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Biomedical subjects

M Smith

Publications and source records attributed to M Smith.

At least 883 records · Page 49Linked to original sources
PubMed1990

Teacher competency testing: what teachers of students with LD need to know.

In 1964, North Carolina became the first state to enact a testing program for initial certification of teachers. Today, almost all states and the District of Columbia are actively planning or implementing teacher testing programs; six are administering tests in the specific area of learning disabilities. The objectives and content areas of knowledge included in competency testing programs within this specialized area of teacher competence were analyzed, and comparisons were completed across knowledge areas and among states. In general, much similarity exists in what teachers of students with learning disabilities in different states are expected to know. This information represents a strong foundation for planning, implementing, and evaluating training programs for all teachers.

Certification↗
PubMed1990

Preoperative therapy for esophageal cancer: a randomized comparison of chemotherapy versus radiation therapy.

Ninety-six patients with operable epidermoid cancer of the esophagus were entered into a phase III, random assignment study designed to compare the efficacy of two preoperative approaches (chemotherapy [CT] or radiation therapy [RT]). Major study end points were objective response rates, surgical outcome, and recurrence pattern. Patients were randomly assigned to receive either two cycles of cisplatin, vindesine, and bleomycin or 55 Gy of radiation before a planned surgical procedure. Postoperative crossover therapy (radiation to those receiving preoperative CT and vice versa) was given to patients with T3Nany or unresectable tumors. Objective response rates of the primary tumor to preoperative therapy were similar (RT 64%, CT 55%), as were operability rates (RT 77%, CT 75%), resection rates (RT 65%, CT 58%), and operative mortality (RT 13.5%, CT 11.1%). Significantly higher doses of CT could be administered when CT was given as initial therapy, rather than after RT/surgery. Local failure or persistence occurred in 33% of operable patients. The median survival for all patients was 11 months; 20% remain alive without disease (median follow-up, 34 months). Because of the crossover design, it was not possible to analyze survival according to the preoperative therapy arm alone. This study suggests that since CT is as effective in treating local tumor as RT, but can also potentially treat systemic disease, investigational programs using CT before surgery as part of initial treatment for localized esophageal cancer should continue. However, if a significant impact on overall survival is to be achieved, more effective chemotherapy regimens or schedules need to be identified. Outside of carefully designed clinical trials, surgery alone or radiation alone remain standard therapy.

Analysis of Variance↗
PubMed1990

Recombinant methionyl bovine prolactin: loss of bioactivity after single amino acid deletions from putative helical regions.

We have previously described a method for producing recombinant methionyl bovine PRL (Met-bPRL), which is as bioactive as the authentic hormone in the Nb2 cell lactogen bioassay; in contrast, a Met-bPRL variant lacking tyrosine 28 was essentially devoid of bioactivity. In the present study we have investigated this loss of bioactivity at the molecular level by determining the bioactivities of a number of Met-bPRL variants engineered to contain specific changes in their primary structures. It was found that the presence of tyrosine per se at the 28 position in Met-bPRL was not essential for high bioactivity, since Met-bPRL variants prepared by replacing tyrosine 28 with other amino acids (arginine, phenylalanine, alanine, and histidine) still had substantial bioactivity (40-74% that of Met-bPRL). Neither was the loss of bioactivity related to a shift in the relative positions of conserved histidines 27 and 30; in fact, histidine 27 was found not to be essential for the bioactivity of the hormone. The loss of bioactivity after deletion of tyrosine 28 from Met-bPRL appears to be related to the removal of an amino acid from the middle of a putative helix (no. 1) rather than to the loss of a residue specific to lactogen function. This suggestion is supported by the finding that Met-bPRL variants obtained by deletion of selected single amino acids from center domains of putative helix 2, 3, or 4 were also essentially devoid of bioactivity. It is speculated that this lack of bioactivity reflects an inability of the proteins to assume a native conformation.

Amino Acid Sequence↗
PubMed1990

Comparison of the erbium-yttrium aluminum garnet and carbon dioxide lasers for in vitro bone and cartilage ablation.

The in vitro bone- and cartilage-ablation characteristics of the solid-state erbium:yttrium aluminum garnet laser were compared to those of the carbon dioxide laser. Ablations of fresh, frozen cadaver septal cartilage and maxillary sinus bone were performed using total energies between 1 and 6 J. Specimens were studied using hematoxylin and eosin stain and digitized, computer-assisted measurements of 35-mm photographs. Erbium-yttrium aluminum garnet-ablated bone averaged 5 microns of adjacent tissue thermal injury, compared with 67 microns with carbon dioxide-ablated bone. Erbium-yttrium aluminum garnet-ablated cartilage averaged 2 microns of adjacent tissue thermal injury, compared with 21 microns with the carbon dioxide-ablated cartilage. The tissue-ablation characteristics of the erbium-yttrium aluminum garnet laser are promising for future otolaryngologic applications.

