3-(2-Methoxyphenyl)-1H-2-benzopyran-1-one

C16H12O3, Mr = 252.3, orthorhombic, Pna21, a = 6.633 (3), b = 13.367 (2), c = 14.056 (2) A, V = 1246.3 (9) A3, Z = 4, Dx = 1.344 g cm-3, lambda (Cu K alpha) = 1.54184 A, mu = 7.17 cm-1, F(000) = 528, T = 296 K, R = 0.027 for 2337 observations (of 2508 unique date). The average deviation from planarity is 0.013 (1) A with a maximum of 0.028 (1) A for the fused-rings system, and 0.003 (1) A with a maximum of 0.005 (1) A for the methoxyphenyl ring. The dihedral angle between the two systems is 4.7 (3) degrees. The methoxyphenyl ring is pushed away from the vinyl proton and towards the endocyclic O atom; the bond angles are 130.13 (9) and 110.13 (8) degrees, respectively.

Cloning and recombinant expression of phospholipase A2 present in rheumatoid arthritic synovial fluid

Synovial fluid from arthritic patients contains multiple forms of phospholipase A2 (PLA2), as resolved by high performance liquid chromatography (Seilhamer, J.J., Plant, S., Pruzanski, W., Schilling, J., Stefanski, E., Vadas, P., and Johnson, L. K. (1989) J. Biochem. (Tokyo), submitted for publication). Here we describe the cloning of a human 4.5-kilobase gene and 800-base pair cDNA encoding the form representing the major peak of activity and protein mass (peak A). The clones encode a mature peptide of 124 amino acids, which follows a prepeptide of 20 residues. The deduced amino acid sequence constitutes an enzyme of the "Type II" class of PLA2s, and resembles PLA2s from other mammalian sources. This represents the first report of a full length mammalian non-pancreatic PLA2 sequence. Active transcription of this PLA2 gene was detected in two different inflammatory cell sources. Recombinant human peak A PLA2 was expressed in vaccinia as a secreted protein which accumulated in conditioned medium.

Choice (CRT) and simple reaction times (SRT) compared in laboratory technicians: factors influencing reaction times and a predictive model

Choice reaction time (CRT) and simple reaction time (SRT) tests were administered to 151 female histology laboratory technicians to determine if occupational exposure to organic solvents and formaldehyde delayed either or both. The relationships between CRT and SRT latencies were evaluated using different testers, sequences of administration, and microcomputers. Formaldehyde exposure, cigarette smoking history, ethnicity, and alveolar CO levels did not significantly influence CRT and SRT. However, slightly different protocols did significantly affect SRT. A linear model demonstrated that logSRT (LSRT) and LogCRT (LCRT) were longer with increasing age, promising further clinical applications. It is concluded that both CRT and SRT measure some overlapping and some different neurologic pathways. Reaction times in large "normal" populations are needed to compare with groups exposed to potential neurotoxins.

Liquid chromatographic determination of ivermectin in bovine serum

A rapid, sensitive method is described for the determination of ivermectin concentrations in bovine serum. Ivermectin is extracted by passing a sample through a reverse-phase C18 cartridge. A silica-packed cartridge is used to purify the extract further. Ivermectin is quantitated by liquid chromatography with detection at 245 nm. Recoveries were 95 +/- 4% for samples fortified with 20 ppb ivermectin. Concentrations as low as 2 ppb can be detected in 5 g samples.

The 1985 national immunisation survey: hepatitis A

In April 1985 a national immunisation survey was carried out, during which sera were collected from approximately 3000 randomly selected children throughout New Zealand. The sample comprised approximately equal numbers of new school entrants (mean age 5 years), standard 3 pupils (mean age 10 years) and form 4 students (mean age 15 years). This collection of sera was tested for antibody to hepatitis A virus, a marker of past infection with this virus, by means of a sensitive ELISA test. Prevalence of infection was found to be less than 1% in the 5 year olds, about 3% in the 10 year olds, and about 9% in the 15 year olds. Amongst the 10 and 15 year olds, but not the 5 year olds, Maori children were approximately three times more likely to have been infected than European children. Children resident in the eastern part of the North Island had a higher risk of infection than other children, even after controlling for ethnic distribution.

