PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “CodY”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed2002

Effect of Navy chaff release on aluminum levels in an area of the Chesapeake Bay.

The U.S. Navy uses aluminized glass chaff as a passive countermeasure for radar-guided threats to aircraft and surface ships. Over the last 25 years, several hundred thousand pounds of aluminized chaff have been released during flight operations over a training area on the Chesapeake Bay. There is concern that these releases have resulted in the accumulation of significant amounts of aluminum in the soil and sediment of this training area. This study compares the exchangeable and monomeric aluminum content of sediment within the affected area with that of samples taken from outside the training area. We found a less than twofold increase in the content of organic monomeric aluminum in samples taken from the affected area versus background samples, whereas inorganic monomeric aluminum concentrations within the affected area were significantly lower than background. These results suggest that chaff releases have not resulted in a significant accumulation of aluminum in this training area.

Aircraft↗
PubMed2002

Radio frequency chaff: the effects of its use in training on the environment.

Chaff is a radiofrequency countermeasure released by military aircraft, ships, and vehicles to confuse enemy radar. Chaff consists of aluminum-coated glass fibers ranging in lengths from 0.8 to 0.75 cm and is released in packets of 0.5 to 100 million fibers. The Department of Defense has determined that use of chaff in training is required for maintaining proficiency in the use of this countermeasure. At least 500 tons of chaff is released annually during training within selected military operating areas in the United States. Concerns have been raised about impact on the environment and its potential toxicity to humans, livestock, and wildlife. Many of these concerns have been addressed or are being researched by the Department of Defense and other agencies, but much of the data are unpublished. Herein, the authors summarize the issues and review scientific data for the impact of chaff use on humans, animals, and the environment.

Animals↗
PubMed1996

Calcium functions as a transcriptional and mitogenic repressor in Syrian hamster embryo cells: roles of intracellular pH and calcium in controlling embryonic cell differentiation and proliferation.

We have investigated the role played by the growth and differentiation factor (GDF)-induced calcium ion second messenger signal in the control of cellular differentiation and proliferation in Syrian hamster embryo (SHE) cells. Blocking the platelet-derived growth factor (PDGF)-induced calcium ion signal with either extracellular/intracellular acidification or pharmacological agents resulted in increased immediate early gene expression and mitogenesis. The increase in immediate early gene expression resulted from a change in the level of immediate early gene transcription and not immediate early gene mRNA stability. Analysis of the promoter elements that control immediate early gene expression indicated that the calcium ion effect is mediated through the CaRE/CRE and AP1 promoter elements. The calcium signal-mediated reduction in PDGF A/B-stimulated SHE cell immediate early gene expression resulted in a reduction in PDGF A/B-induced cellular proliferation. These results demonstrate that in SHE cells, calcium functions to suppress mitogen-induced proliferation at the level of immediate early gene expression, an effect related to the control of cellular proliferation and differentiation by GDFs through the calcium ion second messenger.

Animals↗
PubMed1993

Anti-lipopolysaccharide monoclonal antibodies inhibit macrophage TNF messenger RNA synthesis in vitro.

Gram-negative bacterial lipopolysaccharide (LPS, endotoxin) directly stimulates macrophages to produce tumor necrosis factor (TNF). TNF, in turn, produces a constellation of adverse effects that includes hypotension, systemic acidosis, arterial hypoxemia, and death. Transcription of the TNF gene occurs within minutes of LPS stimulation and appears to be a critical control point in the synthesis and secretion of TNF protein by macrophages. We hypothesized that murine monoclonal antibody (mAb) 8G9 directed against Escherichia coli 0111:B4 LPS would provide protective capacity against an E. coli 0111:B4 bacterial challenge in vivo and would concurrently inhibit LPS-induced synthesis of TNF mRNA and secretion of TNF protein in vitro. E. coli 0111:B4 LPS was used to stimulate a macrophage-derived cell line (RAW 264.7) to produce TNF in the presence or absence of mAb 8G9. Media alone and LPS without 8G9 mAb served as controls against which the effect of 8G9 mAb was compared. Total cellular RNA was purified and analyzed by a Northern blotting technique utilizing a radiolabeled cDNA probe specific for TNF mRNA. TNF mRNA levels from each sample were quantitated by autoradiograph densitometry. Pretreatment with mAb 8G9 provided protective capacity against an intraperitoneal E. coli 0111:B4 bacterial challenge in vivo when compared with saline pretreatment alone (22% versus 90% mortality respectively, P < 0.05). Preincubation of LPS with mAb 8G9 resulted in a significant inhibition of LPS-induced TNF mRNA synthesis (63 +/- 20%, P < 0.01) and TNF protein secretion (88 +/- 10%, P < 0.001) in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1996

