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Biomedical subjects

L W Williams

Publications and source records attributed to L W Williams.

At least 55 records · Page 3Linked to original sources

Intravenous immunoglobulin: new clinical applications.

At the present time there are three commercially available intravenous immunoglobulin (IVIG) preparations. There is no distinct therapeutic advantage for any one product over any other. Intravenous immunoglobulin is currently approved for the treatment of antibody deficiency syndromes and for acute and chronic idiopathic thrombocytopenic purpura. In addition, controlled clinical trials have demonstrated efficacy for the treatment of Kawasaki disease and for the prevention of the following infections: sepsis in preterm neonates, sepsis in infants with AIDS, and cytomegalovirus infection in the immune-compromised host. Open (uncontrolled) studies have suggested benefit in the treatment of neonatal sepsis, chronic Epstein-Barr virus infection, and a number of autoimmune diseases. Additional carefully designed studies must be completed before IVIG therapy can be recommended for these latter categories. In published reports, dosage of IVIG and intervals between infusions have varied considerably. For all current indications, the physician must therefore individualize treatment and thoroughly review any recent literature that may clarify guidelines to IVIG therapy. Significant adverse reactions are rare but high cost remains the main obstacle to more routine implementation.

Clinical Trials as Topic↗

Complement: function and clinical relevance.

There is a remarkable array of proteins participating in the complement cascade, regulating the activation of the system, or recognizing a fragment of a component as a biologic signal. The classical pathway of complement activation depends on antigen-antibody interaction and is important as an effector arm of acquired humoral immunity to microorganisms. The alternative pathway functions as a form of innate humoral immunity by attacking membranes not having the characteristics of self-membrane. In addition, the alternative path provides amplification after triggering by either path. Absence or dysfunction of many of the components is associated with autoimmune or immunodeficiency disease. Absence of the inhibitor C1INH is associated with the unique syndrome of hereditary angioedema.

Complement Activation↗

Forecasting coronary heart disease incidence, mortality, and cost: the Coronary Heart Disease Policy Model.

A computer simulation model was developed to project the future mortality, morbidity, and cost of coronary heart disease (CHD) in the United States population. The model contains a demographic-epidemiologic (DE) submodel, which stimulates the distribution of coronary risk factors and the conditional incidence of CHD in a demographically evolving population; a "bridge" submodel, which determines the outcome of the initial CHD event; and a disease history (DH) submodel, which simulates subsequent events in persons with a previous CHD event. The user of the model may simulate the effects of interventions, either preventive (i.e., risk factor modification) or therapeutic, upon mortality, morbidity, and cost for up to a 30-year period. If there were no future changes in risk factors or the efficacy of therapies after 1980, baseline projections indicate that the aging of the population, and especially the maturation of the post-World War II baby-boom generation, would increase CHD prevalence and annual incidence, mortality, and costs by about 40-50 per cent by the year 2010. Unprecedented reductions in risk factors would be required to offset these demographic effects on the absolute incidence of CHD. The specific forecasts could be inaccurate, however, as a consequence of erroneous assumptions or misestimated baseline data, and the model awaits validation based on actual future data.

Adult↗

Study of the feline and canine populations in the greater Las Vegas area.

Analysis of household dogs and cats, based on age-distribution data and on age-specific birth and survival rates, as well as on pet source, indicated that the dog and cat populations are stable and not increasing in size (lambda congruent to 1). Roaming dogs and cats euthanatized at the pound represented about 5.7% and 8.1% of the estimated dog and cat populations, respectively. The death at the pound seems to be effective in checking pet population growth. Among pets acquired, 84% were less than 1 year of age for dogs as compared with 88% for cats. Breeders and pet shops supplied about 7% of cats and 17% of dogs. About 10% of cats and 10% of dogs were acquired at the pound, while 6.4% of dogs and 14% of cats were acquired as stray. About 45% of dogs and 41% of cats were acquired from pet owners. Some dogs (12.46%) and cats (12%) were imported from outside the Las Vegas area. Of dogs and cats below 2 months of age, 33% and 19.5%, respectively, came from breeders or pet shops or were imported from outside the area. Seventeen percent of unspayed female dogs and 16% of unspayed female cats reproduced. The percentages of spayed females were 77 for dogs and 86 for cats. Forty-five percent of the dogs and 48% of the cats were males. Among dogs at the shelter, 2% were neutered and 26% spayed. At the pound, 24% of dogs were small breeds, 24% medium size breeds, and 52% large breeds.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

Cataracts in Chesapeake Bay Retrievers.

Cataracts developed in 13 of 27 related Chesapeake Bay Retrievers. The posterior pole, "Y" sutures, and equatorial cortices of the lens were predominantly affected. In one affected dog, the cataracts had progressed to hypermaturity, permitting restoration of vision. The trait was believed to be dominant, with incomplete penetrance.

Age Factors↗

Ocular hypotensive effects of carbonic anhydrase inhibitors in normotensive and glaucomatous Beagles.