Aluminum↗
PubMed1990

Increased release of the N-terminus of the atrial natriuretic factor prohormone with increasing absolute atmospheres of pressure in a hyperbaric chamber and reversal with oxygen therapy.

Increasing atmospheres of absolute pressure (ATA) on the cardiopulmonary system results in a marked diuresis. The present investigation was designed to determine if the diuresis observed with increasing ATA is associated with increased release of the N-terminus of the atrial natriuretic factor (ANF) prohormone that contains two potent diuresis-producing hormones consisting of amino acids (aa) 1-30 (pro ANF 1-30; long-acting sodium stimulator) and aa 31-67 (pro ANF 31-67; vessel dilator) of this 126 aa prohormone. Seven healthy volunteers (mean age, 31 years) had the circulating concentration of the N-terminus of the ANF prohormone evaluated at 1, 2, and 3 ATA in a monoplace hyperbaric chamber by two specific and sensitive radioimmunoassays that immunologically recognize (1) the whole 98 aa N-terminus and (2) the midportion of the N-terminus consistent with aa 31-67 (pro ANF 31-67). With increasing ATA from 1 (sea level) to 2 (equivalent to 33 feet of sea water), the circulating concentrations of both the whole N-terminus and pro ANF 31-67 increased threefold. At 3 ATA (66 feet of sea water), their circulating concentrations increased sixfold over their concentrations, at 1 ATA. With the addition of 100 percent O2 while at 3 and 2 ATA, the circulating concentrations of both the whole N-terminus and pro ANF 31-67 immediately decreased to their prehyperbaric ATA levels and remained there with further decompression to 1 ATA and removal of O2 supplementation. The increased circulating concentration of the N-terminus of the ANF prohormone containing two peptides with potent diuretic effects during increasing atmospheres of absolute pressure may help to explain the diuresis that has been observed with increasing ATA.

Adult↗
PubMed1990

A sex difference in field dependence/independence in the absence of vestibular activation and eye movements.

Frame influence on perception of target orientation was investigated using small stimuli presented briefly to central vision. College men and women were equally accurate in their perceptions of the orientations of alphanumeric characters presented without a frame. When the same targets were enclosed in a frame, the performance of women, but not men, was significantly impaired.

Adolescent↗
PubMed1990

Geropsychiatric education programs. Providing skills and understanding.

1. The treatment of mental health problems is a growing concern in long-term care facilities; up to 80% of nursing home residents suffer from some type of mental illness, but most receive no active treatment. 2. Nursing home staff do not receive sufficient training on mental health issues, the aging process, and assessment and management of psychiatric symptoms in the elderly. 3. Psychiatric nurses can provide a number of quality geriatric mental health programs to increase staff knowledge and promote quality of care.

Aged↗
PubMed1990

Care of the patient post-abdominal aortic aneurysm repair.

Caring for the patient post-abdominal aortic aneurysm repair requires knowledge of pathophysiology and surgical procedure. By understanding these, the PACU nurse will be able to set appropriate patient priorities and optimize patient outcome.

Aorta, Abdominal↗
PubMed1990

Phenotypic markers of lymphocyte and mononuclear phagocyte activation within rheumatoid nodules.

We investigated rheumatoid subcutaneous nodules using monoclonal antibodies recognizing functional determinants on mononuclear phagocytes (Mph) and lymphocytes. Mph at the center of rheumatoid nodules showed strong expression of the leukocyte intergrins CR3 and p150,95 which would be consistent with the presence of a central chemotactic stimulus. Mph expression of FcR1, a gamma interferon regulated molecule, was decreased in 5/13 cases despite strong expression of MHC class II. There was a variable unstructured infiltrate of T lymphocytes, a majority of which were CD8 positive. Lymphocytes showed increased MHC class II expression but interleukin 2 receptor expression was low. We discerned no relationship between the number, distribution or phenotype of the T cell infiltrate and the phenotype of the predominant Mph population.

Adult↗
PubMed1990

Pharmacokinetics of misoprostol in the elderly, in patients with renal failure and when coadministered with NSAID or antipyrine, propranolol or diazepam.