Comparison between the effects of aging on antagonist and agonist interactions with beta-adrenergic receptors on human mononuclear and polymorphonuclear leukocyte membranes

Age-related differences in the binding properties of beta-adrenergic receptors on lymphocyte membranes isolated from healthy individuals have been reported. The purpose of the present studies was to determine whether or not beta receptors on polymorphonuclear leukocyte (PMN) membranes showed similar age-related changes. Plasma Percoll gradients were used to isolate PMN and mononuclear leukocyte (MN) cells from blood drawn in the supine position from young (25-34 years) and elderly (60-76 years) healthy volunteers. Both blood pressures and plasma norepinephrine levels were significantly elevated in the elderly subjects. Saturation analysis with [125I]-(-) iodopindolol (IPIN) showed a 2.5-fold higher density of beta 2 receptors on the MN, but not PMN, membranes from the elderly. Neither the affinities of the receptor for IPIN or the agonist isoproterenol, nor the GTP-induced shift in agonist affinity, differed with subject age in either cell type. These results suggest that subpopulations of MN cells on which beta-adrenergic receptors are localized may increase in the elderly and that it is important to measure receptor properties on a more homogeneous leukocyte population such as PMN cells or subpopulations of MN cells as a function of aging.

The potential role of serotonin reuptake inhibitors in the treatment of obsessive compulsive disorder

The authors examine the role of the serotonergic system in the modulation or genesis of obsessive compulsive disorder and the potential for the use of the new serotonin (5-HT) reuptake inhibitors in its treatment. The data available are still preliminary, but are accumulating rapidly, and appear to hold promise in helping to understand this disorder and treat it more effectively. An overview of the data available is presented to assist in the planning of future research in this subject area. At least six major questions need to be addressed by future work: (1) What are the major hypotheses regarding the involvement of the serotonin system in the modulation or genesis of OCD? (2) Is there a serotonin system defect associated with OCD? (3) Is a serotonin system defect the underlying cause of OCD? (4) Are serotonin reuptake inhibitors effective in the treatment of OCD? (5) Are the effects of the serotonin reuptake inhibitors that are effective in treating OCD mediated via the serotonin system or via another mechanism? and (6) Are these drugs worth pursuing as treatment of OCD?

Panic disorder: the potential role of serotonin reuptake inhibitors

The authors review the role of the serotonergic system in panic disorder and the potential for use of the new serotonin (5-HT) reuptake inhibitors in treating panic disorder. Data currently available are only preliminary but suggest a future potential for this class of drug in the treatment of panic/anxiety disorders. The authors present a succinct and comprehensive overview of the data available, which aims to assist in the planning of future research in this area.

The essential role of microsomal deacetylase activity in the metabolic activation, DNA-(deoxyguanosin-8-yl)-2-aminofluorene adduct formation and initiation of liver tumors by N-hydroxy-2-acetylaminofluorene in the livers of infant male B6C3F1 mice