Four carbonic anhydrase inhibitors (acetazolamide, dichlorphenamide, ethoxzolamide, and methazolamide) cause ocular hypotony in normotensive and glaucomatous Beagles. Four dosages of acetazolamide and methazolamide and three dosages of dichlorphenamide and ethoxzolamide were evaluated. The extent of ocular hypotony after these carbonic anhydrase inhibitors was usually greater in glaucomatous Beagles than it was in normotensive Beagles.

Acetazolamide↗

Evaluation of a soluble sustained-release ophthalmic delivery unit in the dog.

A 5-mg hydroxypropyl cellulose soluble ocular insert was evaluated by placement in the upper and the lower conjunctival and bulbar nictitating membrane fornices in normal dogs. The insert was easily placed in the conjunctival fornices, but was difficult to place in the bulbar nictitating membrane fornix. The conjunctival inserts did not produce irritation of the cornea and the conjunctiva. Placement of the inserts beneath the nictitating membrane produced local irritation and chemosis. The sites of highest to lowest retention for the insert were upper conjunctival fornix, bulbar nictitating membrane fornix, and lastly, lower conjunctival fornix. Dissolution was nearly complete in 8 hours.

Animals↗

Uveoscleral flow of aqueous humor in the normal dog.

Fluorescein-labeled dextran and sodium fluorescein perfused in the posterior chamber of the normal dog eye egressed through the trabecular meshwork and intrascleral plexus, as well as posteriorly through the ciliary body into the suprachoroidal space and the sclera. Intraocular pressures of 20, 25, 30, and 60 mm of Hg did not produce detectable changes in the fluorescein-labeled dextran movement. Topical 1% atropine and 10% phenylephrine did not affect posterior passage of sodium fluorescein; 2% pilocarpine impeded posterior passage, causing an accumulation of sodium fluorescein and associated fluorescence in the anterior ciliary body.

Animals↗

Clinical manifestations of inherited glaucoma in the beagle.

Inherited glaucoma was exhibited in 55 beagles. The glaucomatous process was divided into early (6 to 12 months of age), moderate (13 to 30 months of age), and advanced (31 months of age). In early glaucoma the tridocorneal angles, as judged by gonioscopy, were open and without anomalies, intraocular pressure was elevated, and the tonographic facility of aqueous outflow was decreased. With moderate glaucoma, the tridocorneal angles were typically open; intraocular pressure was elevated, facility of aqueous outflow was decreased; and variable optic disc cupping and focal disinsertion of the zonules from the lens were seen. Advanced glaucoma exhibited narrow to closed tridocorneal angles, decreased facility of aqueous outflow, elevated intraocular pressure, lens dislocation, optic disc atrophy, and finally phthisis bulbi. The beagle in the early and moderate stages of glaucoma, before angle closure and lens dislocation, is an animal model for studies in open-angle glaucoma.

Animals↗

The effect of topical pilocarpine on intraocular pressure and pupil size in the normotensive and glaucomatous beagle.

Topical 1, 2, and 4 percent pilocarpine were evaluated in the normotensive and glaucomatous beagles, comparing intraocular pressure (IOP), pupillary size, and time. In normotensive beagles pilocarpine produced maximal decreases of 25 percent (5.5 mm. Hg) at 1 percent concentration; 34 percent (7.26 mm. Hg) at 2 percent concentration; and 25 percent (6.9 mm. Hg) at 4 percent concentration. The maximum reductions in IOP after pilocarpine instillation in the glaucomatous beagle were 30 percent (9.1 mm. Hg) at 1 percent concentration; 44 percent (14.92 mm. Hg) at 2 percent concentration; and 31 percent (10.89 mm. Hg) at 4 percent concentration. The glaucomatous beagles responded with a greater reduction of IOP than did the normotensive beagles.

Administration, Topical↗

Oral rabies vaccine: evaluation of its infectivity in three species of rodents.

The safety of oral rabies vaccine was evaluated in 3 species of rodents, animals which might inadvertently consume field-distributed vaccine baits intended for foxes. The potentials for infection from bait ingestion and transmission through cannibalism were evaluated. Results indicate that ingestion of the vaccine baits used in these experiments will result in infection and disease of some rodents. Of 64 rodents which ate baits, 19 (30%) died of clinical rabies; the diagnosis was confirmed in 11 (17%), and 2 (3%) had demonstrable rabies virus in their salivary glands. Only 3 of 112 (3%) rodents that ate vaccine-infected rodents contracted rabies, and none had demonstrable virus in their salivary glands.

Administration, Oral↗

Prolonging morbidity in rabid dogs by intrathecal injection of attenuated rabies vaccine.

Dogs vaccinated intrathecally with attenuated rabies vaccine developed antibodies that were detected in the cerebrospinal fluid, blood, and brain; dogs similarly vaccinated but with an inactivated vaccine developed no antibodies in the brain. When the attenuated vaccine was administered to rabid dogs, a prolongation of the morbidity period was noted and, in some dogs, recovery from the disease. Rhesus monkeys died when administered any of the available attenuated vaccines intrathecally, and further studies with that species could not be undertaken.

Animals↗