Errors and alternatives in reading the universal genetic code.
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Acylation↗
Biomedical subjects
J Parker
Publications and source records attributed to J Parker.
Psychological-mindedness and the alexithymia construct.
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Affective Symptoms↗
Cooperation of adipocytes and endothelial cells required for catecholamine stimulation of PGI2 production by rat adipose tissue.
Disturbances of prostaglandin I2 (PGI2, prostacyclin) production by adipose tissue contribute to the pathogenesis of diabetic ketoacidosis and may contribute to the pathogenesis of hypertension and vascular disease. We studied the cellular basis of PGI2 production in adipose tissue, measured as release of 6-keto-PGF1 alpha in response to epinephrine. Adipocytes did not produce PGI2 when nonfat cells were removed by repeated washing. The nonadipocyte cellular constituents of adipose tissue (nonfat cells) did not produce PGI2 in the absence of adipocytes. Both adipocytes and nonfat cells were required for PGI2 production in response to epinephrine. Adipocytes pretreated with 0.2 mM aspirin to inhibit PGH synthase nevertheless promoted PGI2 production when mixed with nonfat cells. Nonfat cells preincubated with aspirin did not produce PGI2 when mixed with adipocytes. The nonfat cells converted arachidonic acid to PGI2 but adipocytes did not. Epinephrine stimulated lipolysis and PGI2 production in a dose-dependent parallel manner, but the responses were distinct above 10(-6) M. Characterization of the nonfat cells by fractionation on a Percoll density gradient followed by measurement of angiotensin-converting enzyme activity and 6-keto-PGF1 alpha production indicated that the nonfat cells were predominantly vascular endothelial cells. We conclude that catecholamine-stimulated PGI2 production in adipose tissue results from the cooperation of adipocytes and vascular endothelial cells. The adipocytes provide arachidonic acid, which is converted to PGI2 by the vascular endothelial cells. Because adipose tissue is located near blood vessels throughout the body, adipocytes may be an important source of arachidonic acid for vascular endothelial cells in various circumstances in health and disease. Our findings raise the possibility that adipocytes may, under some circumstances, release arachidonic acid into the systemic circulation where it is used by vascular endothelial cells throughout the body to produce PGI2 and other eicosanoids.
6-Ketoprostaglandin F1 alpha↗
The latent factor structure of the WAIS-R: a factor analysis of individual item responses.
Factor analytic examination of a 166 x 166 intercorrelational matrix that represents individual item scores from the 11 subtests of the WAIS-R provided evidence of five interpretable factors (N = 409). Two of these were identified as the Verbal and Performance factors previously encountered in traditional WAIS-R subtest-based factor analyses. The other three factors were characterized readily as involving (1) Advanced Vocabulary skills; (2) Basic Responsivity and (3) Advanced Computational ability. All three of these "new" factors accounted for at least 10% of the total variance, and comments are made with regard to the possible significance of their discovery to such topics as subtest variation and profile psychodiagnostics, theories that pertain to the nature and structure of human intellectual functioning, and subtest-based personality measurement theories.
Adult↗
Maternal weight gain and preterm delivery.
This study examined the relationship between maternal weight gain and preterm delivery in 2163 women who participated in the Prenatal Nutrition Project at the University of California, San Diego between 1978-1986. Multivariate analysis of the data indicated that the risk of spontaneous preterm birth increased 60% in women with a low rate of weight gain (less than 0.27 kg/week) compared with those with an average rate (0.27-0.52 kg/week). Women with a low rate of gain were more than twice as likely to experience a preterm delivery as those with a high gain (higher than 0.52 kg/week); the odds ratio was 2.54 and 95% confidence interval was 1.49, 4.88. This difference in weight gain appeared after 20 weeks' gestation.
Adult↗
Transient absorption by a Rydberg atom in a resonant cavity.
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Journal Article↗
Cerastes cerastes (Egyptian sand viper) venom induced platelet aggregation as compared to other agonists.
