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L D Gottlieb

Publications and source records attributed to L D Gottlieb.

35 records · Page 2Linked to original sources
PubMed1984

Subunit hybridization and immunological studies of duplicated phosphoglucose isomerase isozymes.

We examined structural and functional properties of the recently duplicated cytosolic isozymes of phosphoglucose isomerase (PGI) (EC 5.3.1.9) of the wild plant Clarkia xantiana and related species. A new purification protocol yielded PGIs with high specific activities. The duplicated PGI isozymes showed similar substrate affinities (apparent Km) in both catalytic directions. A newly devised competitive enzyme-linked immunosorbent assay (ELISA), using polyclonal antibodies, distinguished sodium dodecyl sulfate (SDS)-denatured PGIs coded by the duplicated loci but did not discriminate between allelic products of one of the loci. In vitro dissociation and reassociation experiments revealed that the duplicated subunits differed in their efficiency of reassociation. The difference was closely correlated with differences between the isozymes in their in vivo accumulation. In contrast, allelic subunits in species with or without the duplication were able to reassociate with similar efficiency. The duplicated PGI isozymes have diverged more in structural properties than kinetic ones. The total evidence suggests that mechanisms have evolved which reduce the potential consequences of the duplication.

Cytosol↗
PubMed1984

Plant triose phosphate isomerase isozymes : purification, immunological and structural characterization, and partial amino Acid sequences.

We report the first complete purifications of the cytosolic and plastid isozymes of triose phosphate isomerase (TPI; EC 5.3.1.1) from higher plants including spinach (Spinacia oleracea), lettuce (Lactuca sativa), and celery (Apium graveolens). Both isozymes are composed of two isosubunits with approximate molecular weight of 27,000; in spinach and lettuce the plastid isozyme is 200 to 400 larger than the cytosolic isozyme. The two isozymes, purified from lettuce, had closely similar amino acid compositions with the exception of methionine which was four times more prevalent in the cytosolic isozyme. Partial amino acid sequences from the N-terminus were also obtained for both lettuce TPIs. Nine of the 13 positions sequenced in the two proteins had identical amino acid residues. The partial sequences of the plant proteins showed high similarity to previously sequenced animal TPIs. Immunological studies, using antisera prepared independently against the purified plastid and cytosolic isozymes from spinach, revealed that the cytosolic isozymes from a variety of species formed an immunologically distinct group as did the plastid isozymes. However, both plastid and cytosolic TPIs shared some antigenic determinants. The overall similarity of the two isozymes and the high similarity of their partial amino acid sequences to those of several animals indicate that TPI is a very highly conserved protein.

Journal Article↗
PubMed1983

Adequacy of antitetanus prophylaxis in six hospital emergency rooms.

We studied the adequacy of antitetanus prophylaxis given to 620 patients with open soft-tissue injuries by 169 physicians in six hospital emergency rooms. Twenty-three per cent of the patients were treated incorrectly (6 per cent were undertreated and 17 per cent were overtreated) with tetanus toxoid or human tetanus immunoglobulin. Undertreatment ranged from 4 to 11 per cent, and overtreatment from 5 to 38 per cent at the different hospitals (P less than 0.01). Patients at highest risk for tetanus (those with tetanus-prone wounds who had never been given a complete initial course of immunizations) had the lowest likelihood (27 per cent) of receiving correct antitetanus treatment. By following an immunization protocol based on time since injury, mechanism of injury, estimated bacterial contamination, presence of devitalized tissue, wound depth, and past immunizations, physicians can better protect the population against tetanus while lowering the risk of adverse drug reactions and not increasing the cost of care.

Emergency Medical Services↗
PubMed1982

Immunological similarity between a cyanobacterial enzyme and a nuclear DNA-encoded plastid-specific isozyme from spinach.

The immunochemical properties of the plastid and cytosolic isozymes of phosphoglucose isomerase (glucosephosphate isomerase; D-glucose-6-phosphate ketol-isomerase, EC 5.3.1.9) in spinach (Spinacia oleracea) and the single phosphoglucose isomerase enzyme from the cyanobacterium Synechococcus sp. were compared by an application of the enzyme-linked immunosorbent assay. Utilizing antibodies made in rabbits against subunits of purified plastid and cytosolic phosphoglucose isomerase isozymes from spinach, we demonstrate that the plastid isozyme is immunochemically more similar to the cyanobacterial enzyme than to the spinach cytosolic counterpart. The antiserum to plastid phosphoglucose isomerase crossreacted strongly with plastid phosphoglucose isomerases from other flowering plants. The antiserum to cytosolic phosphoglucose isomerase crossreacted with other plant cytosolic phosphoglucose isomerase isozymes. The results are consistent with the hypothesis [Weeden, N. F. (1981) J. Mol. Evol. 17, 133-139] that the nuclear gene specifying plastid phosphoglucose isomerase was derived from a prokaryote after the incorporation of a plastid-like symbiont into the ancestral plant cell.

