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Although childbirth educators may not all have known her by name, the lovely redhead who was the star childbirth educator in the 1970s film The Story of Ericwas a familiar face. After viewing the film numerous times in our classes, early childbirth educators all felt that we knew her. Ferris Urbanowski was an early crusader for the Lamaze method of childbirth preparation in California in the 1960s. She worked to convince physicians in the Los Angeles area of the merits of the method, to establish classes for expectant parents, and to start a chapter of ASPO (now, Lamaze International, Inc.) in Los Angeles. Her book about yoga illustrated how additional methods of relaxation could benefit pregnant women. Today, Urbanowski attributes her past involvement in childbirth education to her current professional role as a teacher and counselor in the field of stress reduction at the Stress Reduction Clinic at the University of Massachusetts Medical Center.

Tuberculosis (TB) is the leading cause of death from a single infectious agent, requiring at least 6 months of multidrug treatment to achieve cure1. However, the lack of reliable data on antimicrobial pharmacokinetics (PK) at infection sites hinders efforts to optimize antimicrobial dosing and shorten TB treatments2. In this study, we applied a new tool to perform unbiased, noninvasive and multicompartment measurements of antimicrobial concentration–time profiles in humans3. Newly identified patients with rifampin-susceptible pulmonary TB were enrolled in a first-in-human study4using dynamic [11C]rifampin (administered as a microdose) positron emission tomography (PET) and computed tomography (CT). [11C]rifampin PET–CT was safe and demonstrated spatially compartmentalized rifampin exposures in pathologically distinct TB lesions within the same patients, with low cavity wall rifampin exposures. Repeat PET–CT measurements demonstrated independent temporal evolution of rifampin exposure trajectories in different lesions within the same patients. Similar findings were recapitulated by PET–CT in experimentally infected rabbits with cavitary TB and confirmed using postmortem mass spectrometry. Integrated modeling of the PET-captured concentration–time profiles in hollow-fiber bacterial kill curve experiments provided estimates on the rifampin dosing required to achieve cure in 4 months. These data, capturing the spatial and temporal heterogeneity of intralesional drug PK, have major implications for antimicrobial drug development.

The article presents the analysis of methods for selecting dimensions of bone wedge for high tibial osteotomy. The existing methods are described along with the procedure. In the following paragraphs, deficiencies in the selection of bone wedge dimensions and global trends in this field have been demonstrated. Based on the numerical analysis, the problem appearing in the wrong choice of bone wedge dimensions was illustrated.

A variety of studies note that who and what are published in academic journals can affect individual careers, gender and geographic biases, readership and impact of particular journals, how articles are assigned, and other issues. The Journal of Environmental Studies and Sciences(JESS) is an important new journal due to its foci, the growing number of environmental science and studies graduate and undergraduate programs, the journal’s stated intent to be multi- and interdisciplinary, and its link to the Association for Environmental Studies and Sciences. This short article examines the gender and institutional location of authors published in the first six volumes of JESS(2011–2016), the gender of authors of the books reviewed in the journal, the breakdown of natural science versus social science articles, and the percentage of articles that examine issues related to climate change and teaching. It does so to gather information that might assist JESSimprove intellectually or instrumentally and to provide comparison data for similar studies of other journals.

Effacement of normal lung parenchyma by cavities is an important sequela of pulmonary tuberculosis. Despite its clinical significance, the pathogenesis of tuberculous cavitation is poorly understood, with controversy as to whether the fundamental mechanism involves matrix depletion, lipid pneumonia, or mechanical factors. In this study, a repetitive aerosol infection model using Mycobacterium tuberculosiswas used to generate cavities in 20 New Zealand white rabbits. Serial computed tomography was performed to monitor cavity progression over 14 weeks. Three-dimensional reconstructions were compiled for each time point, allowing comprehensive four-dimensional cavity mapping. Terminally, cavities were processed for histopathology. Cavities progressed rapidly from areas of consolidation, and often showed a pattern of explosive growth followed by gradual contraction. Cavities formed preferentially in the caudodorsal lung fields, and frequently were subpleural. Cavitation was associated invariably with necrosis. Histomorphology showed four distinct cavity types that provide mechanistic clues and insight on early cavity development. Our study shows that cavitation is a highly dynamic process with preferential formation at sites of high mechanical stress. These findings suggest a model for the pathogenesis of tuberculous cavitation in which mechanical stress acts on the necrotic granuloma to produce acute tears in structurally weakened tissue, with subsequent air trapping and cavity expansion.