The Egyptian Sand Viper (Cerastes cerastes) crude venom and subfractions were, for the first time, shown to induce platelet aggregation with agonist activities present in two subfractions. The combined activities of the crude venom components behaved in a unique fashion as compared to the platelet agonists, ADP, collagen and thrombin. The action of the venom was inhibited by conditions that increased cAMP, partially required the formation of thromboxane A2 and was inhibited by the serine protease inhibitor PMSF while being only partially sensitive to leupeptin or soybean trypsin inhibitor. One of the fractionated venom agonists strongly induced serotonin release while the other venom agonist essentially did not. Further characterization of the Cerastes cerastes venom components should broaden our knowledge of the pathology of snake venoms, platelet aggregation and their potential therapeutic value.
Adenosine Diphosphate↗
Loss of low-affinity serotonin receptors upon storage of human platelets.
Platelets actively accumulate virtually all plasma serotonin within their dense granules. As a readily isolated, homogeneous cell type, platelets have served as a model for serotonin uptake into neurological tissue, in addition to defining the role of serotonin in hemostasis. The number of serotonin receptor types on the platelet membrane and the function of these receptors has not been conclusively demonstrated. The presence of different receptor types that may be altered or lost in disease or upon aging (in vitro storage or in vivo) could have significant physiological effects on platelet function. This report demonstrates that at least two receptor types are present on freshly prepared human platelets. However, after 3 to 4 days of storage in autologous plasma, the low-affinity, high-capacity serotonin receptor appears to be lost. This phenomenon probably accounts for some of the discrepancies reported in the literature. The high-affinity receptor present in both freshly isolated and stored platelets binds about 9 x 10(3) serotonin molecules per platelet. Binding can be completely blocked by imipramine; however, some passive diffusion appears to occur even at the low level of extracellular serotonin concentrations employed in these studies (nanomolar range). The influx of serotonin into platelets appears to be poorly reversible, even in reserpine-treated cells, where the extravesicular cytoplasmic concentration would be high. The loss of the low-affinity serotonin receptor type reported in these studies may be directly or indirectly associated with the reduced responsiveness observed in stored platelets.
Biological Transport↗
Monoclonal antibodies directed to the blood group A associated structure, galactosyl-A: specificity and relation to the Thomsen-Friedenreich antigen.
Two monoclonal antibodies, HH8 and HH9, have been established after immunization of mice with galactosyl-A glycolipid antigen having the terminal structure, Gal beta 1----3GalNAc alpha 1----3[Fuc alpha 1----2]Gal beta 1----R, which is the precursor for type 3 chain A (repetitive A) and type 3 chain H (A-associated H). Both antibodies react strongly and specifically with galactosyl-A, but HH8 (IgM) showed strong hemagglutination of blood group A1, A2, O and B erythrocytes after sialidase treatment, while HH9 (IgG1) did not react with human erythrocytes even after sialidase treatment. HH8 and anti-T antibody, but not HH9, reacted with glycophorin A after sialidase treatment. The reactivity of HH8 with glycophorin A was abolished by beta-galactosidase and was inhibited by liposomes containing galactosyl-A, but not other glycolipids. In addition, anti-T antibody and peanut lectin reacted specifically with galactosyl-A glycolipids. These findings indicate that HH8 recognizes the terminal disaccharide Gal beta 1----3GalNAc alpha 1----R, which is the same sequence as the classically known Thomsen-Friedenreich antigen (T-antigen), whereas HH9 does not cross-react with T-antigen but recognizes the entire galactosyl-A structure. The T-antigen was also demonstrated by immunohistology with HH8 after neuraminidase treatment in a subset of cells in stratified epithelium.
ABO Blood-Group System↗
Continuous low-flow supracarinal and subcarinal oxygen insufflation in addition to intermittent positive-pressure ventilation does not improve gas exchange.
