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Biomedical subjects

L Miller

Publications and source records attributed to L Miller.

At least 271 records · Page 15Linked to original sources
PubMed1990

Nucleotide sequence of the sacS locus of Bacillus subtilis reveals the presence of two regulatory genes.

The nucleotide sequence of 3 kb of Bacillus subtilis chromosomal DNA, including sacS, reveals that the regulatory locus for levansucrase synthesis consists of two genes, sacX and sacY. The sacX gene product is remarkably similar to sucrose-specific enzyme II of the B. subtilis phosphoenolpyruvate-dependent phosphotransferase system. The product of sacY is similar, both in amino acid sequence and most probably in its function, to BglG, an Escherichia coli transcriptional antitermination factor.

Amino Acid Sequence↗
PubMed1990

Isolation, characterization, and in vitro culture of larval and adult epidermal cells of the frog Xenopus laevis.

Methods for the isolation and in vitro culture of larval and adult Xenopus laevis epidermal cells have been developed. Epidermal cells of stage 52-54 tadpoles and adult epidermal cells were enzymatically dissociated and purified (98%) by Percoll-density centrifugation and unit-gravity sedimentation. Both cell types attached on fibronectin-coated dishes and proliferated for 1 wk when the proper medium was used. There were four significant differences between larval and adult cells: a) Adult cells had a greater buoyant density than larval cells. b) Keratin synthesis patterns were markedly different. c) A combination of medium F12 and Eagle's minimum essential medium was optimal for growth of larval cells whereas MCDB151 medium was optimal for adult cells. d) Adult cells needed fetal bovine serum (greater than 5%) whereas larval cells grew without fetal bovine serum. In contrast to these differences, larval and adult cells had two similar properties: a) Insulin had a potent effect on the growth of both cells, and b) The optimal Ca++ concentration for cell growth was quite low for both cell types; 0.1 mM for larval cells and below 0.05 mM for adult cells. These results suggest that low Ca++ levels are essential for both cornifying (adult) and uncornifying (larval) amphibian keratinocytes. The culture techniques described herein for larval and adult epidermal cells provide a new in vitro model for analyzing development of the epidermis during amphibian metamorphosis.

Aging↗
PubMed1990

A retrospective evaluation of 301 TMJ Proplast-Teflon implants.

A retrospective review of 301 meniscectomies with Proplast-Teflon implants was performed. Factors such as interincisal opening, occlusion, joint sounds, joint degeneration, and patient satisfaction were examined. The overall surgical success rate was 88.7%, with an average follow-up period of 33 months. Although many patients demonstrated significant condylar degeneration at 1-year follow-up, such change did not necessarily result in symptomatology or joint dysfunction. Only 10% of implants resulted in removal. Surgical and postoperative procedures are contrasted with those of other clinicians experiencing lower success rates.

Adolescent↗
PubMed1990

Follicular-phase serum progesterone levels of nonsmoking women do not differ from the levels of nonsmoking men.

Because we had observed that smoking has a pronounced effect on serum progesterone levels, we reinvestigated in healthy nonsmokers the relative progesterone levels of men and follicular-phase women. Each of eight women had multiple measurements of serum progesterone during the follicular phase of a menstrual cycle (10 days through 3 days prior to the luteinizing hormone peak of that cycle), and the average of those values was taken to represent the basal progesterone level for that woman. Seven men had blood samples drawn at 20-minute intervals between 6:00 and 9:00 AM, through an indwelling venous catheter, and the average of those values was taken. The mean follicular-phase serum progesterone level in the women was 21.4 +/- 5.4 ng/dl and the mean level in the men was 18.1 +/- 3.1 ng/dl. The difference was not statistically significant. In view of this finding, we conclude that there is essentially no ovarian secretion of progesterone during the follicular phase of the menstrual cycle.

Adult↗
PubMed1990

Subnormal follicular-phase serum progesterone levels and elevated follicular-phase serum estradiol levels in young women with insulin-dependent diabetes.