Proficient readers self‐monitor and self‐correct to derive meaning from text. This article reviews research on how students learn to self‐monitor and self‐correct and describes a Reciprocal Teaching (RT) instructional routine that was successfully used with early readers to build their metacognitive processes. The RTroutine included teacher modeling, guided practice with scaffolding for students to mentor each other, and independent practice in which students applied more than one source to draw inferences for self‐monitoring and self‐correcting. Scaffolding techniques within this process included visuals and teacher prompting to build student confidence in sharing their thought processes aloud with their peers.

Introduction/Objectives: In the US, reactivation of latent tuberculosis infection (LTBI) accounts for 80% of new cases. In 2016, the US Preventive Services Task Force provided a new recommendation that primary care providers (PCPs) should conduct LTBI screening, whereas in the past, LTBI cases were evaluated and treated by specialty providers. This shift in care revealed knowledge gaps surrounding LTBI treatment among PCPs. This study assessed changes in PCPs’ confidence for performing key aspects of LTBI care before and after participation in an LTBI Extension for Community Healthcare Outcomes (ECHO) course.Methods: The ECHO Model™ is an evidence-based telementoring intervention. Participants were primary care team members from clinics throughout Massachusetts who voluntarily enrolled in the ECHO course. In this mixed-methods evaluation, primary outcomes were PCP self-reported confidence changes by pre- and post-course surveys and post-course semi-structured interviews.Results: Twenty PCPs (43% of registered PCPs) attended at least 3 of the 6 sessions and 24 PCPs (31% of registered PCPs) completed at least one survey. Confidence increased in selecting a test (P= .004), interpreting tuberculosis infection test results (P= .03), and selecting a treatment regimen (P= .004). Qualitative interviews with 3 PCPs revealed practice changes including switching to interferon gamma release assays for testing and using rifampin for treatment.Conclusions: Use of the ECHO model to train PCPs in LTBI management is feasible and efficacious. For continuing medical education, ECHO courses can be leveraged to reduce health disparities in settings where PCPs’ lack of familiarity about a treatment topic contributes to poor health outcomes.

A personal narrative is presented which explores the author's experience of collaborating with the Valley Soaring Club of Middletown, New York for teaching the mathematical and engineering concepts of flight to the students of the Academy of Information Technology & Engineering in Connecticut.

Public policy impacts on the occupational life spectrum of individuals and communities are ubiquitous. This paper explores the nexus between policy science and occupational science. Public policy is defined and the relevance to occupational life and occupational salience is explored. Two occupational science meta-value propositions are put forward to support interdisciplinary dialogue within policy science that can be used to respond to societal transformations and the development of public policy. Economic downturns and globalization are two scenarios used to provide examples of the intersections of occupational science and policy science. These scenarios are used to expand on the value and potential of occupational science to inform public policy through the application of policy levers. This paper opens the door for occupational scientists and public policy scientists to begin to engage in dialogue on the benefits of interdisciplinary approaches that can support the holistic consideration of knowledge needed to address the occupational complexity of lives and communities when occupation is disrupted.

Abstract: An upper second permanent molar from a human was found alongside numerous tools of the Micoquian tradition and was excavated in Stajnia Cave, which is located over 100 km North of the Carpathian Mountains in southern Poland. The age of these finds has been established within a time-span of late Saalian to early Weichselian, most likely to OIS 5c or 5a, according to the palaeontological, geological, archaeological and absolute dating of the layer from which they were obtained. An examination of the morphology of the human molar indicates that this tooth exhibits many traits frequently occurring in Neanderthal upper molars. Although the occurrence of derived Neanderthal traits in the Stajnia molar cannot be firmly established because of degradation of its cusps, the presence of the above-mentioned features allows the assertion that this tooth belonged to a Neanderthal. The age of the Stajnia tooth and the archaeological context of this find also indicate that this molar is of Neanderthal origin.

