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Biomedical subjects

L A Ross

Publications and source records attributed to L A Ross.

At least 55 records · Page 3Linked to original sources
PubMed1988

Branhamella catarrhalis septicemia in an infant with AIDS.

Branhamella catarrhalis was isolated in blood culture from a 6-month-old infant with AIDS. The child had a nasopharyngeal infection with respiratory syncytial virus and pneumonitis with Pneumocystis carinii. Commensal organisms such as B. catarrhalis may be potential pathogens in infants with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Need for measles revaccination in adolescents: correlation with birth date prior to 1972.

Measles hemagglutination inhibition (HI) antibody titers of less than 1:4 were significantly (P less than 0.05) more prevalent among subjects born from 1962 through 1971 and vaccinated with a single dose of live measles virus vaccine at 12 months of age (14.5%) than among subjects born during the same years but vaccinated at 13 months or older (2.3%). For subjects born in 1972 through 1976, however, this difference was not statistically significant; titers of less than 1:4 occurred in 6.2% of those vaccinated at 12 months, compared to 0% in those vaccinated at 13 months or older. A decline in maternally derived measles HI antibody may be related to the increased rate of HI antibody titers of 1:4 or greater following vaccination of more recently born subjects. Following revaccination of subjects whose measles HI antibody titers were less than 1:4, measles HI titers were lower than would be expected after successful primary vaccination. Nevertheless, measles HI antibody persisted at a level of 1:4 or more until the latest titer measurement of this study (one to two years after revaccination) in 87.5% of those whose initial vaccination had been at 11 or 12 months of age. No adverse reactions to revaccination occurred. Revaccination programs should be considered for adolescents and young adults born before 1972 who received live measles virus vaccine at or before 12 months. Children born from 1972 through 1976 who were vaccinated at 12 months or later are not in need of revaccination.

Adolescent↗
PubMed1983

Murine metabolism and disposition of iron:adriamycin complexes.

Previous studies have reported antitumor activity and reduced cardiotoxicity for a putative 3:1 complex of iron:Adriamycin (ADR). We have studied the tissue distribution and metabolism of a wide variety of freshly prepared and lyophilized iron:ADR preparations after administration to BALB/c mice (ADR, 16 mg/kg i.v.). Tissue concentrations of ADR given without iron were initially highest in kidney and liver, and ADR fluorescence was lost from all tissues except the spleen with a t1/2 of 15 to 18 hr. ADR remained the major fluorescent species in liver and kidney from 0.5 to 72 hr after treatment. Freshly prepared iron:ADR (1:1) behaved similarly to ADR except for a slightly longer tissue t1/2 in heart, liver, and kidney. The tissue distribution of freshly prepared 2:1 and 3:1 iron:ADR was very different from that of ADR without iron; lung containing the highest concentrations of ADR fluorescence. Administration of freshly prepared 1:1, 2:1, and 3:1 iron:ADR resulted in some increase in adriamycinol in the liver, but ADR was always the major fluorescent species present. The tissue distribution of 1:1 iron:ADR that had been aged for 48 or 96 hr was similar to that of fresh 2:1 and 3:1 iron:ADR rather than ADR or fresh 1:1 iron:ADR. When lyophilized iron:ADR preparations were reconstituted and administered, the 0.5-hr tissue distribution of 0.1:1, 0.2:1, 0.25:1, and 0.33:1 iron:ADR was the same as ADR alone, but 0.5:1, 1:1, 2:1, and 3:1 iron:ADR were all accumulated primarily in the lung. Physicochemical studies confirm the production of microaggregated iron:ADR complexes and light microscopy allows visualization and sizing of these aggregates. We feel that trapping of these iron:ADR aggregates in the pulmonary vascular bed accounts for the observed dramatic alteration in tissue distribution. Light and electron microscopic studies confirm the intravascular sequestration of iron in pulmonary capillaries.

Animals↗
PubMed1982

Effect of dietary phosphorus restriction on the kidneys of cats with reduced renal mass.

Cats with reduced renal mass were fed a phosphorus-restricted diet (0.24% P, dry weight) or a normal phosphorus diet (1.56% P, dry weight) for 6 5 to 343 days. Renal function was determined biweekly by blood urea nitrogen and plasma creatinine measurements and by initial and terminal inulin clearance procedures. Neither diet caused a significant change in renal function during the study. However, histologic examination of kidneys obtained at necropsy clearly separated the cats on the basis of dietary phosphorus. The kidneys from cats fed the normal phosphorus diet had mineralization, fibrosis, and mononuclear cell infiltration, whereas the kidneys from cats fed the phosphorus-restricted diet had little or no changes.

Animal Feed↗
PubMed1981

Relationship of selected clinical renal function tests to glomerular filtration rate and renal blood flow in cats.

