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Biomedical subjects

R Phillips

Publications and source records attributed to R Phillips.

At least 73 records · Page 4Linked to original sources
PubMed1986

Long-term performance of polyurethane pacing leads: mechanisms of design-related failures.

Environmental stress cracking has been identified as a crack propagating mechanism in polyurethane-insulated, heart pacemaker leads, which is directly related to specific lead design parameters. Lead designs imposing excessive stress on the polyurethane insulation through an interference fit between the coil and polymer have demonstrated insulation failures. Conversely, low-stress designs have shown virtually no insulation problems. The higher-stress designs have used organic solvents to facilitate coil placement during manufacturing, which may result in lowering the polymer's ability to resist the higher stress. In addition, a specific silver-containing coil wire composition has been found to galvanically corrode upon body fluid intrusion into the lead, ionizing the silver. These ions interact with the polyurethane polymer resulting in the loss of polymer strength. All polyurethane lead failures to date have been specific to high stress and/or chemical interaction. Leads using low-stress designs and nonreactive coil wire compositions continue to demonstrate a positive clinical experience.

Animals↗
PubMed1986

Zopiclone: a new nonbenzodiazepine hypnotic used in general practice.

Ninety-one insomniacs completed a four-week study of the efficacy and safety of zopiclone (Z), 7.5 mg. Patients were randomly allocated to one of two groups, each of which received placebo (P) during one week of the study. Forty-six subjects received medication in the sequence of ZPZZ, and 45 received it in the sequence of ZZPZ. Twice each week, patients filled out presleep and postsleep questionnaires and reported their morning complaints. Compared with placebo, zopiclone produced statistically significant improvements (P less than 0.05) in sleep induction time, duration of sleep, number of awakenings per night, quality and soundness of sleep, morning state of rest, and daytime sleepiness. Headache, dizziness, nausea, and bitter taste were the predominant complaints. Zopiclone can be considered an efficient and safe hypnotic for chronic insomnia.

Adult↗
PubMed1986

Double-blind comparison of ketoprofen and placebo in the treatment of sprains and strains.

Sixty patients (42 men and 18 women between the ages of 18 and 37 years) with grade 2 or grade 3 sprains or elongations participated in a seven-day double-blind study. By random determination, they were treated with either 100 mg of ketoprofen or placebo TID. Pain evaluation, vital signs, concomitant medication, and side effects were determined on days 1,3, and 7. Compared with placebo, ketoprofen produced statistically significant reductions (P less than 0.05) in investigator-rated pain at rest (day 3), on palpation (days 1, 3, and 7), on motion (days 1 and 3), and on the subject-rated analog scale (days 1 and 3). It also achieved a greater relief of pain (days 1 and 3) and greater overall efficacy, as expressed by the statistically significant improvements in the total pain scores on motion and on palpation, on the total pain relief score, on the total pain analog score, and on the sum of pain intensity differences for pain at rest, on palpation, and on motion. Tolerance to the seven-day ketoprofen treatment was excellent. Results from the study indicate that ketoprofen is efficacious in relieving pain following sprains and strains.

Acetaminophen↗
PubMed1985

Exercise after myocardial infarction: long-term rehabilitation effects.

Long-term effects of an exercise programme for patients who had experienced myocardial infarction were investigated. Questionnaires were sent to 305 patients who during a three and a half year period had been invited to participate. Replies from 58 exercised patients, 13 who had dropped out, 75 controls and 69 who declined the invitation were analysed. The amount of exercise now being taken was positively correlated with scores on cardio-vascular and general health, and negatively correlated with symptoms during exercise and taking medication. The exercised group differed from the other groups in that a greater proportion were still taking heavy exercise. The latter scored significantly higher than the rest of the patients on most of the measures used. For effective long-term rehabilitation the problem of encouraging and enabling patients to continue vigorous exercise needs to be resolved.

Exercise Therapy↗
PubMed1985

Defective monocyte function in patients with systemic lupus erythematosus.