Transcription of the Pseudomonas aeruginosa type III secretion system (T3SS) is induced under Ca2+-limiting growth conditions or following the contact of the bacteria with host cells. The regulatory response to low Ca2+levels is initiated by the T3SS-mediated secretion of ExsE, a negative regulatory protein that prevents T3SS gene transcription. In the present study, we demonstrated that ExsE plays an analogous role in transcriptional induction following host cell contact. By using a flow cytometry assay, the host contact-dependent induction of T3SS gene expression was found to be dependent upon the presence of functional type III translocation machinery. Using three independent assays, we demonstrated that ExsE was translocated into Chinese hamster ovary cells in a T3SS-dependent manner. Deletion mapping experiments indicated that the amino terminus of ExsE is required both for secretion under Ca2+-limiting growth conditions and for translocation into host cells. A P. aeruginosa mutant expressing an exsE allele lacking codons 3 through 20 was deficient in ExsE secretion and translocation and showed constitutive repression of T3SS gene expression under Ca2+-limiting growth conditions. The mutant also failed to induce T3SS gene expression following host cell contact and demonstrated a significant reduction in T3SS-dependent cytotoxicity towards Chinese hamster ovary cells, indicating that the translocation of ExsE is required for the host contact-dependent induction of T3SS gene expression.

ABSTRACTTranscription of the Pseudomonas aeruginosatype III secretion system (T3SS) is induced under Ca2+-limiting growth conditions or following the contact of the bacteria with host cells. The regulatory response to low Ca2+levels is initiated by the T3SS-mediated secretion of ExsE, a negative regulatory protein that prevents T3SS gene transcription. In the present study, we demonstrated that ExsE plays an analogous role in transcriptional induction following host cell contact. By using a flow cytometry assay, the host contact-dependent induction of T3SS gene expression was found to be dependent upon the presence of functional type III translocation machinery. Using three independent assays, we demonstrated that ExsE was translocated into Chinese hamster ovary cells in a T3SS-dependent manner. Deletion mapping experiments indicated that the amino terminus of ExsE is required both for secretion under Ca2+-limiting growth conditions and for translocation into host cells. A P. aeruginosamutant expressing an exsEallele lacking codons 3 through 20 was deficient in ExsE secretion and translocation and showed constitutive repression of T3SS gene expression under Ca2+-limiting growth conditions. The mutant also failed to induce T3SS gene expression following host cell contact and demonstrated a significant reduction in T3SS-dependent cytotoxicity towards Chinese hamster ovary cells, indicating that the translocation of ExsE is required for the host contact-dependent induction of T3SS gene expression.

ABSTRACTExpression of the genes in the ADEregulon of Saccharomyces cerevisiaeis repressed by the presence of purine bases in the extracellular medium and derepressed when cells are grown in the absence of purines. Derepression requires the transcriptional activators Bas1 and Pho2, as well as the biosynthetic intermediates 5'-phosphoribosyl-4-succinocarboxamide-5-aminoimidazole (SAICAR) and 5'-phosphoribosyl-4-carboxamide- 5-aminoimidazole (AICAR). In this study, we investigated if nuclear localization and binding to promoter DNA by the activators are regulated by purines. Using indirect immunofluorescence, we found that Bas1 is localized to the nucleus under both repressing and derepressing conditions. Importantly, we detected Bas1 bound to promoter DNA under both conditions using chromatin immunoprecipitation assays at several ADEpromoters (ADE1, ADE2, ADE4, and ADE5,7) and HIS4. We analyzed the binding of Bas1 to wild-type and mutant sequences of the ADE5,7promoters in vivo, and found that Bas1 binds independently to each of its two binding sites. Pho2 was not required for the association of Bas1 with chromosomal DNA, but it was required for an increase in Bas1-immunoprecipitated DNA. The presence of Pho2 at promoters was dependent on Bas1 and occurred only under derepressing conditions when the ADEgenes are transcribed at elevated levels. We propose a model for regulation of the ADEgenes in which DNA-bound Bas1 is inactive due to masking of its activation domain and Pho2 binds poorly to promoters when cells have sufficient purine nucleotides. Upon limitation for purines, the SAICAR/AICAR regulatory signal is transmitted to the nucleus to increase Bas1 and Pho2 interaction, recruiting Pho2 to promoters and freeing the activation domains for transactivation.

