Short-term memory factors in oral retention

Study or exploration time and retention interval duration between orignal-form exploration and test-form exploration were varied to assess the effect of these two variables on performance accuracy on an oral stereognostic memory task. Irregularly shaped, four-sided plastic forms were used as stimuli. Retention performance improved significantly with an increase in exploration time of up to 15 seconds, but was not effected by delays in testing of up to 60 seconds. Clinical and theoretical implication for oral stereognosis are discussed.     

DNA "melting" proteins. IV. Fluorescence measurements of binding parameters for bacteriophage T4 gene 32-protein to mono-, oligo-, and polynucleotides

The quenching of the intrinsic tryptophan fluorescence of T4-coded gene 32-protein on binding to nucleotide ligands, which was described in the preceding paper, is here exploited to measure thermodynamic parameters of the single-stranded nucleic acid-gene 32-protein interaction. It is shown that binding of small ligands follows a single site binding isotherm, with association constants increasing from approximately 20 M-1 for phosphate, to approximately 10(3) M for ribose or deoxyribose 5'-phosphate, to approximately 10(4) M-1 for mononucleotides, and to approximately 10(5) M-1 for dinucleoside monophosphates (all in 0.1 M Na+). The measured binding constants appear to be about the same for homologous ribose- and deoxyribose-containing ligands and to be independent of oligonucleotide base sequence and composition. Furthermore, beyond the dinucleotide level and up to octanucleotides, the increase in binding constant with increasing chain length is only about that expected from the statistical factor resulting from the increased number of ways a longer oligonucleotide can form a protein complex. This suggests that the basic binding unit involved in gene 32-protein associations with single-stranded nucleic acids can be approximated by a dinucleoside monophosphate. Oligonucleotides long enough to accomodate two or more protein monomers are characterized by much larger association constants, indicating that binding is cooperative in protein concentration. A cooperativity parameter (omegac) of approximately 10(3) is estimated from these data, in good agreement with that deduced from the application of ligand-perturbed helix in equilibrium coil transition calculations. Values of association constants (Kcomegac) of approximately 10(8) M-1 (in 0.1 M Na+) and site size (nc) of approximately 5 (+/-1) nucleotide residues/protein monomer are determined by the fluorescence titration technique for the cooperative binding of gene 32-protein to both poly(dA) and poly(rA); these values are also in agreement with those measured by Jensen et al. (Jensen, D.E. Kelly, R.C., and von Hippel, P.H. (1976) J. Biol. Chem. 251, 7215-7228). Possible in vivo consequences and correlations of these findings with proposed roles for gene 32-protein in replication and recombination are discussed.     

Trilinolein Identified as A Sex-Specific Component of Tergal Glands in Alates of Coptotermes formosanus

Hexane extracts of the tergal glands from female alates of the Formosan subterranean termite Coptotermes formosanus were analyzed by high performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry with collision-induced dissociation. Double bond configuration was determined by chemical modifications with gas chromatography-mass spectrometry. A single component, identified as the triacylglycerol, trilinolein, was unique to the female tergal glands. This compound was not found in other areas of the female alate abdomen or in the corresponding area of male alates. Neither gland extract nor trilinolein caused a behavioral response from male alates. However, significant differences were found between males and females for responses from neurons within sensilla of the maxillary palps.     

A quality improvement approach to reducing use of meperidine

BACKGROUND: In 1991 the University of Wisconsin Hospital and Clinics formed a pain management QI team whose goal was to improve pain management through education, outcome monitoring, and the development of programs intended to improve clinical practice. Longitudinal monitoring mechanisms were established to audit medical records and survey patients to examine both staff practice patterns and patient outcomes. The QI team targeted use of meperidine, one of the most widely used opioid analgesics for the treatment of moderate to severe pain, which is now discouraged as a first-line agent for most painful conditions. IMPLEMENTING THE QI PROCESS: A QI process was implemented using a traditional plan-do-check-act (PDCA) model, resulting in a successful and sustained reduction of inappropriate meperidine use. A cause-and-effect diagram helped highlight the multiple factors contributing to the drug's overuse and was used to prioritize targets for action. A flow chart helped to uncover some of the interrelationships between the myths about meperidine and the resultant customary prescribing and administration practices. While most of the strategies were implemented in 1996 (formulary guideline release, change in stock supply and physician orders, staff education and feedback), a significant impact in practice was not seen until late 1997. Ongoing tracking and feedback loops were established to ensure continued low use of meperidine. CONCLUSION: Use of a QI approach in pain management has been shown to affect the visibility of pain as a clinical priority, enhance interdisciplinary collaboration, facilitate the implementation of clinical guidelines at the bedside, and improve the quality of care for patients.     