Peripheral blood adherent cells from patients with systemic lupus erythematosus (SLE) were shown to have markedly reduced phagocytic activity as compared to normal adherent cells or those from non-SLE patients receiving corticosteroid therapy. Both resting and phagocytosing monocytes showed decreased hexose monophosphate shunt and glycolytic activity. Mononuclear cells from SLE patients showed grossly impaired proliferative activity after NaIO4 activation. Furthermore, addition of SLE adherent cells to normal adherent cell-depleted lymphocytes decreased [3H]thymidine incorporation of the latter cells following NaIO4 treatment. Addition of normal adherent cells to SLE lymphocytes corrected the previous defect, indicating that an adherent abnormality is responsible for the defect in SLE mononuclear cell proliferation to NaIO4 activation.

Blood Bactericidal Activity↗
PubMed1985

Modulation of the sodium periodate (NaIO4) response in systemic lupus erythematosus (SLE): effect of interleukin-1 (IL-1), interleukin-2 (IL-2), phorbol myristate acetate (PMA), and indomethacin.

The proliferative activity of peripheral blood mononuclear cells (PBMN) from patients with systemic lupus erythematosus (SLE) activated by sodium periodate (NaIO4) is greatly diminished. The effect of the cytokines Interleukin-1 (IL-1) and Interleukin-2 (IL-2) on the NaIO4 reaction was investigated. Addition of IL-1 resulted in partial restoration of the reaction of SLE PBMN to NaIO4, and a similar effect was demonstrated in the presence of phorbol myristate acetate (PMA). Addition of IL-2 to NaIO4 activated SLE PBMN, however, caused a marked improvement in their proliferative activity. The presence of indomethacin resulted in only a slight increase in [3H]thymidine incorporation by the NaIO4-treated SLE cells. The results suggest that the defect in the response of SLE PBMN cells to NaIO4 is due to inadequate availability of IL-1 and IL-2. Excessive production of prostaglandin in SLE might also contribute to the defective response to NaIO4 but does not appear to play a major role.

Female↗
PubMed1985

Seventh-Day Adventist vegetarians have a quiescent proliferative activity in colonic mucosa.

The proliferation of epithelial cells in colonic mucosa was studied in humans at varying degrees of risk for colon cancer. Seventh-Day Adventist vegetarians, known to have significantly lower mortality from colon cancer than the general U.S. population, had the most quiescent proliferative activity of mucosal epithelial cells. Increased replication and expansion of the proliferative compartment accompanied increased colon cancer risk. The analytical methods of this study may be useful in assessing the influence of dietary components involved in the initiation, promotion or inhibition of colon cancer, and in developing strategies for nutritional intervention.

Adult↗
PubMed1985

Chromosome banding in salmonid fish: nucleolar organizer regions in Salmo and Salvelinus.

Chromosome banding patterns obtained by silver staining (Ag-NORs) were analyzed in three species of Salmo (rainbow, brown trout, and Atlantic salmon) and three species of Salvelinus (brook trout, lake trout, and arctic char). In rainbow trout and Atlantic salmon the Ag-NORs were found at the secondary constrictions of a single chromosome pair, while in brown trout the Ag-NORs were found on the short arms of one or two of the two longest subtelocentric or acrocentric chromosome pairs. The location of the Ag-NORs was multichromosomal in the three Salvelinus species, occurring on one or both members of four to six different chromosome pairs in different individuals. The Ag-NOR sites were on the short arms of some acrocentric pairs and at the telomeres of other acrocentric pairs and one or two metacentric pairs. Chromomycin A3 positive bands were found at the same sites as the Ag-NORs in all species. In the species with multichromosomal location of Ag-NORs, polymorphisms in the size and location of the NORs were extremely common, so that almost every individual fish had a different pattern of Ag-NOR sites.

Animals↗
PubMed1985

Effects of mineralocorticoids and glucocorticoids on compensatory adrenal growth in rats.

