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Biomedical subjects

J Aldrich

Publications and source records attributed to J Aldrich.

28 records · Page 2Linked to original sources

Orthostatic effect of imipramine and doxepin in depressed geriatric outpatients.

Blood pressure measurements were collected from 36 depressed geriatric outpatients (ages 55 to 81 years) enrolled in a double-blind, placebo-controlled study of the efficacy of doxepin and imipramine. Mean systolic postural changes were 25.9 mm Hg for imipramine, significantly higher than the 10.5 mm Hg for doxepin, and 12.4 mm Hg for placebo. The orthostatic drop in the imipramine group was only weakly related to dose and did not correlate with amount of pretreatment orthostatic hypotension or with duration of treatment. The increased orthostatic hypotension occurred early in treatment and at low doses of imipramine. Accordingly, caution is advised in the use of imipramine for the elderly.

Age Factors↗

The effects of a partially purified fraction of an ant venom in rheumatoid arthritis.

A partially purified extract of an ant venom from the South American tree ant Pseudomyrmex sp. was tested in a double-blind, controlled study of patients with rheumatoid arthritis. Venom treated patients demonstrated an improvement in global efficacy and a decrease in the number of tender/painful joints and swollen joints. Swollen joint index improved in 60% of venom treated patients. Other parameters did not demonstrate significant change. Reduction of joint swelling was followed by symptomatic improvement that was sometimes delayed by weeks. Reactions were limited to erythema at the injection site (all patients), local pruritus (two-thirds of the patients), and fever with malaise (one-third of the patients). Further study of this venom in rheumatoid arthritis appears warranted in view of its apparent favorable efficacy-to-toxicity ratio.

Adult↗

Purchasing power of U.S. Social Security benefits abroad, 1970-82.

This article examines whether the small number of Social Security beneficiaries living abroad enjoy a higher standard of living than they would with the same benefits if they lived in the United States. The article addresses this question using two methods. First, absolute comparisons of U.S. dollar purchasing power abroad are made using "purchasing power parities," a method recently developed to allow international comparisons of real standards of living. Second, the effects of changes in Social Security benefit levels, exchange rates, and rates of inflation on the relative value of benefits abroad are measured. Both methods show considerable instability in purchasing power of Social Security benefits in the 1970's. Although beneficiaries in 1970 generally could live better abroad than in the United States, this advantage eroded considerably during the 1970's, followed by some improvement in 1981-82.

Economics↗

Extranuclear DNA of a Marine Chromophytic Alga : RESTRICTION ENDONUCLEASE ANALYSIS.

Two extranuclear DNA species have been isolated from the marine alga Olisthodiscus luteus. Rapid lysis of cells followed by the immediate addition of CsCl to the lysate was critical to the preservation of these satellite DNA species. Restriction endonuclease analysis demonstrates a molecular weight of 99 x 10(6) for chloroplast DNA and 23 x 10(6) for a second satellite species. The origin of the second satellite is not known. However, this smaller satellite DNA which originates from a nonnuclear, DNAse insensitive cellular component, displays no sequence homology with ctDNA by hybridization experiments. Constancy of restriction endonuclease fragment patterns of chloroplast and second satellite species during all phases of the growth cycle, whether cultures were maintained synchronously or asynchronously, was demonstrated.

Journal Article↗

The earnings replacement rate of old-age benefits in 12 countries, 1969-80.

This article reports the findings of the first cross-national study since 1975 of earnings replacement rates--the proportion of immediate preretirement earnings replaced by social security retirement benefits. In the countries studied--Austria, Canada, Denmark, France, the Federal Republic of Germany, Italy, Japan, the Netherlands, Sweden, Switzerland, the United Kingdom, and the United States--the replacement rates in recent years seem to have continued their upward trend, although they appear to be rising more slowly than before, and under some interpretations seem to be leveling off. In 1980, the United States was fifth among the countries studied in replacement rates for retired couples (one working spouse, one nonworking spouse) and fell within the middle range for single aged beneficiaries: Six countries provided higher benefit levels, four provided lower benefits, and one provided benefits at the same level.

Aged↗

Isolation and Characterization of Chloroplast DNA from the Marine Chromophyte, Olisthodiscus luteus: Electron Microscopic Visualization of Isomeric Molecular Forms.

Chloroplast DNA (ctDNA) from the marine chromophytic alga, Olisthodiscus luteus, has been isolated using a whole cell lysis method followed by CsCl-Hoechst 33258 dye gradient centrifugation. This DNA, which has a buoyant density of 1.691 grams per cubic centimeter was identified as plastidic in origin by enrichment experiments. Inclusion of the nuclease inhibitor aurintricarboxylic acid in all lysis buffers was mandatory for isolation of high molecular weight DNA. Long linear molecules (40 to 48 micrometers) with considerable internal organization comprised the majority of the ctDNA isolated, whereas supertwisted ctDNA and open circular molecules averaging 46 micrometers were occasionally present. Also observed in this study were folded ctDNA molecules with electron dense centers ("rosettes") and plastid DNA molecules which have a tightly wound "key-ring" center. The ctDNA of Olisthodiscus has a contour length that is median to the size range reported for chlorophytic plants.A minor component of the total cellular DNA, which originates from a DNase insensitive cellular structure, has a buoyant density of 1.694 grams per cubic centimeter. This DNA consists predominantly of linear molecules, but open circles 11.5 micrometers in length and rare 22-micrometer dimers were also present.This study represents the first analysis of the extranuclear DNA of a chromophytic alga.

