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Biomedical subjects

R L Anderson

Publications and source records attributed to R L Anderson.

At least 325 records · Page 18Linked to original sources
PubMed1985

A review of the environmental and mammalian toxicology of nitrilotriacetic acid.

This article provides a review of available information on the chemistry, environmental toxicology, and mammalian toxicology of nitrilotriacetic acid (NTA). The ability of NTA to chelate metal ions such as Mg++ and Ca++ into water soluble complexes makes NTA useful as an additive to boiler water, as a builder in laundry detergents, and as a stabilizer in textile, paper, and pulp processing. Environmental fate studies show NTA biodegrades in wastewater treatment plants, in natural waters, and in soils under a wide variety of conditions. Studies on the environmental effects of NTA indicate that no adverse effects occur in treatment plants or receiving waters at anticipated levels. Monitoring programs have established that only low steady-state concentrations of NTA occur in natural waters as a result of NTA usage. In mammalian systems, NTA is not metabolized and is excreted rapidly by filtration in the kidney. No reproductive, teratogenic, or adverse bone effects have been observed at highly exaggerated doses. In numerous genotoxicity assay systems, both in vivo and in vitro, NTA is nongenotoxic. Chronic oral exposure of rodents to high doses of NTA is associated with tumorigenicity in, and restricted to, the urinary tract. The urinary tract tumors are the consequence of chronic toxicity that is caused by changes in Zn and Ca distributions between the urinary tract tissues and urine at high doses of NTA. Thresholds for the effects of NTA on Zn and Ca distributions are 10(5) to 10(6) greater than the possible maximum human exposure resulting from the low levels of NTA that are known to occur in the environment.

Acetates↗
PubMed1985

Sonography, a complementary examination to alpha-fetoprotein testing for fetal neural tube defects.

Neural tube defects (NTDs) are among the most common congenital anomalies in the United States, with an estimated prevalence of 16 per 10,000 births. The measurement of amniotic fluid alpha-fetoprotein (AF-AFP) concentration has been used to detect NTDs since the early 1970s. When the AF-AFP concentration is elevated, ultrasonography is commonly used to confirm the presence of a NTD. In this study, patient charts, amniocentesis records, and ultrasound reports from a three-year period were reviewed. The 97 fetuses identified as being at high risk for NTDs were divided into four groups: those with high AF-AFP concentrations (Groups 1 and 2, with from 3 to 5 standard deviations (SD) above the mean and with more than 5 SD above the mean, respectively): those referred from other institutions because of suspicious sonographic results (Group 3); and those at risk because of a previous sibling with a NTD (Group 4). Ultrasonography was 100 per cent sensitive and 100 per cent specific in diagnosing NTDs. Thus, in pregnancies with an elevated AF-AFP concentration, ultrasonography can reliably identify normal fetuses as well as differentiate between those with NTDs and those with other congenital anomalies. Also, since AF-AFP concentrations decline after 20 weeks' gestation, ultrasonography may be a better test than a repeat amniocentesis in equivocal cases of AF-AFP elevation.

Adult↗
PubMed1985

Differential effects of hyperthermia on the Na+,K+-ATPase of Chinese hamster ovary cells.

The effect of hyperthermia in the 41-50 degrees C range on the Na+,K+-ATPase of CHO cells has been investigated. Three separate activities of the enzyme, namely, ATP hydrolysis, K+ uptake, and binding of the specific inhibitor, ouabain, have been measured independently. The results can be summarized as follows: (1) The ouabain binding capacity of intact cells decreased with increasing temperature and with increasing time at any one temperature. (2) The loss of ouabain-sensitive K+ uptake after treating cells at 45 degrees C was very similar to the loss of ouabain binding capacity. In contrast, the ATP hydrolyzing activity was much more resistant to heat. (3) The ouabain binding capacity was more resistant to hyperthermia at 45 degrees C if the cells were given a prior exposure at 45 degrees C 12 hr earlier. In contrast, the ATP hydrolyzing activity did not display this tolerance to heat.

Adenosine Triphosphate↗
PubMed1985

Delayed socket granuloma formation following evisceration.