Expression of the genes in the ADE regulon of Saccharomyces cerevisiae is repressed by the presence of purine bases in the extracellular medium and derepressed when cells are grown in the absence of purines. Derepression requires the transcriptional activators Bas1 and Pho2, as well as the biosynthetic intermediates 5'-phosphoribosyl-4-succinocarboxamide-5-aminoimidazole (SAICAR) and 5'-phosphoribosyl-4-carboxamide- 5-aminoimidazole (AICAR). In this study, we investigated if nuclear localization and binding to promoter DNA by the activators are regulated by purines. Using indirect immunofluorescence, we found that Bas1 is localized to the nucleus under both repressing and derepressing conditions. Importantly, we detected Bas1 bound to promoter DNA under both conditions using chromatin immunoprecipitation assays at several ADE promoters (ADE1, ADE2, ADE4, and ADE5,7) and HIS4. We analyzed the binding of Bas1 to wild-type and mutant sequences of the ADE5,7 promoters in vivo, and found that Bas1 binds independently to each of its two binding sites. Pho2 was not required for the association of Bas1 with chromosomal DNA, but it was required for an increase in Bas1-immunoprecipitated DNA. The presence of Pho2 at promoters was dependent on Bas1 and occurred only under derepressing conditions when the ADE genes are transcribed at elevated levels. We propose a model for regulation of the ADE genes in which DNA-bound Bas1 is inactive due to masking of its activation domain and Pho2 binds poorly to promoters when cells have sufficient purine nucleotides. Upon limitation for purines, the SAICAR/AICAR regulatory signal is transmitted to the nucleus to increase Bas1 and Pho2 interaction, recruiting Pho2 to promoters and freeing the activation domains for transactivation.

Background:Antiviral drugs that target viral proteins are very successful but have certain limitations. Consequently, cellular proteins have begun to be considered as potential targets for novel antivirals. Cyclin-dependent kinases (CDKs) are arguably the cellular proteins best studied as potential targets. Several pharmacological CDK inhibitors (PCIs) have antiviral activity against wild-type or drug-resistant strains of HIV, human cytomegalovirus, herpes simplex virus (HSV), Epstein–Barr virus, varicella-zoster virus, Kaposis sarcoma herpesvirus, and human T-cell leukemia virus. Some PCIs such as roscovitine are apparently well tolerated and are scheduled to enter clinical trials as antivirals in 2005. However, the antiviral mechanisms of PCIs remain incompletely characterized, and PCIs with different molecular specificities may inhibit different viral functions. Objective:To evaluate whether PCIs with different molecular specificities target common viral functions. Methods:We evaluated the activities of structurally unrelated PCIs against a single model virus, HSV, in primary and immortalized fibroblasts. We tested whether roscovitine, flavopiridol, aloisine, and DRB, which preferentially inhibit different subsets of CDKs, inhibit HSV replication, transcription, or gene expression. Results:Aloisine was effective only in primary fibroblasts. Roscovitine, DRB, and to a lesser extent flavopiridol, inhibited HSV replication at lower concentrations in primary than in immortalized fibroblasts. These PCIs inhibited initiation of HSV transcription and accumulation of a viral protein into replication compartments. Flavopiridol also inhibited HSV transcription elongation. Conclusions:Structurally unrelated PCIs have common antiviral targets, although targets unique to certain PCIs also exist. We have identified two novel functional targets for antivirals, initiation of viral transcription and subcellular localization of viral proteins.

The transcriptional activator protein Bas2 is required to express more than 20 genes in pathways for purine nucleotide and histidine biosynthesis, phosphate utilization, and the HO endonuclease by acting with co-regulator proteins Bas1, Pho4, and Swi5. The role that Bas2 plays in transcriptional activation may be to unmask latent activation domains in the co-regulator and to promote ternary complex formation between Bas2, the co-regulator, and DNA. We show that Bas2 also contributes to transcriptional activation by providing an activation domain. We localize this domain in Bas2 to the C-terminal 156 amino acids using deletion analysis and fusion to a heterologous DNA binding domain. Additionally, we show that Bas2 makes direct contacts with Bas1. This interaction is detected by co-immunoprecipitation and by two-hybrid analysis. We localize the interaction region to the central portion of Bas2, from amino acids 112 to 404.

The Lee, Oehme and Yang (LOY) theory of time evolution in two state subspace of states of the complete system is discussed. Some inconsistencies in the assumptions and approximations used in the standard derivation of the LOY effective Hamiltonian, HLOY, governing this time evolution are found. Eliminating these inconsistencies and using the LOY method, approximate formulae for the effective Hamiltonian, H||, governing the time evolution in this subspace (improving those obtained by LOY) are derived. It is found, in contradistinction to the standard LOY result, that in the case of neutral kaons (〈K0|H|||K0〉−〈¯K0|H|||¯K0〉), cannot take the zero value if the total system the preserves CPT-symmetry. Within the use of the method mentioned above formulae for H||acting in the three state (three dimensional) subspace of states are also found.