Journal Article↗

Kinetic Complexity, Homogeneity, and Copy Number of Chloroplast DNA from the Marine Alga Olisthodiscus luteus.

The kinetic complexity of chloroplast DNA isolated from the chromophytic alga Olisthodiscus luteus has been determined. Using optical reassociation techniques, it was shown that the plastid DNA of this alga reacted as a single component with a second order rate constant of 4.1 molar(-1) and second(-1) (Cot((1/2)) 0.24 molar second) under conditions equivalent to 180 millimolar Na(+) and 60 degrees C. Given the 92 x 10(5) dalton complexity calculated for this chloroplast genome, an Olisthodiscus cell contains 650 plastome copies. Although this complement remains constant throughout the growth cycle of the organism, the ploidy level of an individual chloroplast shows significant plasticity and is dependent upon the number of chloroplasts present per cell. Experiments with the DNA fluorochrome Hoechst dye 33258 (bisbenzimide) demonstrate that plastids isolated from all phases of cell growth each possess a ring-shaped nucleoid containing detectable DNA. Olisthodiscus chloroplast DNA showed no sequence mismatch when thermal denaturation profiles of reassociated chloroplast DNA were examined, thus all plastome copies are essentially identical. Finally, reassociation studies demonstrated that no foldback (short inverted repeat) sequences were present in the plastid genome although significant hairpin loop structures were observed in control nuclear DNA samples.

Journal Article↗

Urogenital tract abnormalities in sons of women treated with diethylstilbestrol.

Since in utero exposure to diethylstilbestrol (DES) is known to cause abnormalities of the female genital tract later in life, exposed male offspring were located, surveyed by mail, and compared with unexposed male offspring from the same period and medical practices. The exposed and unexposed respondents appeared comparable and did not differ in their response to most medical questions. However, a larger proportion of exposed than of unexposed boys had experienced problems in passing urine (12.9% vs. 1.8%, P = .0003) and abnormalities of the penile urethra (4.4% vs. 0%; P = .017).

Abnormalities, Drug-Induced↗

Central nervous system disorders after renal transplantation in cats.

OBJECTIVE: This study describes the incidence and severity of postoperative central nervous system (pCNS) disorders in feline renal transplant recipients. STUDY DESIGN: A retrospective study based on the medical records of cats that received renal allografts from 1987 to 1996. ANIMALS OR SAMPLE POPULATION: Fifty-seven client-owned cats received renal allografts for the treatment of renal failure. METHODS: The frequency, duration, severity, and treatment of episodes of pCNS disorders were recorded from the medical records. RESULTS: Twelve (21%) of 57 cats had pCNS disorders 1 hour to 5 days after the surgical procedure. Seven cats survived; four had single or multiple seizure episodes, and two had seizure episodes or disorientation followed by a period of coma. One cat became temporarily ataxic and blind after restraint for venipuncture. Five cats died; all had episodes of disorientation or seizures, or both, that progressed to a nonrecoverable comatose state, respiratory arrest or cardiac arrest, or both. There were no significant differences between the two groups in preoperative serum creatinine, blood urea nitrogen, or cholesterol levels, and intraoperative blood pressure measurements. There were no significant differences in the postoperative serum glucose levels, electrolytes levels, or osmolality between the two groups. The cats with pCNS disorders had a mean preoperative trough cyclosporine A (CyA) whole blood level of 429 ng/mL; cats without pCNS disorders had a significantly (P = .0116) higher mean preoperative trough CyA whole blood level of 736 ng/mL. CONCLUSION: Central nervous system disorders are a common and often fatal complication of renal transplantation in cats. CLINICAL RELEVANCE: Recognition of pCNS disorders, and possible causes, will help develop hypotheses to investigate the problem.

Animals↗

Silica-containing urinary calculi in dogs (1981-1993).

Silica-containing urinary calculi obtained from 773 dogs and submitted by veterinarians throughout the United States were analyzed by quantitative crystallographic analysis to determine mineral composition. Specimens were composed of either multiple mineral layers (535 specimens) or 1 mineral layer (238 specimens). Most multiple-layer calculi were composed of 80% or greater silica (300 of 535, 56%) or 20% to 79% silica (184 of 535, 34%) in any mineral layer. Most 1-layer calculi were composed of 100% silica (212 of 238, 89%). Most dogs forming silica-containing calculi were of male gender (679 of 773, 88%). Bacterial cultures of calculus or urine or both were performed on 49% (376 of 773) of the specimens, and bacterial growth was obtained from 37% (139 of 376) of samples cultured. The prevalence of calculus-associated urinary tract infection was 35% (113 of 321) in males and 47% (26 of 55) in females. The gender prevalence for infection with Staphylococcus species was 16% (51 of 321) in males and 33% (18 of 55) in females. The breed and gender of dogs that formed calculi (silica population) were compared with the hospital population (Veterinary Medical Teaching Hospital [VMTH] population) and with a population of calculus-forming dogs (Stonelab population) to determine risk factors for silica calculus formation. For all breeds compared, the ratio of males to females was higher in the silica population. The German Shepherd Dog and Old English Sheepdog were significantly overrepresented when the silica population was compared with either the VMTH population or the Stonelab population. We conclude that male German Shepherd Dogs and Old English Sheepdogs are at increased risk for formation of silica-containing urinary calculi.

Animals↗