Epidermal cytokinetics, DNA adducts, and dermal inflammation in the mouse skin in response to repeated benzo[a]pyrene exposures.

Few studies have investigated the chronic cytokinetic effects of carcinogen exposure in the mouse skin. We report two experiments involving the repeated application of benzo[a]pyrene (BaP) to the dorsal skin of female Ha/ICR mice. In the first experiment, the cytokinetic, inflammatory, and DNA adduct responses were studied daily over a 9-day period encompassing the fourth and fifth weekly applications of BaP at doses of 16, 32, and 64 micrograms. The second experiment involved the same cytokinetic measurements at 1, 3, 5, and 8 months, and the weekly BaP doses were 4, 8, and 16 micrograms. The first study showed that after each application of 32 or 64 micrograms BaP, there was a wave of slow DNA synthesis in the epidermis which peaked at 24 hr, in coincidence with a wave of BaP-DNA adducts, followed by the appearance of dead and damaged keratinocytes. For the first few days after BaP application there was a depression in the mitotic rate which recovered several days before the next BaP application. There was a predominantly monocytic dermal inflammation throughout the observation period. In the second experiment, at the lower BaP doses, there was proliferative depression at 1 month, without dermal inflammation. With continued exposure, the proliferative depression changed to a dose-dependent increase in the rate of proliferation and dermal inflammation. The level of BaP-DNA adducts was followed in the 4 micrograms/week dose group, which showed a threefold increase after 4 months with the appearance of inflammation and heightened cell proliferation. These results suggest that the delayed inflammatory reaction, possibly based on a cell-mediated immune reaction to BaP, might have been responsible for the late cytokinetic responses and the associated increase in the level of BaP-DNA adducts.

Animals↗
PubMed1993

Conformational analysis of human dihydrofolate reductase inhibitor complexes: crystal structure determination of wild type and F31 mutant binary and ternary inhibitor complexes.

These structural studies reveal unusual intermolecular interactions for the binding of inhibitors and cofactor in ternary complexes with both wild type and F31 mutant recombinant human DHFR and show that these inhibitors have flexibility in occupying the active site. These studies also possibly indicate the first structural data for a ternary complex with a folate inhibitor and a polyglutamate side chain. However, further refinement of this data is necessary before this can be confirmed. In contrast to the ternary complexes of folate and MTX, the lipophilic antifolate PTX binds with its methoxybenzoyl ring oriented toward the cofactor nicotinamide ring, while that of TMQ it is bound closer to the Phe-31 position. Furthermore, the nicotinamide ring makes a close contact to the N10 amine of TMQ, significantly different from its binding site interactions in MTX complexes. These data also reveal that the conserved contacts between the cofactor carboxyamide with the enzyme backbone residues Ala-9 and Ile-16 are dictated by the enzyme and that changes in the orientation of the structural elements requires only subtle changes in the secondary structural units in which they are contained. Therefore, only by careful analysis of a series of enzyme complexes can the mechanisms of binding action be delineated.

Binding Sites↗
PubMed1994

The 13C chemical shifts of amino acids in aqueous solution containing organic solvents: application to the secondary structure characterization of peptides in aqueous trifluoroethanol solution.