Journal Article↗
PubMed1982

Dissociation, reassociation, and purification of plastid and cytosolic phosphoglucose isomerase isozymes.

The plastid and cytosolic isozymes of the dimeric enzyme phosphoglucose isomerase (EC 5.3.1.9) from spinach (Spinacia oleracea) and cauliflower (Brassica oleracea) were purified to apparent homogeneity. The isozymes from sunflower (Helianthus annuus) and Clarkia xantiana were partially purified. When subunits from two electrophoretically distinguishable cytosolic isozymes, either from the same or from different species, were dissociated and allowed to reassociate in each other's presence, an active hybrid enzyme, consisting of one subunit of each type, was formed in addition to the two original homodimers. Active hybrid enzymes were also formed by dissociation and reassociation of plastid isozymes. Hybrid molecules were not produced between the plastid and cytosolic subunits, suggesting that they are not able to bind with each other. Additional differences between the plastid and cytosolic isozymes are described.

Journal Article↗
PubMed1981

Biochemical properties of duplicated isozymes of phosphoglucose isomerase in the plant Clarkia xantiana.

The structural gene locus specifying subunits of cytoplasmic isoenzymes of phosphoglucose isomerase (PGI) is present in duplicate in many diploid species of Clarkia (Onagraceae), a genus of annual plants native to California. We studied the kinetic properties and molecular weights of a large number of genetically defined and highly purified PGIs in C. xantiana, a number of species with the duplication, as a means of examining the biochemical consequences of the evolution of a new gene locus. This species is primarily outcrossing, but also includes several previously described predominantly self-pollinating populations. Both cytoplasmic PGI loci in the outcrossing populations are polymorphic and their enzyme products are readily separated by electrophoresis. The PGIs from the outcrossing populations were rated by electrophoresis. The PGIs from the outcrossing populations were generally closely similar in molecular weight, pH optimum, heat sensitivity, energy activation, and apparent Km (fructose-6-phosphate). The PGI loci in the selfing populations are monomorphic and specify enzymes having identical electrophoretic mobilities to those coded by the most frequent alleles of the outcrosser. The PGI isozymes in the selfers differed fivefold in Km, suggesting that they have a very different catalytic effectiveness. The high Km of the PGI-3A' isozyme (1.1mM) was anomalous among the PGIs examined and would likely be disadvantageous in a species which lacked other more normally functioning PGIs. But in the cytoplasm of the selfing plants, it is present with other PGIs that have low Km values. The PGI-3A' enzyme is a good candidate for a gene product coded by a "forbidden" mutation that could not have been established in the absence of the duplication. The rationale for this suggestion is described and it is also pointed out that the divergence of duplicated genes is influenced by many factors such as the breeding system and other population factors as well as the effect of particular mutations.

Catalysis↗
PubMed1981

Gene number in species of Astereae that have different chromosome numbers.

Differences in the gametic chromosome numbers (n = 4, 5, 9) of species in the Astereae tribe of the Compositae have been variously interpreted. One hypothesis proposes that n = 9 was the original base number of the group and that the lower numbers resulted from aneuploid reduction. The alternative hypothesis asserts that the ancestral base number was n = 4 or n = 5 and that species in which n = 9 are allotetraploids derived by hybridization between taxa with the lower numbers. Electrophoretic analysis of 17 enzyme systems in five species of Machaeranthera, in which n = 4, 5, and 9, and two species of Aster in which n = 5 and 9, demonstrates that all of these species have the same number of gene loci specifying the tested enzymes. The absence of isozyme multiplicity in the species in which n = 9 suggests that they did not arise by polyploidy.

Journal Article↗
PubMed1980

Biochemical properties and level of expression of alcohol dehydrogenases in the allotetraploid plant Tragopogon miscellus and its diploid progenitors.