Two-dimensional (2D) nanomaterials are ultrathin, layered materials with a high surface-to-volume ratio that can deliver various therapeutics including small-molecule drugs, peptides, and large proteins. Their high surface area allows for high therapeutic loading and sustained therapeutic release over time. Some 2D nanomaterials respond to external stimuli, providing control over triggered or on-demand therapeutic release. 2D nanomaterials explored for biomedical applications include carbon-based (graphene), nanoclays, black phosphorous, layered double hydroxides, metal organic frameworks, covalent organic framework, 2D metal carbides and nitrides, transition metal dichalcogenides, transition metal oxides, polymer nanosheets, and hexagonal boron nitride. Most of these nanomaterials are biocompatible and degrade into nontoxic products, which is advantageous for therapeutic delivery systems. In this article, we will evaluate these nanomaterials for therapeutic delivery. We will highlight some of their unique physical and chemical characteristics, discuss their biological stability, and investigate their ability to deliver various therapeutics. Recent developments in 2D nanomaterials as drug delivery systems will also be discussed.

Iron transport across the plasma membrane appears to be a unidirectional process whereby iron uptake is essentially irreversible. One of the major sequestration sites for iron is the vacuole that stores a variety of metals, either as a mechanism to detoxify the cell or as a reservoir of metal to enable the cell to grow when challenged by a low iron environment. Exactly how the vacuole contributes to the overall iron metabolism of the cell is unclear because mutations that affect vacuolar function also perturb the assembly of the plasma membrane high affinity transport system composed of a copper-containing iron oxidase, Fet3p, and an Fe(3+)-specific iron transporter, Ftr1p. Here, we characterize the iron transporter homologue Fth1p, which is similar to the high affinity plasma membrane iron transporter Ftr1p. We found that Fth1p was localized to the vacuolar surface and, like other proteins that function on the vacuole, did not undergo Pep4-dependent degradation. Co-immunoprecipitation experiments showed that Fth1p also associates with the Fet3p oxidase homologue, Fet5p; and disruption of the FET5 gene results in the accumulation of Fth1p in the endoplasmic reticulum. We also found that loss of this protein complex leads to elevated transcriptional activity of the FET3 gene and compromises the ability of the cell to switch from fermentative metabolism to respiratory metabolism. Because the Fet5 protein is oriented such that the oxidase domain of Fet5p is lumenal, this complex may be responsible for mobilizing intravacuolar stores of iron.

The metF gene in Escherichia coli and Salmonella typhimurium is under negative transcriptional control by the MetJ repressor. Expression of an S. typhimurium metF-lacZ gene fusion is repressed up to 10-fold by methionine addition to the growth medium in E. coli hosts encoding wild-type MetJ repressor; this repression is not seen in metJ mutants. metR mutations which eliminate the MetR activator protein result in two- to threefold-more-severe repression by the MetJ repressor. In a metJ metR double mutant, however, the level of metF-lacZ expression is the same as in a metJ mutant, suggesting that MetR antagonizes MetJ-mediated methionine repression of the metF promoter. A DNA footprint analysis showed that MetR binds to a DNA fragment carrying the metF promoter and protects two separate regions from DNase I digestion: a 46-bp region from position -50 to -95 upstream of the transcription initiation site and a 24-bp region from about position +62 to +85 downstream of the transcription initiation site and within the metF structural gene. Nucleotide changes in each of the MetR-binding sites away from the consensus sequence disrupt MetR-mediated regulation of the metF-lacZ fusion.

This pilot study evaluated the effectiveness and safety of a topically applied 2.5% solution of flutamide (a nonsteroidal antiandrogen) versus its placebo vehicle in the treatment of acne vulgaris. A total of 80 patients (33 males and 47 females) were treated for a period of 16 weeks. Inflammatory lesions (papules, pustules and nodules combined) responded better to flutamide (-56.7%) than to placebo (-36.7%; P=0.01). There was no meaningful difference between the effect of flutamide (-48.6%) and of placebo (-45.3%) on noninflammatory lesions (comedones). A relatively high level of local side-effects such as scaling, burning/stinging, pruritus, erythema and vesicles were observed in both the flutamide (60.0%) and the placebo (56.4%) groups. However, there were no systemic side-effects reported. This first clinical study demonstrated that flutamide 2.5% solution is effective in the topical treatment of acne vulgaris.