The rapid compensatory growth seen in the remaining adrenal gland of the rat after unilateral adrenalectomy appears to require a functioning neural arc between the adrenal glands and the hypothalamus, but the role of adrenal or pituitary hormones is unclear. We have examined the effect of several steroids on the compensatory adrenal growth (CAG). Female and male rats (average wt 140 g) were unilaterally adrenalectomized and treated with aldosterone (2.1 micrograms/day), corticosterone (B, 28 micrograms/day), dexamethasone (28 micrograms/day), 9 alpha-fluorocortisol (9 alpha FC, 28 micrograms/day), or deoxycorticosterone (DOC, 28 micrograms/day) by continuous infusion for 3 days and then killed. The growth in the remaining adrenal was compared both with sham-operated rats treated with steroid infusions and with noninfused controls. In rats of this size females have larger adrenals than males; untreated male rats have significantly heavier left than right adrenals. In male rats the extent of CAG after no treatment or treatment with aldosterone B, 9 alpha FC, or DOC depended on the size of the adrenal gland removed. In both male and female rats CAG was not significantly affected by aldosterone, in contrast with a recent report, nor by B, 9 alpha FC, or DOC; no significant CAG was seen after dexamethasone. Taken together, these results and previous reports suggest that neurally mediated activation of pituitary and/or local adrenal growth factors may be responsible for CAG.

Adrenal Glands↗
PubMed1985

A new pendant storage oxygen-conserving nasal cannula.

With increasing interest in reducing the cost of oxygen therapy, we recently designed an oxygen-conserving cannula. It reduces the oxygen supply flow necessary to achieve adequate oxygen saturation, but because it requires the use of a reservoir situated under the nose, some patients find it obtrusive. We therefore designed a similar system but displaced the reservoir away from the face and onto the anterior chest wall where it could be hidden from view by the patient's clothing. We evaluated this pendant conserving nasal cannula (PNC) in seven hypoxemic patients with chronic obstructive pulmonary disease. We compared oxygen saturations achieved using the PNC vs the standard steady flow nasal cannula (SNC) at 0.5 through 4 L/min. The mean improvement in oxygen saturation using the PNC vs the SNC was 3.3 percent at 0.5 L/min, 4.3 percent at 1 L/min and 3.1 percent at 2 L/min. These differences were statistically significant (p less than 0.001). The saturation achieved by the PNC at 0.5 L/min was equivalent to that achieved by the SNC at 1.8 L/min. We conclude that the PNC provides effective oxygen delivery to patients at supply flows substantially less than the SNC. The device is aesthetically acceptable to patients and its widespread use in patients requiring chronic oxygen therapy could bring about significant financial savings.

Adult↗
PubMed1985

Low-concentration oxygen therapy via a demand oxygen delivery system.

Recent heightened concern about the costs of medical care has stimulated research and development in devices and schemes for saving costs while retaining quality of care. Consistent with that concern is the fact that standard steady-flow oxygen delivery is so wasteful. Almost its entire benefit occurs at the very beginning of inspiration. We compared the efficacy of nasal oxygen delivery via a new demand oxygen delivery system (DODS) with the standard steady-flow (SF) method. The DODS incorporates a valve and sensor interposed between the oxygen reservoir and the patient, which meters oxygen to the patient only during early inspiration. Twelve COPD subjects with hypoxemia at rest received oxygen at flow settings of 1 to 4 L/min via SF and at various breath interval settings via the DODS method, calculated to match the above spectrum of the SF. We measured oxygen delivery using an ear oximeter. The results indicate that significantly less oxygen was required to provide equivalent saturations using the DODS compared with the SF method (p less than .001). The mean comparative savings in oxygen is better than seven to one favoring the DODS over the SF method. Further study is warranted, since the widespread use of such a device could result in substantial cost saving while increasing the range of portable oxygen delivery.

Aged↗
PubMed1985

A comparative trial of the antidepressant, anxiolytic, and cardiovascular effects of trimipramine and doxepin in depressed hospitalized patients.

After a 1-week placebo washout, 25 depressed hospitalized patients were treated for 4 weeks with trimipramine or doxepin in a fixed equivalent dosage schedule ending in 150 mg h.s. The study used a parallel group double-blind design. Comparisons over time revealed that both drugs improved patients' overall well-being as indicated by the rating scales studied. Significant (p less than .05) differences between the treatments favored trimipramine over doxepin: the Hamilton scale diurnal variation cluster at Week 1 and the sleep disturbance factor at Week 4; the Clinical Global Impressions improvement index at Week 1; and the Anxiety Status Inventory somatic symptoms cluster at Week 4. No differences in blood pressure, heart rate, PVCs, or PACs were observed in any of the comparisons. The total number of side effects reported was greater in the doxepin-treated patients.