This study demonstrates that homoeologous genes in two diploid plant species that specify different amounts of an enzyme maintain the same relative level of expression in an allotetraploid derivative. The three predominant alcohol dehydrogenase (ADH) isozymes (DD, DP, PP) in seeds of the recently evolved allotetraploid plant Tragopogon miscellus (Compositae) are dimers specified by Adh3-D and Adh3-P genes derived from its diploid progenitors T. dubius and T. pratensis. Seeds of T. pratensis contain twice as much ADH activity as those of T. dubius, while T. miscellus is intermediate. The three isozymes were similar in a number of catalytic properties; the densitometric ratio of the isozymes purified from T. miscellus was 1 DD : 4DP : 4PP for both ADH activity and protein; and dissociation-reassociation of the DP enzyme gave a 1:2:1 ratio of the three isozymes. Therefore, the enzymes were similar in specific activity, but twice as many P as D subunits were present in active enzymes in T. miscellus, precisely the difference in activity between the parents. In T. miscellus, the specific activity of ADH and its activity per mg tissue are intermediate to those of the diploids, because relative expression of the Adh gene in each genome is not influenced by the presence of the other genome.

Alcohol Oxidoreductases↗
PubMed1980

Isolation of cytoplasmic enzymes from pollen.

The cytoplasmic isozyme of many cytoplasmic-organelle isozyme pairs, as well as other cytoplasmic enzymes in plants, can be readily obtained from pollen by soaking it in an appropriate buffer for 4 hours. Enzymes localized in subcellular organelles appear not to be released during the soaking period, although they are released if the pollen is crushed. The technique is a useful initial step in studies of subcellular localization of enzymes or for obtaining small quantities of cytoplasmic enzymes free of organellar contaminants.

Journal Article↗
PubMed1979

Distinguishing allozymes and isozymes of phosphoglucoisomerases by electrophoretic comparisons of pollen and somatic tissues.

The different electrophoretic patterns of dimeric phosphoglucoisomerases extracted from haploid pollen and diploid somatic tissues of plants may be used to distinguish allozymes and isozymes. The analysis depends on the presence of two alleles at each locus in somatic tissues but only one or the other allele in pollen grains. Consequently, in heterozygotes, heterodimeric allozymes can be identified because they are formed in stems and leaves but not in pollen. The procedure is described in enzymes extracted from the diploid annual plant Clarkia dudleyana, which possesses three gene loci for PGI subunits. Comparison of the electrophoretic patterns of stem and pollen extracts makes it possible in many cases to identify allelic state without breeding tests. The technique also is likely to be useful in the interpretation of zymograms of other multimeric enzymes coded by more than one gene locus.

Alleles↗
PubMed1974

Gene duplication and fixed heterozygosity for alcohol dehydrogenase in the diploid plant Clarkia franciscana.

All individuals of the diploid plant Clarkia franciscana, an annual species native to California, have duplicated genes for the dimeric enzyme alcohol dehydrogenase. Since each gene specifies a polypeptide with a distinct charge, the species has a fixed heterozygous phenotype consisting of three isozyme variants. The enzyme is coded by a single gene in closely related species. Clarkia franciscana is highly self-pollinated and monomorphic at all but one of its loci that have been examined. Consequently, the duplication provides enzyme variability in the absence of genetic variability.

Alcohol Oxidoreductases↗
PubMedDate not supplied

Social and clinical features as predictors of outcome in outpatient alcohol withdrawal.

OBJECTIVE: To identify patient features--both social and clinical--that may be associated with treatment failure in outpatient alcohol withdrawal. DESIGN: A prospective observational cohort study of patients who underwent outpatient management of the alcohol withdrawal syndrome. SETTING: Community hospital-based outpatient alcohol treatment program. PATIENTS: The 179 patients who were eligible for and participated in a clinical trial of drug therapy for outpatient management of the alcohol withdrawal syndrome. MAIN RESULTS: Treatment failure occurred for 45% (80/179) of the patients. Failure rating did not vary according to diverse sociodemographic features such as age, level of education, income, medical insurance status, and marital status. Persons who were homeless did as well as those who were not. In contrast, two clinical features of withdrawal were associated with significantly higher rates of treatment failure: craving and withdrawal symptom severity. High cravers had a treatment failure rate of 56% (22/39), compared with 36% (41/115) for those with lower scores (p less than 0.03). Among those with moderate-to-high withdrawal symptom severity, 49% (74/151) represented treatment failures, compared with 22% (6/27) of those in the low-symptom group (p less than 0.01). CONCLUSIONS: While these data do not confirm that socially disadvantaged persons are at increased risk for withdrawal treatment failure, two clinical features--craving and withdrawal symptom severity--may help identify high-risk patients.