Abstract: The nondecay probability of an unstable particle at a definite moment of time is investigated provided this particle existed at all earlier observation moments separated with the time interval Delta. Using the usual postulates for quantum measurements it is proved that this probability is described by the exponential function of Delta0, and it tends to 1 as Deltararr 0. An approximate formula is found for the effective decay width Gamma(Delta) appearing in the case of multiple measurements. It is shown that Gamma(Delta) rarr 0 as Deltararr 0. For Deltararrinfin, the width Gamma(Delta) rarrGamma0, with Gamma0 being the standard decay with in Weisskopf-Wigner theory. At finite delta's Gamma(Delta) may be smaller or greater than Gamma0 depending on the parameters of the theory.

The vitamin B12 (B12)-mediated repression of the metE gene in Escherichia coli and Salmonella typhimurium requires the B12-dependent transmethylase, the metH gene product. It has been proposed that the MetH-B12 holoenzyme complex is involved directly in the repression mechanism. Using Escherichia coli strains lysogenized with a lambda phage carrying a metE-lacZ gene fusion, we examined B12-mediated repression of the metE-lacZ gene fusion. Although B12 supplementation results in a 10-fold repression of metE-lacZ expression, homocysteine addition to the growth medium overrides the B12-mediated repression. In addition, B12-mediated repression of the metE-lacZ fusion is dependent on a functional MetR protein. When a metB mutant was transformed with a high-copy-number plasmid carrying the metE gene, which would be expected to reduce intracellular levels of homocysteine, metE-lacZ expression was reduced and B12 supplementation had no further effect. In a metJ mutant, B12 represses metE-lacZ expression less than twofold. When the metJ mutant was transformed with a high-copy-number plasmid carrying the metH gene, which would be expected to reduce intracellular levels of homocysteine, B12 repression of the metE-lacZ fusion was partially restored. The results indicate that B12-mediated repression of the metE gene is primarily a loss of MetR-mediated activation due to depletion of the coactivator homocysteine, rather than a direct repression by the MetH-B12 holoenzyme.

In the case of multiple measurements we have found that there is nonzero decay width Γ (Δ) (even for bound states) and that, for relatively long time intervals Δ separating successive measurements, Γ (Δ) tends like Δ−k (k ≥ 1 according to the investigated model) to the asymptotic value Γo for unstable states and to zero for bound states. We have shown that the detector efficiencyZ ≠ 1 is responsible for this effect and that the evolution operator acting in the considered subspace of states should be renormalized to avoid this effect. As an illustration we have considered electromagnetic levels in the Coulomb field as an example of unstable states.

A quantum-mechanical model of a detector monitoring the decay of an unstable object is constructed. Detailed investigation of the time evolution of this model shows that under some conditions the non-decay probability of many successively measured unstable particles coincides with that following from the state-reduction postulate. The probability of realizing continuous measurement without the Zenoparadox is demonstrated for this model.

Using the equation for a projection of a state vector, the exponent of a damping factor for a given state, corresponding to the effective decay width appearing in the case of multiple measured unstable states, is obtained numerically in some models for early time period t → 0. is found to be nonzero (even for stable states) at this time period; thus, for early times, this damping factor is always smaller than unity. It is shown that at finitet's may be smaller or greater than the standard decay width γα in Weisskopf-Wigner theory depending on the parameters of a model considered.

Clinical education or fieldwork requires a collaborative relationship and coordinated effort between the university and the clinic. Although the literature notes the increased recognition and responsilDility given to clinicians as a teaching resource, minimal attention has been given to describing the clinical educator's perspective or in preparing clinicians for the role of educator. The purpose of this study was to explore the support and educational needs of Saskatchewan occupational therapists as they related to providing clinical education. Focus group interviews were conducted with 70% participation of the practicing registered occupational therapists in Saskatchewan. Emerging themes related to the participants (needs and responsibilities of the student, the clinical educator, the facility and the university), the process (positive and negative elements of communication, placement coordination and student evaluation), and the environment (clinical education models, length and number of placements). Recommendations were made for enhancing the clinical education experience in Saskatchewan.