Deacetylation of N-hydroxy-2-acetylaminofluorene (N-hydroxy-AAF) to N-hydroxy-2-aminofluorene (N-hydroxy-AF) has been proposed as one of the critical metabolic steps in the formation of hepatic DNA adducts and the initiation of liver tumors in 12-day-old male B6C3F1 mice. In this study, the importance of the microsomal deacetylase activity for N-hydroxy-AAF in the initiation of hepatocarcinogenesis in these mice was demonstrated by using a carboxylesterase and amidase inhibitor, bis(p-nitrophenyl)phosphate (BNPP), that is much less toxic in vivo than is paraoxon. Pre-incubation of liver microsomes from 12-day-old male B6C3F1 mice with 10(-3) M BNPP reduced the deacetylase activity by 80% while paraoxon inhibited the deacetylase activity completely at a concentration of 10(-4) M. Pretreatment of 12-day-old male B6C3F1 mice with 4 X 75 micrograms doses of BNPP/g body weight before the administration of N-hydroxy-AAF reduced the hepatic N-(dGuo-8-yl)-AF adduct levels to 1.09 and 0.68 pmol/mg DNA compared with 2.87 and 1.64 pmol/mg DNA for mice treated once with 0.06 or 0.03 mumol of N-hydroxy-AAF/g body weight respectively. However, BNPP pretreatments did not affect the levels of the acetylated DNA adducts, N-(dGuo-8-yl)-AAF and 3-(dGuo-N2-yl)-AAF, formed by these doses of N-hydroxy-AAF. The initiation of liver tumors by N-hydroxy-AAF was also inhibited by BNPP pretreatment. Thus, for mice that received single doses of 0.12, 0.06 and 0.03 mumol of N-hydroxy-AAF/g body weight, the multiplicities of liver tumors at 10 months were reduced by BNPP pretreatments to 5.6, 1.0 and 0.3 compared with multiplicities of 11.8, 4.8 and 1.7 without pretreatment respectively. On the other hand, BNPP pretreatments had no significant inhibitory effects on the levels of the hepatic DNA-N-(dGuo-8-yl)-AF adduct or on the liver tumor multiplicities induced by comparable doses of N-hydroxy-AF. It is concluded that deacetylation of N-hydroxy-AAF to N-hydroxy-AF is essential for the metabolic activation, DNA-N-(dGuo-8-yl)-AF adduct formation and liver tumor initiation in infant male B6C3F1 mice by N-hydroxy-AAF.

Dental service use by older people living in long-term care facilities

Since 1980, a mobile program has delivered dental care to 14 different long-term care facilities that care for frail and functionally dependent older persons. These facilities lie within a 60-mile radius of the University of Iowa College of Dentistry. This paper reports comparisons between characteristics of users versus nonusers of dental care in the program. Of the 853 residents in the long-term care facility who were screened, it was determined that 66% would benefit from some type of dental care. When the residents and their families were approached for treatment permission, 48% of those recommended permitted treatment; treatment was completed on 38% of those persons recommended for treatment. No differences were observed in the distribution or diagnoses of major medical problems for the users versus nonusers of care. Recommended treatment was similar for users and nonusers in nursing homes. The majority of nonusers refused treatment because they or their families did not perceive a need for dental care.

Quantitative autoradiographic analysis of 125I-pindolol binding in Fischer 344 rat brain: changes in beta-adrenergic receptor density with aging

Age-related changes in beta-adrenergic receptor density in Fischer 344 rat brain were examined using in vitro 125I-pindolol (IPIN) binding and quantitative autoradiographic analysis. Localized protein concentrations were determined using a new quantitative histological technique, and these were used to normalize the densities of receptors. Saturation binding studies in brain sections revealed 40-50% decreases in beta-adrenergic receptor density in the thalamus of 23-25-month-old and the cerebellum and brainstem of both 18-19-month-old and 23-25-month-old compared to 4-6-month-old rats. The loss of cerebellar beta-adrenergic receptors may be correlated with reports of deficits in sensitivity to beta-adrenergic-mediated transmission in the cerebellum of aged rats. No changes in specific IPIN binding with age were observed in rat cortex or hippocampus. In all areas examined no age-related differences were observed in receptor affinity. No changes in protein concentration were found in any of the areas examined in the different aged animals. These results demonstrate a region-specific loss of beta-adrenergic receptors with age in the brain of Fischer 344 rats.

The mechanical role of the trunk and lower extremities in a seated weight-moving task in the sagittal plane

A two-dimensional, sagittally-symmetric biomechanical model was developed to analyze the joint moments required to stabilize the trunk in a seated, dynamic, weight-moving task. Kinematic and reaction force data were measured while subjects moved a hand-held weight (0-4 kgf) at shoulder level to and fro at 1 Hz. These data were then used for model input and validation purposes. A second, simpler model was used to simulate how joint loads varied with weight held, trunk inclination, and movement frequency. The results for this seated task demonstrate a) significant trunk, hip, knee, and ankle joint moments (37, 13, 4, 13 percent of maximum strength values, respectively) were required, b) considerable intersubject differences in mean joint moments (more than 66 percent) were found, which primarily were due to subtle differences in body segment kinematics and lower extremities use, and c) the important role of the lower extremities in stabilizing the trunk in the seated posture.