Adult↗
PubMedDate not supplied

The impact of gender on clinical characteristics and outcome in alcohol withdrawal.

Few studies have compared the social and clinical features of alcoholism for women and men, and none has focused on patients entering treatment for withdrawal. We investigated the role of gender by analyzing the data for 179 patients (34 women, 145 men) who underwent outpatient withdrawal. Our analysis focused on two questions: 1) How do women and men compare in terms of baseline social and clinical features? and 2) Do women and men have similar treatment outcomes in alcohol withdrawal? Baseline sociodemographic features revealed that women were more likely to be poor (90% vs. 71%, p = .03) but less likely to be uninsured (32% vs. 51%, p = .05), homeless (6% vs. 20%, p = .05), or have legal problems (29% vs. 54%, p = .02). Surprisingly, women and men reported a similar mean daily alcohol intake (240 g vs. 243 g). Women reported a shorter duration of alcohol abuse prior to entering treatment (16.1 y vs. 19.1 y). Although women experienced a higher treatment failure rate (53% vs. 43%), this difference is not significant. Our analysis highlights gender similarities and differences among patients entering treatment for withdrawal. We conclude that women and men have similar treatment outcomes in the management of alcohol withdrawal.

Adult↗
PubMedDate not supplied

Randomized controlled trial in alcohol relapse prevention: role of atenolol, alcohol craving, and treatment adherence.

Previous studies suggest that beta-adrenergic blockers reduce craving levels during acute alcohol withdrawal. We conducted a new study to assess whether the daily use of atenolol by the abstinent alcoholic could maintain a blunted craving for alcohol and result in a decreased rate of relapse for alcohol abuse. The study was designed as a randomized, controlled, double-blind clinical trial. Among all 100 patients (50 atenolol, 50 placebo), only 15 stayed in the trial and remained fully abstinent for 1 year (7 atenolol, 8 placebo). Of the remaining 85 patients, 30 withdrew early while still abstinent (17 atenolol, 13 placebo). In the 57 high-risk patients who reported craving for alcohol at baseline, the treatment failure rates were 90% for patients receiving placebo, and was reduced to 65% in those who received atenolol (risk reduction = 28%, 95% confidence interval, -3% to 49%). The data from this trial also support the observation that poorer levels of treatment adherence are strongly associated with adverse outcomes for alcoholics during follow-up. This relationship was present both for patients who received atenolol and for those who received placebo.

Adult↗
PubMedDate not supplied

Clinical pathway for pneumonia: development, implementation, and initial experience.

BACKGROUND: As part of a large multidisciplinary project to reduce cost, decrease hospital length of stay, and improve efficiency of patient care at Saint Mary's Hospital, a clinical pathway for pneumonia was developed and implemented. METHODS: After using analysis of severity-adjusted data to determine which conditions would be best targets for improvement, a utilization management steering committee created a multidisciplinary group to develop a clinical pathway for pneumonia. This group was led by physician champions and consisted of representatives from nursing, respiratory therapy, pharmacy, and home healthcare. With information gained from chart abstraction, which identified "best practice" patterns, guidance from the medical literature, and local expertise, this group developed a clinical pathway that included an auxiliary protocol for respiratory care and a detailed educational brochure for patients. Before implementing the clinical pathway, extensive educational activities were undertaken involving the medical staff, house staff, nurses, and other staff. Data collected on consecutive patients discharged after implementation of the pathway were compared with data collected on patients discharged before the pathway in 1994. RESULTS: For DRG 89, the patients who were on the pathway in comparison to the control patients from 1994 had a lower average length of stay by 1.45 days (5.84 vs. 7.29 days) and a lower average total charge by $1,453 ($9,511 vs. $10,964). For DRG 90, the patients who were on the pathway in comparison to the control patients from 1994 had a lower average length of stay by 1.83 days (3.45 vs. 5.28 days) and a lower average total charge by $1319 ($5450 vs. $6769). CONCLUSIONS: The pneumonia clinical pathway that was implemented was associated with reductions in the length of stay and total charges. These reductions were seen in relationship to historical controls and to patients cared for concurrently who were not placed on the pathway. Although not fully used on all pneumonia patients, the presence of the pathway probably had some positive effects even on patients not formally on the pathway, through systems changes and educational influences. The pathway also positively influenced other conditions by the use of ancillary algorithms for conditions other than pneumonia, and the more rapid administration of antibiotics for other infectious diseases. Also, lessons learned in the creation of this first pathway have been helpful in streamlining the process of future pathway development.

Connecticut↗