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Biomedical subjects

R L Anderson

Publications and source records attributed to R L Anderson.

At least 451 records · Page 25Linked to original sources
PubMed1979

Neuromyopathic ptosis: a new surgical approach.

Neuromyopathic ptosis is a progressive disorder frequently associated with other ocular abnormalities. These include dry eyes, absent Bell's phenomenon, protractor weakness, and heterotropia. Thus, correction of this ptosis has not been well described and is avoided by many surgeons. Since ptosis usually occurs early in life, correction is of functional, economic, and cosmetic importance. Clinical and histologic findings suggest that degeneration and defects of the levator aponeurosis contribute to the ptosis. During the past two years, we have used the aponeurotic approach to correct neuromyopathic ptosis. We describe 19 eyelids with a minimum one-year follow-up. Most eyelids were purposely undercorrected. A mean lid elevation of 3.3 mm with good symmetric results was obtained. Procedures were performed under local anesthesia. Advantages of this technique are (1) patient cooperation for adjustment of lid height and contour at surgery; (2) preservation of other suspensory structures (Müller's muscle and Whitnall's ligament); (3) easy adjustment of lid height postoperatively; (4) preservation of all tear-producing structures; (5) avoidance of corneal irritation from posterior sutures; and (6) maintenance of anatomic planes, which simplifies reoperation, if necessary. We believe this conservative approach corrects most eyelids with neuromyopathic ptosis.

Adult↗
PubMed1979

The use of thymoxamine in eyelid retraction.

We observed substantial narrowing in 75% of fissures in patients with various types of lid retraction after topical application of aqueous 0.5% thymoxamine (moxisylyte). Even contralateral normal-appearing fissures in thyroid patients responded in this manner. The nonresponders in the lid retraction group included a patient with an orbital pseudotumor and patients with long-standing and stable euthyroid eye disease. No normal subjects' fissures responded greatly to thymoxamine. A substantial reduction in palpebral fissures was seen in all patients with thick extraocular muscles and in 14 of 18 (78%) of all fissures of thyroid patients; the average response was 2.3 mm. This effect may last for five hours after thymoxamine administration. Thymoxamine may be of use as a diagnostic test for thyroid eye disease, and if it can be modified to cause less ocular irritation, it may be beneficial in the medical treatment of eyelid retraction.

Adult↗
PubMed1979

The tarsal strip procedure.

We have developed a procedure that is particularly useful for (1) paralytic or senile upper and lower eyelid laxity, (2) lateral canthal tendon laxity or malposition, and (3) iatrogenic phimosis associated with recurrent entropion or ectropion after traditional lid-shortening procedures. Lateral canthal tendon laxity or elongation is the primary problem in the majority of these cases, and eyelid tightening with use of lateral tarsal strips corrects this deformity. The midtarsal portion of the eyelid, which is usually resected in traditional lid-shortening procedures, is seldom elongated, and recurrences of laxity are common secondary to further stretching of lax tendons. The technique involves a lateral canthotomy and transection of the appropriate crus of the lateral canthal tendon. The eyelid is then split into anterior and posterior lamellae, and tarsal strips are fashioned from the posterior lamella. The tarsal strips are sutured to periosteum at the lateral orbital wall, adjusting the height and tension of the lateral canthus. This technique gives a normal appearance to the lateral canthal angle and has yielded good results in 51 cases.

Aged↗
PubMed1979

Reconstruction by myocutaneous eyelid flaps.

The combined loss of skin and deeper tissues of the eyelids and periorbital regions can frequently be reconstructed with use of an eyelid myocutaneous flap. This technique alone can be used for most eyelid defects not involving the lid margin, or it can be used in conjunction with other procedures when the lid margin is involved. Defects, sometimes quite large, in 37 patients have been reconstructed with good results. The technique provides one-stage reconstruction, avoids volume loss and depressed scars, provides an excellent blood supply to the flap, gives an optimum tissue match, decreases patient morbidity, and increases the likelihood of a good cosmetic result. The generalized applications of this technique make it valuable for reconstructive surgery of the orbital region.

Aged↗
PubMed1979

Aponeurotic defects in congenital ptosis.

Levator aponeurosis disinsertion is an accepted etiologic factor in some acquired ptosis cases, but it has not previously been reported as a cause of congenital ptosis. Forty-six congenitally ptotic eyelids in 36 patients with no history of birth trauma were surgically explored and three eyelids were found to have levator disinsertions. All three cases were treated by aponeurotic repair with excellent results. These cases and suggestions that help to preoperatively identify congenitally ptotic eyelids with levator disinsertions are presented. We feel the aponeurotic approach to ptosis correction is applicable to cases of congenital ptosis with at least 5 mm of function.

Adolescent↗
PubMed1979

Indications, complications and results with silicone stents.

Fifty-two patients with complicated lacrimal problems were treated with silicone stents. Our overall success rate, judging from a minimum 6-month follow-up, was 40% in these complicated cases, accepting only positive dye tests as our criteria for success. We divided these cases into six groups with successes ranging from 0--68%. Twenty-nine percent of patients had complications related to their stents. While silicone stents are probably the most important recent advance in lacrimal surgery, one must be aware of their indications, limitations and complications.

Female↗
PubMed1979

Carcass deposition of dietary long-chain odd carbon fatty acids by rats and their effect on plasma glucose and ketone bodies during starvation.