We report a rare granuloma of the socket that simulated a conjunctival squamous cell carcinoma in a patient treated with evisceration six and a half years earlier. An excisional biopsy revealed loose connective tissue with marked capillary proliferation and lymphocytic infiltration. The cut end of a silicone exoplant, used to treat a preceding traumatic retinal detachment, was found at the base of the lesion. Prior operative procedures should be reviewed in patients presenting with socket lesions to exclude the presence of an iatrogenic foreign body.

Adult↗
PubMed1984

Levator myectomy in synkinetic ptosis.

A procedure for obliterating levator palpebrae superioris function is useful in stopping synkinetic movements of the upper lid in jaw winking and related disorders. The central element of the procedure is division of the levator muscle above Whitnall's ligament. This process obliterates the synkinetic movement completely without extensive dissection and injury to eyelid structures. Eight patients observed for up to five years have had complete and permanent resolution of synkinesis with no complications.

Adolescent↗
PubMed1984

Hematoporphyrin derivative photoradiation therapy in managing nevoid basal-cell carcinoma syndrome. A preliminary report.

Hematoporphyrin derivative (HpD) is a photodynamically active dye that is preferentially retained by malignant tissues and initiates a cytotoxic reaction when exposed to red light. Normal tissues adjacent to a tumor retain HpD to a lesser degree and are thus spared damage from the light-induced reaction. We describe the treatment of 40 basal-cell carcinomas in three patients with nevoid basal-cell carcinoma syndrome. All treated lesions showed disappearance of clinically apparent tumor within four to six weeks, and there was no damage to surrounding skin. Thirty-three lesions (82.5%) showed complete response on biopsy findings, while seven showed residual tumor cells. The recurrence rate was 10.8%, with the follow-up ranging from 12 to 14 months. Tumor response was related to the total light dose delivered and the size and location of the tumor.

Aged↗
PubMed1984

Oriental eyelids. An anatomic study.

Dissection of the eyelids and sagittal sections of the orbital blocks identified the anatomic features of the oriental eyelids responsible for their unique appearance. The basic distinction involves the formation of the eyelid crease and fold. In the occidental eyelid, the orbital septum fuses with the levator aponeurosis below the superior tarsal border. However, in the oriental eyelid, the orbital septum fuses with the levator aponeurosis below the superior tarsal border. The accompanying preaponeurotic or orbital fat is allowed to proceed to the anterior tarsal surface, resulting in a full or thickened eyelid. The inferior extension of the orbital septum, beyond the superior tarsal border, prevents anterior aponeurotic fibers from fanning toward the subcutaneous tissues to produce the normal eyelid crease. Appreciation of the unique anatomic features of oriental eyelids is important for those persons who evaluate or surgically explore these eyelids.

Asian People↗
PubMed1984

Cyanoacrylate adhesive used to stop CSF leaks during orbital surgery.

Butyl-2-cyanoacrylate (Histoacryl Blue) tissue adhesive successfully sealed three cases of CSF leaks encountered during orbital surgery. The application of tissue adhesive was followed by prompt cessation of leak. We have found this tissue adhesive to be a valuable technical adjunct in the intraoperative management of this difficult problem and have not seen any general or local toxic reaction to the material.

Adult↗
PubMed1984

One hundred twin pregnancies in a prenatal diagnosis program.

One hundred pairs of twins were encountered in 8,500 pregnancies having genetic amniocentesis. Only 5 of 27 (18.5%) pairs were recognized before the institution of routine ultrasonic examination, while 69 of 73 (94%) twin pairs were found after ultrasound use. Amniotic fluid was obtained from both sacs in 71 of the 73 (97%) identified twin gestations in which both twins were living at the time of amniocentesis.

Albinism↗
PubMed1984

Radiographic clues to fractures of the unossified medial humeral condyle in young children.

A fracture involving the trochlear ossification center as well as the medial epicondyle is a more serious injury than simple avulsion of the medial epicondyle. This diagnosis may be difficult in young children before the secondary centers are ossified. Radiographic clues to this injury in a young child are localized soft tissue swelling over the medial aspect of the elbow accompanied by a metaphyseal flake and/or a positive fat pad sign. In the older child, separation of the ossified medial epicondyle with a positive fat pad sign suggests a more complex injury.