The 13C chemical shifts for all of the protonated carbons of the 20 common amino acid residues in the protected linear pentapeptide Gly-Gly-X-Gly-Gly have been obtained in water at low pH as well as in aqueous solution containing 10, 20 and 30% acetonitrile or trifluoroethanol. Dioxane was used as an internal reference and its carbon chemical shift value was found to be 66.6 ppm relative to external TMS in water. Comparison of the different referencing methods for 13C chemical shifts in organic cosolvent mixtures showed that an external standard (either TMS or TSP capillary) was the most appropriate. In the present study, external TSP was chosen to define the 0 ppm of the 13C chemical shift scale. When the difference in referencing the dioxane carbon resonance is taken into account, the carbon chemical shift values of the amino acids in aqueous solution are similar to those previously reported (Richarz and Wüthrich (1978) Biopolymers, 17, 2133-2141; Howarth and Lilley (1979) Prog. NMR Spectrose., 12, 1-40). The pentapeptides studied were assumed to be in a random coil conformation and the measured 13C chemical shifts were used as reference values to correlate carbon chemical shifts with the secondary structure of two well-characterized peptides, bombesin and the 1-29 amino acid fragment of Nle27 human growth hormone-releasing factor. In both cases, the C alpha chemical shifts exhibited a characteristic positive deviation from the random coil values, which indicates the presence of alpha-helices.

Amino Acid Sequence↗
PubMed1991

Phase II trial of cisplatin and etoposide in patients with metastatic melanoma.

Fourteen patients with metastatic melanoma were treated with cisplatin and etoposide by bolus intravenous infusion daily for 5 consecutive days each month. All patients were evaluable for toxicity and twelve for response. Eight patients were treated with cisplatin 20 mg/m2 and etoposide 100 mg/m2 daily. Because of excessive myelosuppression, the daily dose of etoposide was reduced to 75 mg/m2 in the remaining six patients. There were no major responses among 12 evaluable patients (major response rate less than or equal to 24% with 95% confidence). The median time to progression was one month. One patient with a liver metastasis had a minor response lasting 6+ months. The combination of cisplatin and etoposide in these doses and schedule lacked sufficient clinical efficacy in the treatment of metastatic melanoma.

Adult↗
PubMed1989

Vibration-evoked reciprocal inhibition between human wrist muscles.

Reciprocal inhibition of the voluntarily contracting wrist extensor (extensor carpi radialis, ECR) evoked by proprioceptive afferent input from the flexor (flexor carpi radialis, FCR), was studied in healthy human subjects. Vibration of the FCR tendon was used to elicit Ia-dominated afferent discharge whilst inhibition of ECR was assessed as the reduction in asynchronous, on-going EMG. A small early phase of inhibition (I1) was evident in 25% of trials. The latency (ca. 25 ms) of this component suggested that it was mediated by an Ia oligosynaptic. possibly 'classical' disynaptic, inhibitory pathway. A later and apparently separate phase of reduced activity (I2, ca. 40 ms) was, however, far more consistently observed (96% of trials) and of greater magnitude. The I2 component was usually followed, some 20 ms later, by a phase of elevated activity (E1, 72% trials). Reductions in simultaneously recorded net extensor torque commenced at about 60 ms following the onset of flexor tendon vibration, i.e. some 20 ms after the main I2 EMG component. These mechanical responses must have almost exclusively resulted from reciprocal inhibition of extensor EMG since vibration of the relaxed FCR evoked minimal excitatory flexor activity. The reflex pattern, in any individual subject, was relatively unaffected by altering the duration of the vibration train between one and nineteen cycles (125 Hz). This suggests that the entire response complex resulted largely from the initial afferent volley. The sizes of both the I1 and I2 reductions in ECR activity increased with increasing voluntary extensor contraction so that their depths remained constant proportions of background EMG. Very similar results were obtained when reciprocal inhibition of FCR was produced by vibration of the belly of ECR. Thus, reciprocal inhibition between wrist muscles is mainly expressed as a rather stereotyped, short duration reduction in EMG whose depth is determined by the pre-existing level of motor activity. Some functional implications of this form of reflex behaviour are discussed.

