon. We describe a procedure involving tightening the lower eyelid and supraplacing the lateral canthus in combination with in-glove lysis of the lower eyelid retractors and scar tissue. This is accomplished through a small lateral incision. To date, we have treated over 200 eyelids using this technique with excellent results. We recommend this technique for the treatment of mild to moderate degrees of lower eyelid retraction.

Eyelid Diseases↗
PubMed1990

Amelanotic malignant melanoma of the conjunctiva with local metastasis to the eyelid.

Conjunctival melanomas are uncommon. The amelanotic variety is extremely rare. We describe a patient with an amelanotic melanoma of the superior conjunctiva that was primarily excised, followed by extensive conjunctival resection and liquid nitrogen cryotherapy applied to the tumour bed. Eight months later a local metastatic lesion was noted in the lower eyelid. Eyelid metastasis in conjunctival melanoma is uncommon but may occur owing to the rich lymphatic vasculature within the conjunctiva.

Aged↗