Child↗
PubMed1984

Renal pelvic and ureteral dilatation in male rats ingesting trisodium nitrilotriacetate.

Renal pelvic and proximal ureteral dilatation has been observed in male Charles River (CD) and Fischer 344 rats ingesting comparable doses of Na3NTA X H2O. Ureteral dilatation is accompanied by epithelial surface ulceration and erosion. Taken together with previous work (Anderson, Alden & Merski, Fd Chem. Toxic. 1982, 20, 105), these findings demonstrate that the ingestion of high doses of NTA results in similar effects on the transitional epithelium throughout the urinary tract.

Acetates↗
PubMed1984

Trochleitis with superior oblique myositis.

Thirteen patients complained of recent fluctuating aching of one orbit, punctuated by stabbing pains. All had exquisite point tenderness over the trochlea and in half of the patients the pain was aggravated by eye movement. Standardized A-scan echography demonstrated swelling of the peritrochlear tissue and thickening of the superior oblique muscle with low internal acoustic reflectivity, typical of myositis. CT scan showed a soft tissue density in the region of the trochlea. Biopsy, performed on two patients, revealed peri-trochlear inflammation. In all patients the symptoms resolved within a period of weeks or months: indomethacin or naproxen were not effective, but oral or locally injected corticosteroids shortened the course compared to no treatment. None of the patients had ptosis, proptosis, Brown's syndrome, or a click, nor did they have echographic or radiographic signs of sinusitis or inflammation away from the trochlea. This probably represents a highly localized subtype of idiopathic orbital inflammation ("pseudotumor").

Adult↗
PubMed1984

Orbital malignant melanoma and oculodermal melanocytosis: report of two cases and review of the literature.

Oculodermal melanocytosis is a congenital melanoblastic hamartoma affecting ocular tissues and facial skin. It is seen more commonly in oriental and black patients. Malignant degeneration, once believed to be rare in this syndrome, occurs in 4.6% of all reported cases, and is more frequent in whites. The actual incidence of malignant melanoma in this syndrome is difficult to determine as many uncomplicated cases go unreported. The most common site of malignant melanoma associated with this entity is in the choroid. Four previously described orbital tumors represent the second most frequent area of presentation. A review of the literature in this disease is discussed as well as a new case of orbital malignant melanoma associated with it. A second case of presumed orbital melanoma associated with oculodermal melanocytosis is also discussed.

Adolescent↗
PubMed1984

Combined clinical and computed tomographic diagnosis of orbital glioma and meningioma.

The clinical information on 22 patients with orbital optic nerve gliomas and 47 patients with meningiomas was correlated with computed tomographic findings obtained in both axial and coronal studies. Most of the gliomas occurred in children, although 7 patients presented after 20 years of age. Among the patients with meningiomas, the majority were women in early middle age, although two tumors occurred in children less than 20 years of age. Low grades of proptosis (median, 2 mm for both tumors), frequent significant visual field obscurations with eye movements, and opto-ciliary shunt vessels pointed toward the diagnosis of an optic nerve tumor. Patients with gliomas generally manifested massively swollen fusiform optic nerves with clear-cut margins due to circumscription by an intact dura. Kinks and bucklings of the optic nerve as well as infarctive cysts distinguished the glioma CT-scan patterns from the meningiomas. Distinctive axial CT-scan features of the meningiomas not shared by the gliomas were narrowly and diffusely enlarged nerves with polar expansions either at the orbital apex or immediately behind the globe; calcification; irregular excrescent margins signifying extradural invasion into the orbital soft tissues; a negative optic nerve shadow running down the center of the lesion; and bone erosion near the orbital apex. Coronal studies often revealed irregular margins signifying transgression of the dura. A diffusely and narrowly enlarged optic nerve shadow with regular margins (intrasheath lesions) was the one morphologically overlapping pattern displayed by 11 meningiomas and three gliomas. In these cases there tended to be more profound visual loss in the gliomas compared with the meningiomas, as well as the more frequent presence of opto-ciliary vessels in the meningiomas. Arteriography may be helpful in this particular category by demonstrating a tumor blush for the meningiomas, whereas this finding is typically absent with optic nerve gliomas. Meningiomas may be very closely simulated by dural or intraneural inflammations.

Adolescent↗