Transcription of the metH gene in Salmonella typhimurium and Escherichia coli is positively regulated by the metR gene product, a DNA binding protein. The interaction between the MetR activator protein and the S. typhimurium metH control region was investigated. In vitro gel mobility shift assays and DNase I protection assays established that the MetR protein binds to and protects a 24-bp sequence in the metH promoter region from DNase I attack. This region includes the proposed metR recognition sequence 5'-TGAANNNNNCTCA-3'. Single-base-pair changes were introduced into the proposed MetR recognition sequence within the promoter region of a metH-lacZ gene fusion by oligonucleotide-directed mutagenesis. Two classes of mutations were identified. In the first class, the mutations caused reduced activation of the metH-lacZ fusions that correlated with reduced MetR binding. In the second class, activation of the metH-lacZ fusion was reduced, yet there was no appreciable reduction in MetR binding, indicating that the presence of bound MetR is not sufficient for activation of metH-lacZ gene expression. These two classes of mutations in the DNA binding site are grouped spatially, suggesting that the proposed MetR recognition sequence can be divided into two functional domains, one for binding and the other for activation.

We isolated an Escherichia coli methionine auxotroph that displays a growth phenotype similar to that of known metF mutants but has elevated levels of 5,10-methylenetetrahydrofolate reductase, the metF gene product. Transduction analysis indicates that the mutant carries normal metE, metH, and metF genes; the phenotype is due to a single mutation, eliminating the possibility that the strain is a metE metH double mutant; and the new mutation is linked to the metE gene by P1 transduction. Plasmids carrying the Salmonella typhimurium metE gene and flanking regions complement the mutation, even when the plasmid-borne metE gene is inactivated. Enzyme assays show that the mutation results in a dramatic decrease in metE gene expression, a moderate decrease in metH gene expression, and a disruption of the metH-mediated vitamin B12 repression of the metE and metF genes. Our evidence suggests that the methionine auxotrophy caused by the new mutation is a result of insufficient production of both the vitamin B12-independent (metE) and vitamin B12-dependent (metH) transmethylase enzymes that are necessary for the synthesis of methionine from homocysteine. We propose that this mutation defines a positive regulatory gene, designated metR, whose product acts in trans to activate the metE and metH genes.

We used an in vitro DNA-dependent protein-synthesizing system to demonstrate de novo synthesis of the leader peptide specified by the tryptophan (trp) operons of several bacterial species. Peptide synthesis was directed by self-ligated short restriction fragments containing the trp promoter and leader regions. Synthesis of leader peptides was established by demonstrating that they were labeled in vitro only by those amino acids predicted to be present in the peptides. Leader peptide synthesis was abolished by the addition of the Escherichia coli trp repressor. The E. coli trp leader peptide was found to be extremely labile in vitro; it had a half-life of 3-4 min. In a highly purified DNA-dependent peptide-synthesizing system, synthesis of the di- and tripeptides predicted from the Salmonella typhimurium trp operon leader sequence, fMet-Ala and fMet-Ala-Ala, also was observed. Using this dipeptide synthesis system, we demonstrated that translation initiation at the ribosome binding site used for trp leader peptide synthesis was reduced 10-fold when the transcript contained a segment complementary to the ribosome binding site.

The DNA sequence of the Salmonella typhimurium metA control region is presented. S1 nuclease mapping was used to determine the transcription initiation site. By measuring beta-galactosidase levels in Escherichia coli strains lysogenized with lambda phage carrying a metA-lacZ gene fusion, the MetR protein was shown to activate the metA gene. Homocysteine, an intermediate in methionine biosynthesis, plays a negative role in the MetR-mediated activation mechanism. Gel mobility shift assays and DNase I protection experiments showed that the MetR protein binds to a DNA fragment carrying the metA control region and protects a 26-bp region beginning 9 bp upstream of the -35 promoter sequence.

Using an Escherichia coli lac deletion strain lysogenized with a lambda phage carrying a metH-lacZ gene fusion, we isolated trans-acting mutations that result in simultaneous 4- to 6-fold-elevated metH-lacZ expression, 5- to 22-fold-lowered metE-lacZ expression, and 9- to 20-fold-elevated metR-lacZ expression. The altered regulation of these genes occurs in the presence of high intracellular levels of homocysteine, a methionine pathway intermediate which normally inhibits metH and metR expression and stimulates metE expression. P1 transductions and complementation tests indicate that the mutations are in the metR gene. Our data suggest that the mutations result in an altered MetR activator protein that has lost the ability to use homocysteine as a modulator of gene expression.

The metR-mediated activation of the Salmonella typhimurium metE and metH genes was shown to be modulated by homocysteine, an intermediate in the methionine biosynthetic pathway. Homocysteine stimulates expression of a metE-lacZ gene fusion four- to fivefold by increasing transcription from the metE promoter. In contrast, homocysteine plays an inhibitory role in the metR-mediated activation of the metH gene, decreasing expression of a metH-lacZ gene fusion threefold.