A new densitometric procedure to measure protein levels in tissue slices used in quantitative autoradiography

A new quantitative staining technique for the assay of protein in tissue sections using the dye Coomassie brilliant blue G 250 is discussed. This densitometric procedure uses commercially available hardware and software employed in the quantitation of receptor autoradiographs. Rather than assuming a homogeneous distribution of protein in the tissue section, regional levels of protein are measured in the same tissue slice used to produce the autoradiograph. Additionally, the process of staining tissue with Coomassie blue for protein is reversible; the tissue can be destained after the measurement of protein is complete and then restained with a standard histological stain such as Cresyl violet. This technique is a more reliable method for normalizing receptor densities by tissue protein levels and allows for a more accurate comparison between QAR and membrane binding techniques.

Age-related reduction in responses of rat hippocampal neurons to locally applied monoamines

Age-related changes in the responsiveness of hippocampal pyramidal neurons to norepinephrine (NE) and serotonin (5HT) were investigated using electrophysiological techniques. Local application of each monamine via pressure micro-ejection was employed to establish the dose which elicited a 50% change in spontaneous discharge rate of single pyramidal neurons; these data were used to construct dose response curves for the population of neurons tested in 3-6, 11-13, 18-20, and 27-30 month old rats. The percentage of cells responding in rats 18-20 and 27-30 months old decreased for both NE and 5HT. There was also a progressive increase with age in the population ED50 for 5HT starting at 18-20 months. For neurons which demonstrated a response to NE, no decrease in the population ED50 was observed. Taken together these data indicate that there is a progressive age-related decline in the postsynaptic response to NE and 5HT in the rodent hippocampus.

Lumbar disc degeneration: correlation with age, sex, and spine level in 600 autopsy specimens

Using data from 16 published reports, the authors correlated macroscopic disc degeneration grades with age, sex, and spine level in 600 lumbar intervertebral discs from 273 cadavers (ages: 0-96 years). Male discs were more degenerated than female discs at most ages; significantly so in the second, fifth, sixth, and seventh decades. On average, L4-L5 and L3-L4 level discs showed more degeneration than discs at other lumbar levels. These macroscopic findings corroborate radiographic data from epidemiologic studies. The calculations suggest that higher mechanical stress, perhaps combined with longer nutritional pathways, may be responsible for the earlier degeneration of male discs.

Detection of activated proto-oncogenes in N-nitrosodiethylamine-induced liver tumors: a comparison between B6C3F1 mice and Fischer 344 rats

DNA from B6C3F1 mouse and Fischer 344 rat liver tumors induced by N-nitrosodiethylamine (DEN) were examined for the ability to induce morphological transformation of NIH3T3 cells. DNAs from 14 of 33 of the mouse liver tumors induced by a single injection of DEN at 12 or 15 days of age were positive in this assay while DNA from only one of 28 DEN-induced rat liver tumors was active. Southern blot analysis of the NIH3T3 transformants derived from the mouse liver tumors revealed amplified and/or rearranged restriction fragments homologous to the H-ras proto-oncogene. DNA from two independent foci induced by the rat tumor DNA did not hybridize to probes for members of the ras gene family or c-raf. Activating mutations in the H-ras genes from the DEN-induced mouse liver tumors were characterized by selective oligonucleotide hybridization and the detection of a new XbaI restriction site by Southern blot analysis. In activated H-ras genes from the DEN-induced mouse liver tumor DNA, seven of 14 had a CG----AT transversion at the first base of the 61st codon, three of 14 had an AT----GC transition and four of 14 had the AT----TA transversion at the second base of codon 61. This spectrum of mutations is very similar to that recently observed in activated H-ras genes found in spontaneously occurring B6C3F1 mouse liver tumors. Taken together, the data suggest that the DEN-induced rat and mouse liver carcinogenesis may involve genetic targets other than or in addition to the H-ras gene.