In a search for possible hormonal reasons for the loss of protection from myocardial infarction seen in diabetic women, serum levels of estradiol, progesterone, and luteinizing hormone were compared throughout a menstrual cycle (17 points) in eight healthy nonsmoking women and five otherwise healthy nonsmoking insulin-dependent diabetic women. The total length of the menstrual cycle and the lengths of the follicular and luteal phases did not differ between the groups. During the periovulatory and luteal phases, there was no significant intergroup difference with respect to any of the three hormones. During the follicular phase, in both groups, there was a plateau in serum progesterone concentration, with the level approximately 42% lower in the diabetic group (12.0 +/- 6.6 ng/dl versus 20.7 +/- 5.7; P less than 0.0001). Follicular-phase serum estradiol showed a rising curve in both groups; day-by-day comparison (days -10 to -3 before the luteinizing hormone peak) showed consistently higher levels in the diabetic group (mean, 108 pg/ml versus 95 pg/ml; P less than 0.001). The follicular-phase serum estradiol to progesterone ratio was nearly twice as high in the diabetic group as in the normal group (8.9 versus 4.6), a difference that was highly significant. The finding of elevated serum estradiol and subnormal serum progesterone concentrations during the follicular phase is so far unique to women with insulin-dependent diabetes mellitus. The possibility that this pronounced abnormality in diabetic women may be related to coronary disease merits testing in suitable in vivo and in vitro models of atherogenesis.

Adult↗
PubMed1990

The effect of smoking on serum progesterone, estradiol, and luteinizing hormone levels over a menstrual cycle in normal women.

Since smoking has been shown to affect serum progesterone and estradiol levels in postmenopausal women, we evaluated the levels of these hormones and luteinizing hormone (LH) over an entire menstrual cycle (17 points) in eight healthy nonsmokers and eight healthy smokers. The total length of the cycle and the lengths of the follicular and luteal phases did not differ between the groups. There was no difference in estradiol, progesterone, or LH levels during the periovulatory and luteal phases. Follicular-phase serum progesterone, which had a level 37% higher in smokers, showed a plateau in both groups (28.3 +/- 5.7 ng/dl versus 20.7 +/- 5.7; P less than 0.0001). Follicular-phase serum estradiol showed a rising curve in both groups. The mean value in smokers was slightly higher than that in nonsmokers (107 pg/ml versus 95; P approximately 0.05); during the early part of the follicular phase, prior to the rapid preovulatory increase, the difference was greater (23%) and of higher statistical significance (80 pg/ml versus 65; P less than 0.001). The follicular-phase LH levels of smokers were skewed downward from the levels in nonsmokers, presumably by negative feedback from the elevated estradiol and progesterone levels; the difference was significant (P less than 0.001). The elevations of serum progesterone and estradiol in smokers probably represent activation of adrenocortical secretion by smoking. The greater and more clear-cut rise of progesterone than of estradiol is probably due to the fact that essentially all of the follicular-phase serum progesterone is secreted by the adrenal, while only part of the follicular-phase serum estradiol comes from the adrenal (via androstenedione and estrone).

Adult↗
PubMed1990

Establishment and characterization of a chicken mononuclear cell line.

A new chicken mononuclear cell line (MQ-NCSU) has been established. The starting material used to initiate this cell line was a transformed spleen from a female Dekalb XL chicken which had been experimentally challenged with the JM/102W strain of the Marek's disease virus. After homogenization, a single cell suspension of splenic cells was cultured using L.M. Hahn medium supplemented with 10 microM 2-mercaptoethanol. Under these culture conditions, a rapidly proliferating cell was observed and then expanded after performing limiting dilution cultures. These cells were moderately adherent and phagocytic for sheep red blood cells and Salmonella typhimurium. When tested against a panel of monoclonal antibodies (mAb) using the flow cytometry, MQ-NCSU cells stained readily with anti-chicken monocyte specific (K-1) mAb but did not stain with mAb detecting T-helper, T-cytotoxic/suppressor, and NK cells. MQ-NCSU cells expressed very high levels of Ia antigens and transferrin receptors. In addition, cell-free supernatant obtained from MQ-NCSU culture contained a factor which exhibited cytolytic activity against tumor cell targets. Based on their cultural, morphological, and functional characteristics and mAb reactivity profile, we conclude that MQ-NCSU cell line represents a malignantly-transformed cell which shares features characteristic of cells of the mononuclear phagocyte lineage.