Adult↗
PubMed1995

Cortical control of human soleus muscle during volitional and postural activities studied using focal magnetic stimulation.

The surface-recorded electromyographic (EMG) responses evoked in the ankle musculature by focal, transcranial, magnetic stimulation of the motor cortex were studied in healthy human subjects. Such soleus evoked motor responses (EMRs) were characterised over a wide range of background levels of motor activity and using different stimulus intensities. EMRs were recorded during predominantly (1) volitional and (2) postural tasks. In the former task subjects were seated and voluntarily produced prescribed levels of soleus activation by reference to a visual monitor of EMG. In the latter task subjects assumed standing postures without EMG feedback. Comparison of the EMRs of soleus, traditionally considered a slow anti-gravity extensor muscle, during these tasks was used to evaluate its cortical control in primarily volitional versus primarily postural activities. The form of soleus EMRs produced by single magnetic cortical stimuli comprised an initial (approx. 30 ms) increase and subsequent (approx. 50 ms) depression of EMG. Cortical stimulation could elicit substantial excitatory soleus EMG responses; for example, responses evoked by mild, magnetic stimuli (125% threshold for inducing a response in the relaxed muscle) as subjects exerted full voluntary plantarflexor effort averaged almost 20% of the maximum M-wave which could be elicited by an electrical stimulus to the posterior tibial nerve. Excitatory EMRs could be elicited in the voluntarily relaxed soleus muscle of the majority of subjects during sitting. The amplitude of soleus responses, induced by threshold stimuli for the relaxed state or approximately 125% threshold intensity, increased approximately linearly with background EMG over a wide range of volitional contraction levels. By contrast, there was no systematic change in the latency of excitatory soleus EMRs with increasing voluntary effort. The excitatory responses evoked in the voluntarily relaxed soleus of seated subjects by magnetic stimulation were regularly facilitated by incremental, voluntary contraction of the contralateral ankle extensors in a graded manner. However, such facilitation of responses was not observed when subjects voluntarily activated the muscle in which EMRs were elicited. The pattern of the responses elicited in soleus by magnetic stimulation during the postural task generally resembled that found during the volitional task. The amplitudes of excitatory soleus EMRs at a given stimulus intensity, obtained when subjects stood quietly, leaned forwards or stood on their toes to produce differing levels of ankle extensor contraction, increased with background EMG.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

An in vivo and in vitro trial of aclarubicin in metastatic breast cancer: a novel approach to the study of analogs.

Aclarubicin is an anthracycline antibiotic that differs from doxorubicin in its structure, mechanism of action, and preclinical toxicity profile, especially its reduced cardiotoxicity. We therefore conducted a side-by-side in vivo and in vitro trial of this agent in metastatic breast-cancer patients and their biopsied tumor specimens, respectively. Aclarubicin (100 mg/m2) was given by intravenous infusion every 3 weeks to 22 patients with objectively measurable metastatic breast cancer, 15 of whom had not previously received doxorubicin. The dose-limiting toxicity consisted primarily of leukopenia and severe nausea and vomiting. No objective response was observed in the 19 evaluable patients. After disease progression, 10 of the 15 doxorubicin-naive patients were treated with doxorubicin; 6 patients achieved a partial response, including 4 who responded to doxorubicin alone and 2 who responded to doxorubicin in combination with thiotepa and vinblastine. Tumor specimens were obtained from 14 of the 22 patients prior to the start of therapy and were tested for in vitro sensitivity to aclarubicin and doxorubicin using a soft agar colony-forming assay. Adequate colony growth occurred in 9 of 14 cultured tumor specimens. All 9 specimens, including 3 obtained from doxorubicin-naive patients, demonstrated in vitro resistance to aclarubicin. In all, 1 of 3 specimens taken from doxorubicin-naive patients demonstrated in vitro sensitivity to doxorubicin, whereas 6 tumor specimens obtained from patients who had undergone prior doxorubicin therapy demonstrated in vitro resistance. The patient whose tumor demonstrated in vitro doxorubicin sensitivity responded to a doxorubicin regimen after failing aclarubicin treatment; in vitro doxorubicin resistance correlated with clinical resistance in all cases. We conclude that aclarubicin is inactive in metastatic breast cancer at the dose and schedule used. Side-by-side in vivo and in vitro trials are feasible and could be useful in the development of investigational agents with activity greater than that of aclarubicin and, particularly, in the evaluation of analogs of clinically active drugs.

