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Biomedical subjects

M M Anderson

Publications and source records attributed to M M Anderson.

71 records · Page 4Linked to original sources
PubMed1976

Role of Galactolipids in Spinach Chloroplast Lamellar Membranes: II. Effects of Galactolipid Depletion on Phosphorylation and Electron Flow.

A galactolipid lipase from primary bean (Phaseolus vulgaris) leaves has been used to partially deplete spinach chloroplast inner membranes of their galactolipids. Chloroplasts treated with the lipase in the absence of bovine serum albumin lost 91% of their monogalactosyl diglyceride, 83% of their digalactosyl diglyceride, all of their phosphatidyl choline, but none of their sulfolipid. Electron microscopy of this sections revealed that the treated chloroplasts were greatly enlarged and lacked membrane stacking. Linolenic acid had similar effects on the structure of the chloroplasts. Chlorophyll, carotenoids, and coupling factor 1 remained bound to the treated membranes.To minimize the inhibition of phosphorylation and electron flow by fatty acids released by the lipase, bovine serum albumin (15-24 mg/ml) was added to the lipase incubation mixtures. Bovine serum albumin inhibited the extent, but not the initial rate, of fatty acid release by the lipase. Electron microscopy of chloroplasts treated with the lipase in the presence of bovine serum albumin showed that membrane stacking was partially maintained. Chloroplasts treated with lipase under these conditions retained about 30% of their monogalactosyl diglyceride, 50% of their digalactosyl diglyceride and phosphatidyl choline. The sulfolipid and phosphatidyl glycerol contents were unchanged. Electron flow through photosystems I and II with artificial electron donors and acceptors was not affected by lipase treatment in the presence of bovine serum albumin. In contrast, oxygen evolution and phosphorylation were partially inhibited. These reactions are also very sensitive to fatty acids and it is possible that the inhibition is the result of interaction of fatty acids with the membrane prior to their binding to bovine serum albumin.In view of the irreversible inactivation of electron flow and phosphorylation by fatty acids, it is difficult to assess the role of galactolipids in these processes when a specfic lipase is used to deplete the membrane.

Journal Article↗
PubMed1974

The role of galactolipids in spinach chloroplast lamellar membranes: I. Partial purification of a bean leaf galactolipid lipase and its action on subchloroplast particles.

A galactolipid lipase has been isolated and partially purified from the chloroplast fraction of the primary leaves of Phaseolus vulgaris var. Kentucky Wonder. The lipase hydrolyzed monogalactosyl diglyceride rapidly and phosphatidyl choline relatively slowly. Triolein and p-nitrophenyl stearate were not hydrolyzed.Spinach subchloroplast particles were excellent substrates for the lipase. Initial rates of fatty acid release from subchloroplast particles at 30 C by the lipase as high as 60 microequivalents per minute per milligram protein were observed. At completion of the reaction, about 2.7 microequivalents of fatty acid were liberated per milligram of chlorophyll in the subchloroplast particles, indicating that major amounts of lipid in the particles were rapidly attacked by the lipase.The treatment of subchloroplast particles with the lipase resulted in a rapid inhibition of light-dependent electron flow. This inhibition was largely prevented when the incubation was carried out in the presence of high concentrations of defatted bovine serum albumin. These results suggest that when precautions are taken to prevent the binding of fatty acids to the subchloroplast particles, large amounts of lipid may be removed without a marked effect on electron flow.

Journal Article↗
PubMed1972

Implementation of the Abortion Act: report on a year's working of abortion clinics and operating sessions.

The results of the first year's working of abortion clinics and operating sessions are reported. Seventy-eight per cent. of patients were managed on the basis of day admission and 20% were able to leave the hospital within four hours, operation having been carried out by either Karman catheter or by Bierer suction curette under paracervical block. These results were possible because of quick reference of patients to the clinics and the absence of delay in admission for operation.The measures detailed go some way towards managing the abortion problem within the hospital service; similar arrangements could be instituted elsewhere by the responsible regional hospital boards.

Abortion, Legal↗
PubMed1971

Results in 1,000 cases of therapeutic abortion managed by vacuum aspiration.

A prospective study of 1,000 cases of termination of pregnancy by vacuum aspiration is presented and the safety of the method emphasized. By setting up special clinics and an additional weekly operating session, the maximum delay from a request to appointment is 5 days, and, if operation is advised, from appointment to operation a further 7 days.

Abortion, Legal↗
PubMed1970

Vacuum aspiration of the uterus in therapeutic abortion.

A prospective study of vacuum aspiration in 400 cases of therapeutic abortion is described showing that the procedure was quick, involving little blood loss in most cases, and that the complication rate was low. The routine use of this method in therapeutic abortion is recommended.

Abortion, Therapeutic↗
PubMedDate not supplied

Early drinking onset and its association with alcohol use and problem behavior in late adolescence.