Recent studies in animals have demonstrated that continuous insufflation of oxygen near the tracheal carina results in ventilation and carbon dioxide removal that is proportional to the flow rate. The purpose of this study was to determine whether the addition of supracarinal and subcarinal low-flow oxygen insufflation to conventional intermittent positive-pressure ventilation (IPPV) of critically ill and anesthetized patients results in increased ventilation and improved oxygenation. In eight studies a supracarinal catheter (3.7 mm OD) was placed 1 to 2 cm above the carina, and in another eight studies two subcarinal catheters (1.7 mm OD) were placed 2 cm below the tracheal carina under direct vision with a fiberoptic bronchoscope. Both supracarinal and subcarinal catheters were passed within the lumen of an 8 mm ID endotracheal tube. In both groups, conventional IPPV consisted of a tidal volume of 10-12 mL/kg, respiratory rate of 8 to 10 breaths/min, 0 cm H2O positive end-expiratory pressure (PEEP), and F1O2 of 1.0. In both groups, continuous oxygen insufflation flow rates were 0.05, 0.10, and 0.20 L/ kg/min. It was found that compared with control conditions (no insufflation), oxygen insufflation at all flow rates in both supracarinal and subcarinal insufflation groups did not cause any significant change in either oxygenation or ventilation. There was a significant increase in proximal peak airway pressure with each incremental increase in continuous oxygen flow rate. Conversely, there was a significant decrease in mean arterial pressure and cardiac output with each incremental increase in continuous oxygen flow rate. It is concluded that use of continuous low-flow insufflation of oxygen with simple administration systems (catheters within the lumen of endotracheal tube) in addition to conventional IPPV is contraindicated at the present time. Further studies using different insufflation systems may prove to be worthwhile.
Adult↗
Measurement of malarial infectivity of human populations to mosquitoes in the Madang area, Papua, New Guinea.
The proportion of blood meals taken on humans which are infectious to mosquitoes in the Madang area, Papua New Guinea was estimated by two methods. In the first, laboratory reared Anopheles farauti were fed on individuals of all ages at village surveys. The results showed that 3.8% of people were infectious and that the mean percentage of mosquitoes which became infected by feeding on these people was 37.9%. From the average proportion of mosquitoes infected, the probability that a mosquito feeding on a human would pick up infection was 0.013 +/- 0.005. In the second approach mosquitoes were fed on identified Plasmodium falciparum, P. vivax and P. malariae gametocyte carriers. The results indicated that 46% of gametocyte carriers were infectious and that the mean probability of a mosquito becoming infected after feeding on a gametocyte carrier was 0.151 +/- 0.029. Gametocyte prevalence rates in all ages measured over 18 months in three villages averaged 3.3% P. falciparum, 4.0% P. vivax and 0.7% P. malariae, totalling 8.0 +/- 0.7%. Combining gametocyte prevalence rates with the probability of a mosquito becoming infected from a gametocyte carrier, the probability of a mosquito becoming infected following a blood meal on a member of the human population was estimated to be 0.012 +/- 0.003.
Age Factors↗
Bipolar patients taking lithium have increased dark adaptation threshold compared with controls.
Recent epidemiological studies of mania suggest that admissions correlate with length of day and sunlight. As well, seasonal affective disorder--a depression occurring in winter, is reported to respond to light therapy and it has been proposed that supersensitivity to light is a trait-marker of manic-depressive illness. Dark adaptation threshold (D.A.T.)--a measure of night vision--was assessed in 19 euthymic manic-depressive patients stabilized on lithium, and in 19 drug-free healthy controls. The D.A.T. was significantly raised in the patients taking lithium. It is concluded that lithium induces subsensitivity to light.
Adult↗
Stimulation of arachidonic acid release and prostaglandin synthesis by bryostatin 1.
The mechanism of tumor promotion may involve stimulation of prostaglandin production. Previous studies with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) have identified two effects of TPA on prostaglandin production. TPA stimulates both arachidonic acid release and de novo synthesis of prostaglandin H synthase. Activation of protein kinase C by TPA appears to be part of the mechanism to cause arachidonic acid release. However, it is unclear if induction of prostaglandin H synthase also involves activation of protein kinase C. Bryostatin 1 is known to activate protein kinase C and to mimic some of the effects of TPA. We compared bryostatin 1 with TPA for the ability to cause arachidonic acid release and induce synthesis of prostaglandin H synthase. Bryostatin 1 induced arachidonic acid release and caused some prostaglandin production but only marginally induced synthesis of prostaglandin H synthase. Furthermore, we found that bryostatin 1 could inhibit the effect of TPA both in stimulation of arachidonic acid release and in the induction of prostaglandin H synthase.
Animals↗
The CAMDEX: a standardized instrument for the diagnosis of mental disorder in the elderly: a replication with a US sample.