Aclarubicin↗
PubMed1990

Behaviors, beliefs, and intentions in skin cancer prevention.

This study investigated knowledge, behaviors, and health beliefs of Australian university students (n = 312) regarding skin cancers and evaluated the effects of videotaped presentations. Students' knowledge and health beliefs were assessed, and they then viewed either an informational video, an emotionally involving video, or a control video. Knowledge and beliefs were assessed immediately and 10 weeks later. Postvideo skin protection intentions increased significantly from prevideo assessment among the two intervention groups compared to the controls. Maintenance of skin protection intentions was higher with the emotional video. Health belief variables, particularly perceived barriers, were significant predictors of knowledge, intention, and behavior. However, other variables such as skin type and previous experience with skin cancer were more important. Females had greater knowledge and stronger intentions to prevent skin cancer than males but reported fewer high-risk behaviors.

Adult↗
PubMed1991

Comparison of dual photon and dual energy X-ray bone densitometers in a clinic setting.

In clinical practice, decisions must be made about whether and how to convert to newer technologies. To address this issue, two separate studies were conducted. We evaluated the relationships between results of lumbar spine measurements using two dual photon absorptiometry (DPA1 and DPA2) instruments and one dual energy X-ray (DXA) instrument with the same subjects (49 volunteers), and also in 65 patients who were measured on the DPA1 and DXA machines. Second, we measured the lumbar spine and the proximal femur in three groups of 12 female volunteers three times on one instrument within 1 week. We purposely simulated a busy clinic setting with different technologists, older radioactive sources, and a heterogeneous patient group. The comparison study indicated a significant difference between the mean bone density values reported by the machines, but the results were highly correlated (R2 = 0.89-0.96). The short-term precision errors (coefficients of variation) differed among the instruments, ranging from 1.3% (DXA of the spine) to 5.1% (DPA1 of the spine), and in the femoral neck, 2.3% and 2.4% (DXA and DPA1, respectively) versus 3.5% by DPA2. This study emphasizes the differences between instruments, the potential for greater error in busy clinic environments, and the apparent superiority of dual energy X-ray absorptiometry under these less than ideal conditions.

Absorptiometry, Photon↗
PubMed1984

Female orgasmic experience: a subjective study.

Human female orgasm was studied by collecting and analyzing the subjective orgasmic histories of 30 women, ages 18 to 59 years. Virtually all of the 93% who reported they had experienced orgasm also reported some level of conscious control over whether or not they reached orgasm. Women differed widely as to preferred types of physical stimulation and/or mental activities to facilitate orgasm. Orgasms were experienced as centered in the clitoral and/or vaginal areas. Women over 40 were more likely to have experienced orgasm in more than one anatomic site than were women aged 18 to 29. Marital status, religion, occupation, educational level, experiences of pregnancy and childbirth, various reported characteristics of relationships with partners, and early sexual experience were not associated with where orgasm is experienced within the body or with other variables of adult orgasmic experience. The variation among women as to how orgasm is best reached, differences in where it is experienced within the body, and the reasons why an individual woman experiences orgasms differently over time remain poorly understood phenomena.

Adolescent↗