Weanling rats were fed diets containing various levels (0 to 40% of total dietary acids) of long chain, odd-carbon fatty acids (OCFA, 15:0 + 17:0) for 5 weeks. The OCFA did not significantly alter growth or feed efficiency and the OCFA were deposited in the carcass fat in proportion to their concentration in the diet fat. After the 5-week ingestion period, the rats were starved for 48 hours and the effect of carcass OCFA content on weight loss, fat loss, urinary total nitrogen, plasma glucose concentration and plasma ketone body concentrations was determined as a function of starvation time. The results demonstrate that OCFA catabolism during starvation results in a dose related increase in plasma glucose and dose related decrease in plasma ketone bodies without significantly altering the total weight loss, carcass fat loss, or urinary total nitrogen. Finally, the carcass percentage of OCFA did not change during starvation showing that these acids are as readily lost from the carcass during starvation as even chain fatty acids.

Animals↗
PubMed1979

Lymphoblastoid cell lines are polyclonal activators of human T lymphocytes.

Following stimulation with autologous or allogeneic lymphoblastoid cell lines (LCL) human T lymphocytes acquire two properties which suggest that LCL act as polyclonal activators. Cytotoxic activity, which has an antigen-specific component, is produced towards normal lymphocytes and LCL, and the cells become capable of mounting proliferative responses to antigens on human B lymphocytes which have accelerated secondary-type kinetics. Only weak responses to autologous cells occur. In addition, repeated restimulation with the original LCL leads to a progressive increase in the number of cells in the culture for a period of about 4 weeks. This approach may prove a useful way to grow large numbers of human T lymphocytes for further study.

Cell Division↗
PubMed1979

Antigenic polypeptide complex from the Melvin strain of Neisseria gonorrhoeae: isolation and properties.

An antigenic complex has been isolated in a highly purified from from the Melvin strain of Neisseria gonorrhoeae. The complex has a molecular weight of 9.3 x 10(6) and on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was found to consist of several subunits; the most predominant had the following molecular weights: 110,000, 94,000, 68,000, a smear containing (52,000, 48,000, and 44,000), 42,000, 36,000, 29,000, 28,000, 26,000, and 12,000 comprising 89% of the total protein. With the exception of the subunit of molecular weight 110,000, no change in the content or the mobility of other subunits was observed when beta-mercaptoethanol was omitted from the denaturation solution of sodium dodecyl sulfate electrophoresis. Amino acid analysis of the complex showed a predominance of hydrophobic amino acids. These data implicated noncovalent interactions between the subunits. When the cells were labeled with fluorescamine it was possible to obtain a fluorescent complex with identical properties. Among several buffers used for the isolation of the complex, 0.2 M tris(hydroxymethyl)aminomethane buffer (pH 7.5) gave maximum yield with low amounts of lipopolysaccharide and phospholipid; the choice of the buffer for column chromatography did not seem to make any difference. The high protein content and low amounts of lipopolysaccharide and phospholipid are characteristic properties of the complex.

Amino Acids↗
PubMed1979

[Ptosis surgery: anterior approach for levator aponeurosis shortening (author's transl)].

A simplified method for ptosis surgery has been used in 33 patients. The levator aponeurosis is exposed by the anterior approach. It is folded or excised and reattached to the anterior surface of the tarsus, matching the level and the contour of the two upper lids. The cosmetic appearance of the lid is improved by the skin closure technique. This method for ptosis surgery meets the anatomical and physiological needs best. It has given very satisfactory functional and cosmetic results.

Adolescent↗
PubMed1979

Enzyme replacement therapy by fibroblast transplantation: long-term biochemical study in three cases of Hunter's syndrome.

We have assessed the effectiveness of transplanted histocompatible fibroblasts as a long-lived source of lysosomal enzymes for replacement therapy in three patients with Hunter's syndrome, over periods ranging from 2.5 to 3.75 yr. The level of Hunter corrective factor excreted by all three patients increased after transplantation, as did the activity of alpha-L-idurono-2-sulfate sulfatase in serum, when measured directly with a radioactive disulfated disaccharide substrate. Sulfatase activity was also raised in leukocyte homogenates from the two patients that we were able to assess. These increases in enzyme activity were accompanied by corresponding increases in catabolism of heparan and dermatan sulfates, as shown by (a) a decrease in sulfate:uronic ratios of urinary oligosaccharides, (b) an increase in iduronic acid monosaccharide, and (c) a normalization of Bio-Gel P-2 gel filtration profiles. Both the increase in enzyme activity and increased catabolism were maintained during the period of study and were not affected by either a gradual decrease or total withdrawal of immunosuppressive therapy.

Child↗
PubMed1979

Human-mouse mixed lymphocyte cultures. II. Partial separation of functionally distinct populations on discontinuous albumin gradients.

Human-mouse mixed lymphocyte cultures (MLC) develop stable, strain-specific responses directed towards antigens determined by the mouse major histocompatibility complex (MHC). By restimulation in vitro a two- to four-fold increase in total cell numbers can be achieved. Sensitized cells can be fractionated on discontinuous BSA gradients to produce fractions with predominantly proliferative or cytotoxic activity towards the intiating antigens. Mixing experiments show that fractionation of biological activity is the result of fractination of specifically sensitized effector cells rather than fractionation of inhibitory or collaborative elements. Since biological activities or can be separated on the basis of physical properties into distinct cell populations these experiments support the idea that these functions are the properties of distinct subclasses of human T lymphocyte. Xenogeneic MLC coupled to physical separation measures is a useful approach to the study of antigen-specific human T lymphocytes.

Animals↗
PubMed1979

The effects of nicotine on cell division of HeLa cells.

A time lapse cinemicrographic study shows that, at low concentrations, nicotine can speed up cytokinesis and, at high concentrations, prolong the duration of metaphase in HeLa cells. Based upon the known effects of the alkaloid in other systems, it appears that it may stimulate microfilament activity and inhibit microtubule function by increasing the level of cytosolic calcium ions.

Cell Division↗