The pharmacokinetics of misoprostol were examined in the following contexts: in coadministration with the nonsteroidal antiinflammatory agents (NSAID) aspirin, diclofenac, ibuprofen, indomethacin and piroxicam; in coadministration with agents extensively metabolized by the liver--i.e., antipyrine, propranolol and diazepam; in healthy elderly subjects; and in patients with various degrees of renal failure. No clinically important interactions between misoprostol and NSAID were observed. Similarly, no metabolic interactions between misoprostol and antipyrine, propranolol or diazepam were noted. Pharmacokinetic variable values in elderly subjects did not differ in a clinically significant manner from those in younger subjects. Finally, although values for some pharmacokinetic variables--maximum concentration of misoprostol acid, area under the concentration-time curve and elimination half-life--were increased in patients with renal failure compared with controls, these alterations do not warrant changes in misoprostol dosage. These factors are particularly relevant to safety of misoprostol administration in elderly individuals, who not only consume more NSAID than young adults, but are also more likely to have intercurrent nonarthritic illness requiring additional medication and potentially modifying drug kinetics.

Adult↗
PubMed1990

[Broncholithiasis in a case of silicotuberculosis].

Broncholithiasis is usually a late complication of tuberculous lymphadenopathy. Clinical symptoms are not suggestive of the condition in most cases, except for lithoptysis which occurs in 5 to 34% of the patients. Owing to the currently low frequency of tuberculosis, broncholithiasis is a rare and sometimes surprising diagnosis, as in the case reported here. In this 65-year old silicotic man, broncholithiasis was manifested by blood-stained expectoration. Fibroscopy established the diagnosis by showing 2 broncholiths, about 1 cm wide, which were endoscopically extracted. The second peculiarity of this case is that broncholithiasis was associated with active tuberculosis.

Aged↗
PubMed1989

Activation of protein kinase C in platelets by epinephrine and A23187: correlation with fibrinogen binding.

Activation of protein kinase C (PKC), as revealed by phosphorylation of a 47 kd protein (p47), occurs in platelets stimulated by some agonists (eg, thrombin or phorbol esters). It is not known if activation of PKC occurs with pairs of agonists, such as epinephrine and A23187, that do not individually phosphorylate p47, nor is it known what role the concentration of cytoplasmic Ca++ ([Ca++]i) plays in these events. We stimulated aequorin-loaded platelets with subaggregating concentrations of epinephrine and A23187, neither of which by itself phosphorylated p47. The combination of agonists resulted in p47 phosphorylation, an increase in platelet-bound fibrinogen, and aggregation, but only if the concentration of each agonist was sufficient to increase [Ca++]i if it was added separately. Subaggregating concentrations of A23187 alone released platelet fibrinogen and increased platelet membrane binding of [3H]-phorbol dibutyrate, but these were not enhanced by epinephrine. Epinephrine and A23187 did not increase production of diacylglycerol. Thus, epinephrine and A23187 together activate PKC by a mechanism that does not require phospholipase C or enhanced binding of PKC to the plasma membrane; PKC activation in turn is correlated with enhanced platelet fibrinogen binding and aggregation. These events require an initial elevation of [Ca++]i above a threshold.

Blood Platelets↗
PubMed1989

Identification by ENDOR of Trp191 as the free-radical site in cytochrome c peroxidase compound ES.

The chemical identity of the amino acid free-radical site that represents one of the two oxidizing equivalents stored in the H2O2-oxidized intermediate (compound ES) of the mitochondrial heme enzyme, cytochrome c peroxidase (CcP) has been sought for almost a quarter of a century. Site-directed mutagenesis alone cannot yield this answer. Low-temperature 35-gigahertz (Q-band) electron nuclear double resonance (ENDOR) spectroscopy was used to examine compound ES prepared from proteins containing specifically deuterated methionine or tryptophan, as well as the amino acid replacement Trp51----Phe. The results definitely identify the site of the radical in compound ES as tryptophan, most likely Trp191.

Binding Sites↗
PubMed1989

A method for introducing random single point deletions in specific DNA target sequences using oligonucleotides.

We describe a method for the generation of random point deletions in any target DNA sequence using synthetic mixed oligonucleotides. A mixed pool of oligonucleotides, which contain single nucleotide deletions randomly distributed throughout the full length, was generated by a modification of the synthesis cycle of an automated DNA synthesiser that allowed the inefficient incorporation of nucleotide monomers during each cycle of synthesis. A family of oligonucleotides was used to prime in vitro synthesis of the complementary strand of a cloned DNA fragment in an M13 vector which had previously been passaged through a dut-, ung- Escherichia coli host. Strong selection for progeny from the newly synthesised strand is provided by transforming the heteroduplex into a dut+, ung+ host. This procedure introduced point deletions at 10-25% efficiency. It has been used to introduce point deletions into operator sequences which bind the yeast regulatory proteins encoded by MATa1 and MAT alpha 2.

Base Sequence↗