OBJECTIVE: To examine the relationship between age of drinking onset and patterns of use, abuse of other substances, and the prevalence of other alcohol-related problems in a population of midwestern high school seniors. DESIGN: We analyzed self-report survey data on public school students' history of alcohol and other drug use and related problems from the Minnesota Student Survey conducted in 1989. The sample consisted of 2,650 male and female seniors, representing a 10% random sample of all white seniors in the study. RESULTS: The findings suggest that early onset of alcohol use (by age 12) is associated with subsequent abuse of alcohol and related problem behaviors in later adolescence, including alcohol-related violence, injuries, drinking and driving, and absenteeism from school or work, as well as increased risks for using other drugs. CONCLUSION: This paper identifies the preadolescent years from age 10 to 12 as a particularly vulnerable period for the development of early alcohol dependence and abuse. Delaying alcohol use onset to age 13 may significantly reduce the risk of severe alcohol abuse in later adolescence.

Adolescent↗
PubMedDate not supplied

Gene frequencies in the domestic cats of Reno, Nevada: confirmation of a recent hypothesis.

On the basis of a sample of 156 animals, allele frequencies for the cat population of Reno, Nevada have been estimated. Comparison of this population with populations of 22 other cities shows that Reno's cats are more similar to those of northeastern North America than to those in the southwest. This is consistent with a recent hypothesis that suggests there were two distinct European sources of North American cats, and that present gene pools in North American cities depend primarily on their history of early settlement.

Animals↗
PubMedDate not supplied

Quassinoids exhibit greater selectivity against Plasmodium falciparum than against Entamoeba histolytica, Giardia intestinalis or Toxoplasma gondii in vitro.

The in vitro activities of a series of quassinoids against Plasmodium falciparum, Entamoeba histolytica, Giardia intestinalis and Toxoplasma gondii have been compared with their in vitro cytotoxic effects against KB cells (human epidermoid carcinoma of the nasopharynx). All of the compounds tested were more toxic to KB cells than to G. intestinalis, but four (ailanthinone, bruceine D, brusatol and glaucarubinone) were slightly less toxic to KB cells than to E. histolytica. Glaucarubinone was similarly more toxic to intracellular T. gondii than to KB cells but ailanthinone was more selective (36 times more toxic to T. gondii than to KB cells). All of the compounds were more toxic to P. falciparum than to KB cells; the most selective quassinoids--glaucarubinone, bruceine D, ailanthinone and brusatol--were found to have toxicity/activity ratios of 285, 76, 48 and 32 respectively. These results suggest that quassinoids have a selective action on P. falciparum. Further studies to elucidate the basis for this are in progress.

Animals↗
PubMedDate not supplied

Metabolism of 4-nitroaniline by rat liver microsomes.

The principal rat liver microsomal metabolite of 4-nitroaniline was isolated by high pressure liquid chromatography and was characterized as 2-amino-5-nitrophenol (2-hydroxy-4-nitroaniline) by comparison of its mass, nuclear magnetic resonance, and ultraviolet spectra and HPLC retention time to the synthetic compound. A metabolite with the chromatographic retention time of authentic N-hydroxy-4-nitroaniline was not detected. Pretreatment of rats with phenobarbital and 3-methylcholanthrene increased the rate of conversion of 4-nitroaniline to 2-hydroxy-4-nitroaniline by 2-fold and 4-fold, respectively; the reaction required NADPH and was inhibited by heat treatment of microsomes, by argon and carbon monoxide:oxygen atmospheres and by the cytochrome P-450 inhibitor, 2-[(2,4-dichloro-6-phenyl)phenoxy]ethylamine. In the presence of a molecular oxygen (18O2) atmosphere, 18O was quantitatively incorporated into the metabolite. Microsomes did not catalyze the isomerization of N-hydroxy-4-nitroaniline to 2-hydroxy-4-nitroaniline. A primary isotope effect was not observed upon comparison of the rate of conversion of 2,6-dideutero-4-nitroaniline to 2-hydroxy-4-nitroaniline with that of the nondeuterated compound. The 2-hydroxy-4-nitroaniline derived from microsomal incubation mixtures of 2,6-dideutero-4-nitroaniline contained about 20%, 3,6-dideutero-2-hydroxy-4-nitroaniline.

Aniline Compounds↗
PubMedDate not supplied

Overweight and obesity in native-American adolescents: comparing nonreservation youths with African-American and Caucasian peers.

Previous studies have consistently shown that, compared to national standards, Native Americans across all age groups are disproportionately overweight or obese. Although most available data on rates of obesity in this group come from studies conducted on reservations, the proportion of Native Americans residing on reservation lands is rapidly declining. This study examines the prevalence of overweight and obesity in a population of Midwestern adolescents in public school settings and contrasts Caucasian and African-American adolescents with Native-American youths of the same age. Data were derived from a secondary analysis of an anonymous health-risk survey. Height, weight, and ethnicity were ascertained through self-report. The results call into question whether rates of overweight or obesity in Native-American adolescents are disproportionate relative to those for Caucasian and African-American adolescents. Cumulative comparisons of all overweight and obese adolescents in the sample (n = 5,655) show significant differences among ethnic groups, but age-specific comparisons do not yield a consistent pattern, especially for Native-American girls. To compare the entire sample to national weight standards, we plotted mean body mass index (BMI) for each ethnic group by age against NHANES II reference data. Age-specific BMI means for Native-American and Caucasian girls fell largely below the NHANES II reference data. We present several explanations for these results. Given the study limitations, further objective study of the weight status of Native-American children and adolescents in direct comparison with other ethnic groups is recommended.

Adolescent↗