Animals↗
PubMed1990

Neuropsychodynamics of alcoholism and addiction: personality, psychopathology, and cognitive style.

The literature on the neuropsychology, personality, and psychopathology of alcoholism and addiction is reviewed. Neuropsychological studies of substance abusers have found deficits in abstract concept formation, set-maintenance, set-shifting, behavioral control, and cognitive flexibility. However, the evidence that these deficits are the result of direct substance effects on the brain is slim. Both alcoholics and as-yet nondrinking offspring of alcoholics have been found to be deficient in verbal skills and language functioning. Personality studies of alcoholics and addicts have emphasized such characteristics as field dependency, external locus of control, attenuated time extension, poor ego strength, and disturbed object relations. The psychopathology of alcoholics and opiate abusers seems to be dominated by impulsive character disorder, although there may also be a subgroup of anxious, depressed substance abusers. The present review integrates brain-behavioral perspectives with the data on personality and psychopathology, focusing on the relevance of a multidimensional neuropsychological model to psychodynamic concepts of ego functioning and the substance abusers' problems in the regulation of affect and behavior. It is argued that the concept of cognitive style is useful for understanding the relationship of neuropsychological functioning to personality dynamics, and that this approach can be especially productive in understanding the addictions.

Alcohol Drinking↗
PubMed1990

Treatment of condyloma acuminatum with three different interferon-alpha preparations administered parenterally: a double-blind, placebo-controlled trial.

One hundred seventy-eight patients were enrolled in a placebo-controlled trial to evaluate three interferon-alpha preparations administered parenterally for the treatment of condyloma acuminatum. When all interferon groups were combined and compared with placebo, interferon recipients had greater rates of complete, 75%, 50%, and 25% lesion resolution than did placebo recipients (P = .21, P = .14, P = .02, and P = .02, respectively). Rates of lesion resolution were higher among women than among men, and women were more likely than men to respond to interferon. Virologic measurements in paired lesion biopsies did not correlate with interferon treatment or disease outcome. Although interferon toxicity was observed frequently, no participant withdrew from the study because of side effects, and dosage alterations were not required. Parenterally administered interferon-alpha is more effective than placebo in treating condyloma acuminatum, although rates of complete response are low. Different regimens, including combination therapy, should be evaluated for treatment of this common sexually transmitted disease.

Adult↗
PubMed1990

Obese men have elevated plasma levels of estrone sulfate.

The 24 h mean plasma concentrations of estrone sulfate (ES) were measured in 27 healthy obese and nonobese men (BMI: 21.2-89.5). Plasma levels of ES were found to be elevated in obese men, with ES values significantly correlated to the level of obesity (r = 0.60; P less than 0.001). Thus, an increase in plasma ES concentration (from 524 to 1115 pg/ml), compared to the less than 40 percent increases previously found for estrone and estradiol. Because ES is normally present at an approximately tenfold greater concentration than either estrone or estradiol in men, it may serve as a more easily measurable indicator of adipose tissue aromatization of androstenedione.

Adipose Tissue↗
PubMed1989

Preparative resolution of enantiomers of prostaglandin precursors by liquid chromatography on a chiral stationary phase.

Preparative liquid chromatographic methods were developed for the chiral resolution of two different cyclopentenone precursors of a synthetic prostaglandin. Various solvent combinations of alcohols and alkanes were investigated to determine the method which has the greatest throughput. The effect of particle size on the chiral resolution was also investigated. In addition, the preparative system was automated to allow for unattended operation for up to 10 h.

Chemical Phenomena↗