The Cambridge Mental Disorders of the Elderly Examination (CAMDEX) was developed by Roth, et al (1986) to assist in the early diagnosis and measurement of dementia in the elderly. In this study the CAMDEX was administered to a mixed group of independently diagnosed elderly psychiatric patients and control subjects in the United States. The CAMDEX was found to have a high interrater reliability with a mixed group of clinicians of varying backgrounds. The diagnostic scales and the cognitive section of the CAMDEX demonstrated considerable promise in distinguishing between independently diagnosed populations of depressed, demented, and normal subjects. The results suggest comparability between samples of subjects in England and the US, and that the CAMDEX is a promising instrument for use in both research and clinical settings.
Aged↗
Monitoring problem drug use in Bristol.
A prospective multi-agency survey of problem drug use associated with illicit drugs and solvents in the city of Bristol in 1984-1985 found 759 problem drug users, giving a period prevalence rate of 0.4-0.8% of those aged 10-44 years. The group was a young one, with 92% under the age of 35. Over half had problems associated with opiates, mainly illicit heroin; 17% had problems associated with solvents, 9% with cannabis, 13% with stimulants, mainly illicit amphetamine, and 3% with hallucinogens. There was little indication of problematic use of barbiturates or cocaine. The problems associated with drugs and solvents were wide-ranging and not specific for individual drugs. Future community surveys would find it cost-effective to concentrate on the five best sources identified here, and to supplement these with indications of drug-taking among teenagers. The difficulties of using the definition of problem drug use for research and the value of case-register surveys for community drug monitoring are discussed.
Adolescent↗
Monitoring drug use in a community.
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England↗
Overweight and pregnancy complications.
The association between increased prepregnancy weight for height and seven pregnancy complications was studied in a multi-racial sample of more than 4100 recent deliveries. Body mass indices were calculated and used to classify women as average weight (90-119 percent of ideal or BMI 19.21-25.60), moderately overweight (120-135 percent ideal or BMI 25.61-28.90), and very overweight (greater than 135 percent ideal or BMI greater than 28.91) prior to pregnancy. Compared to women of average weight for height, very overweight women had a higher risk of diabetes, hypertension, pregnancy-induced hypertension and primary cesarean section delivery. Moderately overweight women were also at higher risk than average for diabetes, pregnancy-induced hypertension and primary cesarean deliveries but the relative risks were of a smaller magnitude than for very overweight women. With women of average prepregnancy body mass as reference, moderately elevated, but not significant relative risks were found for perinatal mortality in the very overweight group, for urinary tract infections in both overweight groups, and a decreased risk for anemia was found in the very overweight group. However, post-hoc power analyses indicated that the number of overweight women in the sample did not allow adequate statistical power to detect these small differences in risk. To overcome limitations associated with low statistical power, the results of three recent studies of these outcomes in very overweight pregnant women were combined and summarized using Mantel-Haenzel techniques. This second, larger analysis suggested that very overweight women are at significantly higher risk for all seven outcomes studied. Summary results for moderately overweight women could not be calculated, since only two of the studies had evaluated moderately overweight women separately. These latter results support other findings that both moderate overweight and very overweight are risk factors during pregnancy, with the highest risk occurring in the heaviest group. Although these results indicate that moderate overweight is a risk factor during pregnancy, additional studies are needed to confirm the impact of being 20-35 percent above ideal weight prior to pregnancy. The results of this analysis also imply that since the baseline incidence of many perinatal complications is low, studies relating overweight and pregnancy complications should include large enough samples of overweight women so that there is adequate statistical power to reliably detect differences in complication rates.
Adolescent↗
Coping strategies in rheumatoid arthritis.
Our purpose was to investigate the importance of the coping process for patients with rheumatoid arthritis (RA). Eighty-four patients with classic or definite RA were examined. The relationship between coping strategies and psychological status, functional status, pain, and disease activity was analyzed. Coping was measured by an adapted version of the Ways of Coping Scale, and measures of psychological status, life stress, functional status, pain, and disease activity were also obtained. Canonical correlation revealed a significant relationship between the coping process and psychological status. Coping also was significantly related to functional status, but not to pain or disease activity. Patients who coped by restructuring life goals were found to have better psychological adjustment and functional status than patients who hoped for unrealistic solutions or engaged in self-blame.
Activities of Daily Living↗