Results of 3 clinical tests of renal function--urine concentrating ability and disappearance of plasma phenosulfonphthalein (PSP) and sodium sulfanilate (SS) were compared with those of 2 classic tests, glomerular filtration rate (GFR) and renal blood flow (RBF), in 11 cats before and after reduction of renal mass. Values (mean +/- SD) obtained from normal cats were maximum urine concentration of 2,270 +/- 407 mOsm/kg (specific gravity values of 1.067 +/- 0.015); T 1/2 for plasma disappearance of PSP of 24.27 +/- 3.5 minutes; T 1/2 for plasma disappearance of SS of 44.42 +/- 5.67 minutes; GFR of 2.94 +/- 0.32 ml/min/kg; and RBF of 10.61 +/- 1.71 ml/min/kg. After reduction of renal mass by vascular ligation and nephrectomy, the cats became azotemic and had significant decreases in GFR and RBF (P less than 0.005), but still were able to concentrate urine to a considerable extent. Both maximum urine concentration and PSP plasma decay were poorly correlated with GFR (r = 0.4060 and 0.3694, respectively) and RBF (r = -0.3439 and -0.3427). Sulfanilate half-life had better correlation with GFR (r = -0.7004) than with RBF (r = -0.5716). Both GFR and RBF increased significantly (P less than 0.005) between postsurgical weeks 1 and 9. It was concluded that experimental cats with azotemia retain considerable ability to concentrate urine and that the SS test is superior to both the PSP test and urine concentration test for clinical estimation of renal function.

Animals↗
PubMed1979

Cellular pharmacology of 7(R)-O-methylnogarol: a new anticancer agent.

The cellular accumulation and disposition of 7(R)-O-methylnogarol (7-OMEN), a derivative of the anthracycline antibiotic, nogalamycin, were compared to those of daunorubicin. Although both drugs were avidly accumulated by cells, intracellular concentrations of 7-OMEN were 5 to 10 times those of daunorubicin. Lowered temperature (0 degrees C) reduced intracellular accumulation of both drugs, but 10 mM sodium azide reduced the accumulation of 7-OMEN only. Both drugs exited from cells placed in drug-free medium, a process that was reduced at 0 degrees C. Sodium azide, 10 mM, did not alter the efflux of daunorubicin from cells but hastened the efflux of 7-OMEN. Unlike whole cells, isolated nuclei accumulated more daunorubicin than 7-OMEN. This process was not reduced at 0 degrees C. Both drugs were lost from nuclei placed in drug free buffer with only slight reduction at 0 degrees C. Unlike daunorubicin which localized in cell nuclei, 7-OMEN localized in the cytoplasm with no detectable nuclear fluorescence. Both drugs produced nearly equivalent dose-dependent inhibition of [3H]thymidine incorporation by L1210 and P388 cells. P388/ADR cells proved resistant to both anthracyclines. [3H]uridine and [3H]valine incorporations were inhibited by daunorubicin but were not altered by 7-OMEN.

Animals↗
PubMed1979

Cellular accumulation and disposition of aclacinomycin A.

The cellular accumulation and disposition of the anthracycline antitumor antibiotic aclacinomycin A (ACM) were compared to those of daunorubicin. Although both drugs were avidly accumulated by cells, intracellular concentrations of ACM were two to three times those of daunorubicin. Whereas lowered temperature (0 degrees) reduced intracellular accumulation of both drugs, 10 mM sodium azide had no effect on accumulation of either ACM or daunorubicin. Both drugs exited from cells placed in drug-free medium, a process that was reduced at 0 degrees but not altered by 10 mM sodium azide. Unlike whole cells, isolated nuclei accumulated more daunorubicin than ACM. This process was not altered at 0 degrees. Both drugs were lost from nuclei placed in drug-free buffer, a process that was reduced at 0 degrees. Unlike daunorubicin, which localized in cell nuclei, ACM localized in the cytoplasm with no detectable nuclear fluorescence. Although both drugs produced dose-dependent inhibitions of [3H]thymidine and [3H]uridine incorporation by L1210 and P388 cells, ACM inhibited both processes at lower concentrations than did daunorubicin. While daunorubicin inhibited [3H]thymidine incorporation more effectively than [3H]uridine incorporation, the reverse was observed with ACM.

Animals↗
PubMed1977

Measles immunization. Successes and failures.

As a result of a large outbreak of measles, measles hemagglutination inhibition (HI) titers were measured in 465 immunized children. Titers of less than 1:4 were found in 14.6% of children immunized at 12 months of age as compared to 5.2% of those immunized at 13 months of age or later. Measles antibody titers were higher in the mothers of seronegative children who had been immunized at 11 or 12 months of age than in the mothers of seroposotive children. Measles HI titers of 1:4 or more were present in 94% of children immunized at 13 months of age or later between 1962 and 1964. The findings suggest that vaccine failure and not waning antibody accounts for the majority of titers of less than 1:4 in immunized children. Reimmunization programs should be considered for those who were immunized before 13 months of age.

Adolescent↗