This article discusses spirituality as an integral component of the occupational performance model. Spirituality is defined as the experience of meaning in everyday life activities. Some of the difficulties commonly encountered in operationalizing the concept of spirituality are discussed. Strategies built on minimizing or eliminating some of the difficulties are reviewed. The recommendations for practising therapists encompass suggestions for assessment, goal setting, and practice.

Incubation of human serum with either D- (1-14c)galactose (5 mM), D-(l-14c)glucose (5 mM) or L-(l-14c)fucose (5 mM) in vitro for 7 days under physiological conditions resulted in the accumulation of radioactivity into trichloroacetic acid precipitable material. Separation of the serum proteins by Sephadex G-200 chromatography, revealed the association of radioactivity with the. albumin fraction (95%) and to a lesser extent with IgG (4%) and IgM (1%). D-galactose glycosylated purified human IgG at 2 to 3 fold the rate of D-glucose or L-fucose. The rate of glycose incorporation into IgG increased parabolically with increasing pH and temperature of incubation, and followed a first order dependence with either the glycose or the IgG concentration. The post-translational modification of IgG through nonenzymatic glycosylation may affect its immunological properties in clinical conditions associated with increased blood sugar concentrations.

The DNA sequence of the Salmonella typhimurium glyA gene has been determined. The polypeptide deduced from the DNA sequence contains 417 amino acids and has a calculated molecular weight of 45428 daltons. S1 nuclease mapping experiments located the transcription start point and possible transcription termination region. The nucleotide and amino acid sequences for the S. typhimurium and Escherichia coli glyA genes were compared. The nucleotide sequences show 89% identity, and the amino acid sequences show 93% identity. In S. typhimurium there is an absence of REP sequences between the translation termination site and the proposed transcription termination site that are present in the E. coli sequence. A conserved sequence is found in both organisms extending from 79 to 117 bp upstream of the consensus -35 sequences of the glyA promoters. This conserved sequence shows homology to a sequence preceding the S. typhimurium metE gene determined to bind the MetR regulatory protein.

We isolated and characterized cis-acting mutations that affect the regulation of the metB gene of Salmonella typhimurium LT2. The mutations were isolated in an Escherichia coli lac deletion strain lysogenized with lambda bacteriophage carrying a metB-lacZ gene fusion (lambda JBlac) in which beta-galactosidase production is dependent upon metB gene expression. The mutant lysogens show elevated, poorly regulated beta-galactosidase production. The altered regulation is a result of disruption of the methionine control system mediated by the metJ repressor. The mutations are located in a region of dyad symmetry centered near the -35 sequence of the metB promoter. We propose that these mutations alter the repressor binding site and define the metB operator sequence. In addition, we discuss a highly conserved, nonsymmetric DNA sequence of unknown function which occurs in the control regions of the metA, metC, metE, metF, metG, and metJB genes of both S. typhimurium and E. coli.

The Salmonella typhimurium metE and metR genes share a common control region, with overlapping, divergently transcribed promoters. A double gene fusion was constructed in which the metE promoter directs expression of the Escherichia coli lacZ gene and the metR promoter directs expression of the E. coli galK gene. By using an E. coli strain lysogenized with a lambda bacteriophage carrying the metE-lacZ metR-galK double fusion (lambda Elac.Rgal), two classes of cis-acting mutations were isolated that increase metR-galK expression. The first class of mutations causes a simultaneous decrease in metE-lacZ expression by disrupting the normal MetR-mediated activation of the metE promoter. The mutations are located within a region extending from 17 to 34 base pairs upstream of the -35 region of the metE promoter. Gel mobility shift assays and DNaseI protection experiments demonstrated that the MetR protein specifically binds to a 24-base-pair region encompassing these mutations. The second class of mutations increases metR-galK expression by directly altering the promoter consensus sequences of the metE and metR promoters.

Regulation of the Salmonella typhimurium metR gene was studied by measuring beta-galactosidase levels in Escherichia coli strains lysogenic for a lambda bacteriophage carrying a metR-lacZ fusion. The results indicate that the metR gene is negatively regulated by its own gene product and that this autoregulation involves homocysteine as a corepressor. In addition, the results indicate that the metR gene is negatively regulated by the metJ gene product over a 70- to 80-fold range.

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