Inhibition of nitric oxide metabolism enhances the hypnotic-anesthetic action of the alpha2-adrenoceptor agonist dexmedetomidine in vivo

Treatment of endometriosis with gonadotropin-releasing hormone agonists (GnRHa) is limited to 6 months because of possible adverse effects on bone metabolism. We designed a randomized, double-blind, placebo-controlled, prospective study of 27 patients with endometriosis who were given GnRHa with or without hormone add-back therapy (+ 20 microg of ethinyl estradiol with 0.15 mg desogestrel) designed to suppress the adverse effects of hypoestrogenism while preserving the efficacy of GnRHa. Both regimens showed significant improvements in endometriosis, dysmenorrhea, and pelvic pain; effects were significantly better in the GnRHa + placebo group. The GnRHa + placebo group had significantly higher serum calcium levels and a significantly higher loss of lumbar spine bone mineral density (BMD). Urinary levels of pyridinium crosslinks increased significantly in the GnRHa + placebo group, and declined to normal in the GnRHa + add-back group. The add-back therapy protects women taking GnRHas from severe loss of BMD and accelerated bone collagen resorption, but reduces the efficacy of the GnRHa.     

Germline structure and differential utilization of Igha and Ighb VH10 genes

Ab heavy chains encoded by mouse VH10 genes have been of particular interest due to their frequent association with DNA binding. We reported previously that VH10 sequences are over-represented in the preimmune repertoire considering the apparent number of germline-encoded VH10 gene segments. In this report, we show that the VH10 family consists of three and two germline genes in the Igha and Ighb haplotypes, respectively. The complete nucleotide sequences of these five genes, including promoters and recombination signal sequences, were determined and allow unambiguous assignment of allelic relationships. The usage of individual VH10 genes varied significantly and ranged from 0.2% to an extraordinary 7.2% of the VH genes expressed by splenic B cells. Since the promoter and recombination signal sequence elements of all five VH10 genes are identical, we suggest that the few amino acid differences encoded by these five germline VH10 genes determine their representation in the preimmune repertoire. Rearrangements of the most frequently used VH10 gene have an apparent bias for histidine at position 95 of complementarity-determining region-3 (CDR3). These CDR3s are also biased for asparagine, an amino acid associated with the CDRs of DNA binding Abs. Together, these results suggest that high VH10 gene use is the result of B cell receptor-mediated selection and may involve DNA and/or ligands that share antigenic features with DNA.     

Unusual form of recurrent giant cell granuloma of the mandible and lower extremities in a patient with neurofibromatosis type 1

The high resolution of capillary zone electrophoresis/mass spectrometry (CZE/MS) offers a promising technique to characterize biomolecules in pharmaceutical and biotechnology industries. A novel capillary zone electrophoresis/electrospray ionization time-of-flight mass spectrometry (CZE/ESI-TOFMS) interface was designed in this study to successfully integrate ESI-TOFMS, nanospray, and CZE for biomolecular identification. The interface offers a novel way to take advantage of the high resolution separation achieved during CZE and the detection sensitivity of nanospray ESI-MS. The results showed mixtures of peptides were highly resolved within a few minutes (each CZE electropherogram of a peptide is 2-3 seconds). The novel CZE/ESI-TOFMS interface may simultaneously provide sensitivity, data acquisition speed, mass range, and mass resolution while maintaining resolution of the CZE separation.