Anorexia↗
PubMed1985

Analysis of a hospital-based stomatherapy service.

We have analysed the activities of a hospital-based stomatherapy service between 1980 and 1983. The average numbers of patients seen per annum included 395 out-patients, 307 in-patients and 116 home visits. Of the 276 in-patients with colostomies, 72% had underlying malignant disease; 17% were performed as emergencies and 51% were temporary stomas. Hospital mortality for patients with a temporary stoma was 19% and only 59% had their temporary stoma reversed. Only 45% of colostomy patients received preoperative counselling and 11% had no regular follow-up. Complications were recorded at some stage after colostomy in 25% but only 10% required surgical refashioning. Of the 184 in-patients with ileostomies, 52% had ulcerative colitis and 41% had Crohn's disease. Only 13% of ileostomies were performed as emergencies, and only 11% were temporary. In contrast to colostomy, 83% of ileostomy patients received preoperative counselling and adequate follow-up was provided for 98% of patients. Complications were recorded in 57% of patients after ileostomy but surgical reconstruction was needed in only 18%.

Aged↗
PubMed1984

High mean platelet volume after myocardial infarction: is it due to consumption of small platelets?

Seventy nine men surviving after sustaining a myocardial infarction in 1982, and who had at that time had raised mean platelet volumes compared with controls, were followed up after 18 months. The shape of each man's platelet distribution curve was calculated from the mean platelet volume, platelet count, and platelet distribution width. The calculated curves were in close agreement with the curves plotted by the Coulter counter from the raw data. These curves did not differ significantly from those of a current control group, but the curves plotted from the variables measured at the time of myocardial infarction in 1982 showed a deficit of platelets in the volume range 5-12 fl amounting at maximum to 30% (p less than 0.0001); there were no significant differences above 12 fl. The deficit of small platelets became more appreciable during initial admission, was less at one month's follow up, and had disappeared at one year. The deficit of small platelets is probably an effect rather than a cause of infarction.

Blood Platelets↗
PubMed1984

External beam irradiation of prostate cancer. Experience in 163 patients.

From 1973 to 1979, 163 patients with biopsy proven adenocarcinoma of the prostate were treated with a curative intent utilizing megavoltage external beam irradiation at Rush-Presbyterian-St. Luke's Medical Center or Lutheran General Hospital. The actuarial survival at 5 years for the whole group is 78%. Survival was found to depend on initial stage and grade of disease. Local failure alone occurred in 3% of the patients, yet represented a component of failure in 7%. The effects of stage, grade, dose and field size on survival, patterns of failure and complications are discussed.

Adenocarcinoma↗
PubMed1984

Suppression of interleukin-2 production by human concanavalin A-induced suppressor cells.

When PHA-activated normal responder cells (R cells) were cocultured with mononuclear cells (MN cells) which had been preincubated for 48 hr in medium alone (C cells) an enhanced proliferative response was observed. This enhancement was only obtained when the R cells were cultured with allogeneic C cells or when PHA was in the cocultures for the entire culture period. This effect was due to greater production of interleukin 2 (IL-2) by irradiated C cells in the presence of allogeneic or mitogenic stimulation. Con A-treated mononuclear cells (S cells) cultured with PHA-activated allogeneic or autologous responder cells showed reduced [3H]thymidine incorporation and IL-2 production as compared to activated R cells alone. Glutaraldehyde-treated S cells (which retained the ability to absorb IL-2) did not affect the proliferative response or IL-2 production by the R cells, indicating that passive absorption of IL-2 was not entirely responsible for suppression induced by S cells. S cells, pretreated with IL-2, still inhibited R-cell activity. These results show that Con A-treated MN cells suppressed or prevented [3H]thymidine incorporation by actively inhibiting IL-2 production.

Cell Communication↗